US2830646A

US2830646A - Variable speed feed mechanism for spring forming machines and the like

Info

Publication number: US2830646A
Application number: US364093A
Authority: US
Inventors: Harry H Norman
Original assignee: ZIG ZAG SPRING Co
Current assignee: ZIG ZAG SPRING Co
Priority date: 1953-06-25
Filing date: 1953-06-25
Publication date: 1958-04-15
Anticipated expiration: 1975-04-15

Description

Aprxl 15, 1958 H. H. NORMAN 2,830,646

VARIABLE SPEED FEED MECHANISM EDR SPRING FORMING MACHINES AND TEE LIKE Filed June 25, 1953 8 Sheets-Sheet 1 Apnl l5, 1958 H. H. NORMAN 2,830,646

. VARIABLE SPEED FEED MECHANISM FOR SPRING FORMING MACHINES AND THE LIKE Filed June 25. 1955 8 Sheets-Sheet 2 Apr1l715, 1958 H. H. NORMAN 2,830,646

VARIABLE SPEED FEED MECHANISM FOR SPRING FORMING MACHINES AND THE LIKE Filed June 25. 1953 8 Sheets-Sheet 3 INVENTOR. ape/WA4 Maza/4W H. H. NRMAN April 15, 1958 2,830,646

VARIABLE SPEED FEED MECHANISM FOR SPRING FORMING MACHINES AND THE LIKE 8 Sheets-Sheet 4 Filed June 25. 1953 .INN

April 15, 1958 H. H. NORMAN 2,830,646

vARxABLE SPEED FEED MECHANISM FDR SPRING E EDRMING MACHINES AND TEE LIKE 8 Sheets-Sheet 5 Filed June 25. 1953 Aprll l5, 1958 H. H. NORMAN 2,830,646

VARIABLE SPEED EEED MECHANISM EOE SPRING EoEMING MACHINES AND THE LIKE Filed June 25, 1953 8 Sheets-Sheet 6 BY 7W? @ffm April 15, 1958 H. H. NoRMAN VARIABLE SPEED FEED MECHANISM FOR SPRING FORMING MACHINES AND THE LIKE 8 Sheets-Sheet 7 Filed June 25, 1955 Aprll 15, 1958 H. H. NORMAN 2,830,646

' VARIABLE SPEED FEED MECHANISM FOR SPRING FORMING MACHINES AND THE LIKE Filed June 2s. 195s s Sheets-sheet 8 "JIL 'IllIllIlllllll/Illlllll/111111111111111111111111111llllllillllI/lzl'llll/ IN VEN TOR. #paw A4 faam/4W VARIABLE SPEED FEED MECHANISM FR SPRlNG FORMING MACHINES AND THE LIKE Harry H. Norman, Los Angeles, Calif., assigner to Zig Zag Spring Company, Los Angeles, Calif., a copartnership Application June 25, 1953,- Serial No. 364,093

8 Claims. (Cl. 153-75) This invention relates to a feed for spring forming machines 'and the like. The application is a continuation-in-part of my copending application Serial No. 781,953, filed October 24, 1947, for a Spring Forming Machine. This application has since matured into United States Patent No. 2,645,252.

In the above-mentioned application there is disclosed a spring forming machine wherein wire from which the springs are to be formed is fed toward an oscillator. This oscillator has two upstanding bending pins equally spaced from the axis about which the Ioscillator oscillates. In advance of the oscillator there is a transversely reciprocable shuttle and behind the oscillator there is a longitudinally reciprocable restraining pin. The wire as it is acted upon by the shuttle, the bending pins, and the restraining pin is deformed or converted into sinuous or zigzag wire having transversely extending lateral bars connected at their ends by semi-circular ends'. At this bending portion of the machine, which may be regarded as a first station, the wire which is thus converted into a sinuous wire strip is produced at a uniform and constant rate. This does not necessarily mean that the wire passes the first station of the machine at a constant and uniform speed. Actually, the wire moves past the first station in an intermittent manner, advancing from the oscillator and then being temporarily restrained by the restraining pin. However, the strip of sinuous Wire overa given length of time will pass the first station at a predetermined rate of so many feet per minute.

