US2130001A - Flexible spacer for valve mechanism - Google Patents

Description

'Sept. 13, 1938. G. M. FITTS FLEXIBLE SPACER FOR VALVE MECHANISM Filed Nov. 10, 1936 INVENTOR 4 w a H, m 6 5 a M m u r Ur m m F III/I Hal Patented Sept. 13, 1938 PATENT OFFICE FLEXIBLE SPACER FOR VALVE lVIECHANI George M. Fitts,

Washington, B. 0.

Application November 10, 1936, Serial No. 110,163

7 Claims.

This invention relates generally to valve mechanisms, with more particular reference to valve operating means for internal combustion engines.

It is well known that the conventional tappet nut for automotive valves makes necessary several phases of adjustment in the assembling of the motor. Furthermore, due to the constant wear of the valve mechanism when in operation, the

} tappets have to be readjusted from time to time and present-day construction of streamline automobile bodies, the high crown of the fenders and the manifolding of the motor makes the valve mechanism not easily accessible for adjustment.

One of the principal objects of the present s invention is the provision of means interposed in the valve mechanism adapted to eliminate the necessity for intricate preliminary adjustment and subsequent readjustment. A further object is the provision of resilient means for overcoming 26- lost motion, looseness and play between the valve and the valve actuating device. A still further object is the provision of means for eliminating noises due to the ordinary wear of the valve mechanism. I also have particularly in view the provision of a resilient spacer which for economy in manufacture and installation is made from sheet metal.

I have shown an application of my invention in its preferred form of embodiment in the drawing in which- Fig. 1 shows in vertical cross-section the valve operating mechanism of an engine having combined therewith my invention in its preferred form. r

Fig. 2 is a side view of the preferred form of my resilient spacer.

Fig. 3 is a plan view of Fig. 2.

Fig. 4 is an end View of Fig. 2.

Fig. 5 is an plan view of a sheet metal blank prior to forming my resilient spacer.

Fig. 6 is a side view showing a further step in the forming of the blank.

Fig. '7 is a modification showing a valve stem acting on the modified spacer.

Fig. 8 is a side view of the modified spacer prior to being bent.

Fig. 9 is a plan view of the modified form of Fig. 8.

Having reference to the drawing in detail:

A motor block 20 has a port I forreceiving a valve 3, a valve stem 5 working in valve guide 2. The stem 5 receives a valve spring 6, which is retained between the stem 5 and the motor block by the valve spring seat or retaining cap 4, and a cross pin 8. The lower end. of the stem 5 has a reduced portion l3 adapted to cooperate with the resilient spacer l5. Between the resilient member l5 and the stem 5 is a washer l which prevents the end l3 of the stem 5 from digging sharply into the spacer l5.

Below the resilient spacer i5 is a push-rod l0 mounted in the guide 9 of the motor block. The rod H) has a head 46 at the bottom thereof to cooperate with a cam II. The cam H- is the actuating member for opening the valve 3.

The assembly described supra is conventional structure except for the resilient spacer l5 and its connections with the stem 5 and the top of the push-rod l0.

In the preferred embodiment of my invention, the spacer [5, as shown in Figs. 1 to 6, is formed from a sheet-metal blank 2i (Fig. 5), the lower of the leaves to be folded upon each other being provided with a bulge or protruding recessed knob 22 and the upper leaf with an upwardlydirected, substantially rectangular offset portion 24 centrally apertured at 23. The ends of the blank are provided with bent prongs 25, 25, oppositely disposed prior to the folding operation, whereby, when the blank is folded, these prongs may be brought into flexible or yielding interengagement, as clearly shown in Fig. 2.

Prior to the folding operation, what is to become the lower leaf of the spacer is pressed to concave and what is to become the upper leaf to convex configuration, whereby, upon being folded upon each other, both will be concave-considered as being viewed from above-but with a variant degree of concavity which, augmented by the offset portion 24 in the upper leaf, provides a clearance space between the two leaves. The bulge or knob 22 is adapted to be seated in a correspondingly shaped recess 30 in the top of the push-rod H].

A washer I may be provided, centrally apertured for the reception of the reduced end I3 of the stem 5 (Fig. 1) which is passed into the aperture 23 of the upper leaf 29 of the spacer for the purpose of permanent alignment.

It will be apparent that the spacer I5 is so constructed as to act as a spring under pressure. The force of the resilient spacer is less than the force of the valve springfi. When the cam II is turned downward to allow the valve to close, the force ofthe spring 6 closes the valve, but the 5 slighter force in the resilient spacer acts to minimize lost motion throughout the whole assembly. This construction tends to eliminate any ordinarily increasing looseness or play between the valve stem 5 and the push rod. 55

' in Figs. '7, 8 and 9.

