US2336611A

US2336611A - Strap forming machine

Info

Publication number: US2336611A
Application number: US440618A
Authority: US
Inventors: George M Hill; George S Hill
Original assignee: Individual
Current assignee: Individual
Priority date: 1942-04-27
Filing date: 1942-04-27
Publication date: 1943-12-14
Anticipated expiration: 1960-12-14

Description

Dec. 14, 1943.

G. M. HILL ET AL STRAP FORMING MACHINE Filed April 27, 1942 3 sheets-sheet 1 Dec. 14, 1943. G. M. HILL ET AL STRAP FORMING MACHINE Filed April 27, 1942 51 sheets-sheet 2 .97 27 55 O QFD? l V o 50 i *in .Era-.2.

GEORGE/1l. A744,

INVENTORS Der 14, 1943. G. M, HILL ET A1. 2,336,611

STRAP FORMINCT MACHINE I Filed April 27, 1942 s sheets-Sheet s @mm-M Am,

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Patented Dec. 14, 1943 UNITED STRAP FORMING MACHTLNE George M. Hill and George S. Hill, Long Beach, Calif.

Application April 27, 1942, Serial No. 440,618

(Cl. lill- 74) 12 Claims.

Our invention relates to box strapping machines and has particular reference to a machine for forming and supplying to a box strapping machine a preformed strap adapted to be fed through the strap holding magazine and strap feeding mechanisms of such box strapping machines.

In many fields, particularly in the field of packing of citrus fruits, it has long been the practice to package the fruit in Wood boxes, over which is placed a relatively thin wood slat cover which is nailed to the box ends at each end of the cover while the center is held in close relation to the box by means of a strap of strip metal or wire placed across the cover and secured to the sides of the box on opposite sides of the cover.

One popular form of box strapping machine employed for applying these straps to citrus boxes is that illustrated and described in United States Letters Patent to George D. Parker, No. 1,777,474, issued October 7, 1930, in which is illustrated and described a machine which includes a suitable roller table or conveyor table for supporting a packed box of citrus fruit over which a cover has been placed and nailed but which cover, due to the practice of packing citrus fruit to a considerable level above the top edges of the box, is bowed or bulges up at the center of the cover to a considerable distance above the top edges of the box.

The machine there illustrated includes an arcuately curved presser shoe adapted to be power driven downwardly toward the covered box to engage the cover at its approximate transverse center to press the thin cover downwardly toward the box and to arcuately shape the cover transversely and then, while so holding the cover, a Wire strap pre-formed with inwardly bent sharpened ends is placed across the bowed and shaped cover with the ends of the strap extending a considerable distance on either side of the edges of the cover. The overhanging ends are bent downwardly along the sides of the box and the sharpened preformed ends of the strap are then driven into the sides of the box, securing the strap in place about the cover.

This type of machine includes a magazine for holding a supply of wire straps with their preformed sharpened ends ready to be fed by an automatic feeding device into the strap applying bending and driving portions of the machine. Heretofore it has been the practice to supply wire straps for these machines on cards or other holders which will hold a suitable number of straps in a substantially sheet form ready to be dropped into the strap holding magazine of the strapping machine, requiring that the package or form upon which the straps are mounted to hold them in the flat sheet-like shape to be either torn 01T and discarded or requiring that the forms or holders *or cards or holders is a laborious operation and involves considerable expense for the forms or cards as well as considerable nuisance to the operators of the strapping machines in the necessity for removing the forms and returning the forms to the strap manufacturing establishment.

It is therefore an object of our invention to provide a strap forming apparatus which may be attached to these strap applying machines, adapted to receive a supply of straight wires cut to the desired length, the strap forming apparatus then functioning to form or bend the driving ends of the strap into their correct positions at a point located immediately above the magazine of the strap applying machine so that each strap as it is formed will drop into the magazine, thus loading the magazine with a supply of straps without the necessity of first mounting them upon cards, forms or other loading devices.

