US2525791A

US2525791A - Kit for overhead type valves

Info

Publication number: US2525791A
Application number: US792524A
Authority: US
Inventors: Francis R Good
Original assignee: Individual
Current assignee: Individual
Priority date: 1947-12-18
Filing date: 1947-12-18
Publication date: 1950-10-17
Anticipated expiration: 1967-10-17

Description

Oct. 17, 1950 Y F; R. GQOD KIT FOR ovERHEAD TYPE VALVES 2 Sheets-Sheet l Filed DSC. 18, 1947 Ean 4.

IUIIIIII- INI/EN TOR.. FRANC/S R. GOOD Oct. 11'?,4v 1950Y F. R. GOOD l Kir FOR OVERHEAD TYPE: vALv'Es 2 Sheets-Sheet 2 INVENTOR. FRANC/S R. GOOD Patented Oct. 17, 1950 UNITED STATES PATENT GFFICE (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 4 Claims.

This invention relates to a valve improvement kit, adapted to be installed in the valve actuating linkage` of an overhead valve type engine at the juncture between its cam actuated push rod and the adjacent end of its rocker arm. The improvement kit comprises parts, which when installed, form a hydraulic cushionin the valve opening linkage thereby silencing engine operation and minimizing valve clearance troubles which are experienced as the engine `warms up.

The problem of accommodating changing valve clearance as the engine parts warm up is a perplexing one with which engine designers have concerned themselves for many years. Kits of improvement parts are known which may be installed in the valve operating` linkages of conventional engines without appreciable modication of the engine. However, as a rule, these kits effectuate a mechanical adjustment of the clearance, whereas it is known that for many purposes a hydraulic cushion introduced in the valve linkage will produce much more effective clearance regulation, with a consequent improvement in silence and operation of the engine.

Hydraulic cushion means for automatically achieving proper valve clearance are also known to the art, but in general these parts either require installation at the factory or require considerable modication in the valve actuating linkage `of the engine.

An object of this invention is to provide a kit or" valve improvement parts which may be installed in the conventional valve operating mechanism ofV most types of valve-in-head engines, whereby a hydraulic cushion is formed in the valve actuating linkage with resulting silencing of valve operation and associated benets which come with improvement in regulation of valve clearance.

Itis another object of this invention to `provide a kit of improvement parts-for the valves of an overhead valve type engine, which may readily and simply be installed on the conventional rocker arm of the engine with the discarding of a minimum of the old parts and with maximum simplicity and speed of installation.

In accordance with the instant invention, the kit comprises a cylindrical memberadapted to be mounted around the adjusting stud depending from a conventional rocker arm on an overhead valve engine. This stud is axially slidable within the cylindrical member of this invention, the annular clearance between the stud and the cylinder forming a restricted annular passage for the escape of oil which is compressed within a chamber upon each operating stroke of the valve push rod. The invention also contemplates the provision of means for feeding oil into the chamber, so that in between valve opening operations, the chamber may ll up with oil. Then upon actuation of the valve, through the conventional `push rod, the oil is compressed within the chamber and escapes through the restricted annular passage formed between the stud and the cylindricalmember installed in accordance with this invention, thereby cushioning the valve action.

Two embodiments of this invention have been illustrated, the first` being shown in Figs. 1

. through 5 inclusive, wherein:

Fig. 1 is a partially sectioned `View showing the instant invention applied to the conventional rocker arm of a valve-in-head engine;

Fig. 1A is an enlarged fragmentary section showing particularly the critical operating parts of the instant invention;

Fig. 2 is a plan view of the ringforming part of thekit, which ring constitutes the oil-restrict-` ing cylinder to be mounted around the adjusting stud;

i Fig. 3 is a cross sectional elevation of the ring of Fig. 2;

Fig. 4 is a cross sectional elevation of the spring which holds the ring of Fig. 2 in position atop the push rod; and

Fig. 5 shows a type of spring compressor which may be used in the installation of the instant invention;

The second embodiment of the instant invention is shown in Figs. 6 through 9 inclusive, wherein:

