USRE21802E - Valve operating mechanism - Google Patents

Description

R. c. RUSSELL lle-21,802

vALvE OPERATING MEQHANISM original Filed Aug. 19, 1932 6 sheets-sheet 1 INVENTOR ROBERT c. RusaELL BY @re/ww ORNEYS May 13, 1941.

May 13, 1941. R- Q RUSSELL Re. 21,802

VALVE OPERATING MECHNISM4 Original Filed ug. 19, 1932 6 Sheets-Sheet 2 F |G.7. L F |68.

l 4 BY @lag/GU, 1'

A NEYS May 13, 1941- R. c. Russam.

I I VALVE OPERATING MECHM Original Filed Aug. 19, 19252 Sheets-Sheet 3 5 f 5 .Mmm W W HH WIM mm f//yz l i; Y

May 13, 1941. R. c. RUSSELL VALVE OPERATING MECHANISM original Filed Aug. 179, 1932 G Sheets-Sheet 4 INVENTOR ROBERT C RUSSELL I m m 6. G G m.. m H WVM/NNW@ u m w w f 7 X v m l H ...ll

May 13, 1941.

R. RUSSELL VALVE OPERATING MECHANISM Original Filed Aug. 19, 1932 6 Sheets-Sheet 5 INVENTOR A HUBERT G RUSSELL BY MLM ATI' RNEYS May 13, 1941. R. c. RUSSELL VALVEA OPERATING MECHANI-SM v Original Filed Aug. 19, 1932 6 Sheets-Sheet G H625.

l INVEN-ron ROBERT (LIPUSSELL naw ml mmm W m a:

EMM-Im ATroRNEYs Reissues May 13, 1941 t Re. 21,802l

UNITED STATES PATENT OFFICE vALvE creanme Mechanism Robert C. Russell, Cleveland, Ohio, assigner to Eaton Manufacturing .Company, Cleveland, Ohio, a corporation of Ohio Original No. 2,158,730, dated May 16, 1939, Serial No. 629,474, August 19, 1932. vApplication for reissue November 29, 1940, Serial No. 367,864

(Ci. 12S- 90) 51 Claims.

This invention relates to valve operating mechanism and more particularly to automatic or self-adjusting and hence silent valve liijters or valve tappets for use primarily in connection with internal combustionmotors to maintain a 11o-clearance operating engagement between all` parts o f said mechanism. f f It is a well known fact that the exact time of closing and opening the valves, inl relation to the position of thepiston in an engine cylinder,

are importantfactors which affect the performance of the engine or motor. IA quick opening vibration.

and quick closing valve increases.` cngine horse l powerl but has two deilnite disadvantages, name- 1y, noisy operation andl short life for the valve operating mechanism. On the other hand, a slowor gradual opening and closingV valve has the Atwoadvantages of being quiet in operation and of longer life but does not afford high motor l efficiency. Even with the slow opening and closing valve, having the advantages just' named,

great destructive forces are set up at highspeed due to the necessaryY operating clearance between the. cam and valvemechanism now in general use, and this destructive tendency increases with the speed ofthe engine.

Another disadvantage of conventional valve mechanisms arises from variations in the length `of the valvel stem or push rod and other operating parts. thus varying the operating clearance which is caused byV changes in temperature.

thereby resulting in' the constantly changing consequently lowering the motor eiiiciency. A compensating, i. e., self-adjusting, valve mecha- Vtime of valve opening and closing actions, and v nisxn` which willconstantly maintain its operating clearance at zero or atv a no-clearance relation, despite variations in temperature and Wear of parts, renders practical the use of. quick opening and closing valve operating mechanism', prolongs its life Veven at high speed, and ailords accurately uniform and unvarying valve timing.

It'is, therefore, a general purpose of this invention, to produce novel self-adjusting or compensating valve tappetsor litters for operating the spring loaded valves, usually puppet-type valves, in relation to their seats, as `used generally in machinery, engines and the like, and to automatically, maintain a no4-clearance operat ing engagement or relationship between all parts of the mechanism intermediate the engine or machine driven cam and the valve seat in the cylinder. The -inyention promotes operating eiiciency, improves vaivetiming, avoids impact of parts, avoids wear and destructive hammering of the valve seats, and eliminates noise and Thevnecessity for a solution of these Problems is especially pronounced in high speed internal combustion motors. In aviation englues, the sqmuon of the problem .by eliminating the unusually great valve operating clearance, is

highly desirable to increase engine power, avoid valve trouble, and promote safety. 4 The invention, therefore, seeks to produce several practical commercial forms of silent, automatic, self-adjusting valve lifters or tappets and which are not subjected to wear in the perform-v ance of their automatic compensating or selfadjusting function. and which can be produced sufficiently economically to justify their general use.

to produce novel valve lifters capable of inherently, automatic self-adjustment or a take-up function in the length of all parts of the mecha.-

v`nism for compensation in both directions, i. e..

for both contraction and expansion of the vvalve stem and associated members, occasioned by temperature variation, as well as for wear at the` bearing or engaging and contacting surfaces of all operating parts. i

A further object is to produce silent and selfadjusting valve tappets of a solely novel hvdraulic type and which combine both hydraulic and mechanical features by.employing a novell hydro-mechanical principle of dual aspect and jwhich functions in conjunction with a small volume of oil under light pressure land confined in a variable size liquid o r hydraulic compensating chamber which increases or decreases in volume to @neet wesen-adjusting nmcuon and thus Y maintains the valve operating mechanism in a self-adjusted zero-clearance state.

In an hydraulic' valve lifter it is important that the inilow yof liquid such as oil into the compensating chamber should respond quickly to the slightest compensating movement of the self-adjusting elements, but where it is sought to yuse a spring .to seat the tappet control valve, the

inilow of oil is retarded and thus sensitivity is lost, inasmuch as the spring must iirst be compressed. I find that the control valve for the Y small volume hydraulic lifting chamber should be entirely free of spring means and only urged to its seat by'gravity,or by the up stroke of the' tappet to open the engine valve, or by the pressure in the hydraulic chamber, and certainly not by a spring.V It is an object oi' this invention Vto producea valve lifter meeting 4the conditions by which to attain quick priming of the keepingV with these purposes.' it is my object' hydraulic chamber and instantly added increments of oil to compensate for the slightest contracting of any operating parts.

It is also found that a free circulation of oil should be provided in a hydraulic tappet, since to compress thesame body of oil an infinite number of times causes the oil to become aerated and emulsified into a deteriorated thin jellylike mass and when inthis state it is no' longer non-compressible and loses its capacity -to actuate the engine valve against its stiff closing spring. Serious defects with hydraulic tappets have lbeen caused by air soaked oil which is a condition found dimcult to overcome because at high engine speed the tappet reciprocatesvery rapidly which violently churns and emulsiiles the oil, more esDei cially so when the oil is under great vpressure as indeed it is when lifting the valve against its closing spring unless a great .portionfof the load orpressure offtliat spring is`.f`e liminated. The supply of oil available for the compensating hydraulic chamber should be fed and bled so that the supply is of fresh oilfat all times, otherwise the rapid reciprocation ofthe tappet will churn and render said oil supply useless as a non-compressible body and would fail as such if drawn into the compensating chamber and wou'ldnot force against the heel of the valve operating cam,

wherebyl my novel deviceavoids undue friction and wearagainst said cam during the period the valve is'on its seat. Therefore, the oamiollowers of my tappets have a period of rest and wear'is minimized due to the reduced bearing friction on the heel of the cam.

Another object is to produce a valve lifter having novel overlying self-adjusting wedge means conned within a guide chamber and defining tlierein'the compensating hydraulic lift chamber tran-smit the throw of the camto open the engine i valve. Each valve-opening movement of the tappet should tend to force new oil to the supply receptacle adjacent to and available for feeding l the smaller hydraulic compensating lifting chamber andthe old oil should pass out through an overilow back to the engine crank case.v These desirable features, I now attain by a simple con- A struction of iewv parts and without Special oil pipe leads and without pressure supply lines or y complicated tubing or piping.

A further object of the invention is to produce |a valve lifter wherein the hydraulic compensating means or self-adjusting unit per se actuates through a. greater distance than the'corresponding variation or change in length of the valve operating parts, and this results in providing a low compression hydraulic chamber with minimum tendency to force out or lose its oil when opening the .engine valve. In other words, the

compensators per se in my invention have a proportionately greater travel (say several thousandths of an inch) in maintaining the zeroclearance function, than the movement or change in length (say only one. thousandth of an inch) of the valve stem or push rod and other parts constituting the engine valve operating. mechanism. This characteristic function of my invention produces a quick opening of the compensating oi-l chamber control valve for the slightest variation inlength of the valve'mechanism and draws a comparatively large volume of fresh oil into said chamber for a relatively small variation' in length oi operating parts. Thus by amplifying orV greatly increasing .the compensating movement of the self-adiusting means, relatively to the-shorter change in length of the valve stem and other parts, a rapidly :till-ing and self-priming tappet is-produced. Thus, while in operation, if the oil supply should fail or run low, or if for some'causethe hydraulic chamber should ldrain due to long non-use of the engine, the valve lifterV will function as a conventional tappet without serious harmf and when the engine is started or the oil supply is again available the tappet will immediately pick up oil by sucking it in and resume its functionas a compensating device. This feature is also a great advantage in assembling vbut it lifts only a small per cent' of vthe -valve load. In this way is attained a characteristic and noteworthy reduction of pressure on the oil in the hydraulic compensating chamber to minimize the tendency of the oil to emulsify therein and also avoid loss of oil from the chamber when lifting the engine valve oil' its seat. In this connection, I really employ the hydraulic chamber, the oil therein, to lock or hold apart the wedges in their precisely self-adjusted position, whereas the thrust or great load of the cam Iand engine valve spring isA carried' directly through the coacting wedge faces which are restrained from slipping or displacement by the sealed incompressible oil body between the wedges.

