US3100512A

US3100512A - Looping device

Info

Publication number: US3100512A
Application number: US738473A
Authority: US
Inventors: Richard N Sage
Original assignee: International Business Machines Corp
Current assignee: International Business Machines Corp
Priority date: 1958-05-28
Filing date: 1958-05-28
Publication date: 1963-08-13
Anticipated expiration: 1980-08-13
Also published as: DE1188160B

Description

s- 3, 1963 R. N. SAGE 3,100,512

LOOPING DEVICE Filed May 28, 1958 4 Sheets-Sheet 1 1N VENTOR.

' RICHARD N. SAGE ATTOR EY Aug. 13, 1963 R. N. SAGE LOOPING DEVICE 4 Shee Filed May 28, 1958 Aug. 13, 1963 R. N. SAGE 3,100,512

LOOPING DEVICE Filed May 2a, 1958 4 Sheets-Sheet s Aug. 13, 1963 Filed May 28, 1958 4 Sheets-Sheet 4 100Vdc Q B 7 AUTO. R15 -1 L l Q O 1 0510 J Fm MAN. s10 w" r140 cs1? m R12 I LJ 124 fl- 0/ s11 0911 Q I I 4240 i I 52 W "I 540 0512 \b |"l R12---4Ll l 7 RIZ I s15 1 H4O 0515 JD ["1 I R15 L} R15 7 cs1e AUTO ems A FIG. 8

J74 my L% STATION POSITION n pp FORWARD BLOCK 504x11 OPEN CLOSED FORWARD CARRIER BACK KNIFE FORWARD BLOCK BACK ON MAGNET DOWN TRIGGER L United States Patent 3,100,512 LOOPING DEVICE Richard N. Sage, Endicott, N.Y., assignor to International Business Machines Corporation, New York, N .Y., a corporation of New York Filed lvlay 28, 1958, Ser. No. 738,473 7 Claims. (Cl. 140-102) This invention relates to apparatus for drawing and orienting a predetermined length of strand or filament, and more particularly to apparatus which pulls the strand or filament into a folded loop.

In the automatic manufacture of electrical [wires and other articles wherein specific lengths of long or continuous strands or filaments are isolated and have terminations attached thereto, it is desirable to remove a selected length of strand from a source of supply and maintain the strand in a correct orientation while the various steps in the process are being performed. Forming the strand into a loop one-half as long as the desired length of the article has been recognized as convenient since it leaves the two ends of the strand mutually adjacent.

Accordingly, the main object of this invention is to provide a fully automatic and reliable strand feeding, looping and orienting device.

The characteristics of prior devices include the threading of a loose end of strand into the looping means at each cycle. This requires a straight and somewhat rigid section of strand to avoid feeding failures. Other devices have pushed the strand into a characteristic confinement to which the strand conformed. The strand was necessarily pushed with some force which was expended by pressure-type feeding rolls. Such feeding means require rigid control over the diameter and surface condition of the strand supply, the variation of which causes feed failure.

The end and surface of a strand being pushed is likely to be damaged by rubbing against machine parts. Furthermore, to vary the length of the loop formed, said characteristic confining means must be changed, which reduces the effectiveness of the entire machine. Due to the compressive force on the strand, the exact position of the ends of the wire in the loop may vary causing machine problems at the stations performing operations on said ends.

Another object is to provide a device that pulls the strand into a folded loop without threading, a loose end during normal operation.

Another object is to provide a strand looping device that will not burr the ends nor chafe the surface of the strand.

Another object is to provide such a looping device that will insure uniformity in the position of the ends of the loop so formed.

Still another object is to provide a loop forming means that may readily be adjusted for various loop sizes.

Other objects of the invention will be pointed out in the following description and claims and illustrated in the accompanying drawings which disclose, by way of example, the principle of the invention and the best mode which has been contemplated of applying that principle.

In the drawings:

FIG. 1 is a perspective view, partially broken away, showing the essential parts of one illustrative embodiment of the invention in their positions at the start of a pulling cycle. 1

FIG. 2 is a partially sectioned and broken left side elevation of said embod ment, shown after the forming of the loop.

FIGS. 3a to 3d are plan views of a rotatable device illustrating the manner in which the device rotates,

Wrapping a length of strand into a loop, while retracting to provide clearance for the ends of the preceding loop.