Fig. 6 shows a partially cross sectioned elevation of this embodiment applied to a conventional rocker arm;

Fig. 7 shows the rod `which forms, with the hydraulic cylinder of the second embodiment,

the restrictive oil escape passage;

Fig. 8 is a view of a Washer used in the assern,

bly; and Y Referring to the illustrations of the rst ernbodiment, I i designates the conventional hollow, stationary rocker shaft mounted horizontally above an overhead valve type engine. A rocker arm I2 rocks on the shaft I I, the end I3 thereof serving to @periodically depress a valve stem (not shown), in the conventional manner. The other end I4 of the arm I2 is disposed above a cam actuated push rod I5. The end Ill is bored vertically and threaded to receive an adjusting stud I5, having at its lower end a hemispherical ball I'I which seats in a socket I8 formed in the head I9 of the push rod I5. Screw adjustment of the adjusting stud I is made possible by the provision of a slot 2l, the adjustment being secured by a lock nut 22. A perforation 23 in the wall o f the shaft II registers periodically with a bore 2li in the arm I2, which terminates in a downward passage 25 directly above the ball Il on the stud I6. In operation, oil under pressure is maintained inside the hollow shaft II, and intermittently ows onto the ball I'I as the shaft I2 rocks back and forth, thereby maintaining a film of oil between the ball I'I and its socket I8.

The apparatus and operation thus far described constitute the presently known art to which applicants invention is applied. It will be manifest that with the elements thus far de*- scrihed, each upward thrust of the rod I5 against the stud I6 immediately squeezes substantially all the oil from the hemispherical space (3.3, Fig. 1A) between the ball I'I and socket I8, inasmuch as there is nothing to restrict escape of the oil. This small space 33 is essential in the operation of the engine to assure that the valve will completely close when the push rod I5 is at its lowest extremity; yet it is desirable in the interest of smooth or quiet operation that this gap, or backlash, be cushioned as the push rod I5 starts its upward thrust.

Cushioning means for this purpose are known in the art as hydraulic valve lifters. The instant invention concerns such a cushioning means as may be quickly and easily installed on a conventional rocker arm as described above.

In accordance with the instant invention, there is provided a ring 2S, seated on the upper edge 2l of the head I9 circumjacent the socket I3 and the ball I'I. Ring 26 has an upwardly extending cylindrical portion 28, formed around the inner edge thereof, which constitutes an inner wall of internal diameter minutely larger than the encompassed ball I'i (see Fig. 1A). Ring 255 also has a second upwardly extending wall 29 around its outer edge. Wall 29 forms, with wall 23 and stud I6, an annular reservoirSI, which receives oil as it flows down from the passage 25.

A helical spring 32 is compressed between the ring 25 and the overhanging end ifi of the rocker arm I2, thereby maintaining the ring 2S rmly seated around the edge of the socket I8.

Operation ing stud I 6. At the bottom of the stroke of push body of the fitting 5I for receiving a piston stud 4 rod I5, the head I9 pulls away from the ball I'I, leaving a hemispherical space 33 (Fig. 1A) into which oil ows from the annular reservoir 3I through the restricted annular passage 3d, formed between the ball Il and the circumjacent inner edge of the ring 25. By the time the cycle has reached the point where the push rod I5 again moves up, the space 33 is completely filled with oil.

On the upward stroke of rod I5, the oil in the space 33 is squeezed therefrom, but since the only egress is through the restricted passage 34, a cushion of oil is formed between the head I9 and the ball II, the oil escaping so slowly through the passage 365 that the operation of the valve is materially quieted and smoothed. By the time the upper limit of the push rod stroke is attained, substantially all the oil has been squeezed from the Space 33, thereby assuring full valve clearance when the rod I5 drops.

inasmuch as valve operation is such that the rod I5 is at the lower extreme of its stroke during a major portion of the operating cycle, there is ample time for oil from the reservoir 3l to seep into the space 33 through the annular passage 34, even though it is impelled only by gravity.

