US2688317A

US2688317A - Hydraulic clearance regulator

Info

Publication number: US2688317A
Application number: US130612A
Authority: US
Inventors: Voorhies Carl
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-12-02
Filing date: 1949-12-02
Publication date: 1954-09-07
Anticipated expiration: 1971-09-07

Description

I Sept. 7, 1954 C. VOORHIES HYDRAULIC CLEARANCE REGULATOR Filed Dec. 2, 1949 3 Sheets-Sheet l P 7, 1954 c. VOORHIES 2,688,317

HYDRAULIC CLEARANCE REGULATOR Filed Dec. 2, 1949 3 Sheets-Sheet 2 I Izvr'enfar 1% U04! W z'Z a'es' p 7, 1954 c. VOORHIES 2,688,317

HYDRAULIC CLEARANCE REGULATOR Filed Dec. 2, 1949 3 Sheets-Sheet 3 fH EHt UP 6 013; VqorZz Les Patented Sept. 7, 1954 UNITED STATES PATENT OFFICE 2,688,317 HYDRAULIC CLEARANCE REGULATOR Carl Voorhies, Birmingham, Mich. Application December 2, 1949, Serial No. 130,612

30 Claims. 1

This invention relates to improvements in operating mechanism for the valves of internal combustion engines and in particular this invention is concerned with improvements in a hydraulic lash adjuster for regulating the clearance and play in a valve lifting mechanism in order to secure more efficient and quiet operation of the valve.

This invention is particularly concerned with improvements in a lash adjuster wherein a novel split ring member acts as a check valve to begin the operating stroke of the device and has controlled passageways which limit the leak-down of the fluid in the hydraulic adjusting mechanism.

According to the teachings of the present invention a simple, automatic tappet adjusting mechanism is provided which comprises a hollow cylindrical housing closed at one end and having a follower connection at the closed end for contact by a cam on the cam shaft of the engine, and a connection at the open end for the push rod of the valve lifting mechanism. A ring is disposed inside the cylindrical housing intermediate its ends and in frictional engagement with the inner walls of the cylinder. Adjacent one side of the ring a plunger is slidably mounted atthe open end of the cylinder having a recessed portion defining a storage chamber for a hydraulic medium which may be supplied thereto by any suitable means as by a drilled passage through the rocker arm and adjusting screw assembly. On the other side of the ring, a

ring retainer is slidably mounted in the cylinder being secured to or in abutting contact with the end of the plunger. The retainer coacts with the ring to define an adjusting chamber at the closed end of the cylinder.

A spring disposed between the closed end wall of the cylinder and the retainer constantly urges the retainer, the plunger and the connected valve lifting mechanism in a direction outwardly of the housing to eliminate all clearance from the lifting mechanism. This adjusting movement will move the plunger away from the ring to permit fluid to flow from the storage chamber to the adjusting chamber.

When the cam on the cam shaft begins to actuate the device for unseating the valve, the plunger will move in a direction back into the casing and will seat against the ring, thus sealing oh the adjusting chamber. From this point the casing, the valve retainer and the plunger act as a unit to transmit motion through the push rod assembly to the valve lifting mechanism.

It is a particular feature of this invention to provide an improved tappet adjusting mechanism which is compact and simple in design and which will function to automatically regulate or eliminate clearance in the valve lifting mechanism.

Another object of this invention is to provide a tappet adjusting device in which a liquid medium is used to cause movement of a push rod for the purpose of taking up clearance in the valve lifting mechanism.

A further object of this invention is to provide a valve actuating device of the hydraulic type comprising a ring disposed in a casing and a plunger attached to the valve mechanism and alternately movable away from the ring to permit adjustment of the tappet clearance and movable toward said ring to seal oif the fluid in the casing to cause the casing and the plunger to move as a unit for actuating the valve lifting mechanism.

Other and further features, objects and advantages of the present invention will be apparent to one skilled in the art from the following detailed description, taken in connection with the accompanying drawings.

On the drawings:

Figure 1 is a fragmentary vertical sectional view through the tappet adjusting mechanism of the present invention;

Figure 2 is a horizontal sectional view taken on line II-II of Figure 1;

Figure 3 is a fragmentary vertical sectional view taken on the line III-III of Figure 2;

Figure 4 is a fragmentary vertical sectional view taken through a second embodiment of the tappet adjusting mechanism of the present in vention;

Figure 5 is a fragmentary vertical sectional view taken through a third embodiment of the present invention;

Figure 6 is a top plan View of a ring member adapted for use with the valve lifting mechanism of the present invention;

Figure 7 is a fragmentary sectional view taken on line VII-VII of Figure 6;

Figure 8 is a top plan view of a novel ring combination which may be used with the regulating mechanism of this invention; 1

Figure 9 is an enlarged side elevational view of the ring combination of Figure 8;

Figure 10 is a fragmentary perspective view of another ring combination that may be used with the adjusting mechanism of this invention;

Figure 11 is a fragmentary vertical sectional view through a fourth embodiment of the clearance adjusting mechanism;

Figure 12 is a fragmentary vertical sectional spherical end view through a fifth embodiment of the clearance adjusting mechanism of this invention;

Figure 13 is a fragmentary vertical sectional view of a still further modification of this invention;

Figure 14 is a fragmentary vertical sectional view of a modified form of the adjusting mechanism of Figure 1.

