US 3251350 A
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Description (OCR text may contain errors)
y 7, 1966 M. THOMPSON 3,251,350
ROCKER ARM AND MOUNTING THEREFOR Filed May 20, 1963 6 4|" INVENTOR.
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HOENBA x5e 7702MB vs United States Patent 3,251,350 ROCKER ARM AND MOUNTING THEREFOR Marion Lee Thompson, 2734 Eastvale, Rolling Hills, Calif. Filed May 20, 1963, Ser. No. 281,532 4 Claims. (Cl. 123-90) This invention relates to a rocker arm and, more particularly, to a rocker arm for an internal combustion engine which is rotatably mounted on a full-round transverse shaft.
There are many types of rocker arms which are variously mounted. For instance, one rocker arm in common use is pivotally supported on a vertically disposed shaft by means of a split ball hearing which is bored to receive the shaft. Constant pivotal movement of the rocker arm so mounted causes constant wear on the rocker arm and its ball mounting so that, after a sustained period of use, the mounting becomes worn and the accuracy of the pivotal movement of the rocker arm is lost so that the functioning of the rocker arm is impaired.
To overcome this disadvantage it has been found advantageous to mount a rocker arm on a transverse half-round or full-round. shaft, thus providing greater stability and extended operational life. However, if rocker arms are so mounted by means of standard bearings, metal-to-metal contact results in the ,area where greatest friction is involved.
It is, therefore, an object of the invention to provide a rocker arm rotatably mounted on a full-round transverse shaft, which rocker arm has needle bearings supporting it on the shaft so as to avoid full metal-to-metal contact.
In all rocker arm mountings, the problem of proper lubrication is encountered; It is, therefore, a further object of the invention to provide a rocker arm and a mounting therefor which has simplified means for adequate lubrication of the bearings.
It is still another object of the invention to provide a' simplified mounting for a. rocker arm on which it is.
easy to install the rocker arm and to maintain the rocker arm in accurate position during an extended period of effective life so that, despite constant pivotal movement, the rocker arm will accurately perform its reciprocal functions with a pushrod and a valve stem with minimal wear.
With these and other objects in view, the invention consists of the construction, arrangement and combination of thevarious elements of the device whereby the objects contemplated are attained, as hereinafter set forth, pointed out in the appended claims, and illustrated in the accompanying drawings.
FIG. 1 is a side elevational view of the rocker arm of the present invention supported on an engine block (broken away);
FIG. 2 is a top plan view of the rocker arm;
FIG. 3 is an enlarged view taken on line 33 of FIG. 2;
FIG. 4 is a view taken on line 44 of FIG. 3; and
FIG. 5 is an exploded perspective view of the rocker arm showing details of its mounting.
A vertical shaft 10 is mounted on a head 12 and has a free end 14. A horizontally disposed transverse shaft 20 has a centrally disposed bore 22 therethrough in which the free end 14 of the shaft 10 is disposed and through which the free end 14 of the shaft '10 protrudes. The upper end of the bore 22 is counterbored, as at 24 to receive a sleeve 26, which is internally threaded to mate with a thread on the free end 14 of the shaft 10. The sleeve 26 has a torquing hex 27, so that the sleeve 26 may be threadably tightened on the shaft 10 until the bottom of the sleeve 26 is firmly seated in the counterbore 24, thus firmly securing the transverse shaft 20 on the vertical shaft 10. The sleeve 26 may be locked in its secure position by any suitable means, such as by an externally threaded key 28 inserted in the sleeve 26 and bearing on the free end 14 of the shaft 10, said key 28 having a torquing bore 29 for reception of a suitable wrench.
The ends 30 of the shaft 20 may be of reduced diameter, as best illustrated in FIG. 5 of the drawings, so as to define a centrally disposed collar 32, although it will be recognized that a transverse shaft 20 of uniform outside diameter may be utilized. Lands 34 are formed in the shaft 20, the lands 34 extending outwardly from the counterbore 24, the purpose of the lands 34 being to receive lubricant transmitted to the area of the counterbore 24 in the manner hereinafter described, and to transmit said lubricant outwardly along the shaft 20 so as to lubricate thebearings, also hereinafter described.
A rocker arm, generally designated 40, is provided. The rocker arm 4%) has a centrally disposed body portion 42, an arm 44, and a relatively longer arm 46. The body 42 has a vertical bore 47 therethrough, the bore 47 being laterally elongated so as to receive the vertical shaft 10 and allow rocking movement of the rocker arm 40 relative thereto. The body 42 also has a transverse horizontal 'bore 48 therethrough, the bore 48 intersecting the bore 47 and being adapted to receive the ends of the shaft 20 and the bearings hereinafter described. Bore 47 is enlarged at and adjacent the top of the rocker arm 40 so as to form an open-topped chamber 50 extending into the arms 44 and 46, and a groove 52 extends outwardly along the top of the arm 46 from the chamber 50 to a point closely adjacent the free end of the arm 46.
A socket 5 4 isformed on the lower surface of the arm 44, adjacent the free end of the arm 44 and disposed so as to receive and seat a pushrod 56. A hemispherical insert 57 may be disposed in the socket 54 and secured in position by a stud 58 disposed in a bore '59 in the arm 44.
