US2052306A

US2052306A - Apparatus and method for making valve spring retainer locks

Info

Publication number: US2052306A
Application number: US739557A
Authority: US
Inventors: Kelleher Daniel
Original assignee: Thompson Products Inc
Current assignee: Northrop Grumman Space and Mission Systems Corp
Priority date: 1934-08-13
Filing date: 1934-08-13
Publication date: 1936-08-25
Anticipated expiration: 1953-08-25

Description

Aug. 25, 1936. D. KELLEHER APPARATUS AND METHOD FOR MAKING VALVE SPRING RETAINER LOCKS Filed Aug. 13, 1934 2 Sheets-Sheet 1 Aug. 25, 1936. KELLEHER 2,052,306

APPARATUS AND METHOD FOR MAKING VALVE SPRING RETAINER LOCKS Filed Aug. 13, 1934 2 Sheets-Sheet 2 Patented Aug. 25, 1936.

PATENT OFFICE APPARATUS AND METHOD FOR MAKING VALVE SPRING RETAINER LOCKS Daniel Kelleher, Cleveland, Ohio, assignor to Thompson Products Incorporated, Cleveland. Ohio, a corporation; of Ohio Application August 13, 1934, Serial No. 739,557

14 Claims.

as This invention relates to an apparatus for and a method of forming valve spring retainer locks or valve stem collars as used on poppet valves in internal combustion engines.

More specifically this invention relates to an improved method of forming valve spring retainer locks by'rolling a strip of fiat metal to form a continuous strip of formed lock blanks, and cutting and shaping said blanks to produce 1 substantially semi-cylindrical collars having internal beads formed thereon for fitting into corresponding grooves in the valve stem and having tapered outside surfaces for receiving a valve spring retainer therearound.

It has heretofore been proposed to form a strip of metal with beads running lengthwise, cutting said strip into pieces of the desired length and pressing said pieces into semi-cylindrical form to produce the retainer lock. I have now found that a strip of metal may be conveniently rolled into a continuous strip of lock blanks with the l beads extending transversely across said strip so ithat the cutting and pressing operation may be conveniently performed to produce the finished lock in a continuous operation.

According to my process, therefore, a flat strip of metal is shaped by a squeezing or rolling operation to produce a continuous strip of lock blanks having transverse beads extending across one side and having a tapered surface on the other side for receiving the valve spring retainer.

It is therefore an object of this invention to provide a continuous process for making valve spring retainer locks at low cost.

Another object of this invention is to provide a process for making valve spring retainer locks including the step of rolling a fiat piece of metal into a continuous strip of lock blanks.

Another object of this invention is to provide a process of rolling a fiat piece of metal to form a continuous strip of lock blanks having beaded internal surfaces and tapered outside surfaces.

A further object of this invention is to provide apparatus for forming valve spring retainer locks by successive rolling, trimming and pressing operations.

A further object of this invention is to provide a pair of shaping rollers to produce a continuous strip of lock blanks.

Other and further objects of this invention will be apparent from the disclosures in this specification and the accompanying drawings which form a part of this specification.

This invention, in a preferred form, is illus- I trated in the accompanying drawings and hereinafter more fully described.

on the drawings:

Figure 1 is a fragmentary diagrammatic view, with parts in vertical cross-section, illustrating 6 the rolling operation for forming a continuous strip of lock blanks, and the subsequent trimming and, pressing operations to produce the finished retainer look. I

Figure 2 is a vertical cross sectional view taken 10 substantially along the line 11-11 of Figure 1.

Figure 3 is a cross sectional view taken substantially along the line IIIIII of Figure 2.

Figure 4 is a vertical cross section illustrating the manner in which a flat piece of metal is 15 formed into a continuous strip of lock blanks which are subsequently trimmed, cut and die pressed to produce the finished lock.

Figure 5 is a bottom plan view' of the strip of formed blanks and finished retainer lock. shown 20 in Figure 4.

Figure 6 is a side elevational view with parts broken away and shown in cross-section of a machine for forming the retainer locks showing the drive connection between the shaping rolls 5 and die press.

Figure 7 is a front elevational view of the machine shown in Figure 6.

Figure 8 is an enlarged cross sectional view, with parts in elevation, of the roller clutch used to 30 effect intermittent operation of the shaping rolls.