Behind the first station the sinuous wire is caused to pass about an -arching roll which has teeth engageable with the lateral bars of the sinuous wire strip. This arching roll performs the double function of longitudinally Iarching the sinuous wire strip and feeding it to a cut-off mechanism which isin the form of a punch press. The punch press cuts the continuous arched sinuous wire strip into suitable lengths. During the time that the punch press is operated it is necessary to hold the sinuous wire strip stationary so that if the punch press is regarded as a second station in the machine the feed past this second station is of a decidedly intermittent character. As the zigzag wire is being produced at a constant rate at the irst station but is being temporarily halted in its movement at the pun-ch press or second station while a cutoff is being effected, it is necessary to drive the feed roll or arching roll at a temporarily higher peripheral speed after each cutting operation than the speed at which the Wire is passing the first station so las to make up for or compensatefor the time lost during the halt.

t is, therefore, a primary object of the present invention to provide a mechanism for driving the feed or arching roll in such a manner that at normal speeds the arching roll will be rotating at the same peripheral speed as that at which the wire is being formed and is passing the rst station. At the time of operation of the punch press the arching roll is halted for a dwell period so that the wire may remain stationary while it is being cut by the punch press. Thereafter, the arching roll is rotated at a higher speed than normal speed to make up for the time lost during the dwell or halt and after this has been made up the arching roll is driven again at normal speed. In this'manner, the pun-ch press, or second station, may be located quite close to the oscillator or first station but the overall rate at which the wire passes the two stations may be maintained exactly the same despite the fact that there is a decided or definite period of dwell while the Wire is being cut.

More specicially, an object of the invention is to provide a novel drive for a feed or measuring roll over which strip-like material is caused to pass between two stations which drive is such that the strip-like material will be caused to pass over the feed roll at a constant rate measured over a prolonged period of time, but which actu-ally` causes the strip-like material to stop or hesitate periodically, then travel at a higher than norma-l rate of speed to compensate for the period cf hesitation, and finally return to normal speed.

Still another object of the invention is to provide 'a wire forming machine wherein there is a wire bending mechanism for bending wire into a sinuous form and a cutting mechanism or punch press which cuts the wire into predetermined lengths and between which there is a feed having the above-mentioned characteristics. ln conjunction therewith there is a control mechanism so designed that the cutting mechanism or punch press cannot operate unless the wire has been caused to hesitate. In this manner, the die of the punch press vis protected against breakage inasmuch as it is prevented from operating upon moving wire in the event that the apparatus that causes the dwell or hesitation has failed to function properly.

With the foregoing and other objects in view, which will be made manifest in the following detailed description Aand specifically pointed out in the appended claims, reference is had to the accompanying drawings for an illustrative embodiment of the invention, wherein:

Figure 1 is a View in side elevation of the wire forming machine in which structure embodying the present invention has been incorporated;

Fig. 2 is a partial View in horizontal section taken substantially upon the line 2 2 upon Fig. l in the direction indicated;

Fig. 3 isa partial view in vertical section taken suhstantially upon the line 3 3 upon Fig. 2;

Fig. 4 is a vertical section taken substantially upon the line 4-4 upon Fig. 2 in the direction indicated;

Fig. 5 is a partial view in side elevation, parts being broken away and shown in vertical section, illustrating the punch press land associated structure forming a part of the machine;

Fig. 6 is a partial view in horizontal section taken substantially upon the line 6 6 upon Fig. 5 in the direction indicated;

Fig. 7 is a vertical section taken substantially upon the line 7-7 upon Fig. 6;

Fig. 8 is a view similar to Fig. 4, but illustrating the position assumed by the parts at the end of the period of dwell or hesitation during which period the punch press is effective to cut the wire;

Fig. 9 is 'a .partial View in vertical section illustrating a one-revolution clutch forming a part of the punch press;

and

Figure l0 is a wiring diagram of the machine.

Referring to the accompanying drawings wherein simi'- lar reference characters designate similar parts throughout, the machine consists of a frame generally indicated at 10 within which there is a motor 11 forming a primary source of power. A belt drive 12 connects the rotor of the electric motor 11 with a vertical shaft 13 having near Patented Apr. 15, 1,958.

its upper end a pinion 14 which meshes with a gear 15 on a shaft 16 carrying a bevel pinion 17. The bevel pinion 17 meshes with a bevel gear 18 on a transversely extending shaft 19.

On the forward end of the frame there is shown a conventional wire straightener 20 through which wire 21 is fed from a suitable source of supply toward an oscillator 22. The oscillator 22 is mounted on the top of a vertically arranged shaft 23 and has two spaced upstanding bending pins 24 that are equally spaced from the axis of the shaft 23 and are arranged on the same diameter extending across the oscillator.