Another object is to produce hydraulic valve l lifter compensating instrumentalities including means acting to positively expel the air, or a maximum portion thereof, from the hydraulic' Pursuant to the foregoing `.air-*expelling funcnon, it is a. further object of this invention to produce a hydraulic 'valve operating device having maximum displacement means by which the volume of the hydraulic compression vchamber is reduced to zero or to a minimum spaced. e., Q minute in volumetric capacity '(or the 'chamber .i entirely closesor disappears for complete dis--flv u placement), upon the iirst turn ofthe engine cam, preliminary to sucking a chargent oilinto the maximum displacement oil chamber, and in this way the air is initially expelled fromthe vhydraulic compression chamber and thus said chamber is conditionedto receive and retain a solid body of air-free oil. In this "Mv is minimized the likelihood of the oil becoming air bound or locked, 4aerated and emulsied, and

hence Lprevent the hydraulic oil body from losi ing its incompressible characteristics.

The foregoing object, i. e. the attainment of maximum displacement for the hydraulic chamber, can of course be carried out with either a large or small volume hydraulic chamber. I have, however, illustrated my invention with a reduced size or minimum volume compression chamber of my maximum-displacement type, the object ,being to operate the self-adjusting unit in the device on a comparatively small oil body and thus lmake use of a minimum of aerated oil in any event should there be a tendency toward the presence of air.

A still further object is to produce a hydraulic 4tappet having a comparatively small volume compression chamber in combination with a substantially large size non-draining Yoil receptacle or supply, the inlet or feed leading into the latthe tappet expanded-to compensate for acon' fork having its lifting stem and guide'head which slidably fits in the upper endof the tappet sleeve to enclose the parts named;

Figure 7 is an assembly view of the valve operating mechanism with the hydraulic vaivelifter interposed between the spring loaded valve stem and the engine cam, and this view .shows tracted valve stem, as indicated by the reference line X;

Figure 8 is a view similar to Figure 7 except that Athe self-adjusting parts have automatically contracted into the tappet sleeve to accommodate a somewhat elongated valve stem, as shown ter being located high above the bottom wall lof said non-drainable receptacle, and the outlet leading from said non-drain receptacle into the small hydraulic chamber being located near the bottom wall of said receptacle.

Also it is an objectto produce a hydraulic dro-mechanical features, as follows:

'I'he first form of the invention is illustrated in Figures 1 thru 8 and which I have sometimes referred to as the fork and wedge type of hydraulic valve lifter.`

Figure 1 shows a vlongitudinal section thru va fragmentary portion of a typical internal cornbustion-engine having poppet type valves and in conjunction with which I have illustrated my in ventlon;

Figure 2 shows a longitudinal section thru the valve lifter or tappet as takenon the line 2 2 of Figure 1, on an enlarged scale, and removed from its guide in the engine base:

Figure 3 is a cross-section on the line 3-7-3 of Figure 1, with the tappet also removed from its guide in the engine base;

Figure 4 is a cross-section on the line 4 4 of Y vFigure 1, but with the upper one piece double face or fork type compensating wedge member removed from the tappet sleeve; Y

Figure 5 is a perspective view of a wedge seat or retaining and'gtuide means therefor, as, removed from the tappet sleeve, and within which the self-adjusting wedge means is carried tov form a compensating hydraulic lifting chamber, and this member also carries the characteristic non-spring closed control valve which admits oil into hydrauliccompensating chamber;

VFigure 6 is a cluster or exploded view of the tappet parts removed from the lifter sleeve and disposed in aligned order of assembly, showing the parts, reading from the bottomv unto-wit, the

cam follower tappet sleeve, the wedge seat, a ball valve, a compensating spring, the self-adjusting wedge pair, and the overlying double faced wedge sov ' automatic compensating means embodying hyby the reference line Y. The range of several thousandths of an inch variationin length of operating parts is thus diagrammatically shown at XY;

ond form shows an enlarged non-draining underneath oil supply chamber or receptacle below the hydraulic compensating chamber and which always pOsitively insures a full flow of fresh oil to theA hydraulic chamber formed by the 'selfadjusting wedges even though the engine has stood idle for a long period andthe oil drained away from many of the engine and valve parts. 'Ihis form of the invention also provides means foroiling the cam from the overow of oil issuing from the non-draining tapp'et supply receptacle as an incident to keeping the oil freshly changed inthe supply receptacle beneath the compensating chamber.

Figure 9 shows a perspective view of a compensating wedge means retained guide or wedge seat having an o il intake neck 'to project down into the non-draining fresh oil supply chamber 'and adapted to convey oil to the compensating -hydraulic chamber formed in said guide by the yWedge means, but with the latter removed;

Figure l0 shows a cluster view of this second form of valve lifter compensating mechanism spread apart in order of assembly;

Figures 11 and 12 are comparative assembly views of an engine cam and spring loaded valve with the hydraulic lifter interposed therebetween,

Figure 11 showing the lifter automatically expanded and Figure 12 contracted to maintain a no-clearance engagement in respect to all parts' ofA a conventional valve operating mechanism.

. 'I'he reference lines X and Yshow the range of automatic compensation in these two views.

` A third form of the invention is shown in Figures 13 through 18 which illustrate a hydraulic valve lifter embodying a modified form of compensating wedge means of reduced number of parts comprising an upper and lower wedge means each of which has a double acting face.

Figure 13 is a cluster viewof the third form showing the compensating mechanism removed .of Figure 14 with a push rod omitted and the lifter sleeve removed from its guide in the engine base;

Figure 18 is a cross-section on-the line I8-I8 .of Figure 14 with the upper compensating wedge and push rod removed and looking down on. a freely movable ball valve which controls the inlet to the hydraulic self-adjusting chamber. v

A fourth example of the invention is shown in Figures 19 through 23 and mightbe referred to as the screw jaw type of self-adjusting hydraulic valve tappet.

Figure 19 is a. cluster view with the compensating parts withdrawn from the tappet sleeve and spaced apart in their order of assembly;

Figures 20 and 21 are valve and cam assembly comparative views showing expanded and contracted positions of the valve `lifter to accommodate a contracted valve stem as in Figure 20 and an elongated valve stem as in Figure 21. The spaced reference lines X and Y point out this relationship and shows how the automatic 'device maintains its no-clearance engagement between the cam and valve stem throughout the XY range of variation in length of parts;

Figure 22 is a cross-section on the line 22-22 of Figure 20 .but with the upper self-adjusting screw jaw or wedge means removed, from the tappet sleeve to expose the wedge faces of the lower stationary member; v

Figure 23 is 4a cross-section on the line. 23-23 of Figure 20 illustrating the two spring means tending to expand the valve lifter by rotating the two screw jaw compensators.'

' end forming a cam follower I3.

A ilfth example of construction is illustratedl in Figures 24 through 28 and which also comprises a hydro-controlled triple mechanical wedge means designed to compensate for all variations in length of the valve operating mechanism, and wherein the hydraulic chamber isl remote from the wedge means.

Figure 24 shows the compensating parts in spaced alignment in the order of their assembly and withdrawn from the'tappet sleeve;

Figures 25 and 26 illustrate comparative position and assembly views with the hydraulic valve lifter interposed between the engine cam and ,spring loaded valve, and the reference lines Xv and Y indicate, respectively, the valve lifter in its expanded and contracted positions to compensateforcontracted and expanded valve stem conditions; l

Figures-:27 and 28 illustrate sections on the lines 21 and 28 of Figure 25 with the lifter removed from its guide in the crank case of the engine.

The first ,form of construction in Figures 1 through 8 In illustrating the several forms of my selfv the usual kind includes a valve head 5 adapted to open and close in relation to its seat 4 and an integral valve stem 6 reciprocates in its guide structions also include a tappet or valve lifter` guide II. in which a valve lifter is mounted between the cam 9 and tail end of the valve stem 6.

The foregoing is exemplary of standard engine practice. i

I flare or cup the upper cylindrical end of the guide II to catch` oil from the splash lubrication system or other oiling means of an engine and by which to feed oil down into the valve lifter. In the present instance my invention includes a lifter or tappet sleeve I2 having a lower closed In operation, my valve lifter I2 transmits the throw or thrust of the cam lobe I0 to the spring loaded valve 6 to lift the same against the expanding closing force of the engine valve spring 8. In conventional practice, there is always left a few thousandths of an inch clearance between the old form oftappet in the guide il and the end of the valve stem 6 Ato allow for expansion and contraction due to temperature variations, but in my invention this space is constantly closed throughout all ranges of length change in the valve stem and other mechanism.

