US3089472A

US3089472A - Tappet

Info

Publication number: US3089472A
Application number: US143918A
Authority: US
Inventors: Thompson Marion Lee
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-10-09
Filing date: 1961-10-09
Publication date: 1963-05-14
Anticipated expiration: 1980-05-14

Description

y 14, 1953 M. L. THOMPSON 3,089,472

I TAPPET Fild Oct. 9, 1961 INVENTOR Mme/01v LEE 7 /044, 50

ii 1 42% d/m/ 3,889,472 TAPPET Marion Lea Thompson, 2734 Eastvale, Rolling Hills, Calif. Fiicd Get. 9, 1961, Ser. No. 143,918 9 Claims. (Cl. 123-98) This invention relates to tappets or valve lifters for internal combustion engines, and more particularly to tappets which may be rapidly yet firmly installed in an engine or motor housing and easily removed therefrom, and it also relates to the employment of a novel tool to rapidly and accurately align the tappets with respect to an engine cam shaft and other tappets to achieve proper timing, so as to accomplish efficient engine operation.

A major object of this invention is to provide a tappet employed as a valve lifter for internal combustion engines which may be rapidly and firmly installed into an engine housing and which may be readily removed from the installation.

Another object of this invention is to provide a tappet of the character described wherein the tappet, with the assistance of a tool, may be accurately aligned with respect to an engine cam shaft and other tappets to achieve an accurate timing to effect efficient engine operation.

A more specific object of this invention is to provide a tappet of the character described which includes a body having a taper therein, the taper being encircled by a compressible ring that may be inserted into a bore adapted to receive said tappet, whereby the taper and ring serve to achieve a positive and firm installation of said tappet in the engine housing, but which further serve to provide ready removal of the tappet from its installed position.

Another more specific object of this invention is to provide a tappet of the character described wherein the body of the tappet includes opposed flats adapted to receive a tool to align the tappet with respect to the engine cam shaft and other tappets so as to achieve the lifting of valves at the proper time and in the proper sequence.

Further objects and advantages of this invention will appear in the following specification, wherein the details of construction and mode of operation of a preferred embodiment of the device of the present invention are described with reference to the accompanying drawings, in which:

FIG. 1 is a vertical cross-sectional view illustrating a pair of tappets installed in an engine housing and associated with an engine cam shaft;

FIG. 2 is a cross-sectional view taken on line 22 of FIG. 1, and showing an aligning tool installed on a pair of tappets for aligning the same with the engine cam shaft and each other;

FIG. 3 is a plan view taken on line 3-3 of FIG. 2; and

FIG. 4 is an exploded, fragmentary perspective view illustrating the taper in the body of a tappet and the split ring associated therewith, together with a flat on the body adapted to receive an aligning tool.

Referring to the drawings, and initially, particularly to FIG. 1, engine housing 10, having a plurality of fluid passages and ports 12 and 14 therein, also has a plurality of bores 16 adapted to receive tappets 18. Extending through engine housing is a cam shaft 20 on which are a plurality of cams 22 each of which engage an associated tappet 18 to actuate the same to lift a valve stem 24 of a valve.

The tappets 18 each include a hollow, generally cylindrical body 26 which encircles an elongated cylindrical and reciprocal plunger 28, one end of which is bi- 3,089,472 Patented May 14, 1963 furcated and supports a rotatable roller cam follower 30 engageable by a cam 22. The cylindrical body 26 includes a skirt portion 32 which has a pair of opposed slots 33 therein that receive the cam follower 30 as the actuating cam 22 on cam shaft 20 forces the rise of the roller 30 from the position illustrated on the left in FIGURE 2 to the position illustrated on the right in said FIGURE 2. Spaced from the skirt portion 32 and integral with the cylindrical body 26 is an annular collar 34. The uppermost end 36 of body 26 is externally threaded to receive an internally-threaded nut 38, and between end 36 and collar 34, the body 26 has a tapered surface portion 40. The narrowest portion of taper 40 occurs adjacent threaded end 36, and taper 40 flares outwardly toward collar 34, as may best be seen in FIG. 4.

A split cylindrical sleeve 58 :having an annular flanged end 52 is mounted on taper 4t Said sleeve 50 has a substantially uniform internal diameter and a substantially uniform external diameter.

Initially, each tappet 18 is gently inserted into a bore 16. To achieve an alignment of the tappets, the threaded portion 36 of each tappet has a pair of parallel opposed flats 42 thereon that are in linear alignment with slots 3.3. Flats 42 mate with corresponding flat portions 44 formed in generally oval-shaped openings 46 of an alignment tool 48. When alignment tool 48 is mounted on tappets 18 in the manner illustrated in FIG- URES 2 and 3, the flats 44 of tool 48 are generally in abutting relationship with flats 42, and such relationship assures substantially exact alignment of a pair of adjoining tappets with respect to each other.

Alignment tool 48 may incorporate two or more openings 46 therein and preferably two. While mounting of alignment tool 48 on a pair of adjoining tappets 18, camshaft 24 is manually rotated to achieve proper insertion of the tappet 18 in bore 16, which is accomplished by the lifting of roller 30 by cam 22. It is to be understood that in lieu of a separate alignment tool 48, a permanent holding fixture having openings 46 therein may comprise a permanent installation on the engine housing 10.

