US2861622A - Angularly adjustable device for trimming leading edge of coil spring - Google Patents

Description

Nov. 25, 1958 v A. A. BONDE ETAL ANGULARLY ADJUSTABLE DEVICE FOR TRIMMING LEADING EDGE OF con SPRING 3 Sheets-Sheet 1 Filed Sept. 26, 1955 yz'w WWW QM 8 Z 4w n a r aw V M 111mm Z P J Nov. 25, 1958 A. A. BONDE ET AL ANGULARLY ADJUSTABLE DEVICE FOR TRIMMING LEADING EDGE OF COIL SPRING Filed Sept. 26, 1955 3 Sheets-Sheet 2 1151RPM 04 ..,,o a Z 4 u 4 L M M i w..- m

X65229 r9 Jana (w A 1759 2 344 mm 9r 1958 A. A. BONDE ET AL 2,861,622 v ANGULARLY ADJUSTABLE DEVICE FOR TRIMMING LEADING EDGE OF COIL SPRING Filed Sept. 26, 1955 5 Sheets-Sheet 3 (7556,4015 Uzi/ as 041% 2 M4 Balk- 1. ml wl DAM firm United States Patent ANGULARLY ADJUSTABLE DEVICE FOR TRllVI- MING LEADING EDGE OF COIL SPRING Alfons A. Bonde, Oak Park, and Joseph S. Di Pasquale, Elmwood Park, Ill.

This invention relates to a trimming device for spring coiling machines and in particular to an improved method and apparatus for determining the length of a raw spring.

A particular embodiment of the invention shown is designed for operation with a universal coiler of the type shown in Bergevin et a1. Patent No. 2,119,002, dated May 31, 1938, but the invention is equally applicable to other types of spring coiling machines.

Spring coiling machines of the type indicated embody wire feeding means which feed a predetermined length of wire between an arbor and a coiling point. The length of the spring is determined by the amount of feed imparted by the feed rolls, after which a cutofi device is actuated.

Although the cutoff device always determines the angular position of the trailing edge of the raw spring with certainty, it does not necessarily follow that the length of the spring can be measured by an integral number of convolutions, due to spring back. The variation in angular length will vary from job to job according to the resilience of the stock and the length of spring, but on any particular job, for a given amount of feed, the variation will be of the order of to degrees on either side of a median position. Furthermore, since the raw spring is subjected to subsequent operations, such as the forming of hooks of varying size, it is not always desired that the raw spring contain an integral number of convolutions.

It is an object of the present invention to provide a trimming device by means of which a raw spring can be produced of any desired length, the term length as used herein referring to angular length, and in particular to a fractional part of the convolution as measured in degrees, the number of complete convolutions being disregarded for purposes of this description.

According to this invention, the trimming device operates on the leading edge of the spring substantially simultaneously with the operation of the cutoff device, which determines the trailing edge.

It is another object of this invention to provide an improved method and apparatus for determining the length of a raw spring by operating on both the leading and trailing edges of the spring substantially simultaneously.

A further object of this invention is to provide a trimming device which is angularly adjustable.

Still another object is to provide a trimming device in the form of an attachment which can be readily mounted on a standard type of spring coiling machine.

A still further object is to provide, in a spring trimming device of the type indicated, an improved cutting action.

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Fig. 1a is an elevational view of certain parts obscured in Fig. 1;

Fig. 2 is a side view of certain parts shown in Fig. 1;

Fig. 3 is an enlarged front elevation of the trimming device;

Fig. 4 is a left end view of Fig. 3;

Fig. 5 is a rear elevation of Fig. 3;

Fig. 6 is a view similar to Fig. 5 showing the parts in a changed position;

Fig. 7 is a detailed elevation of a raw spring after trimming;

Figs. 7a and 7b are views taken along lines 7a and 7b respectively of Fig. 7 illustrating the trimming operation.

Fig. 8 is a fragmentary view similar to Fig. 5, but showing an adjusted position of the parts;

Fig. 9 is a view illustrating the trimming operation with respect to the adjusted position shown in Fig. 8,.

and

- Fig. 10 is a view similar to Fig. 5, but showing a modification.

