US2667688A - Method of constructing rocker arms - Google Patents

Description

Feb- 2, 1954 J. R. WINTER, JR

METHOD OF CONSTRUCTING ROCKER ARMS 2 Sheets-Sheet 1 Filed Aug. 11. 1950 INVENTOR. Jab? if 14 272 67, J7:

Feb. 2,1954 R w JR 2,667,688

METHOD OF CONSTRUCTING ROCKER ARMS Filed Aug. 11, 1950 2 Sheets-Sheet 2 A INVENTOR. I 7 0 51 FK 2 173525 7. B

Patented Feb. 2, 1954 John R. Winter, 'Jr.,.:Detroit,

JohnR. Winter, Sr.

Mich.,.zassignor to ,;Detroit,tMich.

Application August 11, 1950; Serial No; 178330 (Cl.';'i29148) 3xGlaims. 1

This invention relates to thea'rt of constructing rocker-arms for internal combustion engines, and constitutes a continuation-impart of myapplication Serial No. 545,597'filed July 19, 1944, now Patent No. 2,578,638.

The ordinary rocker arm used'in an internal combustion engine has -bearing meansat pposite ends and has an opening intermediate itsfends for mounting it on the enginehlock ioroscillatory movement. One endof the arm is moved by cam actuated means engagingthe bea1'in mean-s at that end, while the hearing meansat the other-end is engageable with the valve stem. Usually the latter bearing means is "adjustable. While such rocker arms have beenmade by forgingiandt other processes, the present invention is particularly concerned with the provision of improvedmeans and an improved method 'forfabricating arocker arm from stamped sheet metal, andzwhile it isfnot generally new to provide such a rocker :arm,"the present invention is concerned with-improvements in the method and means by which'itiis manufactured.

Another object of the invention is'=torprovide an improved method for "manufacturingtsuch a sheet metal rocker arm having :a plurality of laminations and a tubular hub 'member; my improved method providing lessexpensive et more effective, means for lockingthe tubular-hub element to the arm laminations'and for sealing such hub member and 'laminati'onsxwith respect to one another, so that unwanted leakage :or escape of oil at the 'joints between'the hub-and the laminations, or frombetween thealaminati'ons themselves, is prevented, yet :wherein no brazed or welded sealing means is required to elTect such firm locking and' sealing against escape of oil.

.Other objects of the invention will :become apparent from the followingidescription, .from the drawing to which it relates and-from the claimshereinafter set forth.

For a better understanding of the invention, reference may be'had to the accompanying drawings wherein:

Figure 1 is aside elevational view; of a rocker arm adapted to be constructed inaccordance with my improved method;

Fig. 2 is a plan view of the rocker a-rmshown in Fig. 1;

Fig. 3 is a cross-sectional view taken substantially on the line 3-3. of Fig. 1;

Fig. 4 is a cross sectional'view takensubstantially on the line i-40f Fig. 3;

Fig.5 is :a cross-sectional view-takensubstan- .tiallyonithe 1ine5-'25 .0:F.ig;:1;

*Figffi is a "'cross' 'secticnal view taken substantially on" the .line' 6 6 of Fig. 1;

:Figf'? 'is'a cross-sectional view of apparatus employed. in formingafirst head on the tubular hubei'em'ent "adapted to extend through the stamping and 'Fig. 8fisa similar" view illustrating the manner inwhichthe tubular element is assembled with the stamping and the second head is formed.