FIG. 4 is a partial side elevation view of the carrier and rotatable device, pant-1y sectioned, illustrating the manner in which the trigger is guided behind the strand to be pulled.

FIG. 5a is a partial side elevation, partly sectioned, illustrating the position of the trigger and the strand prior to pulling the strand into the desired loop.

FIG. 5b is a partial plan view further illustrating the relationship of FIG. 5a.

FIG. 6 is a front elevation of the clamp assembly.

FIG. 7 is a vertical section on the line 77 of FIG. 1. FIG. 8 is a schematic diagram of the control circuitry.

FIG. 9 is a chart showing the sequence of operation of said embodiment.

In the present embodiment, the device is contemplated as being used in the manufacture of terminated electrical wires. In this embodiment the wire is first formed into a small loop and then the small loop is pulled into a larger loop. The end of a wire from a source of supply is gripped and wrapped around a capstan-like device, forming a small loop. A book or trigger then enters behind the wire through a radial slot in the capstan-like device and pulls the small loop radially outward while the end of the wire is still gripped by the capstan-like device, and the wire source freely supplies wire to make the larger loop. The trigger draws the wire into a channel, having wire clamping means, mounted on a rotatable work table. After the loop is pulled, the clamping means secures the wire in the channel and the wire is then severed from the supply by a cutting means. Before the wire is cut, the grippers in the capstan-like device are shifted, releasing the end of the wire and gripping the wire on the source-side of the cutting means. Since the clamping means secures the wire after it has been drawn into a taut loop by the trigger, and cutting takes place thereafter, the ends of the wire on all the loops so formed will be a uniform distance from the clamping means.

The loop of wire is thus drawn off, clamped, and severed from the source of supply. The ends of the loop extend radially from the periphery of the work table on which the clamped wire is rotated ,to the subsequent stations at which work is to be performed on the ends of the wire. In accordance with other features of the invention, the source of supply is left connected to the capstan-like device; it is not necessary to thread a free, loose end of wire into the device for the following cycle; and the wire is easily pulled, not pushed, into position.

The gripping, rotating and cutting portion of the embodiment described is disclosed in the copending application, Serial No. 664,980, Wire Cutting and Orienting Apparatus, R. Durham, Jr., filed June 11, 1957, now Patent No. 2,976,895. The reference numbers from 10' to 49 on this portion of the drawings are the same as those in the Durham application.

Rotating and Cutting Assembly Now referring to FIGS. 1 and 7, a movable slide member 10 having V-shaped ways 11 is mounted to slide in a fixed block 12 having guides .13 to receive the ways 11 respectively, thereby guiding the slide 10 in its movement. Movement of the slide 10 is actuated by an air cylinder (shown schematically as 14a in FIG. 8) having a piston rod 14 fixed to the slide .10. The slide 10 carries a Wire guide 15 spaced from and attached to the slide 10 by means of a dowel rod 16, and the wire guide 15 is drilled toreceive a guide tube 17 adapted to slide in a hole provided in a frame member 18 attachedto the fixed block 12. As the slide member 10 slides in either direction, a gear 25 fixed thereto is caused to rotate by its engagement with a rack 26 attached to the fixed block a 12, which rotation is transmitted by a shaft 24 to a drive disk 21 mounted within a rotatable stop block 20. The stop block 20 is journaled in the slide and hasfixed thereon a gripper block 28. The stop block is drivably connected to the drive disk 21 having inclined surfaces 22 machined into the face of the disk in a manner so that during rotation of the drive disk 21 in one direction, the drop-off step of the inclined surfaces 22 will engage spring-loaded clutch pins 23 carried in the stop block 20 so as to drive the stop block 20, and when the drive disk 21 is rotated in the opposite direction, the clutch pins 23 merely ride up the inclined surfaces 22 and drop off the step. The inclined surfaces 22 on the drive disk 21 are such that 'as the slide 10 is caused to be retracted by the air cylinder throughthe piston rod 14, the gear 25 is rotated (clockwise'in FIG. 1) by the rack 26 and therefore the stop block 20 is rotated through direction is limited by a spring-biased stop pin 19, which is constantly urged to bear against the periphery of the stop block 20, and which engages a notch therein when one-half revolution has been made. The stop pin 19 thereafter ensures that the stop block 20 will not rotate until forced to do so through the clutch pins 23.