With reference now to Figs. 1 and la, the reference numeral 15 indicates generally a spring coiling machine of the type shown in the aforementioned patent, on which machine is mounted the trimming device 23. The machine 15 includes a front plate 16 through which extends an arbor 17 and on which is mounted a coiling point 18, the latter elements being overlain by the trimming device 23 and hence being shown separately in Fig. 1a. A trailing edge cutoff blade 19 is also provided,

' the setup being shown for a righthand spring.

Further objects, features and advantages will become The spring coiling machine also includes a rotating cam shaft 20 which projects through the front plate 16, and feed rollers 21 and guide blocks 22 mounted on the front plate.

In operation the feed rollers 21 feed wire stock to the left through the guide blocks 22 and above the arbor 17 and into engagement with the coiling point 18. The latter deflects or bends the wire stock and the convolutions are displaced by a suitable pitch tool, not shown, all as described in the aforementioned Patent No. 2,119,002. At the conclusion of each cycle of operation, the trailing edge cutoff 19 is actuated to sever the raw spring from the stock.

The trimming device 23 is mounted forwardly of said front plate 16 and arbor 17 and includes a bracket 24 which is secured to the front plate 16 by means of suitable screws 25. A bearing plate 26 is supported from the bracket 24 by means of a hollow post 27 at its lower end, and additional supporting means may be provided at its upper end if desired. The bearing plate 26 is provided with a length adjustment designated generally by the reference numeral 23 in Fig. 4.

A shaft 30 is suitably journaled within the post 27 and carries at its rear end a follower arm 31 which is engaged by a cam 32 mounted on the cam shaft 20. The latter is rotated once during each cycle of operation of the machine 15, and hence the shaft 30 will be rocked once during each cycle of operation. The timing is such that the rocking occurs at the end of each cycle.

Adjustably mounted in the upper end of the bearing plate 26 is a cylindrical plug 33. The bearing plate is split as indicated at 34 and a takeup screw 35 is provided to maintain the plug in any desired angular position. A cutter shaft 36 is journaled in the plug 33 and is provided with a square end 37.

Means are provided to transmit the rocking motion of the shaft 30 to the cutter shaft 36. In this connection, a lever arm 38 is suitably secured to the square end of the shaft 30, and a second lever arm 39 is mounted on the square end 37 of the cutter shaft 36. The lever arm 39 is provided with a star-shaped opening 41 which provides angular adjustment of the lever arm 39 with respect to the cutter shaft 36 in increments of 45. A link 42 connects the outer ends of lever arms 38 and 39, the link including a turnbuckle 43 for purposes of adjustment;

The rear end of the cutter shaft 36 is slotted to accommodate a blade 44 which is suitably secured therein. Also projecting backwardly from the rear surface of the plug 33 is an anvil 45 which cooperates with the blade 44. The anvil is centrally located in the plug 33 and the cutter shaft is eccentrically located so that rotation of the plug, as between the Fig. and the Fig. 8 positions, for example, will cause angular displacement of the shearing plane.

A spring 46 extends between the outer end of the lever arm 39 and the end of shaft 3t) to urge the linkage mechanism 384239 into its unoperated position, as determined by a stop 4:7 projecting from adjustably mounted stop plate 4.8.

At the conclusion of each cycle the follower arm 31 will be rocked by the cam 32. to cause movement of the cutter blade 44' from its normal Fig. 5 position into its operative position shown in Fig. 6. The cutter blade 44i's aligned with the first convolution 49 of the spring 50 so that the first convolution will be trimmed in the desired manner.

The whole bearing plate 2.6 is adjustably mounted on the hollow post 27 by means of the takeup screw 51 in order to secure proper alignment. Additionally, a suitable lock screw 52, having an eccentric dog point, not shown, which engages in a groove in the cutter shaft 36, may be provided for a fine adjustment of the cutter blade 44 with respect to the first convolution 49.