Referring tdFigs. 1, 2'and 3, which illustrate a rocker'arm adaptedto be constructed in accordancewith*myimprovedmethod, the body of the arm comprises a stamping I 0 having laminations-H and I2 integrally connected'at'one end by""'a substantially cylindrical portion i3, and initiallyfthe' laminations H and 12 are stamped fromsheet metal to'the desired shape and then are tent-intermediate their ends to form the cylindrical portion. 'Atthe opposite endof the stampingthe 'laminations H and I2 have outwardly pressed portions I4 and l5,-respectively, so as to'form an openinglt-between them. After the metal is bent into the shape shown, the laminations'may be welded at suitable-points as indicatedatl1, |8, l-9'and 20. p

At that'end of the arm having. the cylindrical portion"l,3,- a bearing'element 22 is mounted on the armbymeans of a shank 23 having a pressed fit in fth'e 'opening in "the cylindrical portion. The-opening It at the other end of th arm has a threaded bearing element 25 threaded therethrough. --A=lock-nut26 adjustably holds the last bearing element in adjusted position.

"Intermediate*itsends, the laminations H and 12 have aligned openings 23 and 29 and these may beformedin-the'metal prior to bending it into laminated form. A tubulareIement- Bt extendsthrough theopenings 28 and 29 and is rigidly and positively-connected to the laminations -bymeans of outwardly hulbed heads 3i and 32 located at the outer sidesof the terminations. These heads; as'will beseen'presently, are formed by axially compressing' the tubular element 3:! and causing 'the heads 3l 'and "32 to draw up tightly againstithe 'laminations and thus when the heads arefinally' formed, the laminations are strongly land-tightly drawn together and at the same time the tubular'elementis strongly and positively connected to "the laminations.

"WithinItheItubular element-'30, a bearing sleeve 345is=provided andthisxmay be madefrom suitablexbearingz'materialsuchas bronze, and preferably. is ssplit :longitudinally atone point. The

arm ;lfl..-:properzis constructed .fromrsheet steel .andathe tubularelement fittmayfbe :cutzfrom. sheet ".steehztubingrlormed in any-suitable manner.

In an arm of this type, lubricant is supplied through a hollow shaft, not shown, which extends through the bearing sleeve 3%. This hollow shaft has'one or more radial openings through which the lubricant may flow and these openings are adapted to register during oscillatory movement of the rocker arm with radial openings 36 and 31 formed in both the sleeve 3 and tubular element 30. The openings as and 31 are located in alignment with the inner contacting faces of the laminations ii and i2 and at this point, the respective laminations along the edges of the openings 28 and 29 are beveled as indicated at 39 and 30 for a part of the way around the opening so as to provide a lubricant space 4| between the beveled faces. This circumferentially extending lubricant space extends slightly beyond the openings 35 and 31 and through either opening will flow circumferentially through the space. Substantially midway between the openings 3% and 31, a vertically extending opening dd is provided between the laminations and this opening communicates with the space ii. Therefore, lubricant will flow to the upper edge of the rocker arm. 1

Immediately adjacent the opening M, the laminations ii and i2 may be provided with bevels 35 and M5 and such bevels may be provided at both sides of the opening. These bevels are useful in limiting the amount of lubricant that will flow toward the ends of the rocker arm and at the same time they cause lubricant to flow transversely over the annular heads 3! and 32 on the tubular element as and then to the ends of the latter and onto the rocker arm shaft.

Attention is directed to several structural characteristics, as may be seen in Fig. 3, particularly. It will be observed that the heads hence lubricant flowing 3| and 32 have substantially full surface engagement with the laminations II and I2 and therefore the inner face of each of the heads SI and 32 is brought substantially into a radial position. It will also be observed that each head actually embeds itself slightly, as indicated at 48, in the lamination the opening. t will also be noted that the outer peripheral surface of each of the annular heads 3| and 32 is substantially axial as indicated at 49, and that the axially outer face of each head is slightly inclined to the radial as indicated at 553. Also, it will be observed in connection with Figs. 3 and 4. that the element 30 is pressed slightly outwardly into the lubricant space M as indicated at 52, thereby forming a circumferential key or look between the tubular element and stamping.