Another object of our invention is to provide a strap forming apparatus of the character set forth, in which the strap forming operations may be performed independently of the operations of the strap applying machine so that a relatively few minutes of operation of the strap forming apparatus will produce a supply of straps in the magazine of the strap applying machine to last for a considerably greater length of time of operation of the strap applying machine.

Another obiect of our invention is to provide a strap forming apparatus of the character set forth, which may be automatically controlled by the depletion and replenishment of straps in the magazine of the strap applying machine whereby the strap forming machine need be operated only during such time as is required to rell the magazine of the strap applying machine.

Other objects and advantages of our invention will be apparent from a study of the following specifications, read in connection with the accompanying drawings, wherein Fig. 1 is a side elevational view of a strap applying machine of the George D. Parker type noted above with my strap forming apparatus attached thereto;

Fig. 2 is a top plan view of the strap forming apparatus shown in Fig. 1;

Fig. 3 is a vertical sectional View taken along line III-III of Fig. 2;

Fig. 4 is a fragmentary plan view of the strap bending and forming portions of the machine shown in Figs. 1, 2 and 3 illustrating the positions of the parts at the time at the completion of the bending or forming of one strap;

Fig. 5 is a fragmentary view similar to Fig. 4

but illustrating the positions of the parts during the bending or forming operations;

Fig. 6 is a perspective View of that portion of the machine shown in Figs. 4 and 5 and illustrating the positions of the parts at the time a fresh cut wire is deposited upon the bending or forming apparatus;

7 is a horizontal sectional view through the magazine portion of the strap applying machine shown in Fig. 1, taken along line VII-VII of Fig. 1, illustrating the supporting plate for my strapping apparatus in phantom or dotted lines; and

Fig. 8 is a diagrammatic View of the control circuits and switches by which the control of my strap forming apparatus is accomplished.

Referring to the drawings, we have illustrated in Fig. l a strap applying machine of the type illustrated and described in the George D. Parker Patent No. 1,777,474 above referred to as comprising a suitable conveyor table I constructed with a plurality of conveyor rollers 2, over which a lled and covered box of fruit 3 may pass to a position in the machine at which a box strap is to be applied across the center of the cover of the box. The conveyor table I is supported upon a suitable frame-work including end frames il and between which may be located a suitable motor and gearing indicated generally at 6, by which a strap applying mechanism indicated at 'l may be caused to reciprocate vertically to press the central portion of the cover into the correct position and shape and by which a wire strap having pre-formed and sharpened ends may be bent into position and the ends of the strap driven into the sides of the box.

The strap applying machine also includes a pair of vertically extending uprights 8 (only one of which is shown in Fig. 1) to provide a vertically extending standard of considerable height, within which is located a strap holding magazine 9 for holding a supply o-f cut and formed straps in vertical alignment one upon the other to be fed from the magazine by suitable strap feeding mechanism IFJ which presses the lowermost strap laterally from the magazine and into a position to be engaged and operated upon by the strap applying apparatus '1.

By referring particularly to Fig. 7, it will be observed that the magazine portion of the machine includes the uprights 8, between which extend cross bars II spaced vertically along the length of the bars 8, the cross bars constituting a support for a pair of elongated strap holding brackets i2 and I3 so shaped and spaced as to engage the oppositely inwardly bent ends I4 and I5 of a pre-formed wire strap I6, the ends I4 and l5 of the strap loosely engaging the brackets I 2 and i3 so as to permit the straps to readily slide downwardly along the brackets as the lowrmost straps are fed out of the magazine by the strap feeding apparatus IJ. All of the foregoing is standard construction in the George D. Parker type of box strapping machine.

Referring again to Fig. 1, I have illustrated my strap forming apparatus as including a suitable base or base plate I'l substantially rectangular in shape and (see Fig. 7) having a width sufficient to extend across and project beyond the upper ends of the uprights 8 of the strap applying machine, the base plate I1 being secured to the top of the magazine portion of the machine by means of suitable angle plates i8 and I9 bolted or otherwise secured to the uprights or the uppermost cross bar II.