Figs. 7, 7a and 7b illustrate the operation of the trimming device. The trailing edge is shown at 53 in Fig. 7a., and the leading edge is shown at 54 in Fig. 7b. A comparison of Figs. 7a'and 7/) will indicate that the length of the spring 5! is approximately 335 (disregarding complete convclutions). It is desired to provide a spring having a length of 285, for example. Therefore, 50 must be trimmed from the first convolution 49, and the plug 33 is, therefore, adjusted accordingly.

Referring now to Figs. 8 and 9, if it is desired to provide a spring having a length of 240, then the plug 33 will be rotated 45 in the counterclockwise direction from the Fig. 6 position. in Figs. 7b and 9, the trimmed portion of the spring is designated by the reference numerals 55 and 55' respectively, and the trimmed edge by the reference numerals 56 and 56 respectively.

Since the coiling machine is a universal machine, meaning that it is adapted to fabricate springs of varying numbers of convolutio-ns, pitch, and diameter, according to setup, the trimming device 23 is provided with the various adjustments previously mentioned to the end that the anvil 45 and cutting blade 44 may be properly located, and so that the throw of the cutter shaft may be regulated accordingly.

A modified type of cutter blade mounting is shown in Fig. 10 in which the cutter shaft 36 terminates in an eccentric pin 6% which engages in a slot 61 formed in the cutter blade The cutter blade 44, in turn, is slidably mounted on the surface of the plug 33 by means of under cut guide pins 63. Thus, rotation of the lever arm 39 in counterclockwise direction will project the cutter blade 2. to the left in a direction toward the anvil thus providing an essentially translational motion of the cutter blade 62 as contrasted with the rotational motion provided by the cutter blade 44. The translational motion has the advantage of facilitating setup since, in the rotational type, the angular disposition of the actual plane of shearing tends to vary with respect to the displacement of the plug 33 when operating on springs of different diameter. in the translational type, however, such variation is not present.

It is understood that the anvil 45 is replaceable since,

for springs of varying diameters, anvils of different diameters may also be required.

To summarize the operation, which has been described in detail in connection with the description of the various parts and sub-assemblies, the spring coiling machine of Fig. l operates in discrete cycles of operation, automatically severing the spring at the conclusion of each cycle. The trimming device 23 serves to trim the leading edge of a spring substantially simultaneously with the operation of the trailing edge cutoff 19, in order to provide a spring of desired length. The length adjustment is obtained by regulating the angular position of the' plug 33 within the bearing plate 26, as illustrated by a. comparison of Figs. 5 and 8, thus shifting the plane of shearing as illustrated by a comparison of Figs. 7b and 9.

It is, of course, understood that in setting up the spring coilingrnachine for a particular job, the rough length of the spring, determined by the amount of feed imparted by the feed rollers 21, is set so that the maximum variation from the median angular length prior to trimming isgreater than the angular distance between the plane of shearing and the angular position of the median rough length. In order words, with respect to Figs. 7b and 9, assuming that the leading edge 54' represents the median rough length, then the amount of feed must be set so that the angular length of the trimmed portions 55 and 5S exceeds the maximum variation expected.

The timing of cam 32 is such that the trimming device is operated just prior to the operation of the cut off device, and after the feeding and coiling operation has been completed. At this time, the spring is maintained in its position shown in Fig. 2 by reason of the fact that it has not yet been severed from the wire stock.

The trimming device may be built into the coiling machine 15 as an integral part thereof, or it may be constructed in theform of an attachment, as shown, the cam shaft 20 which is provided on the machine of the type shown for other purposes being thus readily available as a convenient source of power for actuating the trimming device.

Although only the 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:

1. A trimming device for a spring coiling machine which includes wire feeding means, an arbor, and a cut off de vice located adjacent said arbor and operating along a fixed shear plane, comprising, in combination, a bearing plate mounted forwardly of said arbor, a plug mounted in said bearing plate, an anvil centrally mounted on and projecting rearwardly from the rear surface of said plug, a cutter shaft journaled in said plug, and a cutter blade actuated by said cutter shaft and cooperating with said anvil to sever the leading edge of a spring which is located on said arbor, said plug being adjustably mounted in said bearing plate for angular adjustment so that the shear plane of said cutter blade may be adjusted with respect to said fixed shear plane in order to regulate the length of said spring, and means for operating said cutter shaft at the conclusion of a spring coiling operation and immediately prior to the operation of said cutoff device.