Now referring to Fig. 7, the tubular element 30 is first placed on an arbor 6t and then is subjected to axially compressive forces by means of tubular dies El and 52 slidable on the arbor. The die M has an annular recess formed.- by a radial shoulder B l and a peripheral wall 65 for confining a predetermined end portion of the tubular element 36 and similarly the die 62 has an annular space formed by a radial shoulder 66 and a peripheral wall 61 for confining a major portion of the remainder of the tubular element. At the inner ends of the peripheral surfaces 65 and 61, the die element 6! has an outwardly directed and slightly tapered face 68, the radial dimension of which will correspond to the height of the head to be formed during axial compression of the tubular element. At the inner end of the peripheral surface 6! on the die element 62, a similar end surface 69 is provided, but this around the inner edge of I stantially axial.

" the bulbing head, it presses and on its outer side it is surface is radial in direction. The die 62 has an outer portion 10 projecting axially beyond the end surface 69 and this portion telescopes over a portion H on the die 6|. The two die elements are limited in their movements toward each other by contact as indicated at 12.

The tubular element 30 initially is placed on the arbor 60 and then the two die elements are moved thereover and as the shoulders 64 and 66 press the ends of the portion of the element between the approaching surfaces 68 and 69 bulbs outwardly. The arbor confines the inner periphery of the element in a precise manner so that the inner diameter Of the element is maintained uniform and of the desired dimensions. As the dies continue moving toward each other, the annular head 3! is prevented from expanding outwardly beyond a certain amount by the inner surface of the portion 10 on die element 62 and hence as the surfaces 68 and 69 move toward their final positions, the metal in the head is fined more and more. Finally, the head is formed with the radial surface on one side and the slightly inclined surface at its other, with the outer peripheral surface of the head sub- The tapered surface 68 is parthat as it moves against the radially outer part of the head strongly against the radially outer part of the face 69 so as thereby to insure a full radial surface on the head. Hence the head has a fully radial surface on its inner side reinforced by a tapered ticularly desirable, in

formation.

After the single head is thus formed on the element 30, the dies are removed and the element is inserted through the openings 28 and 29 formed in the laminations BI and 12. The same arbor 60 may be used but in the final assembly operation, additional dies 15 and 16 are employed. The die l5 has an inner recess fitting the already formed head 3| on the tubular element and an end surface H which is adapted to engage the lamination H. The die 16 is formed in the same manner as the die 15 but since the second head 32 is not as yet formed, the die element is as yet substantially spaced from the lamination [2. As the die elements 15 and 16 are moved toward each other, outward bulbing of the head 32 occurs and it is finally shaped in the same manner as the head 3| when the ends of both dies directly contact the arm. During thisaxial compression of the element, the outwardly directed rib or key 52 is pressed outwardly into the lubricant space and at the same time slight embedding of the heads 3! and 32 in the laminations occurs as indicated previously at E8.

While according to the foregoing description, the two heads 3! and 32 are formed in sequential operations, they could also be formed simultaneously. This could be effected by placing the tubular element on the arbor 60, then insert ing the arbor and element through the openings in the laminated arm, and then moving the die elements 15 and 15 simultaneously to form the heads.

It should be understood that substantially full radial surface contact is obtained between the heads 3! and 32 and the respective laminations, and therefore the tubular element is strongly connected theretoby large surface engagement. Furthermore, during this compressing action, the tubular element is expanded within the tubular element, that thereby con-.

openings 28 and 29, and hence is tightly connected thereto by a strong, forceful contact resulting from expansion of the metal forcefully in a hole filling manner. The dies now may be removed along with the arbor.

It is desired to point out several advantages of the invention. In the first place, by manufacturing the rocker arm from a stamping and a separate metal tube, drawing of the sheet metal is avoided and therefore the stamping can be made from a higher carbon steel. Furthermore, no rehardening is necessary, such as would be required if the stamped stock had been drawn. Again, by using the pin 22, and press fitting it into place, welding thereof is eliminated and the pin therefore may initially be heat-treated to obtain the desired hardness. It is of course evident that the pin may be driven out and replaced so as to permit replacement of worn pins.