Vso

Mounted upon the base plate Il is a suitable holder 2li for holding a supply of wires 2l (see Fig. 3) which have been cut to the correct length to form or constitute a wire strap of the character employed in the strap applying machine and such wires `are preferably cut at an angle so as to form a sharpened driving end at each end of the cut wires. Rising from the strap holder E@ is a strap picking apparatus indicated generally at 22 by which the cut wires may be lifted one at ya time from the holder 2li and be deposited in correct position upon a strap bending apparatus indicated generally at 23.

The wire picking apparatus is illustrated as comprising an angularly extending frame secured to and extending upwardly and rearwardly froin the holder E@ as by providing a pair of side members 2li and '25 interconnected at their lower ends by means of cross bars 25 and adjacent their upper ends by a cross bar 27. Adjacent the center of the frame so formed is a trackway which may be constructed of four rails 28, 29, :it and 3l. lThe rails 2S and 38 are secured to the

cross bars

27 and 25 while the rail 2S is disposed immediately above `and in alignment with the rail 28 but spaced therefrom by suitable spacing bolts or sleeves 32, the rail 3l being similarly disposed and spaced from the rail 38. In the double trackway so formed is disposed a traveling carriage provided with wheels 34 and 35, respectively engaging the rail pairs 28--2 and S-SI, the carriage being prevented from undue lateral displacement relative to the trackway by means of flanges provided upon the wheels 3d and 35.

Extending downwardly from the carriage is a mounting bar 3l, to the lower end of which is secured the core 3B of an electromagnet the lower end of the core projecting below the winding of the coil to constitute an extendingr pole piece 4i?. The carriage is adapted to be reciprocated in its trackway by means of a cable 4i connected as indicated at 42 to the upper end of the carriage 33 and trained over the pulley 43 mounted upon the uppermost cross bar 2l, the opposite end of the cable 4! being connected to an oscillating lever 44 which has its lower end pivoted as at 45 upon a bearing member s attached to the under side of the base plate i?. Intermediate its ends the lever fill is provided with a roller il adapted to ride upon `an eccentric cam 43 which is in turn secured to or formed integrally with a drive shaft le adapted to rotated by means of a motor 5S coupled to the shaft e9 by any suitable reduction gearing El and chain and sprocket drive such as is indicated at 52.

Rotation of the shaft 49 will therefore cause the upper end of the lever 44 to oscillate from the full line position illustrated in Fig. 3 to the dotted line position indicated in Fig. 3 to lower the electromagnet 39 downwardly toward the supply of cut wires ZI in the holder 25]. rihen the lever i4 will be moved in the opposite direction to elevate the coil 39 and thus lift from the holder 2t one of the wires at a time.

The winding or" the electroinagnet 39 and the size of the core and pole piece thereof is suitably selected such that the lifting effort exerted by the electromagnet 39 is just sufficient to lift one of the cut wires 2| but insucient to cause more than one of the wires to cling to the electromagnet.

By referring particularly to Fig. 3, it will be observed that the rearmost wall 53 of the holder 29 terminates at its upper edge with a beveled edge, as indicated at 55, disposed immediately below a pair of angle member stops 55 and 55 (see Fig. 2). Thus as a cut wire is being elevated by the electromagnet 39, it will be brought against the underneath surface oi the

angles

55 and 55 at just the time that the wire clears the upper edge 55 oi the wall 53, while the travel of the electromagnet is such as to cause the eiectromagnet 39 to move to a still further upward position. Thus the wire which has been picked up will be released or pulled away from the electromagnet 39 just as it clears the wall 53 and the released wire will then drop downwardly onto the bending and forming apparatus 23.