As shown on the drawings:

In Figures 1 and 2 the reference numeral indicates a cylindrical housing having a bore H, a closed end 12 and an open end l3. The end l2 has an arm 14 extending away from the end with a socket I5 into which the reduced end of the push rod 16 is disposed. ll is a cam follower which actuates the push rod 15. A cam H; on the cam shaft 19 of the engine has a lcbe 23 arranged to raise and lower the push rod ll.

A retainer member 22 is disposed in the bore l I at the closed end thereof. The retainer has a lower annular base portion 23 with a bore 24 and a reduced upper annular portion 25 having a reduced bore 26. The upper portion 25 has two diametrically opposed slots 21 therein which act as fluid passageways, as will be explained hereinafter.

A spring 28 is disposed in the bore 24 with an end in a countersunk recess 30 in the closed end of the cylindrical housing H) and the other end abutting an overhanging flange 3! formed by the upper annular portion 25 of the retainer 22.

The spring 23 tends at all times to urge the retainer outwardly of the housing It against a plunger 33 which has a lower axially projecting portion 34 that extends into the bore 25 of the retainer 22. The adjacent surfaces of the retainer 22 and the plunger 33 are in abutting contact and therefore the movement of the retainer 22 by the spring 28 causes movement of the plunger outwardly of the housing H].

The plunger 33 has two

cylindrical portions

35 and 36 connected by a central portion 31 of reduced diameter. The upper portion 35 fits close against the bore II of the housing In while the lower portion 35 has longitudinal grooves 39 thatv permit passage of fluid between the cylindrical walls and the plunger 33. The portions of the longitudinal face of the lower portion 33 between the grooves 39 provide guide surfaces which prevent canting of the plunger in the cylinder. The

lower edge of the plunger is provided with a flange portion 38 (Figure 3) which fits close against the wall of the casing.

The central portion 31 of the plunger 33 is provided with passages 4|, 42 and 43 which are in flow communication with a passage 45 in a rocker arm 46. The rocker arm 46 is pivotally connected to the plunger 33 by a segmental portion 41 which is disposed in a mating recess 43 in the plunger 33. A snap ring 50 disposed in a groove 5! in the casing l0 limits the outward movement of the plunger 33.

A split ring 52 is disposed in the housing H] in a groove 54 between the plunger 33 and the retainer 22. The ring, which has a slit 53 (Figure 2) fits close against the wall of the cylinder so that it is free to slide therealong but against considerable frictional resistance. This ring 52 may be made of cast iron or steel or of a material having a relatively high coefficient of expansion so that, as the oil temperature rises, the leakage through the slit orifice 53 will be reduced.

When the mechanism is in the position indicated in Figure l, the plunger 33 isv in sealing engagement with the ring 52, thereby defining a lower adjusting chamber 55 and an upper storage chamber 56 into which fluid is directed from the rocker arm passages. When the plunger and the ring are in this sealing engagement, the only leakage of fluid from the storage chamber to the adjusting chamber is by way of the slit 53 in the ring 52. The fact that a flow leakage may occur past the plunger makes it possible for the valve spring (not shown) to effect a downward compensating adjustment of the unit when the clearances are reduced due to the temperature changes in the operating mechanism.

In Figure 1 the position of the various elements is shown at the top of the operating stroke of the push rod. In this position the plunger 33 is in sealing engagement with the ring 52 and therefore the fluid in the adjusting chamber 55 will act as a solid unit to transmit the motion from the casing Ill through the retainer 22 and the plunger 33 to the rocker arm 45.

As the cam 18 continues rotation, the valve spring (not shown) will pivot the rocker arm in a reverse direction, downward as shown in Figure 1. When this positive reverse movement is stopped, the spring 23 will tend to move the retainer and the plunger 33 outwardly of the casing In to take up any clearance in the tappet and valve lifting mechanism. Thus the spring will urge the plunger into the position indicated in Figure 3. In this position the retainer 23 has contacted the ring 52 and moved it upwardly a short distance. When there is a clearance between the plunger and the ring 52, fluid from the storage chamber 55 will flow down into the adjusting chamber 55 through the slots 21 of the retainer and along the outside Wall of the chamber. Thus, the pressure in the storage chamber and in the adjusting chamber will be equalized. Then, as the cam continues to rotate and the lobe 23 engages the push rod 11 urging the casing I0 upwardly, the plunger 33, while maintaining its position holding the tappet mechanism in adjusted clearance position, will move downwardly relative to the casing. Thus, in effect the plunger moves into the casing and down onto the ring 52 to seal the adjusting chamber from the storage chamber. In this position the fluid in the adjusting chamber acts as a solid body and transmits the motion of the casing to the retainer and the plunger for actuating the valve lifting mechan1sm.

A particular feature of this invention is the ability of the device to regulate the operating tappet clearance. As seen in Figure l, the groove 54 is wider than the ring 52 by an amount hereinafter referred to as the regulating clearance.

This regulating clearance is exactly equal to the operating tappet clearance for the following reason.

When the spring 28 expands and moves the plunger 33 outwardly of the housing, it will contact the ring 52 and move it slightly in the cylinder. When this adjusting movement is complate, the regulating clearance of the ring in the groove will be above the ring. This regulating clearance is, of course, of the same magnitude as it was before the adjusting movement.

Then, when the cam-actuated push rod It moves the casing 10 upwardly causing the plunger 33 to move into the casing, the lunger must move a distance equal to the regulating clearance before it seals off the adjusting chamher and causes actuation of the valve linkage. Therefore, the operating tappet clearance is substantially equal to the regulating distance which 1 meter and cause in turn is equal to the difference in thickness of the groove 54 and the ring 52.

