US3032076A - Loop-forming machine for springs - Google Patents

Description

May 1, 1962 A. A. BONDE ET AL 3,032,076

LOOP-FORMING MACHINE FOR SPRINGS Filed July 22. 1957 4 SheeSSheet l @www May 1, 1962 A. A. BONDE ETAL Loop-FORMING MACHINE FOR SPRINGS Filed July 22, 1957 4 Sheets-Shea?l 2 m MEL A. A. BONDE ET AL LOOP-FORMING MACHINE FOR SPRINGS May 1, 1962 4 Sheets-Sheet 5 Filed July 22, 195'? F115. El 65\ May 1, 1952 A. A. BONDE ETAL 3,032,076

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pushers in a changed position; and

3,032,076 LOOP-FORMING MACHINE FOR SPRINGS Alfons A. Bunde, Oak Park, and Joseph S. Di Pasquale,

Elmwood Park, lill., assignors to Accurate Spring Manufacturing Co., Chicago, Ill., a corporation of Illinois Filed July 22, 1957, Ser. No. 673,537 10 Claims. (Ci. 1140-103) -in such a manner with respect to the spring axis that an improved twisting,7 action will be obtained and so that a close control of overall spring length can be obtained.

According to this aspect of the present invention, one

of the pushers is a forked pusher which is oriented at an -obtuse angleto the spring axis so that thelongitudinal .position of the loop can be definitely determined by the throw of a forked pusher.

Another object is to provide improved means for feeding the spring blanks to the pushers and to position them so that the loop will be of the desired angular length, thereby permitting the plane of the loop to be determined with respect to a loop which has been previously formed at the opposite end.

According to this aspect of the invention, the springs are fed up to the pushers by means of a tube, and the tube is rotated so as to cause the spring to rotate until its wire end surface engages a stop-gage.

A further object is to provide improved means for holding the spring in the desired angular position, prior to and during the loop-forming operation, without the necessity of providing spring gripping means or the like.

Further objects, features and advantages will become apparent as the description proceeds.

With reference now to the drawings, in which like reference numerals designate like parts:

FIG. l is a vertical longitudinal section taken along lines 1*1 of FIG. 2 and showing a preferred embodiment of this invention;

FIG. 2 is a plan view of FIG. 1;

FIG. 3 is a view of a spring blank;

FIG. 4 is a similar view, but showing the crossover loop formed at one end;

FIG. 5 is a similar view of the inishedspring;

FIG. 6 is a vertical transverse section taken along lines FIG. 7 is a vertical longitudinal section taken along lines 7 7 of FIG. 2, and showing the stop-slide and its associated parts in detail;

FIG. 8 is an enlarged plan view taken along lines 8 8 of FIG. 7, showing the stop-slide in its projected position;

FIG. 9 is a View similar to FIG. 8 but showing the stopslide in its retracted position;

FIG. l is a View similar to FIG. 8 but showing the parts in a changed position;

FIG. 1l is an enlarged plan section taken along lines 11-11 of FIG. 1;

FIG. 12 is a vertical transverse section taken along lines 12-12 of FIG. 11;

FIG. 13 is a longitudinal vertical section taken along lines 13--13 of FIG. l2;

FIG. 14 is a View similar to FIG. 13 but showing the FIG. 15 is an enlarged perspective view'of a spring end showing the manner in which the end loop is formed.

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3,032,076 Patented May l, 1362 With reference now to FIGS. 13 and 14, the spring S is looped by means of two pushers 2t) and 21, one being a forked pusher 20 and the other a wedge pusher 21. The spring S, While the pushers operate thereon, is held stationary by the cooperation between a rotating tube 22, and a stop-slide 23, as shown in FIG. 11. The tube is a. feeding device for a series of spring blanks S and is rotated by means of bevel gears 24 shown in FIGS. 1 and 2, so that the wire end surface 25 of the spring will be rotated into engagement with the stop-slide 23. As will be seen, the spring blanks S tit loosely within the rotating tube, so that after the rotation of the lowermost spring blank has been blocked by the stopslide 23, the spring blank will remain stationary while the pushers operate thereon, even though the rotation of the tube continues.