My invention, among other things, comprises a combination hydraulic and mechanical self-adjusting means carried' in the tappet sleeve I2 for transmitting the thrust and carrying the load generated by the valve closing'spring 8 and valve. opening cam lobe I0. The valve lifter sleeve I2 has external oil grooves I4 extending longitudinally from the upper open end of the sleeve and communicating with a circumferential groove containing holes I5 thru the sleeve wall. This construction provides a system of passages which convey oil from the upper flared portion of the tappet guide II of the engine to the inside of the' tappet sleeve to feed the compensating mecha- .transversely Aat I8 to form a. system of oil leads to the underneath portion of this wedge seat device IS, This wedge seat IG has an outside diameter adapting it to a, sliding t into and a stationary position at the bottom of the sleeve .I2 and hence on the cam follower I 3. The oil grooves I1 and I8 convey oilfrom the sleeve passages I4 and I 5 downwardly along the inner surface of the tappet sleeve I2 to the very bottom or underneath portion of the wedge seat IG.

'I'he plug-like wedge seat I6 is further characterized by a rectangular opening or chamber-ing slot 2i cutfrom its upper end and extending downwardly and forming a. fiat bottom slide surface 22 formed at an angle to the engine-valve stem 6, say at right angles thereto. A compensating or self-adjusting pair of plunger-like wedges are slidably mountedupon the flat seat 22,.and also within the slotted opening 2| there is formed a hydraulic compensating chamber of variable capacity as will be described. A valve controlled inlet and valve seat 23 is made centrally through the flat bottom wedge seat 22 and connects with the transverse oil grooves I8 to receive oil from the sleeve grooves Il and flared guide i I. The inlet 23 includes a valve seat on which a freely s 21,802 movable ball check or other form of valve 24 tion of all these factors.k Purposely, no springFV means is employed to close this compensating ball valve means -2li and hence its action is sensitive and quickly responsive. to un unseating tendency to allow oil to pass the seat 23 and iiow upwardlyV into the slot 2I and a hydraulic chamber formed therein, as will be explained. The wedge seat member I6 rests within the sleeve, is stationary therein, and reciprocates therewith.

A self-adjusting plunger means in the form of a wedge pair, comprising two symmetrically formed wedges 21 and 28,.in the nature of rectangular faced plungers, having flat bottoms 28, are spaced apart with a compensating spring 30 mounted therebetween with the spring ends seated in a socket 3I made in the adjacent faces of said wedges. Th wedge pairV 21, 28 has its lower flat faces slidably seated on the surface plane 22 with one wedge placed to either side of the oil inlet 23 and the expansion of the compensating spring 3Ilv tends to thrust the wedges apart in the performance of their compensating function in one divrection'to automatically adjust outwardly for a contracting valve stem 6, as at the reference line X, yet this spring 3D yields to afford the reverse compensating function to adjust inwardly for an elongating valve stem 6, as at the reference line A Y. The wedges 21 and 28 have a substantial range of transverse movement at right angles to the' axis of the member I6 and its carrier sleeve I2. The

Y limit of their outward movement is defined by the wedges abutting again'st the inner wall of the sleeve I2 and` the'limit of their inward movement is substantially a dead center position, as in Figure 8, where the wedges have practically closed together and compressed the self-adjusting spring means'3. Thus a double positive stop is provided for the self-adjusting plunger means 21, 28.

sleeve I2. In other words, the outer vertical faces f of the two wings forming the two-faced wedge 33, arecylindrical in form, similar to the head 30, and have aguided fit in the sleeve I2 the same asthe head 35. The wedge member 33 has a verticalr oil groove 31 made in each outer vertical'cy'lindri;r

cal face to lead oil down to the bottom of the,4

wedge seat I6;

The adjacent parallel or vertical facesA of the two-spaced self-adjusting wedges 21 and 23, to-

gethe'r with theupper converging wedged faces l 3B of the member 33, as well as the lower flat face 22, taken all together define or set Off a closed hydraulic compensating chamber 4 0 of small volume with maximum displacement. and of generally rectangular shape, as shown in the assembly views and which varies in size and volume to compensate for contraction and expansion of valve stem E and other parts of the valve operating mechanism. The flat vertical faces 'of all three cooperating wedges 21, 2B and 33 have, a close sliding plunger-like or piston fit withinvthe parallel walls forming the slotted opening 2I in the wedge seat I6.

28 and 33, constitute in effect a three-part plunger A one-piece double-faced wedge member or pilot wedge 33 is carried on the lower end of a thrust post orstem 34 having an upper guide head 35 slidably confined in the upper end of the sleeve I2 to close the latter. This single wedge 33 is made -with'angular or forked 'wing portions operatively ydisposed in the upper end of the slot 2| of the wedge seat I6 and embracing or coacting with the lower wedge pair 21, 28. The three wedge elements have symmetrically coacting angular or wedge faces 36 which cooperate to form an automatic selfadjusting unit within the slotted charn-V ber 2| of thewedge seat I6. The single spreading double-faced wedge 33 includes the two con- '.verging wedge faces 36, meetingor converging g 4centrally at an apex coincident with the axis of thestem 34 and lifter sleeve I2. The compensating spring 30 tends to drive the two self-adjusting wedges 21 and 2B outwardly, thus sliding the coacting wedge faces 36 along the double faced wedge member 33, and thereby urging the latter upward :and longitudinally or outwardly of the lifter sleeve I2. Down Apressure of the forked wedge 33, caused by the heavy valve spring 8, sets up a resultant closing force against the wedge pair 21 and 28 tending to actuate them centrally and toward each other to slide them to the apex of the slotted member I6. The one-piece double faced wedge 33 is adapted to an up and down sliding movement in the chambering slot 2 I, while the two symmetrical wedges 21 and 28 arel adapted to undergo a. transverse sliding movement atright s angles to the axis of the sleeve I2 and stem 34 throughout the operative sliding action df all three wedge means, they maintain a close oil tight fit against the walls of the member I6, and function in effect like a piston in a cylinder Yexcept here are employed flat slidingIsur'faces instead of cylindrical surfaces. i

' The component parts of the self-adjusting hydraulic valve lifter, as shown in Figure 6, re mounted in the sleeve I2 as shown in the assem yly views, and the outer cylindrical surfaces vof the wedge `33 have a free sliding t in the inside cylindrical surface ofthe sleeve I2 and likewise for the outer small cylindrical face on leach-compensating wedge 21 and 2B. When assembled the compensating spring 30 keeps the wedges 21 and 28 spread apart under the single wedge 33 and thus bears the stem 34 and head 35 upwardly against the lower end of the valve stem i to maintain a `zero-clearance relation therewith- The parts are stand apart determines the low or small volumetric capacity of the valve controlledh'ydraulic compensating and lifting chamber 43 and, as the wedges move farther'4 apart.'l they enlarge this chamber and thus produce a suction Atl'ierein with the result that the ball valve 24 is sensitively' lifted off its `seat and fresh oil flows up into the chamber 40, whereupon the ball 24 again seats and entraps the oil in the chamber 4l, thereby locking or positively holding said wedges apart to f fuliillv their function of raising and lowering the The compensating `wedge set, comprising the three self-adjusting members 21,

,i angle the less pressure.

an angle approximately as shown in'" order to spring loaded valve in relation to its seat i against the powerful closing force of the engine valve spring 8.

'I'he ooacting wedge angles or inclined planes at 36 are comparatively fiat. The steeper the angle, the more pressure there would be exerted on the hydraulic chamber 40 by the sliding reaction of the wedges.

Consequently, I choose exert a minimum of pressure onthe oil chamber iii and yet an angle sufficiently steep to permit a retractin'g or approaching movement of the wedges 21 or 28 under the force or" the heavy valve closing spring 8, vwhich occurs when the valve stem 6 expands due to arise in temperature conditions. -An angle in the neighborhood of twenty to twenty-live degrees, as measured from t the horizontal or aline drawn at right angles to the line of thrust or axis of the valve stem ii, is shown and gives satisfactory results. This angle may be varied somewhat and can he increased or made steeper since the oil in the hydraulic chamber 40 will positively hold the wedges apart to lift the valve 5 and compress its spring il.

Conversely the flatter the The inclined thrusting and self-adjusting surfaces 36 in the compensator unit are found te give very satisfactory operating results with approximately the angular measurement herein dis..

closed. As an example of the comparatively low pressure exerted on the oil in the hydraulic chainber 40, let us assume that it requires a thrust of 125 pounds to actuate the engine valve 5 in rele.- tion to its seat 4. 'I'he angular wedge means here disclosed will only transmit about 3 per cent of the load pressure to the oil in the hydraulic chamber. Hence conventional valve springs of 125 pounds compression'al resistance would only subject the oil to a pressure of 3.75 pounds, but inasmuch a's the spring 30 will easily carry part of this load, say 2 or 3 pounds pressure, it is easily seen that only 1.75 or .75 pounds pressure is ultimately 4applied against the oil in the hydraulic chamber. In other words, the oil has to stand only 1 or 2 pounds pressure to hold the wedges 21 and 28 apart while they compress the 125 pound engine valve spring 8.