The pushrod 56 is longitudinally axially bored so as to provide a lubricant passageway 60 therethrough, and a bore is formed through the insert 57 and the arm '44 so as to provide a lubricant passageway 62 extending from the socket 54 to the chamber 50. It will thus be seen that lubricant under pressure in the passageway 60 in the pushrod 56, obtained from a lubricant supply (not shown), will enter chamber 50 to lubricate such parts of the shaft 20 as are exposed therein, and will also flow in the lands 34 to lubricate the ends of the shaft 20 and the bearings mounted thereon as hereinafter described.
A pad 70, preferably having an arcuate contact surface 72, is mounted on the arm 46 adjacent the free end of the arm 46. Mounting of the pad 70 on the arm 46 may be by any suitable means, such as by a stud 74 disposed in a throughbore 76 which is counterbored as at 78 to receive a portion of the pad 70. A bore from the surface 72 of the pad 70 through the stud 74 forms a lubricant passageway 79 from the groove 52 to the surface 72 of the pad 70, so that lubricant in chamber 50 may flow to the surface 72 of the pad 70.
Needle bearings 80 are mounted on the rocker arm 40, disposed in the bore 48, and interposed between the rocker arm 40 and the shaft 20. The free ends of the shaft 20 extend beyond the needle bearings 80, and lock rings 82 may be mounted adjacent the extremities of the shaft 20, as by disposing them in annular grooves 84.
The pad 70 abuts on a valve stem which is springactuated by a coil spring 92 in the manner standard in the trade.
It will thus be seen that, as the rocker arm 40 is actuated by the pushrod 56, it will rock on the shaft 20, and will reciprocally rock when actuated by the spring action of the valve stem 90. Being supported on the shaft 20 by the needle bearings 80, and not by flat ring 3 bearings, frictional wear and tear in the critical area of pivot will be minimized, especially since the shaft 20 and the needle bearings 80 will be adequately lubricated in the manner hereinabove described.
While the instant invention has been shown and described herein in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein, but is to be accorded the full scope of the appended claims.
1.. A rocker arm assembly for an internal combustion engine and mounting therefor which comprises: a vertical shaft mounted on an engine head; a horizontal shaft centrally mounted on the vertical shaft so as to form a T configuration therewith; a rocker arm having a body and protruding arms, one of the arms being disposed so as to be activated by a pushrod, and the other of the arms being disposed so as to be activated by a valve stem; a chamber formed in the body of the rocker arm; a slotted bore in the body of the rocker arm communicating with the chamber, the slotted bore receiving the vertical shaft and permitting pivotal movement of the rocker arm in relation to the vertical shaft; a transverse bore in the body of the rocker arm communicating with the chamber, the transverse bore receiving the horizontal shaft; needle bearings mounted on the body of the rocker arm and disposed in the transverse bore supporting the rocker arm on the horizontal shaft for reciprocal rocking movement thereon; and means on the horizontal shaft for conveying lubricant in the chamber so as to lubricate the needle bearings.
2. A rocker arm assembly as defined in claim 1, wherein the means for conveying lubricant comprises: lands on the horizontal shaft, the lands extending from that portion of the horizontal shaft disposed in the chamber to those portions of the horizontal shaft which are disposed in the needle bearings.
3. A rocker arm assembly for an internal combustion engine which comprises:
a vertical shaft mounted on the engine head, the upper end of said shaft being threaded;
a horizontal shaft formed with a centrally disposed bore that is received by said vertical shaft and with the upper end of said bore being formed with a seat;
a rocker arm formed at its intermediate portion with a transverse bore through which extends said horizontal shaft, said rocker arm also being formed with a centered vertical opening that centrally receives said vertical shaft and is elongated to permit rocking movement of said rocker arm relative to said vertical shaft;
a pair of cylindrical needle bearing assemblies, each disposed upon the outer portions of said horizontal shaft and carried by the outer ends of the transverse bore of said rocker arm, with the free ends of said horizontal shaft extending beyond said bearing assemblies; I
a pair of lock. rings, each mounted adjacent the extremities of said horizontal shaft to retain said needle bearing assemblies in place; and
threaded lock means on the upper portion of said vertical shaft, the lower end of said lock means engaging said seat formed on said horizontal shaft for firmly securing said horizontal shaft upon said vertical shaft.
4. A rocker arm assembly for an internal combustion engine which comprises:
a vertical shaft on the head of said engine;
a horizontal shaft centrally mounted on said vertical shaft;
a rocker arm having a body and protruding arms, said body being formed with a chamber that receives said horizontal shaft;
means for introducing a lubricant into said chamber;
needle bearings mounted on the body of said rocker arm and disposed in said transverse bore supporting said rocker arm on said horizontal shaft for rocking movement thereon; and
lands on said horizontal shaft, said lands being disposed so as to receive the lubricant from said chamber and transmit the lubricant to said needle bearings.
References Cited by the Examiner UNITED STATES PATENTS 2,000,635 5/1935 Edwards 184-6 3,112,740 12/1963 Sampietro 74519 X 3,139,872 5/1964 Thompson 12390 MILTON KAUFMAN, Primary Examiner.