As shown on the drawings:

In Figures 1, 4, and 5, the reference numeral It indicates a fiat piece of metal such as steel which is used to form the retainer locks. This metal is 35 passed through the nip between a pair of shaping rollers II and H to form a continuous strip of lock blanks I 3.

The upper roll I I has a peripheral shaping surface composed of a plurality of transverse extend- 40 ing rounded teeth It. The teeth H are spaced circumferentially on the roller at a distance equivalent to the length of a retainer lock for defining tapered surfaces l5 which taper the outside surfaces IB of the lock blanks.

The lower roller I2 is formed with a peripheral surface having semi-cylindrical depressions I! for forming the beads 18 of the lock blanks.

The rollers II and H are kept in superimposed spaced relation for receiving the metal stock I0 50 therebetween. The rollers are driven by means (not shown) to grip the stock as it passes through the nip between the rolls to form the beads I8 in the grooves H of the lower roll l2, and to taper the upper surface with a uniform taper l6. The

teeth l4 of the upper roller N form beveled edges IS on the top surface of the stock which constitute the bottom of the retainer lock.

The metal is moved transversely of the rolls during the rolling operation to form curved edges 20 (Figure 5) since the forming of the taper by the upper roller decreases the thickness of the metal at the top portion of the lock blank.

It is evident from the above description that a single pass of the metal stock between the rolls H and [2 forms a continuous strip of lock blanks having tapered upper surfaces l6 and transverse extending beads l8 formed on the other surface. In addition the blanks are provided with a beveled end I9 constituting the bottom edge of the finished lock.

The continuous strip of lock blanks l3 may be fed directly from the rollers H and I2 into a die pressing and cutting apparatus shown in Figures 1 to 3 or the continuous strip of blanks l3 may be cut and die pressed to form the finished locks in a separate, unrelated operation. For purposes of convenience, however, as shown in Figure 1, the strip of lock blanks is fed directly into a combined trimming, cutting and die pressing apparatus.

As shown in Figure 1, the strip of lock blanks I3 is passed over a cutting block 2|. A cutting die 22 having two cutting edges adapted to slide alongside of both edges of the cutting block 2| is moved downward to trim the edges 20 of the strip of lock blanks. As shown in Figure 5, the edges 20 are trimmed off to form flat sides 23 which constitute the edges of the flat lock blank.

The trimmed lock blank is then moved forward in spaced relation above the male member 24 of a pressing die. The female member 25 of the pressing die is then moved downward to contact the trimmed lock blank I3 and in its downward movement the die member 25 slides along the cutting block 2| and cuts the blank |3 from the continuous strip of blanks. The segregated blank is then pressed over the male member 24 and shaped into the semi-cylindrical contour of the finished lock. The die member 24 is provided with grooves 26 for receiving the beads ll! of the lock blank.

As shown in Figure 3, the die member 25 is tapered as at 21 for engaging the tapered surfaces l6 of the lock blank.

The finished retainer lock 28 has a substantially semi-cylindrical inside surface 29 for fitting around the valve stem and a tapered outside surface 30 for receiving the valve spring retainer therearound. As pointed out above, the beads 8 fit into corresponding grooves in the valve stem.

It is obvious, of course, that two valve spring retainer locks are positioned in spaced opposed relation on the stem of the poppet valve. The valve spring retainer is then dropped around the locks to force the same into tight engagement with the grooves of the valve stem. Since the bottom of the tapered lock is larger than the largest diameter of the valve spring retainer, the latter is held firmly in position on the valve stem.

As shown in Figures 6 and '7 the shaping rolls and the die pressing and cutting apparatus may be combined in a single machine. In these figures, the reference numeral 40 indicates the frame of the machine comprising spaced vertical legs 4| and 42, a horizontal top portion 43 and a base 44.

43 thereof and extends between the legs. The crank shaft is driven from a pulley fly wheel 46 mounted outside of the frame leg 4|. A connecting rod 41 driven by the crank shaft alternately raises and lowers the top die press and cutter 46. The top press 48 is slidable in

vertical tracks

49 and 50 mounted in the frame 40.

Shaping rollers 5| and 52 are rotatably mounted in supports 53 and 54 on the machine base 44. The roller 5| is keyed to a shaft 55 extending through the supports 53 and 54. A gear 56 is keyed to the end of the shaft 55 and meshes with a gear 51 keyed to a shaft 58 which drives the roll. 52.