Thus, there is provided in this invention a simple mechanism for first automatically adjusting the tappet mechanism to take up all clearance in the linkage and second for maintaining this position of the linkage while moving the push rod into tappet actuating position for opening the valve mechanism.

It will also be seen that the ring 52 acts first as a valve member controlling the flow of fluid from the storage chamber to the adjusting chamber; secondly, as a sealing member to prevent back flow of the fluid from the adjusting chamber to the storage chamber during the actuating stroke of the mechanism; and thirdly, as a control member for restricting the leak-down of the fluid from the storage chamber to the adjusting chamber; and fourth to provide the desired operating clearance of the valve gear.

As explained above, the ring 52 of Figure 1 has a fairly tight frictional engagement with the walls of the housing I so that it moves with the housing toward sealing engagement on the lower surface of the plunger 33. This arrangement provides a positive seating of the ring.

In Figure 14 is illustrated an arrangement wherein the ring 52' is disposed in the bore of the housing ID with a relatively loose fit such that a small amount of pressure will cause movement of the ring along the inner wall of the housing. The fit is not so loose, however, as to permit the ring to drop by gravity in the housing. With this arrangement the shoulder 58 of the retainer 22 serves only to prevent the ring 52' from dropping to the bottom of the housing I9 during assembly.

In operation, as soon as the spring 28 moves the plunger 33 to zero clearance, fluid in the storage chamber will rapidly flow through the opening between the plunger and the upper surface of the ring 52' to fill the adjusting chamber. This passage will act like the throat of a Venturi an increase in velocity and a localized decrease in pressure. As a result, the ring 52' will be drawn upwardly into sealing engagement with the lower surface of the plunger, thus sealing off the adjusting chamber. Subsequent movement of the cam-actuated push rod will cause the entire assembly to move as a unit to actuate the valve. Therefore, this automatically operating device provides a tappet clearance adjusting mechanism that operates at zero clearance.

In Figure 4 is shown a second embodiment of the tappet adjusting mechanism of the present invention. This embodiment comprises a cylindrical housing 60 slidably disposed in an opening 6| in the cylinder block 62 of an engine. The housin 60 has a closed end 6| and an open end 62'. A cam 63 on the cam shaft 64 of the engine is arranged to contact the closed end 6I of the housing 60 and move it upwardly to actuate the valve lifting mechanism of the engine. The housing 60 has an annular groove 66 on its outer periphery intermediate its ends which is in flow communication with a passageway 68 in the cylinder block 62. A radially extending passage 69 in the housing permits fluid supplied to the passage 68 to enter the inner bore III of the housing 60.

A coiled spring 12 is disposed in the bore between the lower closed end thereof and a flange 13 on a retainer member I4 which has an internal bore I5. A plunger 11 has upper and lower cylindrical guide portions 18 and 19 respectively conthis invention.

nected by a central portion of reduced diameter. The lower wall of the plunger I1 is in abutting contact with the retainer 73 while a depending arm portion 82 of the plunger is disposed in the bore I5 of the retainer.

A pair of

rings

84 and 85 are disposed between the flange 13 of the retainer 14 and the lower cylindricalportion 19 of the plunger H. The lower ring 85 is a split ring having an orifice slit (not shown) which permits leak-down of the fiuid from the upper storage chamber 61 to the lower adjusting chamber 88. The upper ring 84 is a solid ring which is fitted with verylittle clearance in the cylinder to serve as a means of reducing the leak-down of the fluid. With this arrangement, the lower cylindrical portion I9 of the plunger :11 need notbe made with a close fit to the cylinder and therefore the flow of oil from the storage chamber to the adjusting chamber will be speeded up.

A push rod is provided with a segmental spherical end portion 9I which is engaged in a mating recess 92 in the upper end of the plunger I1. A snap ring 93 is disposed in a groove 94 in the bore 10 of the housing 69 to limit the outward movement of the plunger 11.

It will be understood, of course, that the embodiment of Figure 4 operates in exactly the same manner as described in connection with Figure 1. This embodiment, however, features the feeding of the fluid into annular grooves on the outer peripheral portion of the plunger and the use of a solid ring and a split ring to control the leak-down and facilitate movement of the fluid from the storage chamber to the adjusting chamber when the plunger is not in contact with the ring.

In Figure 5 is shown a third embodiment of In this embodiment a hollow cylindrical housing 95 is slidably disposed in the cylinder block 96 of an engine having a closed end 96a and an open 96b. The bore 91 of the housing 95 defines an oil sump 98 which may be filled in any suitable manner, as by means of a splash lubrication system. At the lower end of the sump a segmental spherical recess I60 receives the mating end IOI of a generally cylindrical casing I03.

A plunger H0 is disposed in the bore of the casing I03. This plunger has an upper cylindrical portion I II with annular grooves H2 thereon. The grooves have slanted walls H211 to facilitate the draining of oil into the casing I03 and flat walls H27) which obstruct the passage of oil outwardly of the casing. The grooves H2 also tend to de-aerate the oil. The plunger has a central portion I I3 of reduced diameter, a segmental conical portion H4 below the portion II 3 and a cylindrical portion H5 which is in sliding engagement with the cylinder wall. A groove defining portion H6 of reduced diameter is integrally formed on the plunger H9 and has an enlarged collar H8 at the lower end thereof. A ring I20, having slit IZfla and a cut away upper surface I22, is disposed in the groove formed between the shoulder H8 and the cylindrical portion H5 of the plunger. The ring I20 has an internal diameter greater than the diameter of the retainer H6 so that fluid can pass therebetween. The relieved upper surface of the ring permits hydraulic pressure to aid the spring in moving the plunger I I0 away from the ring.