The end of the wire coming from a supply of wire S (FIG. 1) is threaded through the guide tube 17 and the wire guide 15 and into a groove 27 in the rota-table gripper block 28 fixed to the stop block 20. The groove 27 extends inward from and around the periphery of the gripper block 28', which also has a slot 29 extending longitudinally there/through to accommodate a slidable cam plate 30, as well as having vertically extending holes 31 and 32 (FIG. 7) to accommodate gripping pins 33 i and 34 biased by

spring

35 and 36, respectively. The cam plate 30* is slotted to permit the

gripping pins

33 and 34 to extend therethrough and is provided with cam surfaces 37 and 38 to alternately act against

shoulders

39 and 40 on the gripping pins'33 and 34, respectively,

to move in a guide block 43 attached to the fixed block 12. Movement of the slidable block 42 is at right angles to movement of the slide member 110*. An air cylinder (shown schematically as 44a in FIG. 8) having a piston rod 44 (FIG. 1) connected to the slidable block 42 drives the block 42 toward and away from the slidable cam plate 30. The slidable block 42 also carries a knife 45 for cutting off the wire gripped in the groove 27 of the gripper block 28. The knife 45 is adapted to enter one of two identical cutouts 46a, 461) provided in the gripping block 28, which cutouts also provide a cooperating surface for the knife 45 during the cutting operation. The drive pin 41 is disposed in the slidable block 42 in a manner so that it will engage the slidable cam plate 30 and move it laterally until the slidable cam plate 30 strikes a stop pin 47 secured in the fixed block 12, so that the pin which had been gripping the end of the wire (shown at A in FIG. 1) releases its grip and the nongripping pin (shown at B in FIG. 1) moves into a gripping position to grip the wire from lthe supply S prior to the knife 45 severing the wire. Hence as the wire is severed from the supply S, the newly createdend from the supply S will'be already gripped. It is neces- 'sary to spring load thedrive pin 41 so as to allow further travel of the slidable block 42 to move the knife 45 into the cutting position after the drive pin -41 has moved the slidable cam plate 30 into the stop pin 47.

The gripper block 28 has two'notches 48, 49 which permit the trigger 61 to get down behind the wire after the wire has been wrapped into a small loop. Each notch has a pair of

pins

48a, 49a, respectively, disposed midway on either side of the notch. The pins cause the wire to be stretched across the notch in a manner to allow suf- -ficient clearance for the trigger to lower itself behind the wire.

Pulling Assembly Referring now to FIG. 1 and FIG. 2, two

tubular slides

51 and 52 are fixed as cantilevers on a main frame -A carrier 60 is slidably disposed on and between the slides and has a central slot in which a wire-pulling trig- I get 61, a lever 63, and a switching pin 65 are all mounted.

the clutch pins 23. Movement of the slide :10 in this Y placed away from the trigger by a shoulder 68 when the The trigger 61 is held in an operating position (FIG. 5). by the lever 63 under the action of a spring 64 as the carrier travels outwardly on the slides and is held in a restoring position (FIG. 2) by a leaf spring 62 as the carrier returns toward the main frame. The switching pin 65 is held by a spring 66 against a flat 67 on the trigger'when the trigger is down (FIG. 5) and is distrigger is up (FIG. 2). Also disposed on the slides is a switch block 70' which is moved to the desired operating position and then looked in place by tightening a screw adapted to pinch the slide 52 within the slotted hole 71 (FIG. 1). The switch block holds two

interlock switches

72 and 74 with actuating

pins

73 and 75 adapted to be restrains a pin 84 on an armature 85 of a restoring magnet 86. When energized as in FIG. 2, the magnet rotates the link clockwise against the action of a spring 87. The restoring bail 80 serves to rotate the lever 63 counterclockwise so as to permit the rotation of the trigger into the retracted position by the leaf spring 62. The main frame 50 also supports a switch 76 having an actuating pin 77 adapted to be operated by the carrier 60 when in its forward position. An air cylinder 54a operates a rod 54 which drives the carrier along the slides.