The oscillator 22 is caused to rotate or oscillate through an are of approximately 360, as set forth in detail in my copending application above referred to. This oscillatory movement is accomplished by means of a pinion 25 keyed to the bottom of the shaft 23 and meshing with a transversely extending rack 26 that is mounted on the reciprocatory portion of a Scotch yoke. This portion is indicated at 27 and is slidable on transversely extending guide 2S, and is equipped with a slot 29 in which the roller 30 is disposed that is rotatably mounted eccentrically of the gear 15. In this manner, as the gear 15 is continuously driven in one direction by means of the motor 11, the rack 26 will be moved laterally in one direction during one-half of a revolution of the gear 15 and will moved laterally in the opposite direction during the remaining half revolution of the gear 15. Consequently, the oscillator will be rotated in one direction through an arc of approximately 360 and then rotated in the opposite direction through an arc of approximately 360.

In advance of the oscillator 22 there is a laterally movable shuttle having two spaced rollers one of which is indicated at 31 on Fig. 2. These rollers are disposed on opposite sides of the center line through the wire straightener and the wire 21 passes between the two rollers 31 of the shuttle in proceeding toward the oscillator 22. The rollers 31 are rotatably mounted on an arm 32 of an oscillatory vertical shaft 33 which is rotatably mounted in suitable bearings on the frame, and carries at its lower end a crank 34 that is connecte-d by means of a connecting rod 35 to an eccentric 36 on the shaft 16. Consequently, as the shaft 16 rotates the eccentric 36 will impart an oscillatory movement to the crank 34, causing the arm 32 to oscillate in a lateral direction about the axis of shaft 33 as a center. As explained in my copending application, during a portion of each rotation or oscillation of the oscillator 22, the shuttle is swinging sympathetically therewith, but during another portion of each rotation or oscillation of the oscillator 22, the shuttle is moving in opposition thereto.

The shaft 13 also carries a disk 37 on which a roller 38 is rotatably mounted at a location eccentrically of the axis of the shaft. This roller is rotatably disposed in a transversely extending slot of a Scotch yoke 39. It is connected to slides 40 on which a restraining finger or pin 41 is pivotally mounted for swinging movement about the axis 42. The pin forms a crank on the transversely extending shaft and a crank 43 which is also on this shaft is connected by means of an adjustable pitman 44 to a slide 45 that may be adjusted by a hand screw 46.

As the shaft 13 rotates continuously a reciprocatory movement will be imparted by means of the Scotch yoke to the slides 40, causing the axis 42 to be reciprocated in a longitudinal direction or in a direction coincident with the length of the wire feed. As the pitman 44 is held against such movement, it will be apparent that as the slides 40 move toward the wire straightener that the restraining pin 41 will be swung downwardly and forwardly. Conversely, as the slides 40 move rearwardly or away from the wire straightener, :the restraining pin 41 will be swung upwardly and rearwardly in order to permit the lateral bearing of the convolution that has just been formed by the bending pins 24 to pass therebeneath. The

restraining pin 41 is consequently reciprocated toward and away from the oscillator 22 in timed relation to the oscillation of the oscillator, as explained in detail in my copending application. The combination of the laterally oscillated shuttle formed by the rollers 31, the oscillator pins 24 and the restraining pin 41 is effective to transform the straight Wire feed to the machine into sinuously formed wire or zigzag wire, a portion of which is depicted in Fig. 6.

The oscillator 22, insofar as the present invention is concerned, may be regarded as `the first station of the machine through which the wire passes. While the wire in the course of being converted from straight wire into sinuous wire and being discharged from the oscillator may not be moving at a constant uniform speed at any particular instant, the zigzag or sinuous wire is being delivered from this first station at a uniform or constant average rate. In other words, the sinuous wire may have consecutive convolutions released by the restraining pin 41 at successive instants but the average production of sinuous wire by the oscillator may be regarded in terms of a certain number of feet per minute so that in this respect the flow or movement of sinuous wire through the first station may be regarded as being at a constant average rate.

