US3314453A - Wire forming machines - Google Patents

Description

April 18, 1967 F. c. HOLMES 3,314,453

WIRE FORMING MACHINES Filed June 10, 1964 4 Sheets-Sheet l I NVENTOR.

A ril 18, 1967 Filed June 10, 1964 F. C. HOLMES WIRE FORMING MACHINES 4 Sheets-Sheet 2 INV NTOR. BY zwmiw April 18, 1967 F. c. HOLMES WIRE FORMING MACHINES 4 Sheets-Sheet 5 Filed June 10, 1964 INVENTOR. BY MK $4M arr/mums.

Patented Apr. 18, 1967 3,314,453 WIRE FORMING MACHINES Frank C. Holmes, Trumbull, Conn., assignor to The U.S. Baird Corporation, Stratford, Conn., a corporation of Connecticut Filed June 10, 1964, Ser. No. 374,040 6 Claims. (Cl. 140103) This invention relates to Wire forming machines and, more particularly, to a spring forming machine for producing coil springs having open spaced body coils.

In United States Patent 3,025,889, which issued Mar. 20, 1962, to Murray G. Clay, there is disclosed a wire forming machine, including a plurality of individual defleeting tools which are movable into and out of an operative position in front of an orifice provided in a guide through which the wire is fed. These tools cause deflection and coiling of the wire in different directions and in different planes. The three tools are programmed in such a manner that, as the wire issues from the orifice, a first tool forms a loop. As the first tool is withdrawn, a second tool moves into position so that the portion of the wire projecting from the orifice is deflected down wardly. Further wire that issues from the orifice is then curled against the side of a guide to form the body portion of a coil spring. After the prescribed number of coils have been formed, the second tool is retracted and a third tool moved into position to form another loop. The completed spring is then cut off and the operation is performed again on the succeeding length of wire.

Although the machine disclosed in the above mentioned patent is highly successful for the manufacturing of coil springs, all the springs which it produces are of the type wherein the coils lie tightly against one another. Many applications, however, require springs having open spaced coils and it would be desirable to form such coils with a machine of the general type disclosed in the above patent. Furthermore, it would be desirable to produce such springs without the use of additional wire deflecting tools.

Accordingly, it is a primary object of this invention to provide an improved wire forming machine. Other objects are to provide such a machine which is capable of producing coiled wire springs having open spaced coils; which is capable of producing open spaced coil springs having end loops; which is capable of producing such springs while utilizing the same number of defiective tools as the patented machine; and which is capable of producing springs having variable coil spacing.

The manner in which the foregoing objects are achieved will be more apparent from the following description, the appended claims, and the figures of the attached drawings, wherein:

FIG. 1 is a front view of a wire forming machine embodying the present invention;

FIG. 2 is a right elevational view of the machine of FIG. 1;

FIG. 3 is a cross section taken along the line 33 of FIG. 2;

FIG. 4 is a perspective view of the wire guide and associated tools in which a tool has moved into position .for forming the first loop of a coil spring;

FIG. 5 is a view similar to FIG. 4 showing the coil body forming tool moving into position as the first loop forming tool is retracted;

FIG. 6 is an enlarged plan view of the wire guide showing the second loop forming tool moved into position to function as a coil spacer;

FIG. 7 is a perspective view showing the relationship of the machine parts during the production of the spring body;

FIG. 8 is a view similar to FIG. 6 showing the body forming tool retracted and the second loop forming tool beginning to move around the end of the wire guide to form the second loop;

FIG. 9 is a view similar to FIG. 8 shOWing the second loop forming tool forming the end of the second loop;

FIG. 10 is an illustration similar to FIG. 9 showing the completed spring being severed by the cutoff tool;

FIG. 11 is a cross section taken along the line 11-11 of FIG. 3; and

FIG. 12 illustrates the operation of the machine employing a second loop forming tool having a broader wedge angle.

The machine of this invention has certain basic similarities to the machine disclosed in the above-mentioned patent. In the drawings, the machine 10 is adapted to form a length of wire W into a predetermined spring configuration. The machine comprises a head 20 secured to a face plate 21. The head 20 includes a forwardly protruding wire guide 22 having a longitudinal guide channel 24 extending therethrough. Rocker arms 26, 28, and 30 are mounted on the head to carry forming tools into and out of a forming position in front of the wire guide.