Inv the nrst form of the invention thes'upply of oil for the hydraulic chamber 40 flows down thru the sleeve grooves I4 and enters the inside of the tappet sleeve I2 thru the circumferential groove -and passage means -I5, and thence the oil feeds down thru the groovesA 31, I1, I8 and then up thru the valve controlled inlet 23 leading to the hydraulic chamber 40. To insure a free ow of oil along these passages, it is preferable to provide vent holes 4I in thellifter head 35 and its stem 3@ so as to equalize the air pressure in the sleeve under the head to avoid all possibility of an air lock in. order that the oil may run freely down thru the passages and stand available at the ball check valve 24 to be admitted to the chamber Ml upon the slightest outward movement 'of thewedges 21 and 28 under the expansive force of the spring 30. ,In other words, the open spaces lin vthe sleeve are under normal atmospheric pressure the chamber 46, due to the preferably restricted size yof the latter, merely serves to keep the plunger wedges apart and substantially all of the thrust delivered from the cam lobe I6 is transmitted thru the coacting Wedge faces 36 of the compensator unit, Whereas, only a small percentage of the load is exerted in the form of pressure against the oil in the compensating chamber stil. Hence there exists little or no tendency to emulsify the oil because it is not pounded and compressed by the `continuously running cam lobe iii. The upward thrust to open the engine valve 5 as Well as the downward pressure te' close it, is substantially and largely carried on, at or thru the engaged wedge faces made at an angle between fifteen or twenty and say thirty degrees. By eliminating the continuous pounding and minimizing the pressure ori-the small body of oil in the hydraulic lifting chamber dii, it follows that the oil is not air soaked and emulsiied into a thin jelly-like substance to lose its capacity as an lli-compressible agent to positively hold the wedges 21 and 2 apart, and consequently the Wedges perform their function perfectly and do not slip on their seat 22 'during normal operation when no compensation is required due to constant engine temperature conditions.

Ari important structuralfeature which contributes to the successful operation of several forms of my invention resides in the fact that the self-adjusting wedge pair 21, 2S has a long range of travel and is multiplied in fact many times over the shorter travel of the single wedge 33. attain this characteristic by the ratio -wedge means.I It is apparent that the angle E@ `compels an outward sliding or separating moveber in larger measures, many times over, and the ball valve unseats and there occurs a substantial intake of oil, increments which could not be added to the oil already in the chamber except for my amplification of the self-adjusting action greatly in excess of the slight change in length of operating parts. 'This feature also makes for quick'priming and ypositive filling of the hydrau- I lic chamberwhen the mechanism is first installed. It is also noteworthy that there exists a minimum of frictional pressure between the cam heel 8 and the cam follower I3 during the period the valve head 5 is on its seat 4. This mode of operation follows by reason of the fact that the selfadjusting or compensating spring 30 is comparatively light, but more particularly because its expansive force is absorbed ortaken up and resisted.-v somewhat by the coactlng angular wedge faces 36. By the time the self-adjusting spring '30 expends its force'thru the wedge faces, there is comparatively little reaction pressure from this spring transmitted to the cam heel 9, Hence the cam 9 is rested soto speak and relieved of undue wearing pressure during the time the heel traverses said cam with the result .that heat and friction is reduced between the bearing face of the cam 9 and follower I3 .with the result that oil more readily nds its way to these engaging .surfaces so that the Wear of these parts is' mini-` mized.

When the valve lifter is flrst assembled, it is dry, i. e., its small chamber 48 contains no oil.

l The first turn of the cam I .causes the plungers 21 and 28 to reciprocate toward each other and vclose up with their adjacent vertical faces coming together. VThis action displaces or completely eliminates the hydraulic chamber and consequently displaces all-air therefrom or a` maxi-l mum portion thereof. By'ths maximum displacement function, all air is expelled from the compression chamber. Also thel action of the plungers 21 and 28 coming together provides a stop or inward travel limit to' prevent over-compensation in one direction, i.,e., prevents con` traction of the self-adjusting unit into its tappet body or sleeve I2. As vthe cam I0. continues to turn and its heel 9 engages the camlfollower I3, the return or compensating spring 38 beginsto Vexpand and thereby separates the wedges 21 and 28,v thus sucking oil past the ball check 24 into `the air-free hydraulic chamber 48. The tappet has an Aoutward limit of compensating travel for the plunger lmeans 21, 28 by virtue of the outer end of each plunger coming into engagement with the inside wall of the sleeve I2, and thereby the'self-adjusting unit is limited as to its over-compensation in the other direction, i. e.,

expansion outwardly of the sleeve I2. The small volumev of oil .now trapped in the compression chamber locks the plunger wedges apart in compensated position, whereby said plungers transmit therlift of the cam lobe at the next and all successive turns of the cam. g

The small volumetric capacityof'the compen,-'v

sating chamber 4l| simply means that thesmaller the amount of oil contained therein the smaller will be the amount of air occluded in the oil and the less will be the gas or bubbles liberated by the oil when it becomes heated and is working under pressure. It is appreciated therefore that the small volume chamber l4l), coupled with the fact that this chamber is capable of complete or maximum displacement, constitutes important features of construction and operation in my invention'. This principle, by which I have solved-certain preblems which heretofore caused failure of long sustained-operation of hydraulic valve lifters, is also shown or employed in the design, construction and-operation of modifiedA -forms of my invention,

A description will now be made of the other forms of the invention, but in doing so the reader will take into account the above description of the first form inasmuch as many explanations already given apply in effect to the succeeding heretofore used, are applied to the conventional engine parts, such as the spring loaded valve, its operating cam, and other standard parts.

A tappet sleeve 42 is very similar to the former lifter sleeve I2 and has a closed bottom 43 as a cam follower and an open upper end to receive a compensating unit to be described. vThis sleeve 42 is designed to positively retain a substantially large supply of fresh oil in its lower end and in this connection there are made a number of oil holes 44 thru the sleeve high above the bottom end 43 thereof and within a circumferential groove 45, thus providing a deep non-draining oil receptacle 48 in the sleeve. Longitudinal oil feed grooves 46 are cut externally inthe sleeve from the top end downward and communicatel oil from Vtime to time. In this way, there is always provided a larger inflow of oil to the nondrain deep receptacle 48 than is afforded by the discharge passage 41 of less conveying capacity than the several feed passages 4B. The recipro-l I eating action of the sleeveV 42 effects circulation of oil therethru to keep the supply fresh. Any

suitable means may be used to feed oil into the `oil inlet 44 placedhigh in the sleeve 42.

'I'he lifter sleeve 42 is made with a slightly larger upper internal bore than the lower portion which forms an annular shoulder means 49 above the oil feed passages 44 and 45 and which f acts as a rest or support for awedge seat member 5I, shown in Figure 9, and whichcloses the upper end o'f the non-drain oil receptacle 48.

spo

forms and for that reason certain established principles and modes Vof operation may hereinafter beonly brieiiy recounted or even omitted where the same are common to the types of valve lifters hereinafter, described.' f

The second form of construction in Figures 9 thru 12 v l ln this species of the invention, the same selfadjusting or compensating means per se is emv ployed las heretofore described, but a characteristically different means of fresh oil supply is afforded the small-volume maximum-displacement hydraulic chamber, by way of a larger and more certain supply, which is always maintained, no matter how lons an engine stands idle to afford opportunities for al1 the oil to' drain away from the parts.' The same reference characters as' This wedge guide retainer seat 5I is similar in function to the rst described wedge seat shown in Figure 5, but is structurally different in that a long oil inlet neck or tube 52 `reaches from the plug portion 5I down to the bottom of the nondrain oil receptacle 48.` 'Ihe neck 52has its upper end integrally formed or otherwise secured 52 projects down into the oil receptacle 48. A

.freely movable ball check valve 55 rests on the seat 53 and normally closes this oil inlet to admit oil up thru the neck 52 but prevents a reverse ow thereof. The lower end'of the tube 52 is always immersed in oil no matter how long an engine stands unused, because the oil supply reservoir 48 never drains. The member 5I comprises-in eii'ect, a partition which divides the tappt body or sleeve into a large oil reservoir orl receptacle adjacent a small compensating space into which is operatively mounted the selfadjusting unit. Y

A pair of automatic self-adjusting wedges 51 havey flat bottoms which slidably rest on the hat upper surface at the bottom of the channel or chamber 54 in the wedge seat 5i. /A compensating spring Il is disposed between the wedge pail l? with the spring ends inserted in a, socket formed in the adjacent face of each wedge and keeps the wedges urged apart. This spring Sii rests horizontally right above the bali valve 55 and serves to prevent it from falling out oi place during assembly operations or during high speed reciprocation of the tappet in event oil has not yet become entrapped in the hydraulic chamber above the ball valve e5.

