US 1844021 A
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Description (OCR text may contain errors)
Feb. 9, 1932. c, STEWART 1,844,021
ENGINE VALVE Filed June 15, 1929 Patented Feb; 9, 1932 f UNITED; STA E-s PATENT; OFFICE cARL n. srnwnm', on nnrnorr, MICHIGAN ENGINE VALVE Application filed June 15, 1929. "Seria1 No. 371,249,
My inventionrelates to engine. valves, and 'moreparticularly to internal combustion engine valves of the poppet type,
One *ob'ectof my present invention is to provide a valve actuating structure which may be automatically lubricated by conneca vention in several forms of embodiment, whlch are illustrated in the accompanylng drawings, in which the same reference-characters indicate. like parts in the several views, and wherein rFigure 1 is a vertical sectionofpart of an internal combustion engine block provided with one form of valve and valve-operating means constructed accordance with; the present invention;
.11 Fig. 2 is a perspective view of the form of push rod shown-in Fig. 1;
Fig. 3 is a vertical section showing a modified form of valvestempand- In the .drawings, 1' designates generally" a fragmentary section of an engine block, provided with a valve seat 2, in-.which is fitted 1 a poppet valve3 having the. usual valve stem 1740 twhich reciprocates in the valve stem -gu1de 5. A coil spring 6, surrounding the valve stem 4 and compressed between one end of the guide 5 and a bearing 6', serves to maintain the valve normally seated. The valve 1s 1 $5315 opened at appropriate periods in the cyclic operation of the engine by means of the arrangement of cam, tappet and push rod which .will now be described.
so The tappet 7, reciprocally mounted in they guide 8 at the lower part of the engine block 'ently be described. Y
the valve stem.
1, is provided with a cam follower shoe 9 which bears upon the usual engine-driven .cam (not shown) In a screw-threaded socket 10 at the upper part of the tapp'et 7 is received thethreaded shank 11 of a push rod generally designated 12. The upper end of this push rod 12 engage'sthe lower end of the valvestem 4', so that the push rod provides connection between the tappet, and the "valve stem to transmit the reciprocating motion of the tappet to the valve stemand thus periodically unseat the valve In each of the modifications of my invention the engaging ends of valve stem and push rod are complementally 'configured'with conical sockets and 6 projections to effect a maximum bearing surrace between the two members and to mduce a tendency toward automatically maintaining the pushrodand the valve stem in coaxial alignment. The complemental conical surfaces also provide a relatively large area for the reception ofa lubricant,as will presn in Fig 1 the ush, rod
1 In the form she 12 is comcally recessed at 13, and t e valve stem is conically extended at 14; while in l the modification illustrated by Fig. 4 this arrangementis reversed, the push rod having a conical extension 1362, and the -valve'stem beingprovided with a complemental conical recessl laf l t 1 7 It will be noted that in the forms of my t .,invention shown in Figs. l,. 2 and 4!, a spe- Fig. l is a vertlcal sectlonof; a further 2.2.1 modified form of valve-stem-and push rod which I have invented, I'may provide a de-i tachable-fitting having a conical projection 14?), as shown in'Fig, 3. A small set screw 14c serves to secure this fittingtothe end of.
. Y The apex angle Jofthe 'complemental con i cal surfacesemployedin my invention may i be of approximately any magnitude between say 20 and degrees. I 'have obtained best results, however, and therefore prefer to "use 0 conical surfaces having an apex angle of about 60 degrees.
In each form of my present invention the push rod 12 is made adjustable axially of the tappet 7 through the medium of the polyhedral face 15 formed on the push rod, and the lock nut 16Ien'gaged with the threaded shank 11 and adapted to bear against the upper end of the tappet 7 By means of this arrangement of parts, ad-j-ustment may be made whenever necessary, in an obvious manner.
To aid in silencing the operation of the parts hereinbefore described, and to pre vent undue wear, I have provided a lubricating system which will now be described.
An Oll passage 17 penetrates the lower part of the block 1 and communicates at its outer end through a coupling 18 with the customary pressure oil supply of the engine. At its inner end the passage 17 communicates with a relatively narrow, vertical channel or slot 19 formed in "the bore of the guide 8; and terminating in this channel 19 is a spiral groove '20 also formed in the "bore of guide 8. The shank 11 of the push rod 12 is formed of such length that whatever may be its operatively adjusted position in "the socket duct 23 axially of the push rod 12 places the valve stem bearing surface of the latter in communication with the'sump 21. In the form shown in Figs. 1, 2 and '3, where the push rod 12 is 'conically recessed, I have found it desirable to make the'u'pper end of the duct 23 slightly enlarged, as shown'at 2a, to provide a large amount of clearance for the apex "of the conical end 14 of the valve stem ti, and in the modification 0f the invention illustrated in Fig. 4, where the valve stem is conic'all-y recessed, a similar cavity 24a is formed in the valve stem. for the same purpose. 7
It will beapparentthat during operatio of an engine provided with the device hereinbefore described, lubricating oil from the pressure supply will be forced through the system formed by the passage 17, channel 19,
groove 21, horizontalduct22, sump 21and vertical duct 23, to lubricate the contacting conical surfaces of the valve stem and push rod. Theconical configuration of these surfaces of the valve stem and push rod provides a relatively large area for the .recep- .tionof the lubricant and resultsin a greater quantity of the lubricant being maintained between the contacting surfaces of these two members than would be possible if the valve stem and push rod were provided with the usual plane contacting faces. The film of oil thus kept between the two surfaces has been found exceedingly effective in minimizing the sound ordinarily caused by impact of the parts when not so lubricated. More- -over, -some of the oil received by the channel 19 will travel down the spiral groove 20 to lubricate the reciprocating movement of the rta apet 7 in its guide 8 and lessen the wear of these parts.
It will be apparent from the foregoing description and the accompanying drawings that I have provided means for conducting a lubricant from a pressure supply to the contacting surfaces of tappet and guide, as well as valve stem and push rod, with the inevitable loss of effective tappet guide bearing'surface reduced to a minimum.
it is to be understood that my present invention is capable of exempliiication in other and further modifications not shown or described in this application for Letters Patent, but all such modifications insofar as they embody the principles of the present invention are to ,be deemed within the scope and purview of the appended claims.
"What Iclaim-anddesire to secure by Letters Patent is:
-1. Thecombination of a-cam shafda valve stem, imeans interposed therebetween for transmitting movement from the shaft to the valve, 'said means *having complementary tazpered Einterfitting members and means for supplying fluid under pressure to the surfaces of said ta-pered members.
2. A tappet assembly comprising a base =memberadapted to be actuated by a cam, a second :member adapted to actuate a valve, said members having complementary interfittingtapered portions, and means for supplying a fluid under pressureto the sui faees ofsaid tapered portions. 7
3. A tappet assembly comprising a base member.adapted to beactuated by a cam, said member having a tapered'opening therein, a second member adaptedto actuate a valve, said second member having a tapered por- =tion fitting with said tapered opening Band means for supplying fluid under pressure to 'the lowerend of said tapered opening for passage'tothe surfaces of said tapered'por- 'tions.
In testimony whereof Iaflix my signature.
CA RL STEWART.