The structure of the looping device, as shown in FIGS. l, 2, and 6, comprises a base plate 26 having an aperture 27 formed therein, through which the finished springs may be ejected. Mounted on the base plate is a front block 2S having a sloping upper surface, and a rear block 29. An L-shaped slide 36 is suitably mounted on the sloping upper surface of the front block 23 and confined thereto by means of a retaining plate 32. The forked pusher 2Q is mounted on the slide 3i). Slide 31 is mounted within a bore 33 in the rear block 29 and carries the wedge pusher 21. Thus, the pushers 20 and 21 are mounted for sliding movement toward and away from each other, and cooperate to deform a spring blank which may be disposed between them.

A slide block 34, within which the stop-slide 23 is received, is mounted on the front of the rear block 29 by means of a bracket 56 and a screw 36. The slide block carries a linger 35 which projects laterally and serves as a thrust bearing for the lower end of the rotating tube 22.

The slide block is provided with a transverse opening 37 to accommodate the stop slide 23, and the latter is moved back and forth by means of drift cams 3S and 39. In other words, after a loop has been formed, the stop slide 23 is retracted to permit the lowermost spring 32 to drop out of the tube and through the aperture 27, and then the stop-slide is immediately projected into its FIG. 8 position so as to be engaged by the next succeeding spring.

By means of a gage surface it), which may be built up on the stop-slide 23 as shown, or depressed, the angular position of the spring, and hence the angular length of the loop, can be closely controlled, since this is the portion of the stop-slide which is engaged by the wire end 25. A clearance block 41 secured to the rear block 29 by a screw 42 overlaps the finger 35 and cooperates therewith to provide a restricted opening through which the springs S may pass. In other words, due to the clearance block, the spring is prevented from jumping up at the time that the wire end 25 is rotated into engagement with the gage surface dil.

To summarize the foregoing, the spring blanks S are gravity fed by the rotating tube 22 one at a time into operating position, and their angular position is gaged by the gage surface 4t). The stop-slide 23 acts as an escapement to release them one at a time, it being retracted during the loop forming operation and projected immediately after ejectrnent so as to block the next succeeding spring.

The device is driven from a suitable motor, not shown, through two drive shafts 45 and 46. The drive shaft 45 drives the bevel gears 24, and the drive shaft 46 drives the slides 30 and 31. The drive shaft 46 may be mounted in a suitable bearing, not shown, and it carries at the end thereof an eccentric 47 which is connected with the slide 30 by means of a link 48. The link 48 extends through a 3 30 and the forked pusher 20, as well as of the drift cams 38 and 39 as will be pointed out hereafter.

Also mounted on the shaft 46 is a cam 52 which engages a roller follower 53 which is suitably mounted on a longitudinally extending slide 54 as shown in FIG. l. The slide is confined against the base plate 26 by means of front and rear brackets 55 and 56. The rear end of the slide 54 is provided with a crosshead 57 secured thereto by a screw 58. One end of the crosshead is provided with a vertical rib 59 which is slideably received in a slot suitably formed in the slide 31 at its rear end. Thus, reciprocation of the slide 54 causes corresponding reciprocation of the slide 31, and wedge pusher 21. A spring 69 maintains the follower 53 in engagement with the cam 52.

The drift cams 38 and 39 are adjustably secured at their front ends to the under surface of slide 30 by means of screws 61 and 62. At their rear ends, the drift cams are received within the slide block 34, and a suitable intermediate support may be provided for the drift cams.

