US 2842111 A
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Description (OCR text may contain errors)
July 8, 1958 G. M. BRAUN 2,842,111
VALVE SILENCERS Filed Nov. A115, 1956 N35 J0 al j INVENTOR 65ans: M. emw
United States Patent O VALVE SILENCERS George M. Braun, Milwaukee, Wis. Application November 13, 1956, Serial No. 621,939
(Cl. 12S-1821) My invention relates to improvements in valve silencers.
The object of my invention is to provide a valve silencer for poppet valve actuation `such as is found in modern internal combustion engines and other poppet valve equipped machinery.
My device is located between the end of the valve stem and the cam follower, and an important feature of my invention is the provision of a simple silencing spring device formed in one piece and so shaped as to be positively located for its operation and to provide the simplest and most trouble free element to take the impact of valve actuation.
In the drawings:
Fig. 1 is a vertical section through that fragmentary portion of an internal combustion enginewhich shows a poppet valve and its environment, my valve silencer being shown in position between the poppet valve` and its spring, and the cam follower.
Fig. 2 is a top plan view of my valve silencer.
Fig. 3 is a side elevation of the silencer shown in Fig. 2.
I am aware that spring elements have heretofore been provided for location between a cam follower and the valve stem which the cam follower is intended to actuate. Such a silencer is shown in U. S. Patent No. 1,395,064 to C. D. Stromgren, October 25, 1921, but it will be seen from the following description that my device is greatly simplified and is much more effective for longer periods of time without service requirement.
As shown in the drawings, the environment in which my silencer is used includes the usual cam follower mounted in a guide 11 carried by flange 12 of cylinder 13 of an internal combustion engine, As shown somewhat diagramrnatically, the lower end of the cam follower is provided with a roller 14 mounted in a roller bracket 15 secured to the lower end of the follower 10. The roller 14 is thus positioned to be actuated by a cam 16 in the well known manner as the cam follower is reciprocated upwardly and downwardly in response to cam action. Valve is guided by valve guide 21 in which valve stem 22 is mounted to reciprocate upwardly and downwardly in response to cam follower reciprocation. At the lower end of the valve stem 22 is a key 23 which may be made in any one of the many acceptable shapes, but which is usually horseshoe shaped and receivable into a groove in the stem so as to provide a stop against which a somewhat cup shaped spring seat 24 may rest under the bias of valve spring 25. This spring 25 is a compression spring bearing at its lower end against the cup shaped spring scat 24 and at its upper end against the lower surface 26 of what is, in this particularly disclosure, an L head engine. Thus the valve stem 22 is constantly urged to its lower position whereby to rrnly seat the valve 20 against a valve seat 27 which surrounds a port 28.
As is customary in valve actuating mechanisms of this general type, the cam follower 10 is provided with an axially aligned adjusting screw 30, which is usually in the form of a cap screw, in threaded engagement with the cam follower 10 and the usual lock nut at 31 is provided. Conventonally, the top of the cap screw 30 is in position to bear upon the unprotected valve stem 22 2 Claims.
Z,842,1 11 Patented July 8, 1958 ICS and as is customary in the adjustment of these valves some clearance is provided between the top of the cap screw and the end of the stem to permit of some tolerance for expansion and contraction of the metals during heating and cooling of the engine.
It is into the environment above described and particularly between the cap screw 30 at the end of the cam follower 10 and beneath the cupped spring seat washer 24 i that my valve silencing device 35 is installed. My device 35 is made of a sheet or strip of spring metal. I shape this in a folding operation so that my silencer includes a lower plate 36 and an upper plate 37 joined by a somewhat cylindrical spring margin 38. The lower plate 36 is imperforate and the upper plate 37 is provided approximately centrally with an aperture 39 through which valve stem 22 is snugly receivable.
The area of the upper plate 37 is sufficient so that the spring seat washer 24 may bear liatly against it when my device is in working position as shown in Fig. 1. When my silencer is removed from its working position, it takes the position shown in Fig. 3.
The strength of the spring action provided by the device 35 is ample to force cam follower 10 downwardly upon the cam 16 throughout the entire working cycle of Cam 16 at all speeds of the engine, but, of course, the
' strength of the spring action of my device is nowhere near adequate to compress valve spring 25. It is merely a booster for the return of cam follower 10 in this respect.
It will be noted that when in working position, my device is so disposed that the valve stem extends through aperture 39 and closely approximates contact with the upper surface of plate 36; therefore, there is no material other than plate 36 between the top of the cap screw 30 and the lower surface at the end of valve stem 22.
It will thus be apparent that my valve silencer is of the greatest simplicity of construction, that it cannot be accidentally mislocated with respect to its work environment and it in no sense complicates the adjustment of cap screw 30 and the clearance relationship which must be maintained in the valve action. The clearance is deiinitely provided between the valve stem and the upper surface of plate 36.
1. A device of the character described. comprising a hat sheet area of spring material shaped intermediately to provide a partially cylindrical spring fold and having areas either side of the fold divergent `from each other when in spring relaxed position, one of said areas being apertured centrally, the other of said areas opposite said aperture being imperforate.
2. A device of the character described for interposition between a cam follower assembly and a valve stem having a cupped spring secured adjacent the end of the valve spring, said silencer comprising an imperforate plate to bear in at contact against the cam follower assembly, integral semi-cylindrical spring margin for said imperforate plate and connected integrally with an upper platc centrally apertured for snug reception of the end of the valve stem and sufficient area to provide full abutment against said spring seat.
References Cited in the file of this patent UNITED STATES PATENTS 399,447 Stiles Mar. l2, 1889 1,613,117 Miller lan. 4, 1927 1,893,098 Murray et al. Ian. 3, 1933 1,913,241 Kuse -n June 6, 1933 2,046,087 Pountnay lune 30, 1936 2,643,069 Carlin lune 23, 1953 2,707,092 Bowditch Apr. 26, 1955