At this point it should be noted that the rear wall 53 of the holder 29 is either formed of two separate sections, one disposed on either side of the center of the holder, is provided with a central slot or opening 51 of suiiicient width to permit the electromagnet 39 to move downward-- ly in the holder to a position at which it will rest upon the front wall 5S of the holder. Also the amount of throw of the lever ed should be euch that when the lever l!!! is moved to the left, as viewed in Fig. 3, the electromagnet will be permitted a total length of downward travel sufficient to cause the electromagnet 39 to rest upon the iront wall 53 of the holder. In this manner the electromagnet will effectively pick up the last cut wires which have been deposited in the holder 2B while at the same time when the holder 2!! is iilled with cut wires 2| the electromagnet 3S will descend into the holder until a sufficient distance to contact the unnermost oi the wires lying adi acent the rear wall 53.

The cut wire 2! which has been picked up from the holder 2Q and deposited upon the bending and forming apparatus 23 is then acted upon. to bend the sharpened ends of the wire inwardly to the correct angle such that when the wire is placed in the strap applying machine these bent ends will be disposed in the proper position to be driven into the side walls of the box.

The strap forming and bending apparatus 23 (see Figs. 4, 5 and 6) includes a pair of anvils 59 and 9u secured to the base plate l? near opposite side edges thereof, the spacing of the anvils 59 and Bil being such that the outermost edge or corners 5I of the anvils are disposed at precisely the point at which the end of the cut wire must be bent to form the driving end upon the iinished strap. The iront faces 62 of the anvils 59 and 59 are disposed in alignment with each other to engage the flat or straight portion of the wires both before and after the driving ends have been bent while the outer faces S3 of the anvils are disposed at an acute angle to the front faces, the angle selected being slightly less than the acute angle which is desired between the driving end of the strap and the straight portions oi the finished strap. The purpose of this is that the ends of the wires will be bent about the anvils to an angle slightly more than the desired angle for the iinished strap and the natural resilience of the wires will then spring the bent end slightly outwardly a suicient distance to free a formed strap from the anvils, thus allowing the nnished formed strap to drop from the anvils downwardly through the slot 64 formed in the base plate Il and disposed immediately above and in alignment with the magazine 9 of the strap applying machine. The ends of the wire 2i are bent about the anvils by means of a pair of bending drivers 65 and 6B.

By referring particularly to Figs. 4, 5 and 6, it will be noted that the driver 66 lcomprises an elongated bar having its rear end pivotally connected as at 5l to an oscillating lever 68 pivoted at 69 to the base plate Il while the cuter end of the driver 65 is formed with a projecting end 79 of a thickness considerably less than the thickness of the body of the driver 66 forming an angularly disposed shoulder 1l.

The mounting of the driver 65 upon the base plate l1 is such that when the driver 56 is in its fully retracted position, as shown in Figs. 4 and 6, the shoulder 'il will be spaced laterally from the front face 62 oi the adjacent anvil 59 by a dism tance somewhat in excess of the diameter of the wires 2| to thus form with the anvil 59 a space for receiving the wirewhich has been lifted by the electromagnet 39 and dropped over the edge 5d of the holder 29, the holder 29 being so disposed relative to the anvils 59 and 69 that the receiving space is immediately below the edge 59 of the holder.

The driver is constructed and mounted like the driver 55 so that the out wire dropped upon the driver will be supported at either of its ends upon the extensions 'i9 of the drivers immediately in advance of the shoulders ll. Since the end walls of the holder 20 are spaced from each other by a distance just slightly in excess of the length of the cut wires, the wires, when deposited upon the drivers 55 and 66, will beautomatically aligned with the opposite ends proe jecting approximately the same distance beyond the anvils 59 and 9i), respectively.

The

drivers

65 and 65 are then moved toward the anvils 59 and 59 to engage the shoulders 'ii with the ends of the wire, pressing the same toward the anvils and about the outer faces of the anvils to produce the angularly disposed bent driving end for the strap. This forward movement of the

drivers

55 and 56 is accomplished by providing upon the lever 58 intermediate its ends a rearwardly projecting block l2, in the bifurcated rear end of which is mounted a roller 'I3 adapted to ride against an eccentric cam 'M similar to the cam 48 and mounted upon the same shaft 39. The driver 55 has its lever 'i5 similarly provided with a roller 16 adapted to engage and ride upon an eccentric cam 'Il identical in all respects with the cam 'I4' and mounted upon or formed upon the shaft 48 with the same eccentricity as the cam ld. Thus as the shaft 49 is rotated the levers 58 and l5 will be swung about their pivots and move the

drivers

65 and 69 forwardly toward the anvils simultaneously.