As shown in FIGS. 7 to l0, the plane of the drift cams intersects the plane of the stop-slide 23, and the latter is provided with an inclined notch 65 to permit this intersecting arrangement. The drift cam 36 is provided with a cam surface 66 which cooperates with cam surface 67 provided by one of the end walls of the notch 65. Thus, when the drift cams 32 and 39 are moved rearwardly, or to the right as viewed in FIG. l0, the stop-slide 23 will be moved from its projected, or FIG. 8, position, into its retracted, or FIG. 9, position by virtue of the cooperation of the cam surfaces 66 and 67, as shown in FIG. l0.

The drift cam 39 is provided with a cam surface 68 which cooperates with a cam surface 69 formed by the other end wall of the notch 65. Thus, when the drift cams are moved forwardly and upwardly, the stop-slide 23 will move from its retracted position into its projected position.

To summarize the operation which has been heretofore pointed out in connection with the description of the various parts and sub-assemblies:

The spring blanks S are fed by suitable means not shown into the rotating tube 22. It will be observed that the diameter of the springs S is somewhat less than the inner diameter of the tube 22 so that they are loosely received within the same. Thus, as the tube is rotated in the clockwise direction, looking forwardly, which corresponds to the counter-clockwise direction as viewed in FIG. 12, the gravity contact between the springs and the interior `of the tube causes the springs to be rotated in the clockwise direction until such time as the wire end surface 25 of the lowermost spring engages the gage surface 40. Then the pushers 20 and 21 move toward each other from the FIG. 13 position to the FIG. 14 position in order to form the loop 72.

It will be observed that the general axis of the pushers 20 and 21 is inclined at an angle to the spring axis, with the result that the axis of pusher 20 forms an obtuse angle with the axis of the spring S. As a result of this angular disposition, and due to the provision of the fork, that portion of the last two convolutions which is engaged by the fork is pushed inwardly so that it lies interiorly of the body 70 of the spring S, to a slight degree. Thus, the longitudinal position of the loop 72 can be determined by adjusting the throw of the forked pusher 20, and to this end, suitable clamping means 73 are provided to adjust the longitudinal position of the forked pusher 20 with respect to the slide 30. In other words, the degree of overlap between the body portion 70 of the spring and the loop 72 can be regulated, thus controlling the overall length of the finished spring shown in FIG. 15. The wedge pusher 21 spreads the last convolution from the body portion 7), and since the two pushers are slightly offset from one another, a force couple is applied to the last convolution which provides the twisting action, as shown in FIG. 14.

As soon as the spring S has been engaged by the forked pusher 20, the latter serves to restrain the spring from dropping out of the tube 22 with the result that the stopslide 23 can be retracted.

The timing of the forked pusher 20 and the drift cams 38 and 39 is such that they both move rearwardly at the same time, and both move forwardly at the same time. Rearward movement of the drift cam 3S causes retraction `of the stop-slide 23, and the timing can be closely adjusted by means of the clamping screw 61.

Similarly, as the slide 30 moves forwardly, the drift cam 39 causes movement of the stop-slide 23 into its projected position as the forked pusher 20 retracts, The timing is adjusted by means of clamping screw 6-2 so that the projection of the stop-slide 23 will be delayed until after the lowermost spring has dropped through aperture 27. However, the timing is such that the stopslide moves into its projected position before such time as the next succeeding spring has an opportunity to pass out of the tube 22.

The gage surface 40 is preferably formed of hardened steel to resist wear since a slight variation in the elevation of the gage surface will affect the angular length of the loop 72. Conversely, substitution of different gage surfaces 40 provides a means of varying the angular length of the loop.

The mechanism described is equally effective in forming either the first or the second loop on the spring S. However, after the first loop 71 has been formed, a variation in the angular length of the loop 72 will affect the angular disposition of the planes of the two loops, assuming a spring having a given number of convolutions. Therefore, in order to obtain coincidence of loop planes, the elevation of the gage surface 40 is critical. However, variation in loop planes is best effected by adjustment of the cut-off in the spring-coiling machine, thus permitting the use of a single gage 40, or stop-slide gage for both ends of the spring.