The wire feeding mechanism comprises a pair of feed rolls 32 and 34 disposed behind the wire guide so as to feed a predetermined length of wire W through the guide during each machine cycle.

The rocker arm assemblies 26, 28, and 30 are mounted on spindles 36, 38, and 40 which extend outwardly from the head in a plane perpendicular to the wire feed axis, the adjacent spindles being perpendicular to each other. Each rocker arm is adapted to oscillate on its spindle in response to action of the operating mechanism at the rear of the head. As is illustrated in FIGS. 1 and 4,'the rocker arm 26 mounted on downwardly extending spindle 36 is provided on one end with a tool holder assembly 42 which carries a forming tool 44 which extends radially inward towards the wire guide. The function of tool 44 is to produce the first loop 16 on the end of the advancing wire as illustrated in FIG. 4.

The rocker arm 28, mounted on horizontally extending spindle 38, is provided on one end with a tool holder assembly 48 which extends laterally above the wire guide and carries forming tool 50. The function of tool St) is also the same as that of the correspondingly numbered tool shown in the patent, namely, to deflect the wire downwardly producing the coils of the spring body. The illustration of FIG. 5 shows coil forming tool 50 positioned for forming the coils.

The present invention is primarily concerned with the movements of rocker arm 39 and the tool which it controls. The rocker arm 30 is mounted on the upwardly extending spindle 40 and is provided at one end with a tool holder assembly 54 which extends downwardly and carries a tool support block 56 at its lower end. Support block 56 is so positioned that its plane of movement during oscillation of the rocker arm 30 is below the axis of the wire guide 22.

A pivot block 58 is mounted on tool support block 56 so as to be pivotable about a pin 69 disposed through the forward ends of the support block 56 and the pivot block 53. Rotation of the block in a counter-clockwise direction (looking downward) is limited by an adjustable stop 61.

The block 58 carries an upstanding wire forming tool 62 which is disposed rearwardly on the block from the pivot pin 60. Tool 62 is generally wedge shaped with the apex 64 of the wedge extending forwardly and a horizont-al wire forming groove 65 (FIG. 6) disposed in the side adjacent the guide. A spring 66 is attached to the support block 56 and bears against the rear portion of the pivot block 58 so that the pivot block is normally urged in a clockwise direction as seen from the top. This results in the tool 62 resiliently bearing against the side of the wire guide 22 during a portion of the machines cycle.

To enable the machine to form a spring having a loop on each end, the forward end portion 68 of the side of the wire guide is substantially fiat, vertical, and parallel to the wire guide channel 24 and the opposite side of the guide is provided with a recess 70 (FIG. 6).

As described in the referenced patent, the operation of the rocker arms 26, 28, and 30 to carry the wire forming tools into and out of the operative position is controlled by pull rods 72, 74, and 76, respectively, and springs 78, 80, and 82, respectively. The pull rods are operated by cam followers 84, 86, and 88 riding, respectively, on cams 90, 92, and 94. The operation of cams 9t} and 92, and the pull rods, springs, and rocker arms with which they are associated, is fully disclosed in the referenced patent. Basically, the springs bias the rods rearwardly tending to pivot the rocker arms so as to move the tools into their operative positions. The action of the cam followers is to permit each spring to move its associated tool into position when the cam follower reaches a depression on the cam surface. The cams retract the tool as the cam followers rise out of such depressions.

A wire cutoff tool 96, (FIGS. 2 and 10) normally disposed below the guide 22, is mounted on a support bar 98 carried by brackets 100 and 102 secured to the face plate 21. Cutoff tool 96 is adapted to be swung upwardly by any suitable mechanism at the completion of a wire forming operation to shear off the wire at the end of the guide channel 24. For controlling the motion of the completed spring after it has been cut off by the tool 96, a deflector 104 is mounted on tool 96 by a resilient arm 106 which prevents upward movement of the spring after it is cut off.