To insure the bending'oi the ends of the wires 2! at the proper angle, the free extending ends l5 of the drivers are guided past the anvils 59 and 69 by means of guide blocks 'i8 and 19 disposed, respectively, adjacent the anvils 55 and 59 so that as the drivers move forwardly their extending ends will engage the guide blocks 18, as shown in Fig. 5, to cause the drivers 65 to not only move forwardly during the bending operations but to be swung inwardly toward each other to insure the straightening out of the bent end of the wire 2l along the sloping or angled face 63 cf the anvils.

As the eccentric cams lli and ll continue their rotation the

drivers

55 and 69 will be retracted by means of springs @Il so that when the drivers return to the position shown in Fig. 4 the wire 2i now formed into a strap will be freed and will slide down the anvils and through the slot 64 into the magazine of the strap applying machine.

By properly locating the eccentric cam G3 on the shaft iii with respect to the location of the cams id and 7l, it will be apparent that the electro-magnet 3Q will feed a cut wire into the strap forming or bending apparatus each time the drivers t5 are retracted to the position shown in Fig. i and that during the operation of the drivers 55 and '65 the electromagnet will be moving through its cycle of operations to pick up a cut wire ready to be dropped onto the bending apparatus at the termination of the bending of the previously fed wire.

My strap forming attachment may be operated at any desired speed, either synchronized with the operations of the strap applying machine so as to form and feed a strap into the magazine each time a strap is fed from the magazine and into strap applying position by the strap extent that whenever the supply of straps in the magazine runs low the strap forming apparatus will be operated to refill the magazine, which con-- trol may be accomplished by arranging a suitable electric circuit for operating the moto-r under the control of switches which will engage i the straps in the magazine to start the motor when the supply has been diminished to a predetermined level and then the motor will be disconnected from the circuit when the replenished supply in the magazine reaches some higher predetermined level.

Referring to Fig. 8, I have illustrated one form of automatic control which may be employed for this purpose as comprising a circuit for the rnctor 5c extending from one line conductor Li through the motor 5@ and thence through the lower contacts a of a relay 8l, and thence to the other line conductor L2. The relay 8l is provided with a coil Sic which may be connected to any suit-- able source of electric power, preferably of low voltage such as a transformer or, as illustrated in Fig. 8, a battery B. Arranged on the magazine portion of the strap applying machine I provide a starting switch Si arranged to have a movable contact 32 project into the magazine a sufficient distance to be engaged by the wire straps in the magazine.

The switch Si is preferably located in such position on the magazine as to engage the lowermost straps in the magazine as, for example, the fifth or sixth strap from the bottom of the magazine so that whenever the supply of straps in the magazine is reduced to four or ve the absence of a strap adjacent the switch arm 82 will permit this switch to close its contacts 33 and 845 and thus complete a circuit for the relay coil iic from the battery B through conductors 85 and S8, the movable contact 83 of the switch Si, the stationary contact 34 of the switch Si, and thence through conductor B1, the coil Bic of the relay 8i and conductor 88 to the other terminal of the battery B. Immediately after the motor 50 is energized, the strap forming attachment will commence to supply the magazine with newly formed straps and therefore a strap will soon thereafter be disposed in front of the movable arm t2 of the switch SI and will move this switch arm to open the contacts 83 and t4.

To insure the continued operation of the motor 50 until the magazine has been substantially filled with straps before permitting the motor to stop, I provide a self-holding circuit for the relay 8l which extends through two additional switches S2 and S3. rIhese two switches are identical in construction with the switch Si but are mounted on the magazine of the strap applying machine in a position adjacent the upper end of the magazine so as to be engaged by straps located in er passing through the upper end of the magazine. Since each strap as it passes down through the magazine would engage and operate the movable arms or contacts of the switches S2 and S3, I provide two of these switches, one with its movable arm located at least one strap width or diameter lower than the other so that at no time will both of these switches be opened by the presence of a single strap in or passing through the magazine.