Valve clearance is usually measured between the end I3 of the rocker arm I 2 and the top of the talvc stem. It is therefore necessary to close space 35 during adjustment. To this end the clamp shown in Fig. 5 is provided, having a lower member 5I adjustably secured to an upper member l2 through a threaded rod 43. A bifurcated toe it on the bottom of portion :II slips under the socket portion of the head I9, and a groove i5 in the upper member-d2 seats over the top of the rocker arm i2. A Vwing nut 46 is then screwed down on the threaded rod 43 to lift the head I9 against the ball I7 and so close the gap 33. Valve clearance may then be checked in the conventional mannergsinceoil is precluded from filling the hemispherical space and thus cannot aiect the clearance.

Modification A modified form of the instant invention is shown in Figs. 6 through 9, inclusive. In this modification the conventional adjusting stud (I9-Fig. l) is removed from the bore 53 (Fig. 6) and discarded, and replaced by a special tting 5I having' a depending, externally 4threaded stud portion 52 which is threaded into the bore 53 of the rocker arm. A vertic'al'bore 54 is drilled upwardly through the stud portion 52 and Vinto the 55 axially slidable in the bore 54. At the upper end of the piston stud/55 clearance `between the stud and the end of the bore'fl forms a chamber 56, having an offset portion 5'! with which cornmunicates a small, vertical bore 58.

The rocker arm I2", already provided with 'the bored oil passageways '25 and 25", is fin-ther` bored at 59 to provide a passageway communicating between the upper end of thev passage 24' and the lower end of the passage 58. interposed between the fitting 5 I andi the rocker arm I 2', is provided with arcuate slots 92 (Fig, 9) so that the interposition ofthe washer will not block flow of oil from the passage 59 to the passage 58. At its bottom end the passage 25. ics plugged to prevent escape of oil in that direcion.

A ball valve 63 seats' at the upper end of the passage 58 and Yisr movable within the chamber AA washer 5 I aseavbi portion 51. Ball B3 constitutes a check Valve which prevents flow of oil from chamber portion 51 to passage 58, while permitting oil flow in the other direction. Tapped holes are provided in the fitting 5 l, pluggedby screws 64, for providing access to the chamber 51 during fabrication and assembly of the device. A tapped hole immediately above the piston stud 55 receives a set screw 65 secured by a lock nut B6, which serves as an upper limit for reciprocation of the piston stud 55. The adjustment of screw 65 in effect determines the valve clearance. At its lower end the piston stud 55 is provided with the customary ball 61 adapted to reside in a socket in the head of the push rod (see Fig. 1). A helical spring 68, compressed between the ball 61 and the overhanging end of the rocker arm I2', biases the piston stud 55 downward into engagement with its socket. A washer 69 is interposed between the bottom end of the spring 68 and the head 61.

Operation of modification The above described modication functions substantially as follows. At the clockwise extremity of the oscillation of rocker arm l2', the passage 24 registers with the perforation 23 and oil is fed upwardly through 24', 59, 62, and 5t. As the arm l2 pivots counter-clockwise, the upward pressure exerted by the push rod on the piston stud 55 is relieved, allowing the spring 68 to extend the stud 55, thereby maximizing the volume of chamber 55. The oil in the passages 2li', 59, 62, and 58 is thus drawn into the chamber portion 51, past the check ball 63, to nll the chamber 56-51 to its maximum capacity.

As the push rod pushes upwardly on the stud 55, the ball 63 covers the passage 58. Back lash between the stud 55 and the arm I2', which in effect corresponds to valve clearance, is thus taken up, for the only way in which the stud 55 can move within the bore 54 is for oil to escape slowly down the sides of the bore around the stud 55 and on to the head 61. This it does at a restricted rate, depending on the closeness of nt of the stud 55 in the bore 54. By the time the stud 55 has been pushed up against the set screw 55, the rocker arm i2' is somewhere near its clockwise extremity. In this way a cushion of oil is continually reinserted in the valve actuating linkage, thereby producing smoother and more silent valve operation.