The operation of a machine similar to that disclosed herein, but without the novel spacing mechanism of this invention, is disclosed in the referenced patent. As therein described, as the feeding of wire W commences, the rocker arm 26 pivots about its spindle to permit tool 44 to move into position in front of the wire guide as shown in FIG. 4. As the wire feed continues, the wire is dedefiected laterally by tool 44 to form loop 16. When loop 16 has been completed, tool 44 is retracted. Just prior to the completion of loop 16, rocker arm 28 has commenced to pivot to start tool 50 moving downwardly. As soon as tool 44 has retracted, tool 50 almost immediately moves into position in front of the wire guide as shown in FIG. 5. The portion of the wire projecting from the guide is thereupon deflected downwardly and further wire issuing fromt he guide is deflected downwardly and coiled against the side 68 of the guide to form the body portion 14 of the spring. In the prior art machine, the tool 62 remains retracted during the formation of the spring body 14 so that the individual coils of the spring lie alongside one another without spacing and tool 62 is not utilized until after the prescribed number of coils have been formed. Thereupon, the rocker arm 30 pivots about its spindle so as to move the tool support block 56 through an are which passes across and under the axis of the wire guide while tool 50 is being retracted. This movement of the support block causes the tool 62 on the pivot block to slide for wardly along the side 68 of the guide so that the apex 64 of the tool passes between the side 63 of the guide and the most recently produced coil which is disposed thereagainst. This causes the body 14 of the spring to move outwardly and tool 62 is then cammed around the end of the guide as shown in FIG. 9 so as to stop in a position in front of the guide channel to form the rear end loop of the completed spring. Tool 62 is thereupon retracted and cut-off tool 96 swings upwardly shearing the wire :at the end of the guide.

It will be apparent that, in the patented machine, the tool 62 is utilized only for forming the rear loop of a coil spring. In the present invention, however, tool 62 is used for another purpose as wellnamely, for spacing the individual coils of the spring body 14 from one another by a predetermined amount. The manner is which this is accomplished is illustrated in FIG. 6. From this figure, it will be noted that, unlike the patented machine, tool 62 has been moved into position between side 68 of guide 22 and the newly forming coil of spring body 14. Tool 62 operates in combination with the coil forming tool 50 to space the coils of the spring body by an amount determined by the wedge shape of tool 62 and by the extent of its advancement into the spring body 14. Upon completion of the spring body, tool 62 is caused to move forwardly along side 68 and around the end of the guide 22 as illustrated in FIGS. 8 and 9, so as to form the rear loop in the manner disclosed by the patent.

The cam 94 which actuates the tool 62 in such a manner as to form a spring body having spaced coils is most clearly illustrated in FIGS. 3 and 11. Cam 94 is made up of three parts, a fixed portion 94:: and two wedge shaped adjustable sectors 94b, 94c. By adjusting the position of sectors 94b, 94c, the dwell time of cam follower 88 at its maximum displacement from the center of cam 94 may be varied as required. Cam 94 operates against cam follower 88 which is secured to an arm 110 rotatably mounted on a pivot 112 and having a depending edge 110. Edge 110 abuts against the back of an adjustable shoulder 114 secured to a rod actuating arm 114. Arm 114 is pivoted to a fixed pivot 116 at one end and to the rod '76 at the other. Cam 94 operates in a clockwise direction as viewed from above. During formation of the initial loop 16, cam rider S8 is displaced to its maximum amount by means of the cam sections 94b, 940. This displaces pull rod 76 outwardly and thereby retracts tool 62 away from the end of guide 22. As coil forming tool 50 be gins to move into position, cam follower 88 rolls off of cam section 94b onto cam section 94a. The correspond ing inward displacement of cam follower 88 allows pull rod 76 to be pulled inward under the influence of spring 82 so that rocker arm 30 pivots about spindle 40 and advances tool 62 into the position shown in FIG. 6. The tool then remains in this position while the remainder of the coils forming spring body 14 are formed. Follower 88 then follows into the recess of cam 94, forcing tool 62 around the end of guide 22 to form the final loo in the manner previously described.

An additional advantage of this invention is that, by proper programming of the various cams, springs may be formed having spaced coils and no end loops. Accord= ingly, by controlling tool 62 in the manner herein de= scribed, there may be formed either tension springs hav= ing spaced coils and a loop at each end or compression springs formed without loops.

A further modification of this invention is illustrated in FIG. 12. This figure illustrates the manner in which the spacing of the coils of a spring body 14 may be varied In the illustrated modification, for example, the tool 62' is designed with a larger wedge angle so that the coils are displaced a greater distance from one another.