Below the cantilever assembly, a device for holding the wire loop is mounted on a rotary work holding table 100. A channel 101 has a longitudinal slot 102 (FIG. 1) within which the trigger may pass when pulling the wire into a loop 103 (FIG. 2). The loop of wire is secured withinthe channel by a wire clamp comprising a lower jaw 104 and a pair of

upper jaws

105, 106. The channel 101 is fastened to the block 107 which in turn is fastened to the table 100. Referring to FIGS. 1, 2 and 6,, a pair of lifting bolts 121 are disposed on either side of the clamp assembly and are restrained downward by springs 122 and secured by nuts 123 to a lifting bar 120 which is displaced upwardly on occasion so as to raise the lifting bolts. The lifting bolts pass through clearance holes in the lower jaw 104 and each bolt is fastened to one ofthe upper jaws respectively. An air cylinder (shown schematically as 124a in FIG. 8) operates a rod 124 against the lifting bar which raises the

upper jaws

105, 106 against the springs 122 releasing the hold on the wire loop 103 and permitting entry lOf another portion of wire into the clamp. Wiring Diagram Shown in FIG. 8 is a schematic representation of a simple control means for the embodiment of the invention shown. The electrical circuit operates on volt DC. power, and includes the aforementioned interlock switches on the cantilever assembly, additional control switches and control relays. The object of the circuits is to operate the solenoid-controlled air cylinder shown schematically on the right side of the diagram, and to operate the trigger releasing magnet 86. When the AUTO/ MAN switch is at AUTO, or at MAN and the start key SK is depressed, the station index switch C810 (not shown mechanically) connects the positive side of the source to S16 through a normally closed relay contact R13a or the normally closed knife-retracted switch C817 (FIG. 1). When S is energized, the air cylinder 14a operates the rod 14 (FIG. 1) so as to push the slide 10 forward (to the ieft). When the slide is forward, the normally open contact of the slide-forward switch C511 (FIG. 1) closes connecting the positive side of the source to S11 through a normally closed relay contact R12a. With S11 energized, the air cylinder 124a causes the rod 124 (FIGS. 2 and 6) to rise, thereby lifting the upper jaws (105, 166) of the clamp, permitting entry of a wire into the channel 101. With the clamp open, the switch C812 is operated by the lifting bar 120, closing the normally open contact thereof which connects S12 to the positive side of the source through the normally closed relay contact R1211. When S12 is energized, the air cylinder 54a causes the rod 54 to pull the carrier 60 toward the main frame 50. The carrier then contacts the actuating pin 77 of the carrierforward switch 76, closing its normally open contact which connects the coil of relay R12 to the positive side of the source. When R12 is energized, the common contact R12b transfers from the normally closed side to the normally open side, which disenergizes S12, and provides holding current to the coil of R12 through the clamp-open switch C812. The air cylinder 54a is thereby reversed, and the rod 54 pushes the carrier 60' back out on the cantileverslides toward the switch block '70. The relay R12 is necessary to prevent re-reversal of the air cylinder 54a afterthe rod 54 pushes the carrier 60* away from the switch 76 sufiiciently to allow its contact to re open. When the rod 54 has pushedthe carrier 60 against the switch 72 mounted on the switch block 70, the normally closed contact of switch 72 is opened, and the normally closed relay contact R12a having opened when R12 transferred, the clamp-opening solenoid S11 becomes disenergized. Air cylinder 124a therefore reverses, causing rod 124 to lower permitting the upper jaws 1115, 106 to be forced down against the lower jaw 104 by the springs 122. As the jaw lifting bar 120 lowers, the

left against the actuating pin 75 of the switch 74. Switch 7'4 is an interlock switch which indicates to the main control circuit of the wire-making machine that the feeding operation is complete. The channel 101 and clamp assembly will then be rotated on the table 106* to present the wire to the next station, and a subsequent, empty channel and clamp assembly will rotate into position under the cantilever assembly.