Furthermore, since no drawing operation is involved, the stamped metal may have a single gage or thickness and no trimming or reshaping is required. By using simple spot welding at the points indicated, the laminations may be connected by welding in a simple and inexpensive manner although it should be understood that the mechanical lock between the tubular element and the laminations is extremely strong and positive. It follows that the weld and mechanical lock provide great strength in the assembly.

With respect to the tubular element, this can be made easily out of tubing and hence it is accurate and no machining is required. Furthermore, it can easily be varied in length so as to provide the desired hub length on the rocker arm. Regardless of length, the tubular element is anchored in proper relation to the arm and in particular the direct contact between the inner ends of the dies and the opposite sides of the arm insures that the axis of the tubular element will be accurately aligned with the axis of the opening in the arm. In other words, the arbor and dies maintain the cylindrical shape and dimensions of the tubular element with accuracy and the final contact between the dies and arm insures alignment of the element and opening in the arm. Hence, the axis of oscillation of the arm can be located uniformly.

Although I have illustrated and described herein a preferred form of my invention, it will be apparent that the invention is susceptible to variation, modification and change without departing from the spirit and scope of the appended claims.

What is claimed is:

1. The method of manufacturing a rocker arm assembly which comprises forming an arm from laminations of sheet metal having aligned circular openings and having an inwardly directed enlarged portion constituting a generally radial enlargement of said openings, rigidly anchoring a metallic tubular element of circular cross section in said openings by peripherally fitting said element in the openings with said element bridging said enlargement, axially compressing the element while simultaneously rigidly and positively confining the tubular element against both inward and outward deformation by means of rigid metallic dies engaging the interior of said element and also engaging the exterior of said element on either side of said laminations, and continuing the axial compression so as to cause a part of said element to deform outwardly into said enlargement.

2. The method of manufacturing a rocker arm assembly which comprises forming an arm from laminations of sheet metal having aligned circular openings and having an inwardly directed enlarged portion constituting a generally radial enlargement of said openings, rigidly anchoring a metallic tubular element of circular cross section in said openings by peripherally fitting said element in the openings with said element bridging said enlargement, axially compressing the element to provide annular, bulbed heads on the element engaging opposite sides of the arm, rigidly and positively confining the outward bulbing expansion of the head metal while simultaneously rigidly and positively confining the tubular element against both inward and outward deformation, all of said confinement being effected by means of rigid metallic dies engaging the interior of said element and also engaging the exterior of said element on either side of said laminations, and continuing the axial compression so as to cause a part of said element to deform outwardly into said enlargement and so as to increase the extent of radial contact between the heads and the arm and to embed the heads at least slightly in the sides of the arm.

3. The method of manufacturing a rocker arm assembly which comprises forming an arm from laminations of sheet metal having aligned openings therein and oil passageways therebetween communicating with said openings, rigidly anchoring a metallic tubular element in said openings by tightly peripherally fitting said element in the openings and then axially compressing the tubular element to provide annular, bulbed heads on the element engaging opposite sides of the arm, and rigidly and positively confining the outward bulbing expansion of the head metal and preventing radial expansion and elongation of the remainder of said tubular element while simultaneously rigidly and positively confining the metal of said tubular element by means of a metallic inner die which directly engages the interior of said tubular element to prevent inward deformation thereof, and continuing the axial compression of the element so as to increase the extent of radial contact between the heads and the arm and to embed the heads at least slightly in the sides of the arm thereby driving the laminations together to form an oil tight seal therebetween and between the heads and sides of the arm.

JOHN R. WINTER, JR.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,278,195 Noack Sept. 10, 1913 1,447,520 Schade Mar. 6, 1923 1,793,874 Skillman Feb. 24, 1931 1,909,430 Skillman May 16, 1933 1,943,631 Skillman Jan. 16, 193% 2,176,083 Leake Oct. 17, 1939 2,299,542 Hedfield Oct. 20, 1942 2,433,631 Sherman Dec. 30, 1947

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