Although FIG. 1 illustrates the formation of second loop 72, which means that the rough end of one spring blank rides on the first loop of the spring blank below, the device is equally operative in forming the first loop, in which the rough end of one spring engages the rough end of the spring below. Of course, in positioning the wire end surface 25 of the lowermost spring, it is necessary to rotate the same through less than 360, and thereafter a sliding contact occurs between the body portion 70 of the lowermost spring and the rotating tube 22.

Although only a preferred embodiment of this invention has been shown and described herein, it will be understood that various modifications and changes may be made in the construction shown without departing from the spirit of this invention as pointed out by the appended claims.

We claim:

l. A loop-forming machine for feeding a series of spring blanks successively into a position for engagement by a pair of oppositely disposed pushers which is characterized by the absence of movable spring engaging members for maintaining the first spring blank stationary during the operation of said pushers, and which is also characterized by the utilization of the frictional engagement between the interior wall of a downwardly inclined open ended rotatable feed tube and a spring blank to r0- tate the spring blank into the desired angular position and to maintain same in said position until said spring blank is engaged by said pushers, comprising a base, a rotatably mounted, open-ended downwardly inclined tube mounted on said base, a pair of oppositely disposed pushers located adjacent the lower end of said tube and mounted for longitudinal sliding opposed movement, stop means located adjacent said lower end and having a gage surface disposed in a plane which is substantially parallel to the axis of said tube for engagement by the wire end surface of a spring which is located in said tube, means for rotating said tube so that the lowermost of a series of springs loosely disposed therein will be rotated so that its wire end surface will engage said stop means to block further rotation and further downward movement of said spring, means for moving said pushers toward each other and into engagement with the end convolution of said lowermost spring in order to form a crossover loop, and means for retracting said stop member after engagement of said spring by said pushers.

2. A loop-forming machine as claimed in claim l in which one of said pushers is a forked pusher, said forked pusher being oriented at an obtuse angle to the axis of said tube, so that the inner portion of the crossover loop formed by said pushers will be disposed within the contines of said spring.

3. A loop-forming machine as claimed in claim l in which one of said pushers is a forked pusher, and in which the other one of said pushers is a wedge pusher, said forked pusher offset above said wedge pusher to provide a force couple for twisting said end convolution into a crossover loop, and said wedge pusher being offset rearwardly from said gage surface for separating the end convolution of said spring from the remaining convolutions thereof.

4. In a loop-forming machine for feeding a series of spring blanks successively into a position for engagement by a pair of oppositely disposed pushers which is characterized by the absence of movable spring engaging members for maintaining the first spring blank stationary during the operation of said pushers, and which is also characterized by the utilization of the frictional engagement between the interior wall of a downwardly inclined open ended rotatable feed tube and a spring blank to rotate the spring blank into the desired angular position and to maintain same in said position until said spring blank is engaged by said pushers, and which includes a pair of oppositely disposed pushers for forming the end convolution of a spring blank into a crossover loop, the combination comprising means for gaging the angular length of said crossover loop comprising a retractible stop member disposed forwardly of said pushers and having a gage surface which is substantially radial with respect to the axis of said spring blank, and said feed tube for rotating a spring blank so that its Wire end surface will engage said stop member to determine the angular position thereof prior to the operation of said pushers, said stop member being separate from either one of said pushers.

5. A loop-forming machine for feeding a series of spring blanks successively into a position for engagement by a pair of oppositely disposed pushers which is characterized by the absence of movable spring engaging members for maintaining the rst spring blank stationary during the operation of said pushers, and which is also characterized by the utilization of the frictional engagement between the interior wall of a downwardly inclined open ended rotatable feed tube and a spring blank to rotate the spring blank into the desired angular position and to maintain same in said position until said spring blank is engaged by said pushers, comprising a downwardly inclined rotatably mounted, open-ended tube= a pair of oppositely disposed pushers located adjacent to the lower end of said tube and mounted for longitudinal sliding opposed movement, a retractible stop slide mounted adjacent the lower end of said tube and having a gage surface disposed in a plane which is substantially parallel to the axis of said tube, and means for rotating said tube so that the lowermost of a serie-s of springs loosely disposed therein will be rotated so that its wire end surface will engage said stop slide to determine the angular position of said spring.

