US2175466A - Horizontal hydraulic valve tappet - Google Patents

Description

Patented Oct. 10, 1939 UNITED STATES PATENT OFFICE 3 Claims.

This invention relates to valve tappets, particularly hydraulic valve tappets which are maintained in adjusted relation to the valves which the tappets operate, preferably through oil sup- 5 plied from the oil system of the internal combustion engine in which the tappets are installed. The present invention is concerned with an improvement in valve tappets generally of the type shown in my Patent No. 2,090,795 issued August l0 24, 1937, and in my pending application, Serial No. 205,525, filed May 2, 1938, but wherein the tappet is located horizontally instead of vertically as disclosed in said patent and pending application. rlhe invention is directed to novel structure for making the tappet practical and particularly successful and workable when horizontally positioned and with means to insure the separation of air from the oil before it enters the hydraulic chamber where said oil is under pressure and should not have any air intermixed therewith.

The invention may be understood from the following description, taken in connection with the accompanying drawing, in which:

Fig. 1 is a longitudinal vertical section through a valve tappet constructed in accordance with my invention.

Fig. 2 is a vertical section substantially on the plane of line 2--2 of Fig. 1, looking in the direction indicated by the arrows.

Fig. 3 is a fragmentary vertical section similar to Fig. 2, showing a slight modification in structure, and

Fig. 4 is a perspective view of a key element which may be used with my invention.

Like reference characters refer to like parts in the different figures of the drawing.

The guiding sleeves I for the tappets will be either integrally cast with the engine block or permanently secured thereto in any suitable manner, and with such sleeves there is an oil conduit 2 through which oil is pumped from the pressure oil circulation system of the engine. A branch 3 leads from said conduit for each tappet, it being understood that the conduit 2 supplies a plurality of the tappets and that each of the branches 3 conducts oil to a single tappet.

The taappet includes a cylindrical hollow body 4 closed at one end, as at 5, which end bears against a cam 6 integral with or secured to a cam shaft which rotates continuously during engine operation for moving the tappet to lift the engine valve. The tappet follows the cam by reason of the usual valve spring associated with the valve which acts to press the tappet (Cl. 12S-90) against the cam. Around the body of the tappet is a continuous groove 'I to which the oil is delivered from the branch 3. From the groove oil passes through an opening 8 made at the upper side of the tappet body, the oil being con- '5 ducted into the interior of the tappet body as is obvious. The opening at 8 is at the upper side of the wall of the tappet body 4 and must be maintained at such upper position. To maintain the tappet against rotation and to therefore hold '10 the opening 8 at the upper side of the tappet body, the wall of the tappet body at the upper side thereof and near the closed end 5 is thickened somewhat, as indicated at 9; and through said thickened wall 9 a slot is cut by a curved 15 cutter in which a Woodruff key I0 is freely received. The key is in the form of a segment of a circular disk. At its upper edge it extends beyond the adjacent outer surface of the tappet body and is received in a longitudinal key-way f II cut in the tappet sleeve guide I. 20

For the escape of air which will naturally rise through oil within the tappet body to the upper portion of the tappet, the key may be made slightly less in width than the width of the slot in which it is seated. Or, as shown in Fig. 3, a 25 small vertical opening, as indicated at I2, may be made through the thickened portion 9. In another form the key IIJ may be grooved at one sideL as indicated at I3 in Fig. 4, for the same c purpose, whereby air separating from and moving upwardly through the oil within the body 4 coming to said key will pass upwardly through the groove I3 and thence into the key-way II.

