US2274650A - Valve actuating mechanism - Google Patents

Description

Mamh 1942- o. H. BANKER VALVE ACTUATING' MECHANISM Ofiginal Fi1 ed July 24, 1936' v 4 girl/1%!!! B W .41 a E e 3 E E E r v mvismon Y Oaciarfl A ORNEY.

Patented Mar. 3, 1942 2,274,650 vaavr. AcrUArmG MECHANISM Oscar H. Banker, Chicago, ill.

Griginal application July 24, 1936, Serial No.

1946, Serial No. 334,503 g 6 Claims. (Cl. 12390) The invention relates generally to a valve actu'- ating mechanism for an internal combustion engine and more particularly to the valve litter of the actuating mechanism. This application is adivision of my prior application Serial No. 92,302, filed July 24, 1936, issued July 9, 1940, as Patent No. 2,206,869.

A general object of the invention is to provide a valve actuating mechanism of new and improved construction rendering the mechanism extremely quiet under all operating conditions, economical to manufacture, efficient, durable, and easy to install either initially or as a replacement for noisy, worn or obsolete mechanism.

A more'particular-object is to provide avalve actuating mechanism of new and improved con.- struction in which metal to metal contact blows are eliminated, thereby avoiding the noise and the periodic vibration incident to such blows.

Another object is to provide a valve actuating mechanism having a two part valve lifter, one part being maintained in constant engagement with the valve stem and the other part being maintained in constant engagement with the valve actuating cam and the parts having a new and improved cushioned engagement of large area, assuring long. life of the cushioning material and ready separation of the engagement so that the parts will be maintained respectively in engagement with the valve stem and the cam.

Other objects and advantages will become apparent from the following detailed description taken in connection with the accompanying drawing, in which:

Fig. l is a fragmentary view, partially in section, of a valve actuating mechanism for an internal combustion engine embodying the features of the invention.

Fig. 2 is a diarnetrical sectionof the valve actuating mechanism shown in Fig. 1.

Fig. 3 is a top plan view of the mechanism illustrated in Fig. 2.

While the invention is disclosed in the drawing and will hereinafter be described as embodied in one form or modification, it is not intended thatthe invention be limitedto the specific embodiment disclosed, but it is intended to cover all modifications and alternative constructions falling within the "spirit and scope of the invention as defined by the appended claims.

Referring to the drawing, particularly Fig. 1, It represents the cylinder block of an internal combustion engine and Il represents a valve having a, valve head 12 controlling a portopening into a cylinder of the engine. The valve is Divided and this application May 11,-

mounted in the usual manner with its'stem l3 projecting slidablythrough a sleeve bushing ll secured in the cylinder block 60. At the end remote from the valve head, the valve stem carries a washer I5 between which and the cylinder block it a compression spring i6 is interposed to urge the valve toward seated position. The valve is opened against the action of the spring It at proper intervals by means of a cam ll formed on a cam shaft 18 and acting through a valve lifter generally designated Ill. The valve lifter is guided for longitudinal 'reciprocatory movement in a bore 29 Pormcd in a portion of the cylinder block [9.

- Herein the valve litter is of unique construction esigned to silence the operation of the valve mechanism. Generally, the valve lifter comprises a first part generally designated 2! maintained in contact with the cam shaft Hi, a second part generally designated 22 maintained in contact with the valve stem l3 and a cushioning means interposed between the parts so as to.avoid metal to metal impact blows during the operation of the engine. The parts have a jointmovement to unseat the valve and a slight'movement relative to one another in order at all times to maintain the parts in contact with the cam shaft and the valve stem respectively and to provide the clearance necessary to take care of expansion of the valve mechanism caused by changes in engine temperature. I

As illustrated, the cam operated part 2| is in the form of a cylindrical cup-shaped member having a bore 26 therein opening through the end remote from'the cam shaft. The second part 22 is formed by a cap M having a diameter substantially equal to the diameter of the bore 26 and a stem Q2 of a substantially reduced diameter. The cap M is normally received partially within the cylindrical member 2i, and in order to facilitate relative movement between the cap and the cylindrical member 2| the latter is cut away at $3 so as to provide suflicient clearance so that the cap will not stick. The cushioning means interposed between the two parts of the valve lifter herein comprises a plurality of annular washers 38 of a composition which is resilient and slightly yieldable but substantially incompressible volumetrically so that in order to yield in one direction or be compressed in part it must have space to expand in another direction or in another part. The resilient qualities are similar to those of rubber, but preferablythe composicommercial product known as Duprene," which is a product made from coal having some of the characteristics of rubber. These washers have an outer diameter substantially equal to the diameter of the bore 26 and an inner diameter substantially equal to the diameter of the stem 42.

Interposed between the washers 38 are a plurality of shims 39 having an outer diameter which is less than the diameter of the bore 26. As a result, a plurality of spaces 44 are formed into which the composition of the washers 38 will fiow when the washers are placed under compression.

during the unseating ofthe valve by the valve lifter or upon expansion of the valve mechanism. The total distortion of the washers 38 into the spaces 44 is comparable to the clearance to be maintained in the valve mechanism when cold. In the form shown the Washers 38 serve the dual function of separating the main body portion 2| and the cap 4| to maintain them respectively in contact with the cam shaft and with thevalve stem and of providing the cushioning means for eliminating the metal to metal impact blow. When the parts are in their separated position as shown in Fig. 2, the plunger stem 42 is spaced from the bottom of the cylindrical member 2| a distance slightly greater than the distance which the washers 38 normally permit the plunger 'to move. This construction thus provides a positive safety limit to the compression of the washers 38 in case of deterioration, which may not be exceeded during the unseating of the valve by the valve lifter.

