US2891525A - Tappet barrel - Google Patents

Description

June 23, 1959 G. R. MOORE TAPPET BARREL 5 Sheets-Sheet 1 Filed Aug. 1, 1955 June 23, 1959 G; R. MOORE 2,891,525

' TAPPET BARREL.

Filed Aug. 1, 1955 s Sheets-Sheet 2 A ,mm

III a x uni F 3 ffirE'z-zfqr Cur RICHARD MoORE June 23, 1959 MOORE 2,891,525

- TAPPET BARREL Filed Aug. 1, 1955 3 Sheets-Sheet 3' GuY RIcHARD Moons TAPPET BARREL Guy Richard Moore, Shaker Heights, Ohio, assignor to Tll11(ipmpsou Ramo Wooldridge Inc., a corporation of Applica tion August 1, 1955, Serial No. 525,485 5 Claims. (Cl. 123-90 This invention relates to an improved tappet or tappet barrel .for use in valve train linkages and the like and the method of making a tappet or tappet barrel. More particularly, the invention deals with a tappet or tappet barrel that maybe economically manufactured and endowed with long wearing characteristics. The tappet or tappet barrel may be used with a hydraulic valve lifter or employed as a solid tappet.

: According to the invention, a tappet or tappet barrel is cold extruded from a slug of mild steel or other formable material. The tappet barrel generally includes a cylindricahbody having an integral cylindrical flange extending from one end of the body. The interior wall of the flange is substantially contiguous with the bore of the body, while the outside surface of the flange is tapered outwardly from a point above the closed end of the body to the free peripheral edge thereof. A disk of wear-resisting material, such as a hardenable alloy iron or steel is formed in a suitable manner, such as by machining same from a cylindrical bar. The disk is annularly grooved and formed to function as a tappet foot, and fastened to one end of the body member. The cylindrical flange on the body member is folded into the disk to lock the two elements into tight engagement with one another. The barrel body is then cut to a desired length. The outside diameter of the barrel body is ground to size and the foot is finished by a polishing, grinding or honing operation.

Where it is contemplated is using the tappet or tappet barrel with a hydraulic valve lifter, one end of the body memberis closed and the connecting flange depends therefrom. In assembling the wear-resisting disk to the flanged end of the tappet barrel, it is important that the disk intimately engages the closed end of the barrel so the load of the valve train may be directly transmitted against the closed end of the barrel. Otherwise, if the load were to be transmitted through the joint between the foot and the barrel, the tappet foot or disk would become loose in operation and the barrel would fail.

-In a solid tappet, the distribution of load may be accomplished in several ways. A shoulder on the tappet barrel may transfer the load from the tappet foot to the barrel and-then to the push rod seat, or the push rod load may be applied directly to the tappet foot. Also,

the push rod load may be applied directly to the tappet.

" Accordingly, it is an object of this invention to obviate the above difiiculties and provide an improved tappet 2,891,525 Patented June v23,

or tappet barrel that may be economically fabricated by mass production and endowed with long wearing characteristics.

Another object of this invention is to provide a method of fabricating a tappet or tappet barrel by cold extrusion.

A further object of this invention resides in the provision of a method of fabricating a tappet or tappet barrel from a formable material by a cold extrusion process and attaching a wear-resisting disk to the bottom of the tappet or tappet barrel for contacting a cam surface.

Still a further object of this invention is to provide a method of fabricating a tappet barrel for use with hydraulic valve lifters, wherein the tappet is cold extruded from mild steel, the barrel bore is chrome plate or otherwise coated with a wear-resistant material, and a hardenable or chilled cast iron disk or a heat treated steel disk is locked to the bottom of the tappet barrel to provide a long wearing cam contacting surface.

Another feature of the invention resides in the provision of a tappet barrel constructed of formable material with a wear-resistant coated barrel bore, and a tappet foot is locked in position on the bottom of the tappet barrel, wherein the tappet barrel assembly may be inexpensively manufactured, but endowed with long wearing characteristics.

Another object of this inventionis to provide a method of fabricating a tappet barrel, wherein the barrel bore need not be machined to provide proper tappet operation.

Still another object of this invention is to provide a tappet of low weight.

Other objects, features and advantages of the invention will be apparent from the following detailed description of the drawings, which illustrates the invention.