When a pair of tappets 18 are substantially exactly aligned with respect to each other and cam 22, nut 38 is tightened against flange 52 of sleeve 50. As the sleeve 50 is thus forced downwardly on taper 40 into bore =16 by nut 38, taper 40 will expand sleeve 50, such expansion being resisted by the wall of bore 16. In this manner tappet 18 is firmly secured in bore 16. Flange 52 provides a stop that limits the insertion of sleeve 50 into bore 16.

To remove tappet 18 from the bore 16, it is merely necessary to back off on nut 38 and lightly tap tappet 18, thus breaking the seating seal of sleeve 50 in bore 16.

Removably supported on the upper end of the cylindrical plunger 28 is a circular pad 54 which includes a projection 56, in turn received in the uppermost end of plunger 28. Pad 54 has a depression therein adapted to receive valve stem 24. Seated against pad 54 for the purpose of forcing cam follower 30 to follow cam 22 is a compression spring 58.

While the inst-ant invention has been shown and described herein, in what is conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of the invention which is therefore not to be limited to the details disclosed herein, but is to be accorded the full scope of the claims.

I claim:

1. A tappet for internal combustion engines comprising: a hollow cylindrical body receivable in a bore to receive a reciprocal cylindrical plunger having a roller cam follower thereon engageable with a cam on a rotatable camshaft, said body having an external tapered portion thereon; a first means encircling a portion of said tapered portion for releasably securing said tappet in the bore; and a second means on said tappet receivable by alignment means for aligning said tappet in said bore with respect to adjoining tappets and with respect to the cam on the camshaft.

2. A tappet according to claim 1, wherein said first means includes a split cylindrical sleeve having a uniform internal and a uniform external diameter.

3. A tappet according to claim 2, wherein said split cylindrical sleeve includes an annular flange disposed so as to limit the urging of said sleeve into said bore.

4. A tappet according to claim 1, wherein said first means includes a compressible and expandable sleeve.

5. A tappet according to claim 1, wherein said second means includes flats.

6. A tappet according to claim 1, wherein said second means includes a pair of opposed parallel flats receivable by alignment means having corresponding fiats.

7. A tappet for internal combustion engines comprising: a hollow, cylindrical body receivable in a bore to receive a reciprocal cylindrical plunger having a roller cam follower thereon engageable with a cam on a rotatable camshaft, said body having an external tapered portion thereon, and having a pair of opposed slots therein to receive the roller cam follower when the plunger is lifted by the action of the cam; a split, cylindrical sleeve encircling a portion of said tapered portion, said sleeve having a substantially uniform internal and a substantially uniform external diameter; a first means on said body for urging said sleeve into said bore to achieve expansion of said sleeve by said tapered portion, said expansion being resisted by the wall of said bore to secure said tappet in said bore; and a second means on said body in linear alignment with said slots to receive an aligning tool for aligning said tappet in said bore with respect to adjoining tappets and with respect to the cam on the camshaft.

8. A tappet according to claim 7, wherein said second means includes a pair of opposed parallel flats.

9. A tappet for internal combustion engines comprising: a hollow, cylindrical body receivable in a bore to receive a reciprocal cylindrical plunger having a roller cam follower thereon engageable with a cam on a rotatable cam shaft, said body having an externally tapered portion thereon, and having a pair of opposed slots therein to receive the roller cam follower when the plunger is lifted by the action of the cam; a split, cylindrical sleeve encircling a portion of said tapered portion, said sleeve having a substantially uniform internal and a substantially uniform external diameter; a first means on said body for urging said sleeve into said bore to achieve expansion of said sleeve by said tapered portion, said expansion being resisted by the wall of said bore to secure said tappet in said bore; and a pair of opposed parallel flats on said body to align in parallel and generally abutting relationship with a mating pair of opposed parallel flats in an opening in an aligning tool.

References Cited in the file of this patent UNITED STATES PATENTS

Claims

7. A TAPPET FOR INTERNAL COMBUSTION ENGINES COMPRISINT: A HOLLOW, CYLINDRICAL BODY RECEIVABLE IN A BORE TO RECEIVE A RECIPROCAL CYLINDRICAL PLUNGER HAVING A ROLLER CAM FOLLOWER THEREON ENGAGEABLE WITH A CAM ON A ROTATABLE CAMSHAFT, SAID BODY HAVING AN EXTERNAL TAPERED PORTION THEREON, AND HAVING A PAIR OF OPPOSED SHOTS THEREIN TO RECEIVE THE ROLLER CAM FOLLOWER WHEN THE PLUNGER IS LIFTED BY THE ACTION OF THE CAM; A SPLIT, CYLINDRICAL SLEEVE ENCIRCLING A PORTION OF SAID TAPERED PORTION, SAID SLEEVE HAVING A SUBSTANTIALLY UNIFORM INTERNAL AND A SUBSTANTIALLY UNIFORM EXTERNAL DIAMETER; A FIRST MEANS ON SAID BODY FOR URGING SAID SLEEVE INTO SAID BORE TO ACHIEVE EXPANSION OF SAID SLEEVE BY SAID TAPERED POR TION, SAID EXPANSION BEING RESISTED BY THE WALL OF SAID BORE TO SECURE SAID TAPPET IN SAID; BORE; AND A SECOND MEANS ON SAID BODY IN LINEAR ALIGNMENT WITH SAID SLOTS TO RECEIVE AN ALIGNING TOOL FOR ALIGNING SAID TAPPET IN SAID BORE WITH RESPECT TO ADJOINING TAPPETS AND WITH RESPECT TO THE CAM ON THE CAMSHAFT.