At its upper end the plunger H9 has a socket portion I2I which receives one end of a push rod I23. The push rod I23 has an annular 7 ridge I23a formed integrally thereon which serves as an abutment member for a washer I24. A coil spring 125 is disposed about the push rod I23 between the washer 124 and a spring support I21 which is disposed in the open end of the casing, and is of an open, spider-like construction permitting passage of oil therethrough.

It is to be noted that the walls of the housing 95 extend above the walls of the casing I03. Thus oil in the reservoir 98 tends to splash over into the bore of the cylinder I03 and pass downwardly along the walls of the casing past the grooves I-I2.

In the position indicated in Figure 5, the mechanism has been returned to its down position by the spring (not shown) on the valve lifting mechanism. The coil spring I25 has exerted a force upwardly on the washer I25 to move the push rod and the attached plunger upwardly to eliminate all clearances from the valve lifting linkages. It "will be noted that the cylindrical portion I of the plunger has moved away from the ring I20. Thus, oil in the chamber above the cylindrical portion II5 will flow past the ring and into the chamber defined therebelow in the closed end of the casing I03.

As the cam continues its rotation the lobe portion raises the casing 95 and causes the easing I03 to move upwardly, thus effecting a relative downward movement of the plunger III) inside of the casing I03. As the plunger moves downwardly it seats on the ring I to seal oil the lower chamber from the upper chamber. From then on the fluid in the lower chamber transmits the motion of the casing 05 to the push rod I2I and then to the valve lifting mechanism.

Thus, the embodiment of Figure 5 is substantially identical to the other two embodiments of this application but further teaches the use of a storage chamber in which oil is delivered for subsequent delivery inside of the casing I03. This embodiment further features a ring member having a split orifice of predetermined size for controlling the leak-down of the fluid from the up per storage chamber to the lower adjusting chamber, and a cut-away or relieved upper edge which cuts down the contact area of "the plunger and the ring.

With a single split ring, such as the ring 52, the size of the split must be very accurately con trolled in order that only the proper of leak down will occur. This accurate slot can be eliminated if two rings are used each of which seals the leak down passage of the other.

In Figures 6 and "7 there is shown such a ring combination. A ring I having a slot I26 therethrough is provided with a radially outwardly extending shoulder portion I21 on which is disposed a smaller ring I20 having a slot I 20 therethrough. It is to be noted that the slots I26 and I29 are approximately 180 apart and the rings are held in this position by a ball or pin I30 that is positioned in aligned indentations I32 in the ring.

Referring to Figure 1, it will be seen that, when the plunger is in sealing engagement on the ring, only the outer peripheral portion of the ring is available for lealtdown control. Thus, in the ring combination of Figure 6, the leakdown through slot I29 will be sealed by abutting contact of a solid portion of the ring I25 while the leakdown slot I26 is sealed by a portion of the ring I20.

In Figures 8 and 9, another modification of a ring combination is illustrated. A ring I30 is provided with a slot I3I and a cut out portion I32 on 8 the face of the ring at the slot. A solid ring I34 is disposed against the ring I30 with a projecting portion I36 extending into the cut-out portion 132 to prevent relative movement of the rings. The solid ring I34 is made of a deformable material and provided with an oval configuration. The projecting portion I36 of the solid, oval ring 1 34 is so located that, when the ring is positioned on the ring 1 30, the widest part of the oval will abut the slot I3I and be wedged tightly against the cylinder wall. Thus, the solid ring I34 will substantially seal the slot in the ring I 30.

In Figure 10 is illustrated still another ring that may be advantageously used to control leakdown. This ring I40 is slit, one end of the ring having a cut-out portion I4I which receives a close fitting projecting arm I 42 extending from the other end. in this ring construction the radially extending passage between the end I43 of the arm and the wall I44 of the cut-out I4I extends only part way through the ring. Also, the passage between the end faces I48 and I41 of the ring extends only part way through the ring. Thus, this single ring provides angularly spaced axial passages that are effective to control leakdown.

In Figure 11 is illustrated a hydraulic clearance regulator in which a plunger I50 is formed integrally on the end of the valve stem I5l. The valve mechanism is provided with the customary valve spring I52, a valve spring retainer I53 and valve locking members I54.

The plunger Q50 has two cylindrical portions I55 and I56 connected by a central portion I51 of reduced diameter. A hollow cylindrical housing I59 receives the plunger I50 and is slidably disposed in the cylinder block of an engine (not shown). The bore I'BI of the housing I59 defines an oil sump which may be filled in any suitable manner, as by means of splash lubrication from the oil supply to the valve gear mechanism.

A ring I03, which may be constructed in accordance with any of the ring disclosures of this invention, is disposed in a groove formed between a shoulder I65 on the lower end of the plunger and the cylindrical portion I55. A snap ring I61 is in a groove I60 in the bore of the housing I59 to limit the upward movement of the plunger I55.

It will, of course, be understood that the mechanism disclosed in Figure 11 operates in the same manner as the mechanism of Figure 1. An important feature of this device, however, is the formation of the plunger on the end of the valve stem itself rather than at the end of the push rod.

In Figure 12 there is illustrated a self-contained unit wherein a plunger I10 is provided with an enlarged collar I1I at the upper end thereof. In all other details the plunger I10 is similar to the lower end of the plunger 11 of Figure 5 having a pair of spaced cylindrical portions I12 and I13, a recessed portion I14, a grooved defining portion I15, and an enlarged collar I16 at the lower end of the plunger. A ring I11 is disposed in the groove formed between the collar I16 and the lower cylindrical portion I13.