Feeding Operation of the device for the first time, or whenever a new spool of wire is to be used, necessitates feeding the wire through the guide tube 17 and the wire guide 15 into the groove 27. The cam plate 30 should be in position shown in FIG. 1, and may be so placed manually. The wire is then fed over the gripper pin shown at B, and the cam plate manually pushed against the stop pin 47, to ward the right in FIG. 1. With the wire in place as described, it remains to rotate the gripper block 28 so as to form the small loop before the desired larger loop may be pulled into being. Since the nature of the solenoidoperated air cylinders is to place their respective rods in the position normally taken at the end of a cycle when disenergized, the slide 11? and knife block 42 will be retracted, the carrier 60 will be out on the cantilever and the clamp will be closed when power is first applied. Before the 100 volt DC. power is turned on, the AUTO/ MAN switch should be at MAN.

To cause the wire to be wrapped around the gripper block 28, the start key SK should be closed for one full cycle, it being released as the block '10 retracts at the end normally open contact of C812 again opens, disenergizing R1312. As S13 is energized, air cylinder 44a causes the knife block rod 44 to move the knife bloc-k forward toward the wire. The knife-in switch C816 is then actuated,

closing its normally open contact which connects R13 to the positive side of the source. R13 operates transferring its relay point R131) to the normally open side, and opening its normally closed relay point R13a (in the circuit of S10). When R1312 transfers, S13 is disenergized, which causes air cylinder 44a to reverse and rod 4-4 pulls the knife block 42 back away from the gripper block 21). R13 is maintained energized through its normally open contact R131) and the clamp-closed switch C815. When the knife block 42 is all of the way back in its normal position (FIG. 1), the knife-back switch C317 is actuated, opening its normally closed contact; R1311 having opened when the knife was in, S10 is thereby disenergized, and the air cylinder 14a reverses causing the rod 14 to retract the slide 10 toward to right in FIG. 1. With the slide retracted all the way, the slide switch C518 is actuated closing its normally open contact which connects the magnet 86 to the positive side of the source. When the magnet is energized (FIG. 2) it causes the bail 83 to rotate the lever 63 permitting the trigger 61 to rotate upward into the retracted position. The shoulder 68 on the trigger -61 forces the switch operating pin 65 to the of the cycle. The interlock switch 74 is rendered ineffective by the AUTO/ MAN switch, so that the work holding table does not index to the next station. The AUTO/ MAN switch is then placed to AUTO, and the machine will automatically proceed through successive cycles thereafter.

Operation Assuming that the machine has been in operation for more than two cycles, the complete operation of the device will now be traced, as shown in FIG. 9, beginning with the approach of an empty channel 101 and clamp assembly to the feed station. When the empty channel 101 is properly indexed under the cantilever assembly, the station index switch C810 closes causing the air cylinder 14a to move the slide 10 forward. As the slide 10 moves forward, the gear 25 and shaft 24 (FIGS. 1 and 7) are rotated counterclockwise by the rack 26, but the clutch pins 23 merely ride up the inclined surfaces '22 of the drive disk 21, so that the spring biased pin 19 holds the rotatable stop block 211, and therefore the gripper block 28, in the same rotational orientation. When the gripper block as sembly is all the way forward toward the work holding table, the slide-forward switch C511 is operated, causing the air cylinder rod 124(FIGS. 2 and 6) to move the lift bar 120 upward. As the lift bar is raised, the bolts 121 cause the upper jaws 1115, 1% to be raised against the action of the springs 12 2. The clamp is now open permitting entry of the wire into the channel 101, and the clamp-open switch C512 is closed, which causes the air cylinder rod 54- to pull the carrier 60 from its position against the switch block 7% as shown in FIG. 2 toward the main frame 50. When the trig er 61 contacts the main frame 50 as shown in FIG. 4, it is rotated clockwise so as to go down into the notch 48 (FIGS. 1, 5a and 5b) or 4 9, as the case may be, and behind the wire stretched across the

pins

48a or 49a, respectively. The magnet 86 has been disenergized and the bail 81) therefore has been up as shown in FIG. 5. The lever spring 64 (FIG. 4) tends to push the lever 63 clockwise so as to latch the trigger 61, so that as the trigger is rotated against the leaf latching of'the trigger by the lever 63 is provided so that the trigger will be latched before being driven flat against the frame 50. The carrier 68 contacts the actuating pin 77 of the carrier-forward switch 76, which reverses the air cylinder 54a, :and the rod 54 then pushes the carrier 60 backout on the cantilever slides 51, 52. The end of the wire is gripped by the gripper pin (33 in FIG. 7) shown at A in FIG. 1, and the source of wire S supplies any amount of wire necessary, under a slight tension, to form the loop as the trigger moves outward. The length of the loop so formed will depend on the position of the switch block 70 on the cantilever slides 51, 52 (FIG. 1). It is a simple matter to loosen a screw (not shown) to relieve the pinching effect of the slot 7-1 on the slide 52, and then slide the block 76 to the desired position; the screw is then tightened to maintain the block 7%) in that position.