The rolls 5| and 52 are driven only when the top die 48 is raised off of the bottom die. This intermittent drive is made possible by a roller clutch 60 keyed to the shaft 55 and in releasable engagement with a link arm 6|. The link arm 6| is reciprocated by a rod 62 driven by an adjustable eccentric device 63 which is keyed on the end of the crank shaft 45.

The roller clutch 60 comprises a metal member 64 keyed to the shaft 55 and having a plurality of fiat tangential faces 65 on which rollers 66 are freely rotatable. The link arm 6| defines an elongated circular aperture 61 circumscribing the roller clutch mechanism and providing a rolling surface for the rollers 66.

As the link arm is moved upwardly the rolls 66 of the clutch climb upwardly and are eventually jammed between the tangential faces 65 and the surface of aperture 60. The link arm 6| is thus engaged with the shaft 55 to drive the same. As the rod 62 moves the link arm 6| downward the rolls 66 are rotated in the opposite direction and fall back in spaced relation from the aperture surface 64 thereby disengaging the shaft 55.

Springs 68 are preferably mounted behind the rollers 66 to prevent slippage of the clutch during the upstroke of the link arm 6|.

As shown in cross-section in Figure 6, the upper reciprocating block 48 (best indicated in Figure 7) has secured on the bottom thereof, a holding and trimming die 10 and a cutting and pressing die H. A bottom die block 12 is provided with a pair of wells 13 adapted to receive the shanks of flat headed bolts 14 movable vertically in said wells. A fiat metal bar 75 is held on the block 12 by the bolts 14. A block 16 of rubber or other resilient material is interposed between the bar I5 and the block 12.

A trimming die 11, located adjacent to the block 12, is adapted to cut the uneven edges of a. rolled strip of lock blanks. A spring retained rod 18 in the upper die block is adapted to hold the lock blank in position over the die 11 during the trimming operation. This rod contacts the lock blank and holds the same against the die 11 until the upper cutting die contacts the edges of the blank. The rod 18 then raises in the tube 19 against the pressure exerted by a coil spring 80 and the die moves downward to cut off the edges 20 of the lock blanks (Fig. 5).

The trimmed lock blank is bent into U-shaped form and cut from the strip by the top die H and a bottom die 8|. The bottom die 8| is mounted upon coil springs such as 82 so that the top die will force it downwardly during the bending operation to sever the lock from the strip.

From the above description it is evident that the rolls 5| and 52 shape a flat metal strip into a strip of lock blanks such as are shown in Figure 5. The rolls are operated only while the die block 48 is in raised position so that the strip of blanks emerging therefrom may be advanced one lock at a time to the die press over the bar 15. During the pressing operation the die 10 holds the strip of lock blanks on the bar 15. The die 10 does not disturb the metal of 'the blanks since the bar 15 is mounted on a resilient cushion. The last two blanks on the strip are operated upon simultaneously by the dies 10, ll, H and BI to be trimmed, shaped and cut in two operations. After the trimming operation,

the trimmed blank is advanced by shaping rolls 5| and 52, over the cutting and shaping die 8| where it is finished into a retainer lock. During the time the rolls advance the strip they are, of course, forming a new lock blank and thus the process is continuous and may be carried out at high speeds.

It will be obvious from" the above description that the process includes the step of rolling a flat piece of steel stock to form a continuous strip of lock blanks which are acted upon in two die cutting and pressing operations to form the finished lock.

Having now described my invention, I am aware that many changes may be made and numerous details of construction may be varied through a wide range without departing from the principles of this invention, and I, therefore, do not purpose limiting the patent granted hereon otherwise than necessitated by the prior art.

I claim as my invention:

1. The process of forming retainer locks which comprises passing a flat strip of metalbetween a pair of shaping rollers to form a continuous strip of lock blanks, trimming the edges of said blanks, simultaneously die pressing the blanks to the desired contour and cutting the locks from the strip.

2. The process of forming retainer locks which comprises feeding a metal strip into the nip between a pair of shaping rollers, trimming the edges of the continuous strip of retainer blanks emerging from between the rollers, cutting each lock blank from the strip and immediately die pressing the .cut blanks to the desired contour.