The plunger I10 is slidably disposed in the bore I10 of a cylindrical housing I which has a closed end I8I and an open end I82. The end IEI has an arm I84 extending away from the end with a socket I85 into which the end of a push rod I80 is disposed. An enlarged collar I88 is formed on the housing I80 at the closed end providing an abutment surface for a resilient I9I is disposed between flanges mm on opposite ends of the sleeve I99 and tend to urge the sleeve into sealing engagement with the opposed collars I'll and I88. To insure tight sealing engagement between the sleeve its and the enlarged collars I'll and I88, each flange portion [90a is provided with an annular bead I83 which is pressed into an annular groove I95 formed in the collars'lll and I88.

The sleeve I90 cooperates with the collars Ill and I88 to define a chamber which may be initially filled with fluid for operating the hydraulic clearance mechanism.

In operation the spring I9! acting against the collar Ill urges the linkage into zero clearance position. The sleeve I Si! is, of course, slightly elongated during this movement. When the cam moves the rod I86 and the housing I89 upwardly to seat the ring I'l'l on the plunger I10, the sleeve I98 will contact again. In other respects this device operates exactly as the device of Figure 1.

Thus, there is provided in this embodiment a hydraulic clearance regulator that has a selfcontained hydraulic system eliminating the necessity for supplying fluid to the mechanism.

In Figure 13 is illustrated still another embodiment of this invention which is identical in all respects to the device shown in Figure l with the exception that the upper portion of the plunger is made hollow providing a. storage chamber for liquid. In this embodiment the plunger I91 comprises a hollow cylindrical housing I98 closed at one end. A cap I99 snugly fits in the open end of the housing to close the same. If desired, the cap I99 may be positively secured to the housing by any suitable means.

A socket 200 in the cap I95 has an aperture ZGI therethrough which is arranged to communicate with a passage 2% in a ball end 205 of a rocker arm 206. A. passage 208 connects the storage chamber formed by the hollow housing I38 to the bore of the cylindrical housing 299.

The clearance regulator illustrated in Figure 13 operates exactly as the device of Figure 1.

From the foregoing description it will be seen that there is provided in this invention a novel mechanism for automatically eliminating clearances in the tappet and valve lifting mechanism of an engine. Further, this invention provides means for automatically holding the zero clearance position of the linkage while transmitting the movement of the push rod to the tappet and the valve linkage.

sleeve I90. A spring The novel ring or ring combination, which performs the four-fold function of a valve, a seal, a controlled orifice member and a tappet clearance regulator, provides an efficient means for carrying out automatic adjusting of the linkages.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim. as my invention:

1. In combination in a hydraulic valve linkage adjusting mechanism, a hollow cylindrical housing closed at one end, a plunger slidably disposed in said housing having an end surface facing the closed end wall of said housing and defining an adjusting chamber therebetween, said plunger having a reduced portion spaced from said end surface and cooperating with the inner wall of said housing to define a storage chamber, means for supplying fluid to said storage chamber, split fiat ring means of metal l0 slidable along the inner wall of said housing adjacent said plunger, spring means for urging said plunger outwardly of said housing and away from said ring permitting flow of fiuid between said chambers, and a cam actuated push rod connected to said housing, movement of said push rod causing movement of said plunger inwardly of said housing into engagement with said ring means to seal said adjusting chamber and cause said housing and said plunger to move as a unit, the split in said ring means permitting a controlled amount of leakdown when said plunger and said ring means are in sealing engagement.

2. In a hydraulic valve linkage adjusting mechanism the combination of a hollow cylindrical housing closed at one end, a plunger disposed in said housing having an end surface cooperating with said closed end to define an ad- J'usting chamber and a portion spaced from said end surface defining a storage chamber, resilient means for urging said plunger outwardly of said housing, and fiat split ring means of rigid material slidable along the inner wall of said housing, said split constituting an axial passage through said ring, said plunger being movable against said ring means to seal said storage chamber from said adjusting chamber, the axial passage in said ring means permitting a controlled amount of leakdown when said ring means and said plunger are in sealing engagement.

3. A hydraulic valve linkage adjusting mechanism comprising a hollow cylindrical housing closed at one end, a plunger disposed in said housing having an end surface cooperating with said closed end to define an adjusting chamber and a storage chamber formed therein spaced from said end surface, resilient means for urging said plunger outwardly of said housing, said plunger having a passageway permitting flow communication between said chambers, a first ring of rigid material in close-fitting engagement with the inner wall of said housing and a second ring adjacent said first ring having an axially extending passage in the peripheral surface of predetermined size, said plunger being movable into sealing engagement on said first ring, the passage in said second ring permitting a controlled amount of leakdown when said plunger and said first ring are in sealing engagement.

l. In combination in a hydraulic valve linkage adjusting mechanism, a hollow cylindrical housing closed at one end, a retainer disposed in the closed end of said housing, a plunger slidably positioned in said housing having a socket at one end adjacent the open end of said housing and a lower wall portion in abutting contact with said retainer, fiat rigid ring means disposed in close fitting engagement with the inner wall of said housing between said plunger andsaid retainer, a slit in said ring means constituting a passage therethrough, and a spring disposed between the inner end wall of said housing and said retainer normally urging said retainer and said plunger outwardly of said housing, subsequent movement of said housing causing said plunger to move into said housing into sealing engagement with said ring means.