When the carrier 60 hits the actuating pin 73 of the carrier-back switch 72, the contacts thereof open and reverse the air cylinder 1240, which retracts the rod 124 downward (FIGS. 2 and 6). The springs 122 displace the nuts 123 downward so that the bolts 121 pull the upper jaws 105, :106 down against the wire 1%, firmly clamping it in place. At this time, the wire 103 is stretched from the gripper block 28 through the clamp assembly as shown in FIG. 3a into the channel 101. With the clamp closed, the switch C815 is closed causing the knife block air cylinder-44a to force the rod 44 toward the upper right in FIG. 1. The rod 44 moves the knife block 42 toward the gripper block 28, and the spring-loaded drive pin 41 pushes the cam plate 30 toward the left of FIG. 7. The cam surface 37 bears against the shoulder 39 of the clutch pin 33 and forces it down against the spring 35-; the cam surface 38 releasesthe shoulder 40 of the clutch pin 34 which is pushed upward by the spring 36 against. the wire within the slot 27. When the cam plate 30' butts against the stop pin 47, the drive pin 41 is also stopped, but the spring loading thereof permits the 'block 42 to continue toward the left in FIG. 7 far enough for the knife 45' to cut the wire, as shown in phantom in FIG. 311. When the block 42 is all the way forward, the knife-in switch C316 (FIG. 1) is closed which reverses the air cylinder 44a, causing the rod -44 to pull the block 42 back to its rest position. With the block 42 back, the knife-back switch C817 is opened, which reverses the :air cylinder 14a causing rod 14 to pullthe slide back toward the retracted position. Referring to FIG. 1 and FIG. 7, as the slide 10 retracts, the fixed rack 26 rotates the gear 25 and shaft 24, causing the drive disk 21 to rotate clockwise. drop-off steps of the inclined surfaces 22, causing the stop block 20 to also rotate clockwise. 'l he spring-biased pin 19 is forced back and out of the detent, and thereafter bears against the periphery of the stop block until the stop block rotates one-half revolution so as to present another detent to the pin '19. The pin 19 will fall into this detent and serve to ensure. stopping the rotation at the correct orientation, in cooperation with the abutment of wire guide and frame member 18. Referring now to FIG. 3, when the knife has made the cut, the wire 1%, gripper block 28, and wire guide 15 are as shown in FIG. 3a. In 'FIG. 3b, the. gripper block and guide have retracted slightly, and the gripper block has rotated part way. The end of the wire from the source is gripped by the gripper pin 36 and is drawn taut over the lower pin 4%. In FIG. 30, the gripper block and guide have retracted about twothirds of the way, and the gripper block has rotated about one-third of a revolution. The ends of the wire loop 103 have almost been cleared, and the wire from the source is now taut over both pins 49a, and is therefore stretched across the notch 49. In FIG. 3d, the gripper block and guide are retracted all the way, and the gripper block has rotated one-half revolution. The ends of the wire loop have been cleared, so that the channel 101 and clamp assembly may be rotated to the next operating station without bending said ends. With the slide 10 completely re- The clutch pins 23 are pushed by the 7 tracted switch C818 (FIG. 1) is closed energizingthei magnet 86 (FIG. 2) causing the bail to bear downon and rotate the lever 63. When the lever 63 clears the lip on the trigger 61, the trigger rotates into the retracted position as shown in FIG. 2 under the action of the leaf spring 62. The-shoulder 68 on the trigger forces the switch operating pin 65 to bear against the actuating pin 75 of the interlock switch '74, the pin 75 having been extended within the hole 69 therebefore. The switch 74' indicates to the main machine control circuitry that the feed operation is complete, and ensures that-the trigger is retracted clear of the channel 101 prior to indexing'said channel to the next station.