The self-holding circuit for the relay 8|' extends from the battery B through the conductor 55 to a junction 89, whence once branch extends through conductor SQ, the contacts of the switch S2 and conductors 9i and 92 to the normally open contacts b of relay 8i, and thence by way of conductor 93, the coil Bic and conductor 35 to the other terminal of the battery B. The branch circuit extends from the junction 89 by way of conductor Sli, the contacts of the switch S3 and conductor 95 and thence by way of conducto-r 92 in the same manner as previously described.

Thus once the motor 5t is started it will remain in operation until a sufcient number of straps have been put in the magazine to fill the maga.- zine to a position at which one strap is disposed opposite to the movable arm of the switch S2 and additional straps are located above that one strap to cause one strap to be disposed adjacent the movable arm of the switch S3, causing both of the switches S2 and S3 to assume open circuit positions. At this time the holding circuit for the relay Si will be opened and the relay will open its contacts a and o-pen the circuit to the motor 5S until this supply of straps has been used up to such extent as will lower the supply of straps below the location of the switch arm or the switch SI.

As hereinbefore pointed out, our strap forming apparatus is preferably made as an attachment for existing Parker type strap applying machines to be attached to such machines so as to permit straight wires cut to desired length to be empioyed as straps in such machines. In the event that it is desired to use the pre-formed straps, pre-formed at the factory, in place of the straight cut wires, the machines do not need to be altered in any manner to permit such use even though our strap forming attachment is then in place upon the machine. All that is necessary is to swing the frame of the cut wire feeding mechanism out of its position above the slot 6M whereupon the carded straps may be fed directly through the base plate i'i and into the magazine in the same manner as though the strap forming apparatus were not attached to the machine.

For this purpose we prefer to mount the cut wire holder 2B and the cut wire feeding mechanism upon the base plate Il by a quick detachable connecting mechanism illustrated particularly in Figs. 1 and 2 as comprising a pair of angle brackets 9B and 91 secured to the base plate Il, the vertically extending portions of these angle brackets being provided with wing bolts 98 which may be readily screwed into the end plates of the strap holder 2. Thus by merely removing the wing bolts the entire wire holding and feeding mechanism may be removed or swung to the right as viewed in Fig. 1 to allow free access to the magazine of the normal strap applying machine.

It will therefore be observed that we have provided a relatively simple strap forming attachment for the Parker type wire strap applying machines, which may be readily attached to emsting machines and allow the users of such machines to employ straight cut wires in place of the preformed and carded straps heretofore required. It will be apparent that such cut wires may be readily supplied in compact bundles occupying but a fraction of the space of the carded or packaged preformed straps, thus minimizing the amount of storage space required for a supply of such straps and eliminating the waste of the cards, packages or holders heretofore employed for holding the pre-formed straps in the correct shape and order for use in such strapping machines.

While we have shown and described the preferred embodiment of our invention, we do not desire to be limited to any of the details f construction shown or described herein, except as defined in the appended claims.

We claim:

1. A strap forming device for bending the ends of a straight wire to define driving ends thereon including anvils about which the wire ends may be bent, drivers for engaging and bending the wire ends about the anvils, means for advancing said drivers toward and retracting the same away from said anvils, means for feeding said cut wires one by one into the space between the anvils and said drivers when said drivers are in a retracted position, said feeding means comprising a holder for a supply of said out wires, means for picking up o-ne wire at a time for transferring said wire to the space between said drivers and said anvils, and means for moving said wire picking means in synchronism with the movement of said drivers to insure delivery o-f said wires to the bending means only when said drivers are in a retracted position.

