US2386003A - Compensating poppet valve - Google Patents

Description

Oct. 2, 1945. w, c 2386,0015

COMPENSAT'ING POPPET VALVE Filed 001;. 28, 1943 nun-n-un-nn r/ IIIl JJ INVENTORY Wasuvr 2. Pac BY ATTORNEYS Patented Oct. 2, 1945 UNITED STATES PATENT OFFICE 2,386,003 GOMPENSATING POPPET VALVE Wesley R. Peck, Sacramento, Calif. Application October 28, 1943, Serial No. 508,015

8 Claims.

' The present invention relates to improvements in a compensating poppet valve, and it consists of the combinations, constructions and arrangements hereinafter described and claimed.

The standard poppet valve'has a number of weaknesses due to its particular manner of mounting in an engine block. These weaknesses will be better understood when it is known that the standard poppet valve has three distinct movements while operating. The first of these movements is the opening of the poppet valve by means of a cam, the second is the moving of the valve toward closed position by a coil spring, andthe third is the lateral movement of the valve head to seat completely after making the initial contact with the seat during the closing movement. The third or. laterally slidin movement of the valve head to close completely is caused by the spring. The spring necessarily exerts more force against one side of the valve stem than against the other due to the spring contacting with the spring seat at one point, and this will cause the valve head to contact first at one point on the valve seat during the closing movement and before the valve entirely seats. The part of the valve head that firstcontacts with the valve seat will be disposed diametrically opposite to that part of the valve stem subjected to the greatest force by the coil valve spring. The third movement of the poppet valve will therefore be a lateral sliding movement of the valve head along the valve seat as the head moves into a fully closed position. During the lateral sliding movement of the valve head in one direc- 'tion, the lower end of the valve stem will be moving in the opposite direction in a pendulumlike action.

From actual experiment it has been discovered that the numberof times the valve can move laterally into completely closed position is about twelve times per second, assuming that all operating conditions are perfect, such as the valve spring being at full strength and the valve guide and the valve stem being polished and properly lubricated. Under the standard operating condition for an internal combustion engine, this would mean that the crank shaft can operate 1440 R. P. M. and give the valves time to com-- pletely close at the end of each opening and closing movement. Any speed above this will therefore prevent the valves from completely closing because not a sufficient time interval is aiforded before the valves are again opened.

A large number of automobiles are driven regand this speed with the average gear ratios will cause the crank shaft to make approximately 3000 R. P.

-plete theirthird operation of side slipping into.

the valve seat to form a complete closure. The valves will therefore be prevented from completely closing, and as soon as this occurs a number of valve weaknesses develop, caused by the valves andvalve seats becoming overheated due to the blow-by of flame when the valve should be closed and prevent this. H

For example, experience under actual operating conditions has proven that valve-seat and cylinder-seat erosion occurs only at the higher speeds of an engine. This is due to the fact that the valve does not have time to close com-' pletely before it is again opened, and the flame of combustion is forced through the opening that is provided between the two surfaces and this flame impinges heavily on both surfaces causing them to burn and erode. The engineers have resorted to different metal alloys and to the cooling of the valves to cause the valves and valve seats to stand up, but the main problem of completely closing the valve after each operation, has not been solved. i i j An object of my invention is to provide a compensating poppet valve that is an improvement over thevalve shown in the patent issued to Royden Birrellon .April fl, 1939, No, 2,152,784. In the patented "device, the valve illustrated in Figures 1 and 2 has a valve stem with a flanged head cap, the cap contacting with a valve head proper that is free to move laterally to aslight extent with respect to the valve stem so that the valve head proper will seat correctly in the valve seat. I have found from practice, that the heat received by the flanged head cap during the operation of the valvein an engine was not dissipated into the valve head proper and thence to the valve seat in order to be carried away by the water in the water jacket of the engine, but instead the heat traveled down the valve stem and caused it to become unduly heated. Apparently, a frictional contact between the flanged head and the valve body is not sufilcient to conduct heat from the fiangedhead to the valve body.

The principal object of my present invention is to provide a valve whose valve head proper can move laterally to a slight extent with respect to the valve stem in order to seat properly, and in which the heat received by the top of the valve during its operation in an engine will be conducted to the valve seat rather than to the valve stem.

In Figure 3 of the Birrell patent, the cap 32 does convey heat from the top of the valve to the valve head proper 2'7, but the cap is made of thin material and cannot stand up under lon use in an engine. A further object of the present invention is to provide a valve which is sturdy in construction so that it will stand up under continuous use.