Several features of the invention should be emphasized. Once the end of wire from a particular source or spool has been threaded into the machine, control is maintained over that the subsequent ends of the wire until the wire is consumed. No end need be threaded during normal operation; the wire is never pushed, but is pulled in every phase of the operation. The wire pulled into the main loop need not go around corners, and no chafing of the surface or burring of the end'thereof takes place. Thetrigger is able to get behind the wire into a position from which the wire may be pulled after the wire is already in place with a minimum of access space, which facilitates use with feeding devices wherein the end of the wire is continuously gripped.

While there have been shown and described and pointed out the fundamental novel features of the invention as applied to the preferred embodiment, it 'Will be under stood that various omissions and substitutions and changes: inthe form and-details of the device illustrated and in its operation may be. made by those skilled in the art without departing from the spirit of the invention; It is the intention, therefore, to be limited only as indicated by the scope of the following claims.

What is claimedis:

. 1. A device for forming an extended loop-from a source of a long or continuous strand'or filament, comprising:

Looping means including movable gripping means for grippingthe end of said strand and means for moving said gripping means to bend an end portion of said strand back upon itself;

movable loop pulling means adapted to engage said strand;

means for causing said loop pulling means to engage said bent portion of said strand; and" 1 means for moving said loop pulling means in a direc tion parallel to the portion of strand extending from the source to said looping means, said means for moving sald loop pulling means thereby exertinga pulling force on said strand while said'end of said strand remains gripped, so as to pull said bent back portion of said strand into an extended loop.

2. A device for forming an extended loop from a source of a long or continuous strand or filament, comprising:

loop ngmeans including movable grippingmeans for gripping the end of said strand and means for movmg said gripping means to bend an end portion of said strand back upon itself;

movable loop pulling means adapted to engage said strand;

means for causing said loop pulling means to engage said bent portion of said strand;

means for moving said loop pulling means in a direction parallel to the portion of strand extending from the source to said looping means, said means for moving said loop pulling means thereby exerting a pulling force on said strand while said end of said strand remains gripped, so as to pull said bent back portion of said strand into an extended loop; and

means for severing said extended loop from the source of supply.

3. A device for forming an extended loop from a source of a long or continuous strand or filament, comprising:

strand gripping means;

operating means for causing said gripping means to grip the end of said strand;

pulling means movable from aposition adjacent said gripping means to a position more remote from said gripping means along a line substantially parallel to the portion of strand extending from the source to said gripping means;

means for moving said gripping means to a point offset from said line;

means coaoting with said strand during said offsetting movement to form a portion of said strand bent away from said line;

means for causing said pulling means to engage said bent away portion of said strand;

driving means for driving said pulling means along said lines;

and means for causing said driving means to operate after said pulling meanshas engaged said bent away portion of said strand to pull a portion of said strand into an extended loop.

4. A device for forming an extended loop from a source of a long or continuous strand or filament, comprising:

strand gripping means;

operating means for causing said gripping means to grip the end of said strand;

pulling means movable from a position adjacent said gripping means to a position more remote from said gripping means along a line substantially parallel to the portion of strand extending from the source to said gripping means;

means for moving said gripping means to a point offset from said line;

means coacting with said strand during said ofi'setting movement to form a portion of said strand bent away from said line;

driving means for driving said pull-ing means along said line;

means for causing said driving means to operate after said pulling means has engaged said bent away portion of said strand to pull a portion of said strand into an extended loop;

and means responsive to said operating means for severing the looped portion of said strand from the source of supply;

said operating means being effective to cause said gripping means to grip a subsequent portion of said strand after said loop is formed, and to operate said severing means after said subsequent portion has been gripped.

5. A device for forming and isolating an extended loop from a source of a long or continuous strand or filament, comprising:

a rotatable gripping device having a pair of alternatively operable strand grippers diametrically disposed thereon;

operating means effective to cause a first one of said grippers to secure the end of said strand;

means to rotate said gripping device one-half revolution after said first gripper secures the end of said strand, thereby forming an end portion of said strand into a small loop;

loop pulling means movable from a position adjacent said gripping device to a position more remote from said gripping device along a line substantially parallel to the portion of strand extending from the source to said gripping device;

means for placing said loop pulling means Within a small loop formed by said rotatable gripping device;

means for moving said loop pulling means away from said rotatable gripping device along said line so as to form an extended loop, said operating means also being effective to cause said first gripper to release said strand and to cause the second one of said grippers to grip said strand after said extended loop is formed;

means for severing said extended loop from the source of supply;

and means responsive to said operating means for causing said severing means to sever said strand at a point on the extended loop side of said second gripper after said second gripper grips said strand.