2. In a strap forming device for use with a strap applying machine havinga magazine for holding a supply of wire straps pre-formed with driving ends; a wire bending means for bending the ends of a straight wire to define driving ends thereon including anvils about which the wire ends may be bent, drivers for engaging and bending the wire ends about the anvils, means for advancing said drivers toward and retracting the same away from said anvils, means mounting said anvils on said strap applying machine in alignment with the entrance of the magazine thereof to allow each wire when bent to drop by gravity into the magazine, means for feeding said cut wires one by one into the space between the anvils and said drivers when said drivers are in a retracted position, said feeding means comprising a holder for a supply of said cut wires, a carriage movable between said holder and a point aligned vertically above the space between said anvils and drivers, an electromagnet on said carriage engageable with said wires to mechanically pick up one of said wires at a time to transfer said wire to said space, and means 'for moving said carriage in synchronism with the movement of said drivers to insure delivery of said wires to the bending means only when said drivers are in a retracted position.

3. In a strap forming device for use with a strap applying machine having a magazine for holding a supply of wire straps pre-formed with `driving ends; a base plate having a slot therethrough of such size and shape as to pass a pre-formed wire strap, means mounting said base plate upon said strap applying machine to align said slot with the entrance to the magazine of said machine, wire bending means mounted upon said base plate including stationary anvil means for denning a form about which the ends of the wire may be bent, said anvil means being disposed'on said base plate in alignment with said slot whereby the wires when bent will drop by gravity from said anvils through said slot and into said magazine, a pair of drivers for engaging and bending the respective wire ends about said anvil means, means for advancing said drivers toward said anvil means to bend said wire ends about said anvil means and for retracting said drivers from said anvil means to denne a space between the anvil means and the drivers, and means for feeding said cut wires one at a time into said space when said drivers are in their retracted positions.

4. A strap forming device for bending the ends of a straight wire to dene driving ends thereon including anvils about which the wire ends may be bent, drivers for engaging and bending the wire ends about the anvils, means for advancing said drivers toward and retracting the same away from said anvils, means for feeding said cut wires one by one into the space between the anvils and said drivers when said drivers are in a retracted position, said feeding means comprising a holder for said cut wires, a carriage movable between said holder and a point aligned vertically above the space between said anvils and drivers, an electromagnet on said carriage engageable with said wires to mechanically pick up one of said wires at a time to transfer said wire to said space, and means for moving said carriage in synchronism with the movement of said drivers to insure delivery of said wires to the bending means only when said drivers are in a retracted position.

5. A strap forming device for bending the ends of a straight wire to define driving ends thereon including anvils about which the wire ends may be bent, drivers for engaging and bending the wire ends about the anvils, means for advancing said drivers toward and retracting the same away from said anvils, means for feeding said cut wires one by one into the space between the anvils and said drivers when said drivers are in a retracted position, said feeding means comprising a holder for said cut wires, a carriage movable between said holder and a point aligned vertically above the space between said anvils and drivers, means on said carriage engageable with said wires to mechanically pick up one of said wires at a time to transfer said wire to said space, and means for moving said carriage in synchronism with the movement of said drivers to insure delivery of said wires to the bending means only-when said drivers are in a retracted position. Y u I y `6. In a strap forming device for use with a `strap applying machine having a magazine for holding a supply of wire straps preformed with driving ends, a wire bending means for Vbending the ends of a cut length of straight wire to define driving ends thereon, means mounting said bending means on said strap applying machine with the bending means disposed in alignment with the entrance of the magazine thereof to allow each wire when bent to drop by gravity into the magazine, drive means for operating said wire bending means, and control means on said magazine responsive to movement of Wire straps therethrough to start said drive means upon removal of a predetermined number oi straps from said magazine.

7. In a strap forming device for use with a strap applying machine having a magazine for holding a supply of wire straps preformed with driving ends, a wire bending means for bending the ends of a cut length of straight wire to define driving ends thereon, means mounting said bending means on said strap applying machine with the bending means disposed in alignment with the entrance of the magazine thereof to allow each wire when bent to drop by gravity into the magazine, drive means for operating said wire bending means, control means on said magazine responsive to movement of wire straps therethrough to start said drive means upon removal of a predetermined number of straps from said magazine, and auxiliary control means on said magazine operable in response to lling of said magazine with wire straps to stop said drive means upon deposit in said magazine of a predetermined number of wire straps.