The structure of the tappet is similar in many respects to that shown in my previously men- 35 tioned application, Serial No. 205,525. Within the body and between its ends an annular inwardly projecting shoulder is formed and a short cylindrical head I4 has a tubular section I5 extending horizontally therefrom toward the 40 closed end 5 of the tappet body, but before reaching said closed end it is turned substantially at right angles and in a downward direction, as at I6, the lower open end of the downward extension I6 terminating a short distance from the 45 the end of a valve stem 20 bears. Said piston also has an inward projection 2l of cylindrical form which is surrounded within the tappet body by a split ring 22, pressed by a coiled compression spring 23, against the larger piston section I8. As shown, the piston may be maintained over to one side by a cross member 24 of spring material carried by the ring 22, as in my pending application, Serial No. 205,525, and for the same purpose. It is to be understood that the tappet structure to the right of the head I4 is identical with that shown in said pending application and need not be further specifically described.

The head I4 divides the tappet body, substantially midway between its ends, providing an oil receiving chamber or reservoir 25, into which the oil passes through the passage 8, and also an hydraulic oil compression chamber 26 between the piston I8 and said member I4 and the valve I1. The oil which is trapped within the chamber 26 cannot escape therefrom when the engine valve is opened on movement of the tappet to the right (Fig. 2), as the valve Il closes against the pas- Sage of oil back into the oil chamber 25. The hydraulic compression chamber 26 is maintained full of oil at all times and the projection I9 of the piston I8 is held against the end of the valve stem 2l) at all times.

With this structure, oil may carry with it, more or less air into the oil reservoir 25. The oil is held and retained in said chamber for a sufficient time that any air carried will naturally tend to separate and move upwardly and thence escape from the upper part of the reservoir 25. It can escape past the key, providing the key is loosely enough tted within the slot in which it seats, or through the passage made purposely therefor, as at I2 in Fig. 3, or in a preferred form through a groove in the key like that at I3 in Fig. 4. The oil which is carried into the hydraulic compression chamber 26 is taken from the lowermost part of the oil reservoir 25, from which lowermost part all of the air will have separated and risen, so that only oil free from air passes into the hydraulic compression chamber 26. The tappet is maintained against rotation so that the opening 8 is always at the upper side of the body, and the entrance to the section I6 is at a lowermost portion of the oil reservoir 25. 0

The construction described is practical and is of a simple nature, one readily produced at a minimum cost. For internal combustion engines which have cylinders and tappets placed horizontally or which approach the horizontal in position, the structure is particularly effective.

The invention is defined in the appended claims and is to be considered comprehensive of all forms of structure coming within their scope.

I claim:

l. In combination, a guide having a substantially horizontal cylindrical guide opening therethrough, a cylindrical hollow tappet body closed at one end mounted for reciprocating movement in said guide opening, a member within the tappet body between its ends extending transversely thereof to provide an oil reservoir between said member and the closed end of the body, said tappet body having an oil entrance passage at its upper side leading to said reservoir, and said body at its upper side having a slot cut therethrough to said reservoir, a key seated in said slot, said guide having a key-way into which said key extends to hold the tappet body against rotation, and means for conducting oil out of said reservoir through said transverse member from the lower portion of the oil reservoir substantially diametrically opposite the key, whereby air in the oil separating therefrom and rising therethrough comes to said key and may escape around the key, as specified.

2. A construction containing the elements in combination dened in claim 1, said key in a side thereof having a groove which connects the reservoir with said key-way.

3. In combination, a guide having a substantially horizontal cylindrical guide opening therethrough, a cylindrical hollow body closed at one end mounted for reciprocating movement in said guide opening, a member within the tappet body between its ends extending transversely thereof to provide an oil reservoir between said member and the closed end of the body, a tubular section connected with said member and extending into the reservoir and having its free end terminating closely adjacent the lowermost portion of the reservoir whereby oil passing through said tubular section from the reservoir is taken from the lowermost portion of the reservoir, said body having an oil entrance opening to the reservoir at its upper side, and means for holding the tappet body against rotation about its horizontal axis, said means extending through the upper side of the tappet body to said reservoir, and around which air may pass outwardly from the reservoir after it has separated and risen from the oil in the reservoir.

CHARLES E. JOHNSON.

Images