US3313325A - Wire coiling machine - Google Patents

Description

April 11, 1967 A. c. WELLS WIRE COILING MACHINE 4 Sheets-Sheet 1 Filed June 25, 1964 April 11, 1967 A. c. WELLS 3,

WIRE COILING MACHINE Filed June 25, 1964 4 Sheets-Sheet 2 April 11, 1967 A. c. WELLS WIRE COILING MACHINE 4 Sheets-Sheet 3 Filed June 25, 1964 April 11, 1937 A. c. WELLS 3,313,325

WIRE COILING MACHINE Filed June 25, 1964 4 Sheets-Sheet 4 In: Vtil T i/r fe United States Patent ()fiice 3,313,325 Patented Apr. 11, 1967 3,313,325 WIRE CQHJNG MACHWE Alfred Charles Wells, Arkley, Barnet, England, assignmto A. Wells 8: Company Limited, London, England, a British company Filed .lnne 25, 1964, Ser. No. 377,937 Ciaims priority, application Great Britain, .i'une 28, 1963, 25,873/63 7 Claims. (Cl. 140-103) It is necessary that helically coiled wire springs should have their ends formed into loops which extend outwardly from the barrel of the spring. When the springs are to be used in anti-vibration mountings, such as those described in specification No. 571,026, it is desirable for the loops to be tucked into the ends of the barrel of the spring.

While machines for coiling wire into a helix have long been known, it has hitherto been necessary to transfer the springs formed by such a machine to a jig upon which the end loops are formed and tucked in one after the other. This has greatly slowed down the production of the springs.

The invention provides a mechanism, which may form part of, and constitute an attachment to, a wire coiling machine which enables the loops to be formed mechanically, so that the loops are formed at the same rate as that at which the coiling operation proceeds.

The invention provides a loop forming mechanism for use with a machine for making helically coiled wire springs, said mechanism comprising means for transferring springs in succession from a coiling station, at which the springs are coiled, to a looping station, jaws for engaging the ends of a spring transferred to the looping station by the transfer means, means for closing the jaws on the spring and afterwards opening them, dies at the looping station for embracing the barrel of the spring held in the jaws, means for closing the dies and afterwards opening them, blades at one side of the spring which are engageable with the end coils of the spring so held, means for advancing the blades to displace the extreme ends of said end coils to positions situated within the internal diameter of the barrel, forming knives at the other side of the spring and means for advancing the forming knives to lift the end coils and displace them into recesses in the jaws to form loops extending outwardly from the ends of the barrel of the spring.

One embodiment of the invention will now be described in detail, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a side elevation of the machine, partly in section,

FIG. 2 is a section on the line IIII of FIG. 1,

FIG. 3 is a section on the line IIIIII of FIG. 1,

FIG. 4 is a plan view, on a larger scale, of parts of the mechanism showing these parts in the same position as in FIGS. 1-3,

FIG. 5 is a section on the line VV in FIG. 4,

FIG. 6 is a view similar to FIG. 5 but showing holding jaws advanced to engage the ends of the spring,

FIG. 7 is a view similar to FIG. 4, showing the barrel of the spring held between dies,

FIG. 8 is a section on the line VIIIVIII in FIG. 7,

FIG. 9 is a view similar to FIGS. 5 and 8 but on a still larger scale, showing the final stage in the tucking of the end coils of the spring into its barrel,

FIGS. 10-13 are perspective views showing successive stages in the formation of the spring, and

FIG. 14 is an enlarged perspective view of one of the forming knives.

The loop forming mechanism shown in the drawings constitutes an attachment for fitting to a conventional wire coiling machine 10, of which only the basic elements are illustrated. The attachment consists of a base plate 11, carrying the various constituent mechanisms described in detail below, which is mounted in front of the machine It The wire coiling machine 10 includes a pair of intermittently driven feed rolls 12 which feed wire up to a stop 14-, constituted by a chisel-ended rod, guides 15, 16 serving to guide the wire through the machine. A mandrel 17 is positioned near the stop 14 and extends in a direction normal to the direction of feed of the wire, and upon rotation of the rolls 12 a length of wire is coiled into a spring which extends horizontally away from the mandrel and towards the plate 11. After the feed rolls 12 have been stopped and braked, a finger (not shown) operates to lift the last formed coil of the spring slightly from its neighbour and a knife 18 then severs the spring from the wire behind it.