6. A loop-forming machine for feeding a series of spring blanks successively into a position for engagement by a pair of oppositely disposed pushers which is characterized by the absence of movable spring engaging members for maintaining the first spring blank stationary during the operation of said pushers, and which is also characterized by the utilization of the frictional engagement between the interior wall of a downwardly inclined open ended rotatable feed tube and a spring blank to rotate the spring blank into the desired angular position and to maintain same in said position until said spring blank is engaged by said pushers, comprising a base, a rotatably mounted, open-ended tube mounted on said base and oriented in a forwardly and downwardly direction, a pair of oppositely disposed pushers located adjacent to the lower end of said tube and mounted for longitudinal sliding opposed movement, a stop slide mounted forwardly of said pushers for transverse sliding movement between a retracted position and a projected position in which the upper surface of said stop slide will be engaged by the wire end surface of a spring which is located in said tube, means for rotating said tube so that the lowermost of a series of springs loosely disposed therein will be rotated and so that the wire end surface of said lowermost spring Will engage said projected stop slide in order to determine the angular position of said spring and to block further rotation thereof and further downward movement thereof, means for moving said pushers toward each other and into engagement with the end convolution of said lowermost spring in order to twist the same into a plane which is parallel to and coincident with the axis of said spring, and means to retract said stop slide after said spring has been engaged by said pushers.

7. A loop-forming machine as claimed in claim 6 in which said stop slide includes a gage member of hardened steel carried at the end of said stop slide for engagement by said wire and surface.

8. A loop-forming machine as claimed in claim 6 in which said upper surface of said stop slide is disposed in a plane which is substantially parallel to the axis of said tube.

9. A loop-forming machine as claimed in claim 6 in which said stop slide retracting means comprises a drift cam having a retracting cam surface and a projecting cam surface, and said stop slide being provided with a notch through which said drift cam extends, whereby engagement of said cam surfaces with the end walls of said notch will cause movement of said stop slide between its retracted position and its projected position.

l0. In a loop-forming machine for feeding a series of spring blanks successively into a position for engagement by a pair of oppositely disposed pushers which is characterized by the absence of movable spring gripping members for maintaining the first spring blank stationary during the operation of said pushers, and which is also characterized by the utilization of the frictional engagement between the interior wall of a downwardly inclined open ended rotatable feed tube and a spring blank to rotate the spring blank into the desired angular position and to maintain same in said position until said spring blank is engaged by said pushers, and which includes a pair of oppositely disposed pushers for forming the end convolution of a spring blank into a crossover loop, the combination comprising means for gaging the angular length of said cross-over loop comprising a stop member disposed forwardly of said pushers and having a gage surface which is substantially radial with respect to the axis of said spring blank, means for rotating a spring blank so that its wire end surface will engage said stop member to determine the angular position thereof prior to the operation of said pushers, said stop member being separate from either one of said pushers, and said blank rotating means comprising said rotatable feed tube, the inner diameter of said feed tube exceeding the diameter of said spring blank, and an adjustably mounted stationary clearance block partially overlapping the lower end 0f said rotatably mounted feed tube to maintain said References Cited in l[he le of this patent UNITED STATES PATENTS Harter Dec. 8, 1908 Sleeper Nov. 23, 1909 Harter Ian. 28, 1913 Peterson Aug. 2, 1932 Carlberg Dec, 14, 1937 Cook Jan. 30, 1940 Smith Mar. 14, 1950 Smith Ian. 6, 1953

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