A further object of my invention is to provide a poppet valve which is simple in construction and which is durable and eflicient forthe purpose intended.

Other objects and advantages willappear in the following specification, and the novel features of the device will be particularly pointed out in the appended claims.

My invention is illustrated in the accompanying drawin forming a part of this application, in which:

Figure 1 is a vertical section through a portion of an engine showing my valve operatively applied in place;

Figure 2 is a top plan view of the valve on anenlarged scale with portions being broken away for clarity; and

Figure 3 is a vertical transverse section through the valve taken along the line 33 of Figure 2.

While I have shown only the preferred form of my invention, it should be understood that various changes or modifications may be made within the scope of the appended claims without departing from the spirit and scope of the invention.

In carryin out my invention, I make use of 'an engine block indicated generally at A. The engine block has a port B therein which may be either an intake or an exhaust port. The port B is water-jacketed as at C. The engine block carries a valve stem guide D in which my valve indicated generally at E has its stem I slidably mounted. The valve stem guide D has a flange I 21 that bears against the engine. block and acts as a seat for one end of a coil spring 3. A valve spring seat 4 is mounted at the lower end of the stem I and the spring 3 has its other end bearing thereagainst.

A valve lifter F is shown in Figure 1 and is designed to contact with the stem I for lifting the valve E at the proper time intervals. All of theiparts described thus far with the exception of the valve E are standard in construction and form no part of my invention except insofar as they cooperate with the parts now to be described. Reference to Figure 3 shows the top of the valve stem I as beingprovided with a flange 5. The flange is in the shape of a discand has its upper surface 6 tapered slightly 'to form a frustum of a cone. The center top of the flange is flatasat I. r

A valve head proper 8 has a depression 9 for receiving the flange 5 and the inner diameter of the depression is slightly larger than, the,

outer diameter of the flange so as to provide a space X for permitting the flange 5 to move laterally in any direction a slight distance before it will contact with an annular shoulder ID. The

receiving the periphery of a cap I3. The cap I3 is slightly conical in shape and has a button-like portion I4 that contacts with the fiat portion I. The periphery of the cap contacts with the shoulder of the groove I2 and is welded thereto around its entire circumference. In this way the cap and the valve body form an integral unit that is free to move laterally with respect to the flange 5 and the valve stem I, in any-direction within certain limits. If desired a valve body retaining member I5 may be placed under the valve body and the member has an opening I6 for receiving the valve stem I. The member I5 is secured to the stem I by welding or other suitable fastening means.

From the foregoing description of the various parts of the device, the operation thereof may be readily understood.

The compensating valve E is placed in the engine and takes the place of the usual poppet valve. The valve is reciprocated by the valve lifter F in the usual manner. Any heat that the cap I3 receives from the engine will be conducted to the valve head 3 due to the fact that the cap is welded to the head. This heat is then transferred from the head 8 to the valve seat G by contacting therewith and is carried away by the water in the water jacket C. The heat will not be conducted down into the stem I to any appreciable extent because the area of contact between the button I4 and the top I is less than the area of contact between the cap periphery and the valve head 8. Moreover the cap is spaced away from the flange 5 as shown at Y, in Figure 3. The cap I3 exerts a spring-like force on the flange 5 to hold the latter in contact with the base II of the recess 9.

Should the valve seat G move out of alignment with the axis of the valve stem I, due to 40 temperature changes in the different parts durmg the operation of the engine, the constant reciprocation of the valve and the successive contacts the valve head 8 makes with the valve seat G, will cause the valve head to move laterally with respect to the stem I in the desired direction so that'the valve head axis will coincide with the vertical axis of the valve seat G. In this waythe valve will close effectively in the valve seat during the entire operation of the engine, regardless of the variation in temperature changes between the different parts. 7 The true seating of the valve head'B in the valve seat G at all times will prevent the valve from partially seating and will preventany gasses from flowing past the valve while the valve: is supposed to be seated. The life of the valve'will be materially increased and the efliciencyof the engine will be maintained at maximum.