The spring 19 is thus formed in a horizontal position as shown in FIG. 10, in which the barrel of the spring is indicated at 20 and the slightly lifted end coils at 21.

Immediately prior to severance of the spring by the knife it is gripped by a pair of transfer jaws 22, 23 (FIG. 2) which embrace the barrel of the spring and transfer it to a looping station, in which the spring is positioned vertically as shown in FIG. 11. At this sta tion, and as later described, the end coils of the spring are first moved inwardly as shown in FIG. 12, so that their extreme ends 21A are positioned within the inner diameter of the barrel 2%). The end coils are then erected and formed into loops tucked into the barrel as indicated at 2113 in FIG. 13.

The mechanism for transferring the springs from the coiling station to the looping station is shown most clearly in FIG. 2, which shows the parts in the position which they occupy shortly after the transfer of the spring to the looping station. The jaws 22, 23 are carried by a swinging transfer arm 24 fixed to a tube 25 which is mounted for rotation in bosses 26, 27 extending forwardly from the frame 11. The jaw 23 is formed on the outer end of a tubular plunger 28 which is slidably mounted in the arm 24 and which is urged towards the jaw 22 by a spring 29 which acts on a head 128 on the plunger 28. The jaw 22 is constituted by the outer end of another plunger 3t), disposed within the plunger 28 and urged to the position shown in FIG. 2 by a spring 31, mounted in compression between the pin 131 on the plunger 28 and the inner end of the plunger 36.

A rod 32 is slidably mounted in the tube 25 and is normally held in the position shown in FIG. 2 by a spring 33. Attached to the rod 32, by a screw 34 which extends through a slot 35 in the tube 25, are cams 36, 37 which respectively bear against the inner ends of the plungers 30 and 28. In the position shown in FIG. 2, the spring 31 holds the jaw 22 retracted and the cam 37 overpowers the spring 29 and urges the jaw 23 away from the jaw 22. As will be apparent from FIG. 2, movement of the rod 32 to the left will cause the cam 37 to allow the jaw 23 to be moved inwardly by the spring 29 and the cam 36 to force the jaw 22 outwardly, thus closing the jaws on a spring 19 positioned between them.

Movement of the rod 32 to the left to close the jaws is effected by a bell crank 38 (see also FIG. 1) which is pivoted on a pin 39 and carries a cam roller 40 which coacts with a cam 41 on a cam shaft 42. The roller 40 is maintained in contact with the cam by a spring 43.

The tube 25 carries a pinion 44 which meshes with a rack 45. As shown in FIG. 3, the rack 45 is formed on the exterior of a tube 46 having a head 47 which is urged downward-1y by tension springs 48 shown in FIG. 1. Within the tube 46 is a rod 49, carrying a roller 50 which coacts with a cam 51 on the cam shaft 42. A

spring 52 is mounted in compression between the rod 49 and the head 47.

As shown in FIG. 1, the transfer arm 24 carries a pair of projecting screws 53, 54. The screw 53 abuts against a stop to locate the arm 28 in its horizontal position at the looping station. When the cam 51 (FIG. 3) lifts the rod 49, movement is transmitted to the cam 28, through the spring 52, the rack 45 and the tube 25, so swinging the arm through 90 to a vertical position to receive a spring at the coiling station, the vmovement being terminated by contact of the screw 54 (FIG. 1) with a stop 56.

\Vhen the arm 24 arrives at the vertical position, the jaws 22, 23 are closed as described above to engage the spring which has just been coiled, the spring is then severed from the wire behind it and the arm returned to the horizontal position shown in FIGS. l-3. After holding jaws 57 have moved in to engage the ends of the spring so brought to the looping station, as will now be described, the jaws 22, 23 on the transfer arm 24 open to release the spring and the transfer arm 24 returns to the vertical position to collect the next spring.