Next in the assembly, there is provided s. single or pilot wedge te having wing means and a double wedge face symmetrically formed in re spect to the two wedges E? and embracing or forkingr over the latter. This double faced wedge 59 rests on top of the two wedges 5l within the slot 5t? of the seat and wedge retainer plug 5i. The outer surfaces of the winged wedge 5% have a cylindrical bearing and sliding fit inside the sleeve 42 and its parallel flat sides have e. close oil tight sliding t between the parallel at walls defining the wedge slot or chamber` 5t. Thus is constituted a hydraulic smal volume compensating chamber 80 (see Figure 11) formed by the underneath convergingwedge surface of the member 59 which constitutes the top closure of the chamber 80,. the ball valve 55 and wedge seat 5i' forms the bottom closure, and finally the ad-4 jacent parallel shorter flat faces of the two selfadjusting wedges' 5i form the other closure walls of this, chamber 8?. The spring 6E is transa versely disposed in the chamber il over the bali valve E@ and out of engagement therewith to leave it free on its seat 55S. The wedge it constitutes a valve thrust member to liftthe engine valve t: and a seat against which the tail end oisaid`valve stem rests with rio-clearance engagement therewith.

The' foregoing self-adjusting parts or compensator per se, comprising the wedge seat 5i' ton gether with the double faced wedge 5t and -intermediate parts, are mounted in the upper end of the sleeve 42 and anchored on its shoulder 4t.V

The automatic tappet is now complete and ready, to be inserted in the tappet guide Si usuallyformedl in the crank case oi" an engine. The self-adjusting parts in the sleeve automatically assume a zero or no-clearance engagement between the engine valve 6 and lifter wedge 59 for 'the reason that the 'compensating spring E@ thrusts outwardly onthe two wedges il. thereby moving wedge 59 upwardly until it'seats positively against the lower end of valve stem 6. The weight of the sleeve and'expansive force of the spring 5l act downwardly on the sleeve l2 to maintain its cam follower ll in no-clearance engagement with the cam. Hence the entire valve mechanism is set up without the slightest play,

beginning with the running surface of the cam and extending all the way to the face of the valve seat l throughout all the mechanism..

In operation, oil is supplied in any suitable manner tothe inlets I4 or collects around the upper cylindrical end of the engine tappet guide Il', from rother' parts of the engine such as the crank case, and ilows downward along the grooves' 46 and thru the holes to illl the oil receptacle I8, When this receptacle is filled, the overflow oil discharges outwardly along Athe groove I1 and pours directly upon'the cam 9, Ill to keep it lubricated. It is noteworthy that the lubrication of the cam from the receptacle ,4l

thru the oil drain groove 1 is very effective because the cam heel is under light pressure and thus readily retains oil to lubricate the lobe i0. The self-adjusting spring. 58 is comparatively light and the wedge means resists its-expansive force and the cam follower end 43 bears lightly on the heel 9. The oil supply never completely drains from` the rebeptacle and, inasmuch as the supply neck 52 dips into the lower portion of lreceptacle 48, it is apparent that there is always available a supply of oil to feed upwardly thru the neck into the hydraulic chamber 6G.

'I'he rotation of the cam I [l thrusts up-4 wardly thru'the lifter sleeve 42, through'the shoulder dfi, through the wedge assembly, into `the valve stem 6 and thus lifts the engine valve 5 ofi its seat 4 by compressing the engine valve spring 8 which resiliently loads the valve i to keep it closed on its seat and maintains the sleeve i2 against the face of the cam as the lobel i@ the space 5 6, quickly fills the hydraulic chamber 'forced in by atmospheric pressure.

6@ with oil by suction. The ball check valve 55 is sensitive to the upward inflow of oil drawn thereinto by suction of the plunger wedges 5l or Instantly the chamber 60 is filled with oil, there remains no vmore lost motion ibetwe'en the cam follower 43 and its driving cam or between thefvalve'stem 6 and its wedge 5, and the device is set for conetant operation.

An angle suflciently steep is chosen for the oo acting wedges 5l and 59, as already expl'ained'in the first form of the invention, which effectively reacts thru the incline planes of the three wedges 5l' and 59 to slide the piston wedges 5l' together in event no oil is entrapped in the chamber 60 'formed therebetween. 'I'helr next outward stroke primes or fills the chamber Bt. This angle is not made too steep for that would place too great 'a pressure on the oil in the chamber 6G. On the other hand, theangle is properly designed as not being too flat because it is desired that the wedge pair 51 have considerable relative motion along the fiat bottom surface of the seat 5l in event no oil is in the hydraulic chamber 60 by which to pump oil up into that chamber. In other words, an angle somewhere between 15 or 18 to,25 or 35 degrees', measured from the horizontal, may be used but the angle shown of approximately 22 to 24 degrees, or threabouts, gives very satisfactory operation, and ,affords the wedge pair 51 a proportionately greater self-adjusting movement than the shorter variation in length of the valve Istem i and other partsdue to changes in tem- Derature.

In event the valve stem 6 gradually shortens, as in Figure 1l by cooling oft, the compensating spring 58 gradually thrusts the wedges 5I apart,

moving them several thousandths of an inch more than the valve stem Gxcontracts, thereby drawing oil from the supply receptacle 48 upwardly thru the tube 52 into the chamber 60 to keep the wedges 51 hydraulically locked in their outermost self-adjusted position. As the lobe I0 thrusts upwardly on the sleeve (2, the pressure or force 21,802 is comparatively light on the oil in the chamber En because most ofthe thrust is carried thruthe wedge pair to the valve stem engaging wedge 59. The plunger wedges have outer stop means to limit their self-adjusting movement in that the outer end of said wedges come to rest against the inner cylindrical wall of the sleeve 42.

On the other hand, 'should the valve stem 6 elongate, as in Figure 12, then the powerful force of the valve closing spring 8, acting thru the inclined plane of the self-adjusting wedge means, i. e., thewedge 59 bearing heavily on the two slidable wedges 51, causes the latter to slidably approach each other sinceA the closing force of the spring 8 is suflicient to enforce acreeping approach movement of the two wedges 51 by com- -pressing the yieldable spring 58. The two plungers 51 have an inward travel limit or stop function when they meet at the apex of the pilot wedge 59. f course, the closing or approach action of the adjusting wedges 51 is resisted by the oil in the chamber 60 but the increased pressure thereon becomes so great, due to the gradually increasing length of the valve stem 6, that the oil leaks out of the 'chamber 60 along the Asides of the wedges or even past the ball valve.

In fact it is not necessary to make the wedge set 51 and 59 with such a close and tight lit in the seat Bland its channel 54 that no liquid can escape from the chamber GII since theviscosity of the oil retards its escape. Furthermore, the

engine valve opening and closing action by the cam III is so rapid that no appreciable amount of oil has time to escape from the .chamber GII during any one valve opening action,'and for the further reason that little force or pressure is normally applied to the hydraulic 'chamber due to the are eliminated and the incompressible characteristic of the oli is preserved. These features.

small-volume and maximum-displacement compression chamber, are important principles in my invention. v

Y The third fbrm cf construction in Figuresvrs thru 1s This form of the invention is similar in principle but modied in structure over the species `heretofore described and I have shown it in connection with an overhead rocker arm type of valve operating mechanism for valve in the head types of engines. As a matter of fact, however, my other valve liftersare also well adapted for use in conjunction with rocker arm types of valve There is shown'a rocker arm 52 of standard form adapted to actuate a valve 63 loaded or closed by its .spring 64. The latter parts are broken away inasmuch as they are not necessary greater portion of the load being carried on the wedges. Inasmuch as the valve stem elongation is slow and gradual, it follows that enough oil leaks out of the chamber 60 during the slow expansion ofthe valve stem 6 to accommodate its increased length. The valve loading spring 8 is Vof sumcient strength to always bring 4the engine valve head 5 to its seat 4 by keeping the volume of oil in the chamber 60 reduced to `a point just where the valve 5 will seat, but no further reduc- 'tioxr can be effected inasmuch as the self-adjustlng. spring 58 always keeps 'the plunger-like wedges outwardly disposed, limited only byengagement of the wedge 5 9 against the valve The spaced reference lines XY 'show the variation in lengthand range of change in both the valve stem and the automatic tappet, and graphically shows the proportionately greater travel of the compensating plungers as compared to the lesser change 'in length of the valve stem 5.

The restricted size or small volume of the hydraulic chamber 460 in comparison to the available supply of oil in the large non-drain refor an understanding of Athis hydraulic form of valve lifter, and in fact the rocker arm 62 is merelyshown for the purpose of bringing out the general purpose of an unusually long push rod 65 which is subject to considerable variation in length resulting from temperature changesv due to its considerable length required to reach from the cam shaft in the engine up to the rocker arm on the cylinder head. A valve lifter or tappet guide 61 is carried by the enginein the usual way and in which the lifter or tappet sleeve reciprocates, and a cam shaft is provided with a cam having a lobe Bland heel B9. The automatic self-adjusting valve lifter constituting the invention is maintained in lio-clearance engagement with and between the push rod 65 and cam means 68,59. The upper end of the guide 61 is flared or cupped to collect oil from the splash or other lubricating system of the engine to feed oil downwardly to supply the hydraulic self-adjuster unit.

A valve lifter sleeve 10 is constructed similar to those heretofore described and has vits lower of apertures 13 which pierce the wall of the sleeve.