- In normal operation a cam (not shown) intermittentlyraisesthe valve lifter F 'and the lifter in turn raises the valve stem". After the cam has done its work, the-spring 3 returns the valve to normal position read for the next operation. It should be noted at this pointyhoweverfthat the spring in-returning the standard poppet valve to its normal position causes this valveto contact with the valve seatG'at one point because the coil spring will exert its greatest force at one point on the spring seat 4. If, for example, the spring 3 contacts with the spring seat'at the point marked Xf, then the'lower end of thefvalve stem will be swung to the left in Figure 1 so that the stem will contact with the lowerend of the valve guide at the point Y. This will causethe upper portion of the valve stem to contact with the top of the valve guide at Z. The result of this is that the valve head in the standard poppet valve will first contact valve seat G at Z. Further movement of the spring seat in a downward direction by the spring will cause the valve head to slide laterally to the left in Figure 1 and the lower end of the valve stem will swing to the right, until the valvebecomes perfectly seated or fully closed.

With my form of invention the valve head proper 8, in contacting with the seat G at Z, will move the valve head proper laterally a distance that is sufficient for the valve head to seat properly thereafter without side slippage, even though the coil spring continues to exert a greater force at the point X than at any other point on the valve seat 4. The result is that the lateral sliding movement of the valve head in a standard poppet valve at the end of each cycle of movement, is entirely eliminated and the valve will therefore have only two operations, an opening operation, caused by the valve lifter, and a closing operation, caused by the valve spring.

It is necessary that a poppet valve have what is termed longitudinal rigidity as well as a sufficient bond between-the head and valve stem. Longitudinal rigidity permits the contacting surfaces between the valve and the valve seat to contact with the full pressure of the spring, whatever that pressure may be. The present invention still permits this longitudinal rigidity, even though the valve head proper may shift laterally with respect to the head. The present invention also provides sufiicient bond between the head and the stem because of the great area between the contacting surfaces of the valve head proper and the parts that connect the head to the valve stem. It will therefore be seen that the present invention has every advantage possessed by the standard poppet valve and has the added advantage of never getting out of alignment. The welding of the cap to the head carries away the heat to the head and valve seat rather than to the stem.

I claim:

1. A poppet valve having a stem with a flanged end, a head having a cap covering the tbp of the flanged end, the head having a depression for receiving the flanged end so that the head can move laterally with respect to the stem in any direction, said cap being welded to the head for conducting heat to the head rather than to the stem, and means carried by the stem for maintaining the axis of the head parallel with the stem axis at all times.

3. A poppet valve having a stem with a flanged end, a valve head having a depression for receiving the flanged end with limited movement permitted between the head and end, said head also having an opening large enough to loosely receive spacing the greater portion of the cap above the flanged end and having a rim contacting with the head, said cap having its rim welded to the 2. A poppet valve comprising a stem with a flanged end, a disc-shaped head enclosing the flanged end and movable laterally with respect to the stem, said head including a cap overlying the flanged end and having a central button contacting with the flanged end and spacing the cap therefrom, said cap being welded to the head for conducting heat to the head rather than to the stem, said head contacting with the opposite side of the flanged end from that of the button for holding the plane of the head at right angles with the stem axis at all times.

head for conducting heat to the head rather than to the stem.

5. A poppet valve having a stem with a flanged end extending at right angles to the stem, a valve head having a depression for receiving the flanged end, said depression being larger in diameter than the flanged end to permit the head to move in a radial direction with respect to the end and stem, a cap overlying the flanged end and having a rim, said head having an annular groove for receiving the rim of the cap which is welded to the head, said head and cap cooperating with the flanged end for keeping the axis of the head parallel with the stem axis at all times.

6. A poppet valve comprising a stem with a flanged end, a valvehead having a depression for receiving the end with freedom of a lateral movement of the head with respect to the stem in a radial direction, a cap covering the flanged end and having a diameter less than the outer diameter of the head, said head having an annular groove for receiving the cap periphery, said cap periphery being welded to the head for conducting heat thereto rather than to the stem.

7. A poppet valve comprising a stem having a flanged end, a valve head having a depression for receiving the end and being larger in diameter than the flanged end, said head having an opening for loosely receiving the stem and having an annular groove concentric with the recess, a cap covering the flanged end and being spaced therefrom except for a central portion of the cap contacting with the end, the cap periphery being received in the groove to provide a smooth top between the cap and head and being welded to the head for conducting heat to the head rather than to the stem.

8. A poppet valve comprising a stem having a flanged end, a head having an opening for the stem and a depression for the end, said head having a conical outer periphery and an annular groove concentric with the recess, a cap covering the end and having its rim received in the groove and welded to the head, and a retaining member secured to the stem and bearing against the underside of the head.

WESLEY R. PECK.

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