The holding jaws 57 (FIG. 1) are mounted on the ends of scissonaction levers 58 which are pivoted, by a pin 59, to a slide 60 (FIG. 2) mounted to slide horizontally in the boss 26. The slide 60 normally occupies a position to the left of that shown in FIG. 2 'but has been advanced to the position of FIG. 2 to enable the jaws 57 to receive the spring from the jaws 22, 23 on the transfer arm. The jaws 57 are normally held open by a tension spring 61 connected between the ends of the levers 58. A cam 62, disposed between screws 63 on the levers 58, serves to close the jaws 57 when required. As shown in FIG. 2, tthe cam 62 is fixed to one end of a pin 64 having at its other end a cranked arm 65, which engages a groove 66 is a vertical slide 67. As shown in FIG. 1, the slide 67 is pivoted to a bell crank 68, pivoted on a pin 69 and connected by a link 70 to a lever 71 (FIG. 3) carrying a roller 72 engaging a cam 73 on the cam shaft 42. A spring 174 attached to the slide 67 maintains the roller 72 in contact with the cam 73. The jaws 57 close on the spring 19 immediately it reaches the looping station and remain closed until the looping operations have been completed.

After the jaws 57 have closed, the slide 60 is returned to the left to its normal position, so transferring the spring .19 from the position of FIG. 5 to that of FIG. 6, in which its barrel is embraced by a fixed die 74. This die extends for the full depth of the barrel and embraces one half of the circumference of the barrel. Movement of the slide 60 is effected by a pin 75 on the bell crank 76 pivoted on the pin 69. The pin 75 engages a slot 77 in the slide 60, as shown in FIG. 2, and the bell crank 76 is connected by a link 73 to a lever 79 carrying a roller 80 which is maintained by a spring 81 in engagement with a cam 82 on the cam shaft 42.

A slide 83, mounted for horizontal sliding movement in the right hand boss 27 and normally urged to the right by a spring 84, is then advanced by an arm 85 pivoted on the pin 39 and actuated from a cam 86 on the cam shaft 42 through the agency of a toggle linkage 87. A roller 88 which coacts with the cam 86 is mounted on an arm 89 and is urged into contact with the cam by a torsion spring 90. The arm 89 is connected by a link 91 to the toggle linkage 87 and a plunger 92, loaded by a spring 93, serves to return the toggle linkage if it should move over dead centre during advance of the slide 83.

A die 94 (FIG. 2) is slidably mounted in the slide 83 and urged to the left by a spring 95. This die is advanced by the slide 83 to embrace the other half of the barrel as shown in FIGS. 7 and 8 and the spring 95 thereafter yields upon further advance of the slide 83. A plunger 96, carried by the slide 83 and loaded by a spring Q7, then engages a lever 98, pivoted on a pin 99 adjacent the fixed die 74 and carrying blades 100 which are respectively situated above and below the fixed die oppoa site the end coils of the spring. The plunger rocks the lever 98 clockwise about the pin 99 as seen in FIG. 4 to cause the levers to set the end coils back as shown at 21A in FIG. 12. As will be seen the blades 11% serve to displace the extreme ends of the end coils to positions situated within the internal diameter of the barrel.

The slide 83 carries top and bottom forming knives 191 attached to it by screws 105. Each knife 101, as shown most clearly in FIG. 14, has a central tooth 102 which slopes forwardly and downwardly and which projects from the end face L93 of the knife which has a rearward inclination. The teeth 1&2 first engage the end coils of the spring at positions opposite the inwardly set parts 21A (FIG. 13) and lift these end coils partially from the barrel. The faces 163 then force the end coils into recesses 104 in the jaws 57, as shown in FIG. 9, so erecting the end coils and forcing them down into the barrel. It is not, however, essential that the end coils should be tucked into the barrel and loops which are not so tucked in may be formed at the ends of the barrel by variation in the shape of the recesses 164 in the jaws 57 and alteration of the angle of approach of the knives 101 to the spring.

After the operation shown in FIG. 9 has been completed, the slide 83 is returned to the right and the jaws 57 are opened to release the finished spring. An air blast may be used, if desired, to facilitate release of the spring.