The grooved and apertured sleeve 10 is adapted to reciprocate in the tappetguide 61 and the passages v4feedoil to the inside lower end of the sleeve where thel oil is available tolow into a ceptacle 48, in combination with the complete closing movement of the compensating plungers 51 acting till they meet at the apex of the pilot wedge 5! causing displacement of the air from `the chamber 60 on the first turn of the cam lobe lli, produces a hydraulic valve lifter of dependablev and unfailing performance. Since the air is ex-y pelled from the chamber 60 before the latter is primed with oil,l and only a small amount of oil is required, it .follows that there can exist only the slightest amount of occluded air or gas bubbles in the oil sucked into the small air-free compressionchamber to be subsequently liberated bypressure and heat. Consequently air troubles hydraulic lifting chamber to compensate for contracting and expansion of the push rod 65 and other parts of the engine or mechanism.

A wedge retainer or seat is provided for holding the self-adjusting members in place and comprises a cylindrically shaped plug-like member 14 similar to that already explained Ain Figures 5 and 9. It has a ilat bottom seat 15 at the lower part of and within spaced parallel upstanding walls 16 defining a deep channel to movably carry a self-adjusting wedge set or pair as will be explained. This wedge guide 14 is also grooved vertically and horizontally on its cylindrical and bottom surfaces, as indicated at 11, by which to -feed oil from .the sleeve holes 13 down underneath thereof and up through an oil inlet and past a ball valve seat 1B and thence into a small volume hydraulic lifting compensating oil chamber 19 (see Figure 14) formed withinV its walls 1e.

closes the oil inlet 18 Which is thus valve controlled to admit oil into the chamber 19 formed by a set of interfitting self-adjusting wedge means -and also by the walls 16 of the wedge seat as will be described. The ball 8| is free in the opening 18 and closes by its own weight or by the pressure of oil thereon.

A pair of automatically compensating interiltting wedges B2 and 83 are operatively mounted in the channel 16. The wedge 82 is adapted as anunderneath member and undergoes slidable adjusting movement along the ilat face 15 across the valved inlet 18 and transversely of the push rod 85 and its line of thrust from the cam lobe E8. The upper wedge 88 rundergoes a resultant adjustment travel in the sleeve 18 at right angles y to the movement of the lower wedge 82 and hence axially in respect to the push rod 85 to maintain a no-clearance engagement with the latter. symmetrically engaging complementary faces 80 inclined to the axis of the push rod 65 and which slidably iit together with a liquid tight seal. They also have parallel vertical ilat faces 84 delining two of the walls of the hydraulic chamber 18 heretofore mentioned. In fact, the two wedges have a pair of coacting angular plane faces 88, disposed in staggered relation, the

aforementioned vertical faces 84 serving to step or stagger saidwedge faces 80 in spaced planes on each plunger-like member.

Each wedge 82 and 8 3 is made with a spring receiving socket l5 adapted to receive an expanding compensating spring 88, the Iends of which force outwardly to'continuously urge or slide the wedge 82 laterally or along its seat 15 transversely to the upper wedge 83 and thereby impart longitudinal movement to the latter in the sleeve 1l. The lower wedge 82 is made with an enlarged port opening 81 to pass oil from the valve controlled passage 18 up into the hydraulic chamber 19. The port 81 is sumciently large to fully expose the ball valve 8l for all positions of the self-adjusting wedge 82 along its seat 15.

The wedge means with its valve and spring assembly just described is mounted within the v rounded lower end oi' the push rod 85 'and the self-adjusting spring. 88 acts to keep `the upper wedge snugly against said push rod at all times.

The hydraulic valve lifter assembly, comprising the sleeve and its self-contained compensating means per se. is mounted in the tappet guide I1 with the cam follower end 1I resting against the cam and the lower end of the push rod 85 resting at 88 against the self-adjusting wedge assembly. As soon as eil ls received into the -chamber'l, the entire mechanism assumes s3.

self-adjusted zio-clearance working engagement between all parts, from the valve Ss all ther-*Jay thru the mechanism back to the carri e9. The

first few revolutions of the cam lobe 68 will serve to/pump or suck oil from the supply passages "i2- and '11 up past the ball 8i and into thev chamber, lil to positively hold thewedge means 32 and apart in their self attained and adjusted position. In the push rod 65 and other parts The two wedge means 82 and 88 havel result of which is to work or adjust it to the left thereby lowering the upper wedge 83.to accommodate for said increased length of ythe push rod 65 and other parts, as caused by a rise in operating temperature vof the engine. Under great pressure of the .engine valve spring E4,l the adjacent hat faces 84 of the wedge means are ,gradually brought together by forcing the oil to leak out past the plunger-like wedges and around 'the four walls defining the hydraulic lift and self-adjusting chamber 19. While the novel plunger means 82, 83 npossesses an oil tight slid-- ing t'within the channelled chamber 16, the oil will nevertheless slowly escape in the minute quantity required during the considerable period that the push rod mechanism is expanding the few thousandths oi' an inch. y

On the other hand, iet usassume that the push rod 85. and related operating parts contract or shorten up due to a drop in engine and valve temperature, as in Figure 14 at the pointer X. Under this condition, the slight Aplay or clearance, which tends to show up between the cam 88 and its follower 1I vor between the rocker arm 82 and valve 68 or at 88, results in quick responsive action from the compressed spring 86 to spread the parallel wedge faces 84 apart, by sliding the wedge 82 to the right and the other wedge 88 upwardly to fill the space and follow the receding push rod 65.' This operation results in sucking oil up through the inlet 18 to fill the` increased size chamber 18 and hydraulically locking the self-adjusted wedge 82 apart in spaced relation from the longitudinally movable wedge 88, and the latter wedgeA is unyieldingly held to its push rod seat 88.

Inasmuch -as the engaged wedges' 82 and 83 carry the greater portion of the load or thrust required to compress the spring B4 and actuate its valve 63, it follows that very little pressure is exerted on the oil chamber 18 between the wedge faces 84. This reduces the tendency of the oil to escape from the chamber 18 during normal operation in actuating the engine valve u against its spring s4 since the 011 is canes upon to do little work. Furthermore, this reduction in pressure avoids oil deterioration and emulsiflcation. Also it is not necessary to so accurately and finely grind the plunger wedges and their retaining walls 15 and 16 inasmuch as there exists ayminimum pressure tending to force theoil to escape.

The angular relation to the horizontal, as

'defined by the adjusting inclined planes 80 of the wedges provides an increased ratio of movement for the laterally adjustable wedge 82, as compared to the lesser change in length of the push rod and other parts of the valve mechanism due to temperature variations and wear between the parts. This latter function of amplified selfadiustment facilitates the priming of the hydraulic chamber 18, `and renders sensitive the ball valve di by causing it to quickly unseat and admit a large volume oi' oil as compared to the extremely small change in length of the push rod 55 and other parts. The compensating out stroke' ci' the wedge B2, i. e., its oil suction intake strokef'may be designed to be many thousanclths of an inch greater than the variation in length of the operating meezianism, and tlnsdesign is with a number attained by employing substantially the angle 80 shown von the wedge plunger members. Hence the intake of oil is more denite and certain,

and larger increments of oil are drawn into the chamber 19, than would occur withV an ordinary piston and cylinder type of hydraulic valve lifter.

engine valve 9| rests with zero clearance when the valve 89 is seated. 'I'he upper face of the head |04, as well as the lower or adjacent face of The small volume compression chamber 19 means that this form of the tappet operates on a .restricted amount of oil to hydraulically lock apart the self-adjusting plungers 82 and 83. Consequently little or no entrapped or occluded air is present in the oil drawn into said chamber which itself is free of air, at the instant of priming. inasmuch as the vplungers have the maximum displacement function, due to the ability of the plungers to close up, on the rst turn of the engine or cam, andthus force out all air preliminary to the priming action.

The fourth form of construction in Figureszo 19 thru 23 This form of the invention represents a sim- A Y pliiled construction of the hydraulic valve lifter and employs a somewhat different form of selfadjusting wedge and 'hydraulic lit-ting chamber from thatrheretofore explained. There are provided two interfitting complementary wedge members having in veiect screw-like jaw means, one of which is self-adjusting by reason of executing a characteristic combined rotary and longitudinal Vmovement in lthe tappet sleeve to compensating chambers. In this forni,V there is a single adjustingV member which executes both motions necessary to adjust by the increased travel ratio principle of my invention. V

A .conventional valve head .89 operates in relation to its sea-t 90 and has a stem 9| adapted to reciprocate in avalve stem guide- 92 under the closing force of anY engine valve spring 93. The lower or tail end ofthe valve stem 9| is seated in no-clearance engagement with the hydraulic self-adjusting unit carried within a tappet or lifter sleeve 94 which reciprocates within a guide 95 ordinarily formed in the engine crank case where it cancollect oilin its flared receiving neck from the splash in the crank case or other engine lubricating system. The sleeve 94 has a lower cam follower end 96 which bears with noclearance engagement on a cam including a heel 91 and operating-lobe 98. These parts are in effect exemplary of standard practice, and a description will now be given of the automatic hydraulic compensating meanscarried in the reclprocating `lifter sleeve 94.