On the drawings:

Figure 1 is an axial sectional view of an extruded tappet barrel for use with hydraulic valve lifters constructed in accordance with the principles of the invention;

Figure 2 is an axial sectional view of a completed tappet barrel for use with hydraulic valve lifters illustrating a tappet foot in locked relationship with respect to the bottom of the tappet barrel;

Figure 3 is a vertical sectional view, with parts in elevation, of an assembly die used to assemble the tappet foot and the tappet barrel according to the invention;

- Figure 4 is an axial sectional view of a solid tappet having an extruded tappet barrel connected to a tappet foot, wherein a shoulder is provided adjacent the foot 7 for transferring the load from the foot to the push rod seat through the tappet barrel;

- Figure 5 is an axial sectional view of a solid tappet of a different form, wherein the push rod load is applied directly to the tappet foot;

Figure 6 is an axial sectional view of a solid tappet of still another form, wherein the push rod load is also applied directlyto the tappet foot; and

. Figure 7 is an axial sectional view of a solid tappet of still a diiferent form, wherein the push rod load is applied directly to the tappet foot through an inter- 3 although other uses and purposes may be apparent to one skilled in the art.

In fabricating the tappet or tappet barrel, a slug of mild steel or other suitable formable material is cold extruded to a desired size to form a rough extruded tappet or tappet barrel, asindicated .at 10 in Figure 1.. While the material used for extruding the barrels could" be any mild steel, it may, for example, be of SAE 1010 steel. In some cases, a light weight material may be preferred to steel. For purposes of setting forth the invention the tappet or tappet barrel will be described as being formed from steel.

During the extrusion process, the steel or formable material is coated with phosphate, soap, or any other suitable material for lubrication purposes. The cold extrusion process is unique in that no additional operations are required on the inside diameter or bore, such as honing or grinding to effect a properly formed bore.

As seen in Figure l, the rough extruded tappet barrel for use with hydraulic valve lifters includes a cylindrical body having an outside cylindrical surface 10a and an inside diameter or bore 10b. The barrel is open at the upper end which is irregular or uneven as indicated at 11, and closed at the lower end by a bottom member 12. Depending from the bottom 12 is an annular flange 13 for locking a disk-shaped tappet foot 14 thereto, as illustrated in Figure 2.

Referring again to Figure l the annular flange 13 is provided with an inside diameter and cylindrical surface 13a which is substantially in axial alignment with the barrel bore 11b. The inside surface 13a merges with a rounded portion 13b, functioning as a bead or lip. An outside wall 130 of the annular flange 13 flares outwardly from a point above the bottom 12 of the barrel to the free end of the flange thereby providing the flange with a thicker Wall than the barrel wall. A somewhat curvate portion 13:?! connects the rounded bead 13b with the flared wall 130 to form the bottom end of the annular flange. It is noted that where the inner surface or wall 13a of the flange meets the bottom wall 12a of the bottom 12, a fillet or rounded section is formed to intimately receive the peripherally rounded edge of the tappet foot 14.

While the tappet foot 14 may be secured to the bottom of the tappet barrel 10 in any suitable manner, such as by welding or crimping, in the instant embodiment, the annular flange 13 is deformed over the upper end of the tappet foot 14.

The tappet foot 14 is generally in the shape of a disk and may be formed by molding, machined from an iron bar, or otherwise suitably formed. The tappet foot is preferably constructed of a wear-resisting material, such as a hardenable alloy iron bar. Preferably, the properties of the alloy iron are as follows:

Total carbon 3.1-3.45 Combined carbon 85-1.25 Silicon 2.15-2.45 Manganese .60-.90 Sulphur .17 Max. Phosphorus .20 Max. Nickel .20.40 Max. Chromium .851.20 Molybdenum .40.60

As already set forth, the tappet foot 14 is generally disk-shaped, and is provided with an upper surface 14a adapted to be placed in intimate contact with the bottom surface 12a of the bottom wall 12 of the tappet barrel 10, and a bottom surface 14b for riding on a cam surface. In forming the tappet foot 14, an annular groove 140 is formed intermediate the top and bottom along the peripheral edge. The groove merges with a bead 14d along the top surface 14a, and with a cylindrical side wall Me, the latter terminating at the bottom surface 14b. The diameter of the cylindrical side wall 142 is slightly smaller than the outside diameter of the tappet barrel 10 to thereby preclude the possibility of the tappet foot from engaging the tappet guide wall.

In assembling the tappet foot 14 and the tappet barrel 10, the top surface 14a of the tappet foot 14 is brought into intimate contact with the bottom surface 12a of the tappet barrel bottom 12, as seen in Figure 1. As also noted the upper rounded edge 14d of the foot 14 inti- 4% mately engages the fillet provided between the inner wall 13a of the flange 13 and the bottom surface 12a of the bottom 12.

It is important that the top surface of the tappet foot 14 be in complete intimate contact with the bottom surface of the tappet barrel bottom 12 in the application of the valve train load to the tappet foot. The load must be imposed directly against the closed end of the barrel and not through the extruded joint where the foot is attached to the barrel. If the latter were to occur, the tappet foot would become loose in operation and the barrel would fail.

The foot and barrel are placed in an assembly die as seen in Figure 3 for deforming the locking flange 13 over the end of the tappet foot 14 to produce a completed assembly as seen in Figure 2.