6. A device for enlarging asmall loop which is on the end of a long or continuous strand or filament, comprising:

retractable loop pulling means;

a carrier member for supporting said loop pulling means;

a slide assembly on which said carrier member is slidably disposed;

means for moving said carrier member along said slide assembly in a first direction toward said small loop or in a reverse direction, alternatively;

means acting on said carrier moving means for arresting the motion in said first direction of said carrier and for causing said moving means to move said carrier in said reverse direction;

means for placing said loop pulling means within said small loop and for maintaining said loop pulling means in contact with the strand as said carrier member slides on said slide assembly in said reverse direction;

limit means for limiting the distance traveled by said carrier member in extending said loop in said reverse direction, said limit means being slidably disposed on said slide assembly;

means responsive to said limit means for retracting said loop pulling means out of engagement with said loop when said carrier is stopped by said limit means;

and means for securing said limit means at selected positions on said slide assembly.

7. A device for forming and isolating an extended loop from a source of a long or continuous strand or filament, comprising:

retractable loop pulling means;

a carrier member for supporting said loop pulling means;

a slide assembly on which said carrier is slidably disposed, said slide assembly being oriented so as to provide a path which is parallel to the direction of the strand extending from the source to said gripping device along which said carrier may slide;

means for moving said carrier member along said slide assembly in a first direction toward said gripping device or in a reverse direction, alternatively;

means for placing said loop pulling means within a small loop formed by said gripping device, and for maintaining said loop pulling means in contact with said strand as said carrier member slides on said slide assembly in said reverse direction;

limit means for limiting the distance traveled by said carrier member in extending said loop in said reverse direction;

means responsive to said limit means for retracting said a loop pulling meansout of engagement with said loop when said carrier is stopped by said limit means, said operating means also being efieetive to cause said first gripper to release said strand and to cause the second of said grippers to grip said strand after said extended loop is formed; 7

means forsevering said extended'loop from the source of supply;

' and means "responsive to said operating means for causing said severing means to sever said strand at a point on the extended loop side of said second gripper after said second gripper grips said strand.

References Cited in the file of this patent UNITED STATES PATENTS Kremer Mar. 1, 1892 Hunt Apr. 7, 1931 Lewis Dec. 14, 1937 OGrady Aug. 1, 1939 Lewis July 6, 1948 Kaupke et a1. Aug. 10, 1948 Dashew Nov. 23, 1948 Raney et a1. July 4, 1950 Brekle Oct. 7, 1952 Pityo June 5, 1956 Durham Mar. 28, 1961

Claims

1. A DEVICE FOR FORMING AN EXTENDED LOOP FROM A SOURCE OF A LONG OR CONTINUOUS STRAND OR FILAMENT, COMPRISING: LOOPING MEANS INCLUDING MOVABLE GRIPPING MEANS FOR GRIPPING THE END OF SAID STRAND AND MEANS FOR MOVING SAID GRIPPING MEANS TO BEND AN END PORTION OF SAID STRAND BACK UPON ITSELF; MOVABLE LOOP PULLING MEANS ADAPTED TO ENGAGE SAID STRAND; MEANS FOR CAUSING SAID LOOP PULLING MEANS TO ENGAGE SAID BENT PORTION OF SAID STRAND; AND MEANS FOR MOVING SAID LOOP PULLING MEANS IN A DIRECTION PARALLEL TO THE PORTION OF STRAND EXTENDING FROM THE SOURCE TO SAID LOOPING MEANS, SAID MEANS FOR MOVING SAID LOOP PULLING MEANS THEREBY EXERTING A PULLING FORCE ON SAID STRAND WHILE SAID END OF SAID STRAND REMAINS GRIPPED, SO AS TO PULL SAID BENT BACK PORTION OF SAID STRAND INTO AN EXTEDED LOOP.