8. In a strap forming device for use with a strap applying machine having a magazine for holding a supply of wire straps preformed with driving ends, a wire bending means for bending the ends of a cut length of straight wire to define driving ends thereon, means mounting said bending means on said strap applying machine with the bending means disposed in alignment with the entrance of the magazine thereof to` allow each wire when bent to drop by gravity into the magazine, drive means for operating said wire bending means, normally closed switch means mounted on said magazine in a position to be held open by wire straps positioned in said magazine and closable upon the removal of all but a few of the straps from said magazine, electric control means operable to initiate operation of said drive means, and a circuit coupling said switch means to actuate said control means upon closing of said switch means.

9. In a strap forming device for use with a strap applying machine having a magazine for holding a supply of wire straps preformed with driving ends, a Wire bending means for bending the ends of a cut length of straight wire to define driving ends thereon, means mountingsaid bending means on said strap applying machine with the bending means disposed in alignment -with the entrance of the magazine thereof to allow each wire when bent to drop by gravityinto the magazine, drive means for operating said wire bending means, normally closed switch means mounted on said magazine in a position to be held open by wire straps positioned in said magazine and closable upon the removal 'of all but a few of the straps from said magazine, electric control means operable toinitiate operation of said drive means, acircuit coupling said switch means to actuate said control means upon closing of said switch means, a second normally 'closed switch means'mounted onsaid magazine 'in a position to be engaged by wire straps in vsaid magazine and opened when said magazine is filled nearly full, a relay associated with said electrical control means and included in said circuit, and a self-holding circuit for said relay including said second switch means.

l0. In a strap forming device for use with a strap applying machine having a magazine for holding a supply of wire straps preformed with driving ends, a wire bending means for bending the ends of a cut length of straight wire to define drivincr ends thereon, means mounting said bending means on said strap applying machine with the bending means disposed in -alignment with the entrance of the magazine thereof to allow each wire when bent to drop by gravity into the magazine, electric motor drive means for actuating said wire bending means, an electrical relay having contacts connected in a circuit to control the operation of said electric motor, a switch on said magazine connected in circuit with said relay and operable in response to the reduction to a predetermined minimum of the number of wire straps in said magazine, and a self-holding circuit for said relay including a pair of normally closed electric switches connected in parallel with each other and `positioned on said magazine near the top thereof in longitudinal spaced relation to each other, each of said switches being so positioned as to be momentarily opened by the movement of a wire strap therepast through said magazine, whereby both of said switches are opened when said magazine is substantially filled.

1l. A strap forming device including a wire bending means operable to engage and bend the ends of a cut wire to define driving ends thereon, and means for feeding said cut wires one by one into said bending means, said feeding means comprising a holder for a supply of said cut wires, a carriage movable along an inclined path between said holder and a point aligned vertically above said bending means, means on said carriage engageable with said wires to mechanically pick up one of said wires at a time, and means responsive to movement of said carriage to said point aligned vertically above said bending means for releasing a wire from said pick up means to allow the same to drop by gravity on to said vbending means.

l2. A strap forming device for bending the ends of a cut length of straight wire to define driving ends thereon including a base plate having a slot therethrough of such size and shape as to pass a bent wire, anvil means mounted upon said base plate for defining a form about which the ends of said wires may be bent, said anvil means being disposed o-n said base plate in alignment with said slot whereby the wires when bent will drop by gravity from said anvils through said slot, a pair of drivers for engaging and bending respectively wire ends about said anvil means, means for advancing said drivers toward said anvil means to bend said wire ends about said anvil means and for retracting said drivers from said anvil means to define a space between the anvil means and the drivers, each of said drivers including a lforwardly projecting portion extending across said slot for catching and holding wires placed in said space, and means for feeding said cut wires one at a time into said space when said drivers are in their retracted position.

GEORGE lVi. HILL. VGlllOlftGE S. HILL.