It is believed readily apparent that the invention provides a simple and inexpensive means for insuring quiet operation of the valve actuating mechanism, and furthermore that it may be embodied in forms which fit into existing valve actuating mechanism merely by the removal of portions thereof. herein, the invention is adapted for installation in existing valve mechanism by removing the existing valve lifter part and inserting the present invention, or the present device may be embodied in valve mechanism when originally designed. It is of course, contemplated that various features of the invention may be embodied in original valve mechanism designed to obtain even further simplification. For example, the valve stem part 22 might readily be formed integrally with the valve stem l3.

By maintaining the valve stem and cam shaft parts of the present invention in continual contact with the valve stem and cam shaft respectively, and providing a cushioning engagement between the parts, there will be no impact blows between two metal parts during the operation of the mechanism asis the case in the present day valve mechanism wherein clearance is provided between the upper end of the valve lifter and the valve stem.

By making the washers 38 with a contact area many times that of the lower end of the valve there are no screw devices used for adjusting the Thus as illustratedvalves, shims serving this purpose, the adjustment will be more permanent and will eliminate the tight and loose valves nowadays caused byvibration changes of the screw device adjustments. Heretofore shims were not practical because of the small contact area of the valve lifter parts limiting the size of the shims so that the pressures encountered during operation would crush and destroy them, but the invention herein disclosed, which increases the area to many times that of the valve stem, makes it possible to. use thin metal shims for adjustment purposes when the valve mechanisms are initially installed.

Although the invention is herein illustrated and described in connection with an L-head type of engine, it is to be understood that the invention in its various forms is equally suitable for use in connection with overhead valve engines wherein'the valve operating member 22 would engage the usual push rods of the valve mechanisms-of such engines. Since overhead valve" engines are well known in the art, it is not thought necessary to illustrate the valve actuating mechanism thereof herein. In overhead valve" engines all adjustment screws and lock nuts usually furnished on the rocker arms will be eliminated just as adjusting screws and lock nuts are eliminated in the valve mechanism illustrated.

I claim as my invention:

1. A valve lifter for a valve actuating mechanism comprising a cup-shaped member having a bore therein closed at one end thereof, a plunger receivable within the bore having a portion projecting from the bore, a plurality of annular washers of yieldablebut substantially incompressible rubber-like material surrounding said plunger within said bore having an outer diameter substantially equal to the diameter 01' said bore, and an inner diameter substantially equal to the' diameter of the plunger, and annular shims interposed between the washers each having an area less than that of the adjacent washers to provide spaces into which portions of the washers may flow during the application of force to the valve actuating mechanism 2. A valve lifter for a valve actuating mechanismcomprising a tubular member having a bore therein closed at one end thereof, a plunger receivable within the bore having a stem and a head thereon projecting from said bore, a plurality of annular washers of resilient material having an outer diameter substantially equal to the diameter of the bore of the tubular member and an inner diameter substantially equal to the diameter of the plunger stem, and annular shims interposed between the washers having an inner diameter substantially equal to the diameter of the plunger stem and an outer diameter less than the circumference of the bore to provide spaces into which portions of the washers may flow during the application of force to the valve actuating mechanism.

3. In the combination defined in claim 2, the end of the plunger stem being initially spaced from the closed end of the bore and the spaces providedaround the shims being inadequate to allow distortion of the resilient washers to an extent permitting contact of said stem withsaid closed end of the bore.

4. A valve lifter for a valve actuating mechanism comprising a tubular memberhaving a bore therein closed at one end thereof, a plunger having a head and a reduced stem receivable within said member, and a pair of annular elements interposed between the head or said plunger and the closed end of said tubular member comprising a washer of yieldable but substantially incompressible rubber-like material fitted snu y within said bore and around said stem, and a metallic washer having an area less than that of one face of the yieldable washer and disposed in contact with-said face, thus providing space into which the yieldable material may flow when force is applied axially to the valve lifter, said plunger stem being initially separated from the closed end wall of the tubular member.

5. A valve lifter for a valve actuating mechanism comprising a tubular member having a bore therein closed atone end thereof, a plunger having a head and a reduced stem receivable within said member, and a pair of annular elements interposed between the head of said plunger and the closed end of said tubular member comprising a washer of yieldable but substantially iricompressible rubber-like material fitted snugly within said bore and around said stem, and a metallic washer having an area less than that of one race or the yieldable washer and disposed in contact with said face, thus providing space into which the yieldable material may flow when force is applied axially to the valve lifter, said plunger stem being initially separated from the closed end wall of the tubular member, and said space being inadequate to allow distortion of the yieldablewasher to an extent permitting contact of said stem with said end wall.

6. In a valve tappet, the combination of a body provided with a bore closed at one end and open at the other end, a plunger disposed in the bore, a resilient and yieldable but substantially incompressible element of rubber-like substance fitted initially in contact with the bore and seated between said plunger and said closed end, the seat at one side of said element engaging less than the total area of the element presented at that side and providing space into which the material of'said element may flow when distorted b pressure acting axially of the plunger.

OSCAR H. BANKER.

Images