US3011485A - Valve lifter - Google Patents

Description

Dec. 5, 1961 l., JJVAN sLooTEN VALVE LIFTER Filed May 27, 1960 A TTOP/VEV United States Patent Otitice 3,011,485 Patented Dec. 5, 19h61 3,011,485 VALVE LIFTER Louis J. Van Slooten, West Olive, Mich., assigner to General Motors Corporation, Detroit, Mich., a corporation of Delaware Filed May 27, 1960, Ser. No. 32,430 2 Claims. (Cl. 12S- 90) This invention relates to valve lifters and the like having telescopically slidable members spring biased to a normally elongated relative position of the members, and is particularly adapted to hydraulic valve lifters such as are used for automatically taking up clearance in the operating train of a poppet valve in an internal combustion engine. In the conventional design of such hydraulic valve lifters the fluid press-ure chamber provided between the closed end of the cup-shaped outer body member and the adjacent end of its slidably tting hollow plunger member is replenished as necessary with iluid admitted through a check valve controlled central passage in 'the inner end of the plunger, and a valve retainer in the form of an apertured cup-shaped stamping serves to limit the opening travel of the check valve. This retainer is conventionally held in place against the inner end of the plunger by a coil compression spring within the chamber which operates to elongate the lifter assembly when the poppet valve opening thrust load is relieved, During each lift stroke to open the engine poppet valve a small amount of Huid leaks past the plunger from the pressure chamber, and the amount of this leakage ii'uid is replenished (to the extent necessary to take up't'ne clearance in the valve train) via the check valve control passage when the thrust load is relieved just prior to the lift stroke. In order that suiiicient, yet no-t execssive, leakage of tiuid past the lifter will take place during each such lift stroke, the slidable iit or side clearance between the plunger and the lifter body must be within relatively close limits.

It is a principal object of the invention to improve such devices by reducing the numberof parts, by eliminating the check valve retainer in the case of `a hydraulic valve lifter and designing the plunger return spring to serve this additional function. It is another object of the invention to employ the piunger return spring as a means of coupling the plunger and lifter body together so as to substantially prevent their relative rotation, thereby decreasing the extent of rubbing action between their slidable surfaces and hence reduce wear and resultant development of excessive clearance for sliding action.

While it is old in the Truesdell Patent 2,074,155 to employ the plunger return spring to limit opening movement of the check valve, and in Voorhies 2,237,854 to frictionally couple the plunger land lifter body against rotation, improved results in both these respects are obtained by my invention. My plunger return spring enables obtaining the desired retention of the check valve in proper Iassociation with a fluid passage located centrally of the plunger; and, by terminating the ends of the spring with arms extended at right angles to the adjacent end convolutions of the spring and providing bifurcations in the plunger and lifter -body to receive these arms', a positive inter-engagement of these parts with the spring ends is obtained which prevents their relative rotation while enabling complete freedom of action of all convolutions of the spring and permits assembly of the spring` y with the other parts Without requiring a force t of the spring ends to the other parts during assembly.

A better understanding of the means by which these and other objects and advantages of the invention are `attained will be had from the following description, with reference to the drawing, wherein:

FIGURE l is a longitudinal sectional view through the valve lifter, shown in operative relation between its driving cam and driven push rod, and slidably supported in its guide hole in the cylinder block of an internal combustion engine.

FIGURE 2 is a perspective View of the plunger spring in its free state, shown removed from the valve lifter of FIGURE 1.

FIGURE 3 is a view similar to FIGURE l, but showing a modified form of the invention wherein the plunger return spring is arranged to rotatably cou-ple the telescoping parts of the valve litter together.

FIGURE 4 is `a sectional view in plan, taken substantially along the line 4-4 of FIGURE 3.

Referring now in detail to the drawing, and first to FIGURES 1 and 2, the valve lifter designated generally by the numeral 1 is shown slidably mounted for reciprocation in its guide hole 2 of the engine cylinder block 3, with the lower end wall lor foot 4 of the lifter engaging the lifter driving cam 5. Lifting motion imparted to the lifter by the cam S is transmitted to the lower end of a push rod 6, whose upper end (not shown) ymay be arranged to open the engine poppet valve directly or actuate the conventional valve rocker for such purpose.