2. A trimming device for a spring coiling machine which includes wire feeding means, an arbor, and a cut off device located adjacent said arbor and operating along a fixed shear plane, comprising, in combination, a bearing plate mounted forwardly of said arbor, a plug mounted in said bearing plate, an anvil centrally mounted on and projecting rearwardly from the rear surface of said plug, a cutter shaft journaled in said plug, a cutter blade slidably mounted on the rear surface of said plug, the end of said cutter shaft and said cutterblade presenting opposed surfaces, a slot formed in one of said surfaces, and an eccentric pin projecting from the other of said surfaces into said slot whereby oscillation of said cutter shaft will cause translational movement of said cutter blade toward said anvil to sever the leading edge of a spring which is located on said arbor, said plug being ad ustably mounted in said bearing plate for angular adjustment so that the direction of movement of said cutter blade may be adjusted with respect to said fixed shear plane in order to regulate the length of said spring, and means for oscillating said cutter shaft at the conclusion of a spring coiling operation and immediately prior to the operation of said cutoff device.

3. A trimming device for a spring coiling machine which includes a front plate, wire feeding means mounted on said front plate, an arbor, and a cut off device located adjacent said arbor and operating along a fixed shear plane, comprising, in combination, a bracket secured to said front plate, a post projecting forwardly on said bracket, a bearing plate mounted on said post, a rock shaft journaled in said bracket and extending through said bearing plate, cam means projecting from said front plate for rocking said rock shaft at the conclusion of a spring coiling operation and immediately prior to the operation of said cut off device, a plug adjustably mounted in said bearing plate for angular adjustment, an anvil centrally mounted on and projecting rearwardly from the rear surface of said plug, a cutter shaft journaled in said plug, a first lever arm mounted on said cutter shaft, a second lever arm mounted on said rock shaft, link means connecting said lever arms whereby the rocking motion of said rock shaft will be transmitted to said cutter shaft, and a cutter blade located at the rear surface of said plug and eccentrically thereof and actuated by said cutter shaft.

4. A trimming device as claimed in claim 3 in which said link means includes a turnbuckle so that the effective length of said link means may be adjusted to correspond with the variation in distance between said eccentrically located cutter blade and said rock shaft as said plug is angularly adjusted in said bearing plate.

5. A trimming device as claimed in claim 3 in which the effective length of said bearing plate is adjustable, and in which the effective length of said link means is adjustablc.

6. A trimming device as claimed in claim 3 in which said bearing plate is adjustably mounted on said post for forward and back adjustment to accommodate different lengths of spring which are coiled on said coiling machine.

7. A trimming attachment for a spring coiling machine, which includes wire feeding means, an arbor, and a cutoff device located adjacent said arbor and operating along a fixed shear plane comprising, in combination, a mounting bracket, a post projecting forwardly from said bracket, a bearing plate mounted on said post, a rock shaft journaled in said bracket and extending through said bearing plate, a plug adjustably mounted in said bearing plate for angular adjustment, an anvil centrally mounted on and projecting rearwardly from the rear surface of said plug, a cutter shaft eccentrically journaled in said plug, a first lever arm mounted on said cutter shaft, a second lever arm mounted on said rock shaft, link means connecting said lever arms whereby the rocking motion of said rock shaft will be transmitted to said cutter shaft, and a cutter blade located at the rear surface of said plug and actuated by said cutter shaft.

References Cited in the file of this patent UNITED STATES PATENTS 1,565,405 Blevel Oct. 6, 1925 1,676,598 Blevel July 10, 1928 2,119,002 Bergevin et a1 May 31, 1938 2,388,106 Woller Oct. 30, 1945

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