What I claim as my invention and desire to secure by Letters Patent is:

1. A loop forming mechanism for use with a machine for making helically coiled wire springs, said mechanism comprising means for grasping springs and transferring them in succession from a coiling station, at which the springs are coiled, to a looping station, holding jaws for engaging the ends of a spring transferred to the looping station by the transfer means, means for closing the jaws on the spring and afterwards opening them, dies at the looping station for embracing the barrel of the spring held in the jaws, means for closing the dies and afterwards opening them, blades at one side of the spring which are engageable with the end coils of the spring so held, means for advancing the blades to displace the extreme ends of said end coils to positions situated within the internal diameter of the barrel, forming knives at the other side of the spring and means for advancing the forming knives after advance of said blades to lift the end coils and displace them into recesses in the jaws to form loops extendingoutwardly from the ends of the barrel of the spring.

2. A mechanism as claimed in claim 1, in which each forming knife has a central tooth for engaging beneath and lifting the adjacent end coil of the spring and an inclined face behind the tooth, which thereafter engages the end coil and forces it into the recess in the adjacent aws.

3. A mechanism as claimed in claim 1, in which the forming knives are effective to tuck the ends of the loop into the barrel.

4. A mechanism as claimed in claim 1, in which the grasping and transfer means comprises a swinging arm, transfer jaws on the arm for engaging the barrel of the spring, means for swinging the arm to move the transfer jaws from the coiling station to the looping station and back again and means for closing the transfer jaws upon a spring on arrival of the transfer jaws at the coiling station and opening the transfer jaws after the spring has been brought to the looping station and the holding jaws at said station have engaged the ends of the spring.

5. A mechanism as claimed in claim 1, which includes a frame, first and second slides mounted in the frame on opposite sides of the looping station, the first slide carrying the jaws for engaging the ends of the spring and the second slide carrying a movable die, the forming knives and means for actuating the blades, means for moving the first slide, after the jaws have engaged the ends of the spring, away from the second slide to engage the barrel of the spring with a fixed die located adjacent the blades, and means for thereafter advancing the second slide to engage the moving die with the barrel of the spring, eflFect actuation of the blades and effect formation of the loops on the spring by the forming knives.

6. A mechanism as claimed in claim 5, in which the movable die is slidably mounted in the second slide and backed by a spring which yields after the movable die has engaged the spring and upon further movement of the second slide to actuate the blades and engage the forming knives with the spring.

7. The combination with a wire coiling machine, comprising means for intermittently advancing a wire, means for forming the leading end of said wire to form a spring during advance of said Wire, and a knife for severing the springs in succession from the wire, of a loop forming U mechanism as claimed in claim 1, said transfer means comprising transfer jaws arranged to close upon the barrel of each spring after the spring has been coiled and before it has been severed from the Wire by the knife and to open after the ends of the spring have been engaged by said holding jaws.

References Cited by the Examiner UNITED STATES PATENTS 2,505,942 5/1950 Burge et a1. 140103 3,150,695 9/1964 Gatti 140-103 3,183,944 5/1965 Reddington 140103 CHARLES W. LANHAM, Primary Examiner. L. A. LARSEN, Assistant Examiner.

Claims (1)

1. A LOOP FORMING MECHANISM FOR USE WITH A MACHINE FOR MAKING HELICALLY COILED WIRE SPRINGS, SAID MECHANISM COMPRISING MEANS FOR GRASPING SPRINGS AND TRANSFERRING THEM IN SUCCESSION FROM A COILING STATION, AT WHICH THE SPRINGS ARE COILED, TO A LOOPING STATION, HOLDING JAWS FOR ENGAGING THE ENDS OF A SPRING TRANSFERRED TO THE LOOPING STATION BY THE TRANSFER MEANS, MEANS FOR CLOSING THE JAWS ON THE SPRING AND AFTERWARDS OPENING THEM, DIES AT THE LOOPING STATION FOR EMBRACING THE BARREL OF THE SPRING HELD IN THE JAWS, MEANS FOR CLOSING THE DIES AND AFTERWARDS OPENING THEM, BLADES AT ONE SIDE OF THE SPRING WHICH ARE ENGAGEABLE WITH THE END COILS OF THE SPRING SO HELD, MEANS FOR ADVANCING THE BLADES TO DISPLACE THE EXTREME ENDS OF SAID END COILS TO POSITIONS SITUATED WITHIN THE INTERNAL DIAMETER OF THE BARREL, FORMING KNIVES AT THE OTHER SIDE OF THE SPRING AND MEANS FOR ADVANCING THE FORMING KNIVES AFTER ADVANCE OF SAID BLADES TO LIFT THE

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