The cylindrical sleeve 94 constitutes a housing forthe compensating mechanism and is made cylindrical head |04 with a supporting neck |05 made with an oily inlet and ball valve sea-t |00 l and groovedrout at |01 in itsbottom for passing oil from;` the sleeve receptacle |I| up into.L the neck |05. The memberl04 has its-counterpart in a. twin wedge. head |l3 having an upunder the automatic self-adjusting means th'erein. l Y A lowermost stationary wedge member has a..

Vthe cylindrical Wedge' H3, is formed with twol oppositely disposed inclined wedge or` spiral planes |08,` each of which extends 180 degrees around the engaged or adjacent circular face of both heads 04 and H3. The twosymmetrical wedge faces |08 are not unlike a screw having a half revolution thread means. Each end. of s Y both inclined planes |08 terminates in a vertical shoulder means |09 which is pierced or drilled at ||0 to form a springV receiving socket. When tted Atogether the shoulders |09 operate like jaws rwith acloslng and opening motion.

The""pluglike"membery |04 rests in the lower end ofthe lifter sleeve 94 and has an oil tight nt between its cylindrical surface and the inside of'said sleeve, and the mem-ber ||3 likewise has an oil tight rotary and longitudinal vmotion 'fit in the sleeve and is adapted to undergo that motion by reason of its coaction with the lower member |04. The angle of the spiral plane or planes |08 is chosen as heretofore explained in connection with other forms of the invention. It'is desired that the angle |08 be steep enough to-initiate down rotary motion of the head ||3 when pressure of the engine valve spring 93 is applied thereto. The neck |05 supports the wedge head |04above the cam follower end 96 I9 and prevents its escape therefrom. A pair of compensating springs `are mounted between the adjacent shoulders |09 with the ends of said springs inserted in the spring seats or sockets ||0 p and the expansive force of ,the springs impress a pf external longitudinal oil rotative force on the self-adjusting member I3. The assembly just described comprises the selfadjusting unit which is mounted in the sleeve 94. The two springs -I |1 are under compression and both expand to screw the head I9 relatively on the stationary head |04 thereby forcing it upwardly to maintain the thrusting stem I4 in noclearance engagement with the engine valve stem 9|.

The self-adjusting unit is so manufactured as to normally set the adjacent shoulders |09 in a mid-spaced relation with room for rotative selfadjustment of the part ||3 in either direction so that it may screw up or down on the lower wedge |04 and inthe sleeve 94. The two sets of spaced jaws 09 in partset off and form a restricted size hydraulic' chamber means ||9 ywhich has its formation completed Iby the inside wall of the sleeve. The compensating springs tend to screw the stem ||4 upwardly to accommodate a contracting or shortening valve stem 9| but yield or compress under the greater. force of the engine valve spring 93 to force the self-adjusting head |I3y A.rotatively downward to compensate for elongation of the valve stem 9|. It is significant vthat the inside cylindrical surface of the sleeve 94 closes .in and completes the formation of the-two hydraulic lift chambers I9 (seeFigure 23) which connect radially with the valve controlled oil pas? sage in the neck |05. The volume of the chamber or chambers I9 increases and draws in more oil as the thrust stem 4 screws out or upward and decreases and forces its oil out by seepage as the self-adjusting member I I3 rotates in or downward. Oil Within the chamber I I9 locks or holds the jaws |09 apart in their spaced adjusted position. v

In operation, should the compensating wedges |04 and ||3 be' assembled in a dry state without oil, the first few turns of the cam lobe'99 willy cause oil to be pumped upwardly past the ball valve III into the two-part or radially formed hydraulic chamber. means II9 by reason of the combined rotative and longitudinal screwing movement of the double faced wedge head I I3 in the lifter sleeve 94. In other words, if the chamber' I Il is dry, the engine valve spring 93 forces the head II3 to screw downwardly, while thelighter compensating springs |I1 impart a reverse movement to the member II3, and thus a spiral pumping action occurs between the selfadjusting member ||3 and its stationary mating part |04 during rotation of the cam. In this way, oil issucked fromthe receptacle III in the bottom of the sleeve 94 up into the chambers I I9 to positively hold the spaced shoulders |09 apart by reason of the 4non-coxnpressible oil body-in the chamber ||9,`and the self-adjusting unit is thus -rigidly set up to perform its function of opening the engine valve against the resistance and load of the heavy spring 93.

l the oil is forced by leakage out from the radial chamber II9 to thus compensate for theincrease in length of any parts in the valve mechanism. The pointers vXY are shown spaced apart to a somewhat exaggerated degree to indicate the range of length variation in the valve operating mechanism and consequently show the range of expansion and contracting in the tappet.'

The compression chamber II9 is of comparatively low volumetric capacity and hence it i'evquites little oil to hydraulically lock apart the relatively rotatable shoulders |09. Furthermore,

' the pair of shoulders |09v are adapted to coact or close up as shown in Figure 21, on the first half turn of the cam 99, and thus -by complete displacement or elimination of the chamber II9,

expel the air therefrom. The small measure of oil which now enters this air-free chamber, on

the second half turn of the cam, functions satsistically different in structure, and the self-ad- Justing wedges d o not form the hydraulic lifting chamber.

An engine valve |2I is closed by its spring |22 ,it in place.

heel I 29, the combination hydro-mechanical lifter being interposed between the cam and valve stem and reciprocating in the usual form of tappet guidel21. l;

Ifl'he component parts of -this comblhation hydraulic and mechanical valve lifter are shown `in Figure 24 and include a sleeve I 29 as heretofore described and having external oil grooves |30 I connecting 'with apertures I3I piercing the sleeve wall to lead oil from the upper end of the cylindrical guide |21 down into the sleeve |29 to supply ol to the self-adjusting unit housed within thesleeve.

A cylinder-like tube |33 is grooved in its bottom at |34 and rests on the'inside bottom end of the sleeve |29 together with a flange |35 at the upper end of the cylinder |33 which holds This ilange is pierced at |36 to admit air -to the bottom of the sleeve |29 to 'equalize the air pressure therein so that oil will flow freely from the sleeve passages I3| down into 4the -`bottom of the sleeve. The cylinder |33 is stationary on the bottom of the sleeve and the flange |35 braces it vertically in place. An oil inlet is made thru the bottom of the cylinder |33 and has an upper ball valve seat |31 to convey oil from the sleeve |29 up into this small compensating cylinder.

A ball check valve |39 closes the seat |31 and is freely movable thereon. The ball closes the oil opening |31 by its own weight, or by the pressure of oil thereabove, or by virtue of the rapid up-movement of the sleeve |29. It is to be noted that this ball valve, like others heretofore explained, is not spring actuated and hence is sensitive to the slightest suction or intake tendency to draw oil upwardly thru the opening |31. A` resilient compensating spring |40 is placed-in the bottom end of the cylinder |33 and away from or concentrically with the ball valve |39 so that there is no interference in function between this spring and the ball.

A self-adjusting plunger or piston |42 has an upper at portion or guide |43 which terminatesin a wedge face |44. This piston is reciprocable in the cylinder |33 against the coiled compression spring |40 and the spring continuously urges ythe piston upward in the cylinder to press its wedge face |44, against a self-adjusting wedge nc'w described and having a similar face desig-l 'nated by the same number.

a guide slotl |41 cut inwardly from the longer on its seat |23 in -the usual way and is carried in a standard form of guide |24. The engine valve is actuated by a cam having a lobe |25 and vice.

cylindrical surface of this transverselyslidable wedge |45. In fact the slot |41 defines the inner wedge face |44 for both wedge members |43 and I 45. The two wedge faces |44 coact to'perform a part of the self-adjusting function of this de- The upper face of the transversely movable self-adjusting wedge |45 terminates in an inclined plane or we dging surface M3 which also denotes and defines the angle on a valve thrusti mg plug member iil mounted in the top end of the sleeve to close it.

The aforementioned valve thrusting member |50 has its lower .face M8 as the counterpart of the upper face formed on the self-adjusting member |45. This cylindrical plug-like member 50 slidably fits into the upper end of the tappet temperature of the engine is rising with the result sleeve |29 to enclose all the parts therein and to also act as a thrust seat for the engine valve The self-adjusting three-element wedge means,

.together with the cylinder |33, as well as the spring |40 and ball |39, are assembled. as the compensator or self-adjusting unit" Within the' valve lifter sleeve |29 to complete its organization. The completed device is now mounted in the tappet guide |2`| as shown andthe expansive force of the spring means |40 immediately sets the multiple wedge means |43, |45 and |50 up in operative relation and snugly engages the thrust plug |50 against the tail end-of the valve stem |2|. In assembling the parts, oil may as well be poured in the sleeve |29 or into the cylinder |33 under its piston |42, but in any event the rst few turns of the cam lobe |25 will act to suck oil past the ball valve |39 until .the cylinder |33 is full and no more oil can be drawn thereinto, whereupon the piston |43 attains a selfadjusted stationary `position ready to stand rigid and lift the spring loaded engine valve |2I. If the cylinder |33 is dry when the parts are assembled the coacting Wedge faces |44 and |48 set up a long stroke reciprocation of the piston |42 which instantly primes this automatic tappet by filling the chamber under the piston.