It will be noted that both modifications of the instant invention are quickly and easily installed on conventional valVe-in-head engines, with the replacement of a minimum number of conventional parts. In the case of the first embodiment described, it is necessary to discard no parts whatever from the conventional valve mechanism; while in the case of the modification, only the adjusting stud and its lock nut are discarded.

Two embodiments of the instant invention have been described herein; it will be manifest that this invention may be made and utilized in other suitable embodiments without departing from the spirit and scope thereof as set forth in the appended claims.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon o1' therefor.

What is claimed is:

l. A valve improvement kit adapted to be installed in the valve actuating linkage of an overhead valve type engine at the juncture between 6J the socketed head on the cam-actuated push rod andthe balled end of the depending adjusting stud mounted in the end of the rocker arm, said arm `having an oil passage thru which oil is fed onto said balled end, comprising: a ring adapted to seat on the edge of said socketed head circumjacent said balled end, the internal diameter of said ring being minutely larger `than the external diameter of the encompassed balled end, thereby forminga restrictive annular escape passage for oil squeezed from between the ball and socket as said push rod pushes said stud upward, and a spring adapted to 'be mounted around said adjusting stud and compressed between said rocker arm and said ring, thereby to maintain said ring in engagement against said socket head edge.

2. A valve improvement kit adapted to be installed in the valve actuating linkage of an overhead valve type engine at the `iuncture between the socketed head on the cam-actuated push rod and the balled end of the depending adjusting stud mounted in the end of the rocker arm, said arm having an oil passage thru which oil is fed onto said balled end, comprising: a ring adapted to seat on the edge of said socketed head circumjacent said balled end, the internal diameter of said ring being minutely larger than the external diameter of the encompassed balled end, thereby forming a restrictive annular escape passage for oil squeezed from between the ball and socket as said push rod pushes said stud upward, said ring having an upwardly extending wall around its outer edge forming with said stud an annular reservoir to contain oil owing down from said rocker arm passage, and a spring adapted to be mounted around said adjusting stud and compressed between said rocker arm and said ring, thereby to maintain said ring in engagement against said socket head edge.

3. A valve improvement kit adapted to be installed in the valve actuating linkage of an overhead valve type engine at the juncture between the socketed head on the cam-actuated push rod and the balled end of the depending adjusting stud mounted in the end of the rocker arm, said arm having an oil passage thru which oil is fed onto said balled end, comprising: a ring adapted to seat on the edge of said socketed head circumjacent said balled end, said ring having an upwardly extending cylindrical portion formed around the inner `edge thereof constituting an inner wall of internal diameter minutely larger than the external diameter of the encompassed balled end, thereby forming a restrictive .annular escape passage for oil squeezed from between the ball and socket as said push rod pushes said stud upward, and a spring adapted to be mounted around said push stud and compressed between said rocker arm and said ring, thereby to maintain said ring in engagement against said socket head edge.

4. A valve improvement kit adapted to be installed in the valve actuating linkage of an overhead valve type engine at the juncture between the socketed head on the cam-actuated push rod and the balled end of the depending adjusting stud mounted in the end of the rocker arm, said arm having an oil passage thru which oil is fed onto said balled end, comprising: a ring adapted to seat on the edge of said socketed head circumjacent said balled end, said ring having an upwardly extending cylindrical portion formed around the inner edge thereof constituting an inner wall of internal diameter minutely larger than the external diameter of the encompassed baled end, thereby forming a restrictive annular escape passage for oil squeezed from between the ball and socket as said push rod pushes said stud upward, and a second upwardly extending wall around its outer edge forming with said inner wall and said stud an annular reservoir to contain oil flowing down from said rocker arm passage, and a spring adapted to be mounted around said push stud and compressed between said rocker arm and said ring, thereby to maintain said ring in tight engagement against said socket head edge.

FRANCIS R. GOOD.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,617,986 Blank Feb. 15, 1927 1,729,468 Abbott Sept. 24, 1929 1,865,998 Abbott July 5, 1932