After the tappet barrel has been formed, and before or after the tappet foot has been attached to the barrel, the barrel is cut to a desired length, such as cutting along the dotted line 11a in Figure 1. The outside diameter or surface 10a is subjected to a grinding operation to conform with specified tolerances.

Subsequent to the assembly of the foot and barrel the foot is finished by a polishing, grinding, or honing operation or a combination thereof to provide a precision surface for riding the actuating cam. This operation may, of course, be performed before attaching the foot to the barrel, but the former procedure is preferred.

After the barrel and foot have been assembled, and the barrel has been cut to length, when using with a hydraulic valve the barrel bore may be plated with a thin film of wear-resisting material, and as chromium to minimize internal wear.

The wear-resisting material may be deposited on the barrel bore by any suitable method, such as an electroplating process. Of course, the tappet barrel could be used without plating the bore and the barrel bores of the solid tappet in Figures 4-7 would obviously not be plated.

The cylindrical flange 13 on the bottom member 10 is folded into the grooved tappet foot 14 by any suitable assembly die, such as illustrated in Figure 3. The tappet barrels of the embodiments shown in Figures 4 and 5 may also be joined to their respective seat by this assembly die. However, the tappet barrels of the solid tappets in Figures 6 and 7 would not be attached to their respective tappet feet by an assembly die of this type.

Referring now generally to Figure 3, the assembly die includes a substantially square base 15. Rigidly secured to the base 15 is a die casing 16 by means of a plurality of bolts 17 that may be annularly arranged in a conventional manner adjacent the periphery of the casing. The casing 16 is recessed in the top to receive a die bushing holder 18, the latter of which is centrally recessed to receive a die bushing 19. A die clamp 20 overlies the die bushing 19 and bushing holder 18, and is rigidly secured to the die casing 16 by a plurality of annularly arranged lag bolts 21.

The die casing 16 is centrally bored at 16a to slidably receive a post 22. Abutting the bottom of the post 22 is a pressure pin 23, the position of which is controlled in any suitable manner such as by pneumatic or hydraulic means (not shown). The upper end of the post 22 is diametrically reduced and sized to be snugly received within the tappet barrel bore and abut against the inside surface of the barrel bottom. The die bushing holder 18, the die bushing 19 and the die clamp 20 are provided with aligned centrally disposed apertures 18a, 19a, and 20a, respectively. The aperture 19a of the die bushing 19 is accurately sized to snugly receive the outside diameter of the barrel.

A punch 24, sized to be tolerably received within the bore 1% of the die bushing 19, is provided to abut against the bottom surface of the tappet foot 14 and draw the tappet barrel downwardly through the die bushing to deform the locking flange 13 over the top end of the tappet foot 14. The punch 24 is clamped to a punch holder 25 bya clamp 26., The clamp 26 is guidably received on the punch holder 25 by. a series of doll pins 27 and rigidly secured thereto by a plurality of lag bolts 28. Wherein this assembly die maybe used to assemble the foot and barrel of the solid "tappet shown in'Figure 5, it is understood that'the end ofthe punch 24 may be recessed to accommodate the protrusion on the foot.

In operation of the assembly die, a pressure is exerted against the punch 24 to advance the tappet barrel and foot through the die bushing 19. A suitable pressure, less than the punch pressure, is, of course, exerted against the post 22 by the pin 23 to provide the proper alignment of the tappet barrel with respect to the die bushing 19.

Figures 4, 5, 6 and 7 illustrate forms of solid tappets which may be formed in accordance with the principles of the present invention, as indicated by the numerals 30, 31, 32 and 33. Each tappet generally includes a cylindrical body member or tappet barrel 34, 35, 36 and 37,

respectively, and a disk-shaped tappet foot 38, 39, 40 and 41, respectively.

The tappet barrel of the tappet 30 is provided with an inwardly extending radial flange 34a near the bottom thereof which rests on the upper surface of the tappet foot 38. The tappet foot 38 is provided with an annular groove 38a for receiving a connecting head or lip 34b of the tappet barrel 34 and locking the tappet foot 38 to the tappet barrel. An inverted dome-shaped member 42 having a downwardly extending skirt 42a defines the push rod seat of the tappet 30. The radial skirt 42a rests on an annular shoulder 340 formed on the internal bore of the tappet barrel body 34. Hence, it is seen that the load from the tappet foot 38 is transmitted to the push rod seat through the barrel 34.