The lifter foot, together with an upper tubular part 7 having a bore 8, forms the outer body of the valve lifter. Slidably fitting the bore 8 is the lifter plunger 9 whose inner end 10 defines the upper 4limits of a fluid pressure chamber 11. Forming the sides and lower end of this chamber 11 are the foot piece 4 and tubular part 7 which are xedly and seaiingly bonded together as by Welding or brazing their overlapping surfaces 12 and 13, respectively. In the arrangement shown, the plunger is made hollow to provide a reservo-ir 14 for fluid in the form of oil supplied from the engine lubricating system via the gallery 15 and registering ports 17 and I8 in the side walls of the lifter body and plunger, respectively. EX- tending centrally through the lower end 10 of the plunger to connect the reservoir 14 to the pressure chamber 11 is a passage 19 controlled by a ball check valve 20. This check valve is shown in closed position against its seat 21 on the plunger adjacent the lo-wer end of the passage 19, from which seat the check valve is movable a slight distance (e.g., .00'4.009 in.) downwardly from its position shown to its open position. closing movements the check valve is loosely guided laterally by the side walls of the counterbore 22 formed` in the plunger below the seat 21. Surrounding the passage 19 yand the counterbore 22 is a spring seat 23, the outer extremities of which are dened by a depending skirt Z4 on the plunger end wall lil. interposed in compression between the spring seat 23 on the plunger and the inner end face 25 of the end wall or foot piece 4 of the lifter is a ooil compression spring 26. As best shown in FIG- UREKZ,k this spring has each of its opposite ends terminating with an arm 27 in-turned radially of the axis of the spring (and of the lifter bore 8) from the adjacent end convolution 28 of the spring. Preferably, these arms 27 are attened somewhat, as shown, to forma surface resting area for the ball check valve 2.0 in its open position (it being understood that the spring 26 is invertible from its position shown during assembly of the lifter). In order that the ball check valve may have freedom of movement (e.g., .004-.009 in.) from its closed position of engagement with itsseat 21 to its open position, the plane of the spring seat 23 on the plunger may be located so as to lie below the ball (in its closed position) a distance equal to the amount of such desired free ball movement, and the spring arms 27 should have their extremities end-wise of the spring flush with those end-wise extremities of their associated end convolutions 28 o-f the spring. Of course, the desired free travel of the ball may otherwise be provided for, as by deforming the spring arms 28 as necessary to Aaccommodate different relative During its opening and 3 heights of the spring seat 23 and lower extremity of the seated ball check valve. l

In the embodiment shown in FIGURES 3 and 4 the plunger 9' has its spring seat 23' surrounding a short annular skirt portion 24' depending from the inner end of the plunger, and means is provided in the form of a bifurcation or slot 30 in this skirt portion to receivably embrace the inturned arm Z7 at the upper end of the spring 26. The interengagement of the latter arm 27 and slot 3?, together with the encircling relation of the spring about the skirt portion 24 serves to lock 'the plunger against rotation relative to the upper end of the spring. To similarly lock the lifter body '7' against rotation relative to the lower end of the spring, means is provided in the form of a bifurcation consisting of two laterally spaced projections 31 extending upwardly within the spring from the inner end `face of the body foot piece 4i'. The arm Z7 at the lower end of the spring is received between these projections to effect the locking interengagement, as best shown in FIGURE 4. This lifter may otherwise be of the same design in all other respects as that described with reference to FIGURES l and 2, including the employment of the spring upper arm 27 in limiting opening travel of the ball check valve Ztl.

It is appreciated that numerous minor changes in the construction and arrangement of the parts may be made from those heretofore described and shown. in the drawing, Without departing fromtne spirit and scope of the invention which I now claim.

I claim:

l. In a Valve lifter having `a body member with a bore and an end wall longitudinally opposite the bore, an inner member slidably itting said bore, and a coil spring thrustably interposed between said inner member and said end wall of the body member for biasing said inner member outwardly of said bore from said end wall, said spring having each of its respective ends terminating with an arm turned at substantially a right angle from the adjacent end convolution of the spring, said body member having a portion adjacent its end wall interengaging one of said arms and means on the inner member interengaging the other of said arms, whereby said spring torsionally opposes relative rotation of the members.

2. In a hydraulic valve .lifter having `a body member with a bore and an end wall longitudinally opposite the bore defining a fluid pressure chamber, a plunger member slidably fitting the bore, a central passage in the end of the plunger member adjacent the chamber, a check valve movable to open and close the passage, a seat on the plunger member engaged by the valve when in closed position, a spring seat on said plunger member end surrounding the passage, and a coil spring thrustably interposed between said spring seat and said end wall of the body member for biasing the plunger member outwardly of the bore from said end wall, said spring having its end adjacent said spring seat terminating with a radially inturned larm underlying and limiting opening movement of said valve, the opposite end of said spring also terminating with a radially extending arm, each of said plunger member end and said body member end wall having a bifurcation embracing the spring arm adjacent thereto and locking said member against rotation relative to its adjacent end ofthe spring.

References Cited in the le of this patent UNITED STATES PATENTS 2,654,356 Oldberg Oct. 6, 1953 2,749,892 Line et al. June 12, 1956 2,795,218 Heiss lune 11, 1957

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