5. In combination in a hydraulic valve linkage adjusting mechanism, a hollow cylindrical housing closed at one end, a retainer disposed in the closed end of the housing, a plunger in said hous ing adjacent said retainer and supported thereby, said plunger having a cylindrical portion in close fitting engagement with the wall of said housing and a reduced portion cooperating with the inner wall of said housing to define a storage chamber, the space in said housing between the end of said plunger and said closed end wall defining an adjusting chamber, said cylindrical portion of said plunger having a passageway communicating said storage chamber with said adjusting chamber, means for supplying fluid to said storage chamber, flat split ring means in said housing in close frictional engagement with the inner walls thereof between said retainer and said plunger, said split constituting an axially extending leakdown passage through said ring means, a camactuated push rod secured to said housing for urging it in one direction, a spring between said retainer and said closed end wall normally urging said retainer and said plunger outwardly of said housing, movement of said housing by said push rod causing said plunger to move into said housing into engagement with said ring means to seal fluid in said adjusting chamber, subsequent movement of said housing being transmitted through said fluid and said retainer to said plunger.

6. In combination in a hydraulic valve linkage, a hollow cylindrical housing closed at one end, a retainer disposed in the closed end of said housing having a central opening, a spring between said retainer and the wall of said housing, a generally cylindrical plunger slidably mounted in said housing connected at one end to a valve actuating linkage and having the opposite end portion abutting said retainer and defining an adjusting chamber, said plunger also having interior wall portions defining a storage chamber in flow communication with said adjusting cham ber, fiat split metal ring means disposed in tightfitting engagement in the bore of said housing between said retainer and said plunger, said split constituting a passage through said ring means, and a camactuated push rod secured to said housing, upward movement of said push rod causing said plunger to engage said ring means to seal said storage chamber from said adjusting chamber and causing said housing and said plunger to move as a unit, the passage in said ring means extending axially along the periphery thereof permitting a controlled amount of leakdown of fluid from said storage chamber to said adjusting chamber when said ring means and said plunger are in sealing engagement.

'7. In combination in a hydraulic valve linkage adjusting mechanism, a hollow cylindrical housing closed at one end, a lunger slidably disposed in said housing having an end surface facing the closed end wall of said housing and adjusting chamber therebetween, said plunger having wall portions spaced from. said end surface and cooperating with said housing to define a storage chamber, means for supplying fluid to said storage chamber, said plunger also having a passageway along the peripheral surface communicating said storage chamber with said adjusting chamber, a fiat rigid ring slidable along the inner wall of said housing adjacent said end surface of said plunger, a split in said ring constituting a passage along the peripheral edge thereof and arranged to contact said plunger to seal said storage chamber from said adjusting chamber, a socket portion in said plunger at the open end of said housing for receiving one end of the valve linkage, a spring in said housing normally urging said plunger outwardly thereof to take up clearance in the linkage and to move said plunger away from said ring permitting flow of fluid through said passage from said storage chamber to said adjusting chamber, and a cam-actuated push rod connected to said housing, movement of said push rod causing said plunger to first seat on said ring and then actuate said valve linkage to open the valve.

8. A hydraulic valve linkage adjusting mechanism comprising a first hollow housing closed at one end and having a segmental spherical socket in the innerwall of the closed end, a second hollow housing having a closed end portion in pivotal engagement in said socket, said second housing being disposed inside said first housing with its walls in spaced relation from the inner walls of said first housing and defining a sump therebetween for a fluid, a plunger in said second housing having an end surface facing the closed end of the housing and forming an adjusting I chamber, said plungerhaving a storage chamber formed therein, the walls of said first housing extending above the walls of said second housing causing flow of oil thereinto, a push rod secured to said plunger and extending from the open end of said second housing, a support member disposed about said push rod and over the open end of said second housing having an open construction permitting passage of oil, a spring between said support member and said push rod normally urging said push rod and the attached plunger outwardly of said second housing to take up clearance in the valve linkage, and a flat split ring slidable along the inner wall. of said second housing adjacent the end surface of said plunger and contacting said surface to seal said storage chamber from said adjusting chamber, said ring having a relieved upper surface providing a reduced contact area for said plunger.

9. A device for controlling clearance in a hy draulic valve linkage or the like which comprises means defining a plunger chamber, a plunger assembly slidable in said chamber having a ring groove, a fiat split metal ring in said groove having its peripheral surface in contact with the inner wall of said chamber and having a width less than the width of the groove to float the ring in the groove, the clearance between said widths constituting the clearance at which the device operates, means for supplying fiuid to said groove, spring means for urging said plunger assembly in the chamber to seat the ring against one face of the groove the gap of said split in said ring controlling the rate of leakage of said fluid to opposite sides of the ring.

10. A hydraulic valve linkage clearance regulator comprising a casing having a central hollow portion defining a chamber, a plunger connected to the valve linkage and slidably disposed in said chamber having a reduced portion defining a storage chamber and a groove spaced from said storage chamber in flow communication therewith, fiat split metal ring means in said groove of a width less than the width of said groove and having its peripheral surface in contact with the inner wall of said casing, spring means for biasing the said plunger outwardly from said casing means for actuating said casing, and means for supplying fiuid to said storage chamber, said plunger being movable upon actuation of said casing into contact with said ring means to stop flow of fluid from said storage chamber to said groove, to prevent backflow of fluid to said storage chamber and to limit the movement of the casing before the valve is opened.