Referring now to Figure 5, the barrel 35 of the tappet 31 is provided likewise with an inwardly extending radial flange 35a near the lower end of the barrel body in a similar manner as the tappet 30. This embodiment differs from that in Figure 4 in that the push rod seat is integrally formed with the tappet foot 39 as indicated at 39 to thereby transmit the push rod load directly to the tappet foot. The push rod seat 39a is formed by an upwardly protruding portion which extends beyond the radial flange 35a of the body 35. The tappet foot 39 and the tappet barrel 35 are similarly connected as the embodiment in Figure 4, wherein an annular groove 39b of the tappet foot receives an annular lip or head 350 of the tappet barrel 35.

The embodiment in Figure 6 illustrates another form of a solid tappet, wherein the tappet foot 40 is provided with a push rod seat recessed portion 40a to directly transmit the load from the push rod to the tappet foot. The tappet foot is also provided with an annular groove 40b around its periphery to receive a bead or lip 36a of the tappet barrel 36 for connecting the tappet foot and tappet barrel.

A still diflerent form of solid tappet is illustrated in Figure 7. In this embodiment, the tappet foot is provided with the usual annular groove 41a to receive a lip or bead 37a of the cylindrical body member of tappet barrel 37 for connecting these elements. It is noted that the upper surface of the tappet foot 41 is completely flat as indicated at 41b. A push rod seat is defined in an inverted dome-shaped member 43 having an elongated downwardly extending cylindrical skirt 43a. The bottom peripheral edge of the skirt 43a rests on the upper surface 41b of the tappet foot 41 to thereby directly transmit the push rod load from the push rod seat to the tappet foot.

It will be understood that the tappet barrels of tappets 30, 31, 32 and 33 are formed by extrusion in the same manner as already described in connection with the tappet barrel of Figures 1 and 2. Also, the tappet foots 38, 39,

6 40 and 41' willb'e formed in a like manner as described in connection with the tappet foot 14. The foregoing tappet barrel and method of making the same provides a long wearing assembly that may be economically'produced with a minmum of production time.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention, but it is understood that this application is to be limited only by the scope of the appended claims.

I claim as my invention:

1. A solid tappet comprising a tappet barrel of cylindrical shape and having a circumferential flange extending from one end thereof, a hardened tappet foot of diskshape having an annular groove for receiving the circumferential flange of the tappet barrel for locking the bottom surface of the barrel and the entire top surface of the tappet foot together in intimate contact, an annular shoulder provided on the internal wall of the tappet barrel above the bottom thereof engaging the upper face of the tappet foot, and a push rod seat member received in said tappet barrel in abutting relationship against the annular shoulder, whereby the tappet foot load is transmitted from the tappet foot to the push rod seat member through the tappet barrel.

2. A solid tappet comprising an open ended cylindrical tappet barrel having a locking member at one end thereof, and a tappet foot whose projection upon said tappet barrel lies entirely within the circumference of the latter and which has an annular groove in engagement with the locking member of the tappet barrel and an upwardly extending portion received within the tappet barrel, said portion having a recessed portion defining a push rod seat, whereby the tappet foot load is transmitted directly to the push rod seat.

3. A solid tappet comprising an open ended cylin' drical tappet barrel having a locking member at one end thereof, a tappet foot of disk-shape whose projection upon said tappet barrel lies entirely the circumference of the latter and which has an annular groove in locking engagement With the locking member of the tappet barrel and provided with an upper flat surface, and an inverted dome-shaped member defining a push rod seat and having an elongated downwardly extending skirt portion received Within the bore of the tappet barrel and supported on the upper flat surface of the tappet foot, whereby the push rod seat load is transmitted directly to the tappet foot through the domeshaped member.

4. A tappet barrel for use with hydraulic valve litters comprising a cylindrical body of extruded material, said body being closed at one end and open at the other end, a locking flange extending from the closed end of said body, and a wear-resisting disk-shaped tappet foot whose projection upon said tappet barrel lies entirely within the circumference of the latter and which has a peripheral groove engaged by said locking flange to secure the tappet foot to said body, the upper surface of said tappet foot being in complete intimate engagement with the closed end of the cylindrical body to thereby assure that the tappet foot load is exerted directly against the closed end of the barrel.

5. The combination of a tappet barrel extruded from a slug of formable material and having a deformable annular circumferential flange extending from one end thereof, a locking lip on said flange, a Wear-resisting disc having an annular peripheral groove on the edge thereof, said tappet barrel comprising a cylindrical body having a outer diameter greater than the maximum outer diameter of said disc, said disc being secured to said tappet barrel by engagement of said locking lip on said deformed flange in said annular peripheral groove of said disc.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Church Dec. 8, 1925 McDonald Nov. 13, 1928 McDonald Nov. 13, 1928 Boland Apr. 28, 1931 Almen Sept. 15, 1931 8 Wetherald Mar. 1, 1932 Hothersall Mar. 10, 1942 Rockwell Oct. 19, 1954 Russell June 12, 1956 FOREIGN PATENTS Germany Apr. 30, 1953

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