In operation, the oil under the piston y|42`is ncncompressible and serves to brace and hold the piston in stationary position as the cam lobev |25 lifts `the sleeve |23 to actuate the valve |2|` off its seat |23 against the powerful closing action of the engine valve spring |22. forms of the invention already described, the

that heretofore describedwith the exception that oil must new find its way by leakage from under the piston |42. A little oil may escape past the ball |33 and possibly more oil will escape up pastV the piston |42 because the-superior expansive force of the heavy engine valve spring |22 will under all circumstances keep the piston |42 sufficiently downward, with the oil driven from underneath thereof, to always permit the engine valve |2| to softly but positively close on its seat |23. The powerful engine valve spring |22, if the valve is not reaching its seat |23, enforces a right hand creeping movement ofthe self-adjusting wedge |45, and continues to do so as long as the valve stem |2| is expanding. The angular faces |44 and |48' are designed to set up va. laterally right hand creeping motion, in the views being described, with a resultant downward creeping motion of the piston |42, in event the superior pressure ofthe spring |22 is applied to the plug |50 and this of course happens when the valve stem |2| increases innitesimally the sli'ghest amount.

As in other coacting angular Wedge faces |44 and |43 in the present instance act to transmit substantially all or at least the greater portion of the thrust from the lobe |25 upwardly to compress the spring |22A and open the valve, and the wedging means diminishes the load and pressure on the oil Within the cylinder |33 under the piston |42. The body of oil under the self-adjusting piston |42 is called upon to perform little work and is not whipped and emulsied to lose its` non-compressible characteristics as indeed would occur if all the cam and engine valve spring pressure load was applied to the oil. e

In event the valve stem |2| contracts or shortens, as in Figure 25 at the reference line X, space tends to 'develop between the endof the valve stern |2I andthe thrust plug |50, but so soon as that occurs the spring |4|ly urges the piston |42 upwardly, causing the at wedging member |43 to creep upwardly in the slotl |'41 thereby urging the self-adjusting member |45 to the left along Elongation of the valve stern 2|- occurs so slowly and gradually that the high speed rotation of the cam and lobe |25 aids by vibration the extremely small creeping movement of the plunger- |42 downwardly and the self-adjusting wedge |45 to the right, but the non-compressible oil body under the piston rigidly vholds the latter in non-yielding and thrusting position. In this way, the auto` matic self-adjusting unit yields, shortens up, or draws into its sleeve |29, in precisely the same and exact proportion and at the same rate as the valve stem |2I expands.

General explanation principles of the invention Several types of multiple wedge instrumentalities and sensitive hydraulic chambers have now been described in a number of representative examples of my invention. It is clear therefore that I have combined, into an operative assembly, Y

both mechanical and hydraulic means, and do not rely solely on either to transmit the throw and, load of the cam to the engine valve to actuate it under4 the loading force of its spring. The design of. the several examples presented .herewith affords a thrust mechanism which carries the y load mechanically, resort being had tothe hyits flange seat |35. This operation causes the ,occurs when the engine `temperature drops. Thus the compensating spring |40 and the multiple wedge means, comprising the three parts |42, 45

.and |50, all coact to automatically self-adjust and maintain a positive state of zero clearance from the valve seat |23 itself right down to the running face 'of the cam |23. l

On the other hand, let us nowiassume that the that the valve stem l2 I` is gradually'elongating or growing in length,` as'in Figure26 at Y. The mode of self-adjustment is simply the reverse of -draulic oil body to simply maintain the self-adjusting elements in place. While the many ad. vantages of this combination hydro-mechanical valve lifter have been explained in -connection with eachlexample shown, I will summarize the modes of operation and other pointswhich are conclusively instructive. y

For example, the parts, constituting my automatic tappets, are small in size and the tappet is light in weight. Light weight reciprocating parts are essential for high speed. Since little working pressure need be applied to any of the hydraulic I chambers. the latter may besmall with a consequent small body'of oil therein` which contributes to reduction in weight of the reciprocating mass.

The filling of the hydraulic chambers is positive and instantaneous due to the long suction stroke or travel of the load carrying self-adjusting plunger means. .This characteristic long stroke compensation, for the corresponding short change in length of the train of mechanism to actuate the engine valve, is attained by the inclined planes or wedge faces shown by which to greatly increase the motion in the self-adjusting load carrying unit over the shorter distance traveled by the valvestem or pushl rod variation. Thev valve lifter yand its compensating unit possess unusual rigidity to non-yieldingly transmit the cam throw pressure for the reason that there exists no likelihood of the oil in the hy-' draulic chamber losing its non-compressible character. The small measure of oil used in the compression chamber is not whipped and pounded by the heavy engine valve spring from one direction and the high speed cam from the other directionY Consequently, no air bubbles are admixed in the oil to emulsify-and soften it. Furthermore, Aand even so, such a condition would not adversely affect the rigidity and operation of the self-adjusting units because the extremely light pressure exerted on. the oil body in the hydraulic chamber would be successfully resisted and held by a softened and deteriorated oil mass. The displacement of the air from the hydraulic chamber,

at the instant of priming it, gives an air-free chamber to begin with, and it remains so. I Other advantages and characteristics will become apparent upon understanding the foregoing and the invention fills a need felt for improvements in this field.

What is claimed is:

v l. Valve operating mechanism, comprisingin combination, a spring loaded valve operable in relation to its seat, a cam having a lobe and heel, a lifter sleeve having a cam follower portion 'and interposed between the valve and cam,.self adjusting wedge means including a pair of spaced wedges and an overlapping wedge coacyting with said pair, a retainer guide mounted in the sleeve and inwhich the self adjusting wedge means are operatively seated, an oil chamber enclosed between the wedge means and retainer guide, aA

compensating spring interposed between the wedge pair and urging same apart, anl oil supply in the sleeve and valve controlled inlet leading to the oil chamber to admit the trap oil between th-e Wedge pair to hold them in outwardly adjusted position, whereby the overlapping coacting wedges sustain the pressure and vcarry most of the load imposed by the cam and spring loaded valve during the open period thereof.

2. Valve operating mechanism, comprising in combination, a spring loaded engine valve operable in relation to its seat, a cam having a lobe and heel, a lifter sleeve having a cam follower end traversed by the cam.,l a wedge retainer seat -and guide means mounted in the upper end of the sleeve, an oil supply receptacle formed by and within the lower end of said sleeve, a valvel J other or yieldingly afford an approaching movement to maintain the aforesaid no-clearance engagement, a third wedge adjustable longitudinally in the wedge retainer'seat and guide means and coacting with the wedge pair, a hydraulic compensating chamber formed between the wedge pair within the wedge retainer seat and guide means and enclosed by the bottom ofsaid third wedge and into which opens the aforesaid valve controlled inlet means to lill the chamber with oil and hold the 'wedge pair apart, an oil intake and discharge provided in the sleeve above the cam follower end thereof to keep the receptacle full ofoil and to discharge oil downV the cam traverses the cam follower with minimum pressure while the spring loaded engine valve is on its seat by reason of the wedge pair being seated in the wedge retainer seat and guide means to thus take up the expansive .force of the compensating spring and prevent the full force thereof from riding the follower onV the cam heel to rest said cam while the engine valve is on its seat, and to enable oil from the receptacle aforesaid to reach the lightly engaging cam heel and follower surfaces.

3. A valve lifter for use in connection with valves and operating mechanisml therefor comprising, a dat seat carried bv the valve lifter and at an angle to the anis of the valve to be actuated, compensating devices including wedge means slidable -on the seat, additional wedge means engaging the first wedge means and adjusted axially of the valve by the action of the rst wedge means adjusting on its seat, and a hydraulic chamber cooperating with the compensating devices to x thewedge means in their adjusted position. A

4. A valve lifter for use in connection with valves and operating mechanism therefor comprising, a flat seat carried by the valve lifter 'and at an angle to the axis of the valve to be actuated, compensating devices including wedge means sldable on the seat, additional wedge means engaging the rst wedge means and ad justed axially of the valve by the action o f the rst wedge means adjusting on its seat, and oil locked by a hydraulic chamber disposed between the rst named wedge means and against which the pressure of the wedge means on the seat is sustained to x the latter against displacement.

5. A self adjusting valve lifter comprising coacting wedge means having two, pairs of complementary faces each pair dening an inclined plane at an angle to the axis of a valve to 'be actuated, a hydraulic chamber between the wedge means, and a valve controlled inlet and oil supe ply means communicating with the hydraulic chamber to feed oil thereinto between' the wedge means ras the latter adjustably moves in relation to each-other.

6. A self adjusting valve lifter comprising coacting wedge means havin'g two pairs of comvplementary faces each pair defining an inclined plane at an angle tothe axis of a valve to be actuated, a hydraulic chamber between the wedge means,l a valve controlled inlet and oil supply means communicating with the,hydraulic chamber to feed oil thereinto between the wedge means as the latter -adjustably moves in relation to each other; and spring means disposed within the hydraulic chamber, at an angle to the axis of said valve to be actuated, and each end of the, spring means engaging under pressure against .the Wedgemeans.

' 7. A self adjustingvalve lifter comprising coacting wedge means having two pairs of com- Aplementary faces each pair defining an inclined

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