Many other variations and modifications may be made in this invention without departing from its spirit and scope. Accordingly, the foregoing description is to be construed as illustrative only rather than limiting. This invention is limited only by the scope of the following claims.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. A wire forming machine which comprises: a fixed wire guide having a rear end and a forward end and a bore therethrough terminating at said forward end in a feed orifice; feed means for advancing wire through said bore from said rear to said forward end; a coil forming tool mounted to be selectively advanced to a coil forming position adjacent the forward end of said guide; a coil spacing tool mounted to be advanced into a coil spacing position intermediate said wire guide and the coils being formed by said coil forming tool; and means for selectively advancing said coil spacing tool into said coil spacing position.

2. In a wire forming machine including a fixed wire guide having a rear end and a forward end and a bore therethrough terminating at said forward end in a feed orifice, feed means for advancing wire through said bore from said rear to said forward end, a first loop forming tool mounted to be selectively advanced to a loop forming psition adjacent the forward end of said guide, a coil forming tool mounted to be selectively advanced to a coil forming position adjacent the forward end of said guide, and a second loop forming tool mounted to be selectively advanced to a loop forming position adjacent the forward end of said guide, the improvement which comprises: actuating means for partially advancing said second loop forming tool to an intermediate coil spacing position to space from one another the coils being formed by said coil forming tool.

3. The improvement of claim 2 wherein said actuating means com-prises: rotatable cam means having at least first, second, and third cam surfaces, each cam surface being displaced from the center of rotation of said cam means by a different amount; cam follower means arranged to sequentially contact said first, second, and third cam surfaces during rotation of said cam means; first linkage means supporting said cam follower means and arranged to pivot in response to movement thereof; pivotally mounted rocker arm means having a first end and a second end; second linkage means connected intermediate said first linkage means and the first end of said rocker arm means to pivot said rocker arm means in response to movement said cam follower means; and means sup porting said second loop forming tool at the second end of said rocker arm means.

4. The improvement of claim 3 wherein said cam means is adjustable to vary the length of at least one of said cam surfaces.

5. A wire forming machine which comprises: a fixed wire guide having a rear end and a forward end and a bore theret-hrough terminating at said forward end in a feed orifice, said wire guide including a planar surface along its forward end; feed means for advancing wire through said bore from said rear to said forward end; a coil forming tool mounted to be selectively advanced to a coil forming position adjacent the forward end of said guide; and a wedge shaped coil spacing tool mounted to be advanced into a coil spacing position intermediate said wire guide and the coils being formed by said coil forming tool, one planar surface of said wedge shape being arranged to lie along said planar surface in said coil spacing position.

6. A wire forming machine which comprises: a fixed wire guide having a rear end and a forward end and a bore therethrough terminating at said forward end in a feed orifice; feed means for advancing wire through said bore from said rear to said forward end; a coil forming tool mounted to be selectively advanced to a coil forming position adjacent the forward end of said guide; and a coil spacing tool mounted to be advanced into a coil spacing position intermediate said wire guide and the coils being formed by said coil forming tool, said coil spacing tool being selectively moveable from said coil spacing position to a loop forming position adjacent the forward end of said guide.

References Cited by the Examiner UNITED STATES PATENTS 1,880,606 l0/l932 Vanderploeg 140103 3,025,889 3/1962 Clay 140-71 3,025,890 3/1962 Clay 14071 3,025,891 3/1962 Clay l-7l 3,240,238 3/1966 Sjobohm l03 X WILLIAM J. STEPHENSON, Primary Examiner.

Claims (1)

1. A WIRE FORMING MACHINE WHICH COMPRISES: A FIXED WIRE GUIDE HAVING A REAR END AND A FORWARD END AND A BORE THERETHROUGH TERMINATING AT SAID FORWARD END IN A FEED ORIFICE; FEED MEANS FOR ADVANCING WIRE THROUGH SAID BORE FROM SAID REAR TO SAID FORWARD END; A COIL FORMING TOOL MOUNTED TO BE SELECTIVELY ADVANCED TO A COIL FORMING POSITION ADJACENT THE FORWARD END OF SAID GUIDE; A COIL SPACING TOOL MOUNTED TO BE ADVANCED INTO A COIL SPACING POSITION INTERMEDIATE SAID WIRE GUIDE AND THE COILS BEING FORMED BY SAID COIL FORMING TOOL; AND MEANS FOR SELECTIVELY ADVANCING SAID COIL SPACING TOOL INTO SAID COIL SPACING POSITION.

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