11. A hydraulic tappet clearance regulator comprising a hollow casing closed at one end,

a plunger slidable in the bore of said casing having wall portions defining a storage chamber, an end face opposite the casing wall at the closed end of the casing and defining an ad justing chamber, a fiow passage between said chambers, and an annular groove between said storage chamber and said adjusting chamber, means for supplying fluid to said storage chamber, fiat split metal ring means in said groove having a width less than the width of said groove and having its peripheral surface in contact with the inner wall of said casing, a spring between said closed end wall and said plunger urging said plunger outwardly of said casing, cam means for actuating said casing causing relative inward movement of said plunger into sealing engagement on said ring means to stop fiow between said chambers, the amount of inward movement of said plunger before contact with said ring means determining the operating clearance of the tappet, and seating of said plunger on said 'ring means causing fluid to be sealed in said adjusting chamber and to act as a solid link to transmit movement of said casing to said plunger.

12. A hydraulic valve linkage clearance regulator comprising a hollow cylinder closed at one end, a plunger connected to the valve linkage, slidable in said cylinder and having a ring groove,

' fiat split metal ring means in said groove having a width less than the width of said groove and-having its peripheral surface in contact with the inner wall of said cylinder, spring means urging said plunger in one direction to take up all clearance in the linkage and to move one wall of said groove against said ring means for moving said cylinder while said plunger is stationary causing the other wall of said groove to ap-- proach said ring, the contact of said other wall on said ring determining the beginning ofthe valve opening movement of the linkage, whereby the difference' in widths of the groove and the ring means determines the tappet operating clearance.

13. A hydraulic valve linkage clearance regulator comprising a hollow cylinder closed at one end, a plunger slidable in said cylinder and having a groove, fiat split metal ring means disposed in said groove having a width less than the the width of said groove and having its-peripheral surface in contact with the inner wall of said cylinder, means for moving said plunger outwardly of said casing bringing one wall of said groove against said ring, means for moving said cylinder while said plunger is motionless causing relative inward movement of said plunger and causing said other wall of said groove to seat against said ring.

' 14. A hydraulic valve linkage clearance regulator comprising a casing having a central hollow portion defining a chamber, a plunger connected to the valve linkage and disposed in said chamher and having a bearing portion close against the walls thereof, said bearing portion defining a storage chamber on one side thereof and an adjusting chamber on the other side and having a passage therebetween, a retainer in said adjusting chamber and coacting with said plunger to form a groove, fiat split metal ring means in said groove of a width less than the width of said groove and having its peripheral surface in contact with the inner wall of said casing, spring means for biasing the said plunger outwardly from said casing, a push rod for actuating said casing, and means for supplying fiuid to said storage chamber, said plunger being movable upon actuation of said casing into contact with said ring means to stop flow of fluid from said storage chamber to said supply chamber to prevent backfiow of fluid to said storage chamber and to control the movement of the push rod before the valve is opened.

15. A hydraulic device for controlling clearance in a valve linkage comprising a casing having a hollow portion defining a chamber, a plunger slidable in said chamber having a ring groove, fiat metal ring means in said groove having an axially extending slit controlling leakdown of fluid and having its peripheral surface in contact with the inner Wall of said casing, spring means for biasing the said plunger outwardly from said casing, said. plunger being movable against said rin means to seal the portion of said chamber at the closed end thereof from the portion at the open end, and means for supplying fluid to said chamber, said ring means being made of a metal having a high coefiicient of expansion so that the slit in said ring means will close as the temperature of the fluid increases.

16. In a hydraulic device for controlling clearance in a valve linkage, means defining a chamber, a plunger assembly slidable in said chamber and having a ring groove, a composite ring comprising a first fiat split ring portion disposed in said groove having an annular shoulder portion at its outer peripheral surface, and a second flat split ring portion nested in said first ring portion on said shoulder, the splits in said ring portions being spaced approximately from each other and means for preventing relative rotation of said rings, the peripheral surface of said composite ring being in contact with the inner wall of said chamber.

17. In a hydraulic device for controlling clearance in a valve linkage, means defining a chamber, a plunger assembly slidable in said chamber and having a ring groove, a first flat slit metal ring in said groove and having its peripheral surface fitting against the walls of said chamber, and a second ring of oval configuration made of resiliently deformable material, said second ring being positioned on said first ring so that the portion of the oval ring at the greater dimension thereof lies over the slit in the first ring in sealing engagement thereon and in tight engagement with the wall of the chamber at this point.

18. In a hydraulic device for controlling the clearance in a valve linkage, means defining a chamber, a plunger assembly slidable in said chamber, and having a ring groove, and a flat split metal ring disposed in said groove and hav- .ing its peripheral surface in sliding contact with the walls of the chamber, one end of said split ring having a cut-away portion on its upper surface at the outer periphery adapted to sealingly receive an arm extending from the other end of the ring, the space between the end of said arm and one wall of said cut-away portion defining a leakdown passage.

19. A hydraulic valve linkage clearance regulator comprising a hollow casing closed at one end, a plunger slidably disposed in said casing, a storage chamber in said plunger, a peripherally grooved portion on 'said plunger spaced from said chamber, a fluid inlet passage to said storage chamber, flat split metal ring means disposed in the groove of said grooved portion and contacting the inner wall of said casing to define an adjusting chamber between the closed end of the casing and the plunger, spring means between the closed end of the casing and the plunger, and means for moving said casing relative to said plunger to actuate a linkage connected to said plunger.

20. In combination with a hydraulic valve operating mechanism, a member having a cavity formed therein and closed at one end, a plunger disposed in said cavity forming a compression chamber between said plunger and said closed end, means for supplying fluid to said chamber, and a flat split metal ring disposed in a groove in said plunger and cooperating with said plunger and contacting the inner wall of said cavity to form a sealing means, a check valve, a leakage control and an operating clearance regulator.