The space between the upper and the lower members 29 and 28 of the spacer is so constructed as to give a clearance which is equivalent to any possible clearance necessary for expansion of the valves. The clearance between the members 28 and 29 is determined by the amount of curvature in the two members. This is determined in the construction of the spacer prior to production assembly. v

It is to be understood that the construction of the spacer is such that there is an anchored resiliency or a resiliency which due to the construction at the ends of the spacer is more durable than the ordinary spring leaf.

In operation the upper and lower curved members of the spacer roll together upon actuation of the valve mechanism to open the valve but there is always some tension between the two members since they have a tendency to roll toward the point 40. against the spacer the particular anchoring of the upper and lower members 29 and 28 allows for the tension of the spacer to exert itself resiliently and take up any looseness or play between the working parts. i

When the valve is closed, the spacer resilientlyreturns to the normal clearance between the upper and lower members 29 and 28. This is due to the fact that there is no upward thrust of the cam ll, and'consequently the members 28 and 29 resiliently expand away from each other to take up any play in the mechanism.

A modification of the construction disclosed as a preferred embodiment of my invention is shown In this construction, instead of entirely convexing what is to become the upper leaf of the spacer and providing it with the offset portion 24, I'convex the same at its ends and merge the convexity into a medial concavity adapted to function in largely the same manner as the offset portion 24 of the preferred construction. prongs 25', 25 are present, and that when the blank is bent to form the spacer the two pressed protuberances M and 42 are in axial alignment.

It is also to be noted that with the form disclosed in Figs. 7, 8 and 9 the two depressions 4| and 42 are formed with small holes 43 to provide for passage of exhaust oil.- The bending of the blank to interfit the parts 4i and 42 allows fora pocket to be formed which is capable of receiving the oil from the motor and serves as an auxiliary cushioning means. It has the effect of a hydraulic spacing unit.

In using the words concave and convex, in both specification and claims, it is to be understood that I am considering the spacing device as viewed from the upper side thereof.

Many minor modifications of my improved spacer, together with other uses therefor, will doubtless readily suggest themselves to those skilled in the art to which it appertains, wherefore I do not desire to be limited to the specific construction and the suggested use herein shown and described.

I claim:

1. The method of forming a resilient spacer for interposition in valve actuating mechanism which consists in curving a sheet-metal blank with relatively varying degrees of curvature in When the spring 6 exerts pressure It will be noted thatthe interengaging endopposite halves thereof and providing interfitting lugs at the ends thereof, then bending said blank upon itself to form superposed leaves with the varying curvatures to provide a cushioning pocket therebetween and bringing said lugs into yielding engagement with each other.

2. A resilient spacer adapted for interposition in valve actuating mechanism comprising a sheetmetal blankfolded upon itself and shaped to provide superposed leaves of relatively varying degrees of curvature to normally insure clearance space therebetween, the upper leaf being provided with an upwardly projecting protuberance to provide additional clearance space for operation of the valve-operating-mechanism segments, and means for yieldingly anchoring together the free ends of the folded blank.

3. A resilient spacer adapted for interposition I in valve actuating mechanism comprising a sheetmetal blank folded upon itself and shaped to provide superposed leaves of relatively varying degrees of curvature to normallyinsure clearance space therebetween, and means for interengaging the meeting end edges of the folded blank.

.4. A resilient spacer adapted for interposition in valve actuating mechanism comprising a sheet-metal blankfolded upon itself and shaped to provide superposed leaves of relatively varying degrees of curvature to normally insure clearance space therebetween, the free ends of said folded blank being yieldingly anchored by interfitting lugs. a

5. A resilient spacer adapted for interposition in valve actuating mechanism comprising a sheet-metal blank foldedupon itself after having been shaped to: provide when folded superposed leaves of relatively varying degrees of curvature to provide a cushioning pocket therebetween, the free ends of said leaves having yielding interenga'gement with each other and both leaves being provided withimeans for establishing stabilizing engagement with the valve mechanism parts.

6. The combination, with .a valve and valve actuating means, of an interposed flexible spacer which is expansible to compensate for looseness and play between thevalve and the valve actuating mechanism, said spacer being formed from an integral sheet-metal blank shaped and bent upon itself to result when folded in superposed leaves of relatively varying degrees of curvature to provide a cushioning pocket therebetween, the free ends of said leaves being provided with interengageable lugs to effect a yielding connection.

7. The combination, with a valve and valve actuating mechanism, of a resilient member interposed in said actuating mechanism, said interposed member being formed from an integral sheet-metal blank shaped and bent upon itself to form when folded superposed leaves of relatively varying. degrees of curvature to provide a cushioning pocket therebetween, said leaves being yieldingly anchored together at their free ends by cooperating lugs, the upper leaf having a centrally apertured projection and the lower having a correspondingly located projection, said projections being in axial alignment and provided with means for yieldingly connecting the interposed member with working parts of the valve actuating mechanism.

GEORGE M. FIT'IS.

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