3. The process of making valve spring retainer locks which comprises rolling a flat strip of metal to form a continuous strip of fiat lock blanks, cutting the blanks from the strip and simultaneously die pressing the cut blanks to the desired contour.

4. The process of forming retainer locks which comprises shaping a flat piece of metal to form transverse extending beads on one side thereof and tapered surfaces on the other side thereof, and thereafter die cutting and shaping said metal to form lock blanks of the desired contour.

5. The process of forming retainer locks which comprises rolling a flat strip of metal to produce thereon a plurality of transverse extending beads on one surface thereof and a. plurality of tapered surfaces on the other side thereof, thereafter trimming the edges of said metal and die pressing each tapered portion to produce a retainer lock of the desired contour.

6. ,The process of forming valve spring retainer locks which comprises rolling a flat strip of metal to form thereon a plurality of transverse extending beads on one side and a non-parallel tapered surface on the other side above said beads whereby a continuous strip of flat lock blanks is produced, trimming the edges of said blanks, and die pressing each of said blanks to form a retainer lock of the desired contour.

7. The process of forming valve spring retainer locks which comprises pressing a flat strip of metal to form transverse extending beads on one side thereof and a plurality of tapered surfaces on the other side thereof, trimming the edges of the resulting shaped metal and die pressing each tapered portion of the metal to produce a re tainer lock of the desired contour.

8. The process of forming valve spring retainer locks which comprises feeding a flat strip of metal into the nip between a pair of shaping rollers, one of said rollers being provided with transverse extending depressed portions for forming transverse beads on one side of the metal and the other of said rollers being formed with a plurality of tapered surfaces for shaping the other side of the metal into a plurality of tapered lock blanks, trimming said lock blanks and die pressing each of said blanks for forming a substantially semi-cylindrical retainer tapered outside surface.

9. A machine for forming valve spring retainer locks comprising a pair of shaping rollers, a set of top and bottom dies adjacent to said rollers, driving means to raise and lower said top die, a roller clutch for driving said shaping rollers, a link arm cooperating with said clutch, a rod actuated by said driving means to reciprocate said link arm and engage the clutch only when the top die is in raised position.

10. A machine for forming valve spring retainer locks from a strip of metal which comprises, a base, a bottom die mounted on said base, a drive shaft support on said base, a pair of shafts rotatably mounted in said support, shaping rollers keyed to said shafts in superimposed relation, gears connecting said shafts, a roller clutch keyed to one of said shafts, a vertical frame, a top die vertically slidable in said frame above said bottom die, a crank shaft rotatably mounted in said frame near the top thereof, a connecting rod between said crank shaft and said top die, an eccentric on said crank shaft, means connecting said eccentric with said roller clutch and means for adjusting said eccentric to engage said lock with a clutch only when said top die is in raised position.

11. An apparatus for forming valve spring retainer locks from a strip of metal which comprises a pair of superimposed shaping rollers adapted to receive a strip of metal in the nip therebetween, a pair of cutting and pressing dies adjacent to said rollers adapted to receive a strip of lock blanks therefrom, drive means to open and close said dies, and means actuated by said drive means to rotate said shaping rollers to advance one lock blank at a, time to said dies only when said dies are open.

12. An apparatus for forming valve spring retainer locks from a strip of metal which comprises a pair of superimposed shaping rollers adapted to receive a strip of metal in the nip therebetween, a pair of cutting and pressing dies adjacent to said rollers adapted to receive a strip of lock blanks therefrom, drive means to open and close said dies, a drive shaft for said shaping rolls, a roller clutch keyed to said drive shaft and an'eccentric on said die drive means operatively connected to said clutch to engage said clutch only when the dies are in open position.

13. Die pressing and cutting apparatus for finishing a strip of lock blanks into valve spring retainer locks comprising a resiliently mounted holding die, an edge trimming die adjacent thereto, means for holding a lock blank over said trimlocks from a strip of metal comprising a pair of shaping rollers adapted to receive a strip of metal in the nip therebetween, a set of top and bottom dies adjacent to said rollers adapted to receive a strip of lock blanks therefrom, drive means to open and close said dies and means actuated by said drive means to rotate said shaping roller: for advancing the lock blanks to said dies only when said dies are open.

DANIEL KELLEHER. 10