21. In combination with a hydraulic valve operating mechanism, a member having a cavity formed therein and closed at one end, a plunger supported in the cavity and cooperating with the closed end of the cavity to form a compression chamber, said plunger having a radially disposed surface, a flat split ring supported in the chamber for movement relative to the plunger toward and away from said surface, the peripheral surface of said ring being in contact with the inner wall of said chamber and means in said chamber spaced from the plunger and acting as a stop to limit movement of the ring in a direction away from said surface, the gap of said split in said ring controlling the rate of leakage of said fluid to opposite sides of the ring.

22. In combination with a hydraulic valve operating mechanism, a member having a cavity formed therein and closed at one end, a plunger disposed in said cavity and cooperating with the closed end of the cavity to form a compression chamber, said plunger having a radially disposed surface, a flat split ring supported in the chamher for movement relative to the plunger toward and away from said surface, stop means for limiting movement of the ring in a direction away from the surface, said ring having portions con-- tacting the radial surface of the plunger and the wall of said chamber to provide a restricted passage through said split, between said chamber and a fluid supply means.

23. A hydraulic valve linkage clearance regulator comprising a hollow cylindrical housing closed at one end, a grooved plunger slidable in said housing and cooperating with the closed end thereof to define a compression chamber, said plunger having a hollow central portion with a passage communicating said portion with the compression chamber, a flat split metal ring disposed in a groove in said plunger and cooperating with said plunger and contacting the interior walls of said housing to form a sealing means, a check valve and a clearance regulator.

24. A hydraulic valve linkage clearance regulator comprising a hollow cylindrical housing closed at one end, a plunger slidable in said housing having a surface cooperating with said closed end to define a compression chamber and having a groove spaced from said surface, said plunger having a conduit communicating said compression chamber with said groove, a flat split metal ring member for controlling flow of fluid to said groove, said ring member having its peripheral surface in contact with the inner wall of said housing, a resiilent sleeve disposed between said plunger and said housing and around said cavity to form a sealed storage chamber, and a spring between said plunger and said housing urging said plunger outwardly of said housing.

25. A hydraulic valve linkage clearance adjusting mechanism comprising a hollow cylindrical housing closed at one end, a grooved plunger slidable in said housing and integrally formed on the stem of the valve to be actuated, said plunger having anend surface defining an adjusting chamber with the closed end of the housing, means for supplying fluid to said chamber, spring means for biasing the said plunger outwardly from said housing and a flat split metal ring disposed in a groove in said plunger and cooperating with said plunger end surface to seal off said adjusting chamber from said supply means and contacting the walls of said housing to control leakdown.

26. A valve linkage clearance adjusting device comprising a hollow cylindrical housing closed at one end, a plunger slidable in said housing and having an end surface coacting with said closed end to define an adjusting chamber, means for supplying fluid to said chamber, a flat split metal ring disposed in said chamber in sealing engagement with said end surface and in slidable engagement with the inner wall of said housing, spring means urging said plunger outwardly of said housing to take up slack in the valve linkage, said outward movement of said plunger away from said ring permitting fluid to flow quickly from said supply means into the adjusting chamber through the passage formed by said split and between the plunger and the ring, such rapid movement of the fluid being effective to draw said ring upwardly into sealing engagement with said plunger.

27. In a hydraulic lash adjuster, a hollow cylinder housing closed at one end and open at the other, a plunger positioned within said housing for reciprocation in relation thereto, a plurality of flat metal rings mounted to move with said plunger and positiond to contact and cooperate with the wall of said cylinder, said rings comprising sealing means, said plunger and housing defining together a compression chamber, means defining a community passage to said pressure chamber, said rings positioned to act as a check valve for said passage and having a peripheral surface portion formed to cooperate with the wall of said cylindrical housing to permit a controlled leakage of hydraulic liquid past said rings and yielding means for urging said plunger outwardly from said housing.

28. In a hydraulic lash adjuster, a hollow cylinder housing closed at one end and open at the other, a plunger positioned within said housing for reciprocation in relation thereto, a plurality of flat metal rings, one being split, mounted to move with said plunger and positioned to contact and cooperate with the wall of said cylinder, said rings comprising sealing means, said plunger and housing defining together a compression chamber, means defining a community passage to said pressure chamber, said rings positioned to act as a check valve for said passage and effective to cooperate with the wall of said cylin drical housing to form a controlled leakage of hydraulic liquid past said rings and yielding means interposed between said plunger and said cylinder and biased to urge the plunger away from the closed end of the cylinder.

29. In a hydraulic valve lifter, a hollow cylindrical body closed at one end and open at the other, a partition member extending transversely of said body and dividing it into upper and lower oil chambers, there being an oil bypass around said partition member between said chambers, and a valve ring in floating engagement with the inner peripheral wall of said body adapted to engage said partition member to resist movement of oil from the lower to the upper chamber and to disengage said partition member to permit movement in the opposite direction.

30. In a hydraulic valve lifter, a hollow cylindrical body closed at one end and open at the other, a partition member extending transversely of said body and dividing it into upper and lower oil chambers, there being an oil bypass around said partition member between said chambers, a valve ring in floating engagement with the inner peripheral wall of said body adapted to engage said partition member to resist movement of oil from the lower to the upper chamber and to disengage said partition member to permit movement in the opposite direction, and means for supplying oil to said upper chamber.