From the oscillator 22 the sinuous wire passes through a chute or passage 47 and into a chute or guide 48 that bends it downwardly and directs the wire against an arcuate guide 49 that is arranged beneath an arching roll 5). This arching roll has on its periphery spaced teeth or cogs 51 engageable with the lateral or transversely extending bars of the sinuous wire. This arching roll serves to feed the sinuous wire across the anvil 52 of a punch press where at regular intervals a die descends to cut the sinuous wire into appropriate lengths. rThe motion given to the arching roll or measuring roll Si) is such that it will be held stationary to arrest the feed of the sinuous wire across the anvil 52, while the die 53 is descending and making a cut. Thereafter, when the die S3 has been lifted to its initial position, the arching roll 50 is driven at relatively high speed so as to feed the sinuous wire across the anvil 52 rather rapidly and thus make up for the time lost during the period .that the feed was halted and the cut was being made. After the time lost has been regained, the arching roll or feed roll 50 then returns to a normal speed commensurate with the average rate of flow of sinuous wire from the oscillator 22 or first station.

In the present -machine the anvil 52 may be regarded as the second station at which the wire is temporarily halted for the purpose of making a cut and then is traversed rather rapidly to make up for the period of arrest after which the flow across the anvil continues at a normal rate of speed until the feed of the wire is again halted. Although the movement of the wire across the anvil 52 is temporarily halted or arrested, it is apparent that the average rate at which the wire passes over the anvil at the second station of the machine must be equal to the average rate of production of sinuous wire at the oscillator.

The present invention primarily concerns the mechanism for rotating the feed roll 50. To enable this to be accomplished, the feed roll not only feeds the wire across the anvil 52 at the proper rate but also serves to longitudinally arch the sinuous wire and to this end a shoe 54 (see Fig. 7) cooperates with the ends of the feed roll or arching roll to bend the curved ends of the convolutions of the sinuous wire. This shoe is detachable and replaceably mounted on a slide 55 by means of a screw 56 that can be adjusted toward and away from the arching roll by means of a hand screw 57.

The housing for the slide 55 is yieldably mounted, such as by springs 58, and a -microswitch 59 which controls the main motor 11 is `mounted adjacent the housing so that its button 59a will be normally in engagement with a screw 58a mounted on the housing.

- ln the event sinuous wire is produced which for some unknown reason is imperfect, and because of that fact it forces the shoe 54 away from the arching roll to an excessive extent, the screw 58a for the slide 55 will disengage the button 59a and throw the microswitch 59 and thus automatically shut o the main motor, stopping the machine before any serious damage can be done.

On the shaft 19 there is a sprocket 60 constituting the drive sprocket for an endless chain 61. This endless chain is trained over an idler sprocket 62 that is mounted on an arm 63 pivoted at 64. The arm 63 is continually urged to swing upwardly in a clockwise direction as Viewed in Figs. 4 and 8, by a compression spring 64 so as to continually take up any slack that may exist in the chain 61. The chain 61 is also trained over a sprocket 65 mounted on a shaft 66. From the sprocket 65 the chain 61 extends about a sprocket 67 that is rotatably mounted on an arm 68 which is keyed on a shaft 69. From the sprocket 67 the chain 61 extends about a sprocket 70 that is loose upon the shaft 69 and from the sprocket 70 the chain extends back to the drive sprocket 60. The drive sprocket 60 rotates in a counterclockwise direction, as viewed in Figs. 4 and 8.

On the shaft 66 there is a second sprocket 71 and an endless chain 72 provides a direct drive to a sprocket on the measuring or feed roll 50. The chain 72 thus causes the feed roll 50 to rotate in accordance with the rotary movements that are imparted to the shaft 66 by the sprocket 65.

If the parts above mentioned are in the position shown in Fig. 4, and the sprocket 60 is being driven at a constant speed of rotation, it is apparent that the sprocket 65, and consequently the feed roll 5t), will be driven at a constant speed as long as the parts remain in this position. However, if the lever 68 is released so that it may rotate about the shaft 69 as a center from the position shown in Fig. 4 to the position shown in Fig. 8, it will be apparent that the loop formed in the chain about the sprocket 69 is shortened or is straightened out and that slack in the chain occasioned by the change in this loop will be automatically and instantly taken up by the sprocket 62 on the arm 63.

Thus, as the sprocket 67 moves from the position shown in Fig. 4 to the position shown in Fig. 8, although the sprocket 60 is being continuously driven there is no rotary movement transmitted to the sprocket 65 during the period while the change is being effected. Consequently, while the arm 68 is moving from the position shown in Fig. 4 to the position shown in Fig. 8, the sprocket 65 will halt in its rotation and rotation of the feed roll 5t) will also be arrested. lt is during this period that the punch 53 is operable to cut the wire. After the wire has been cut, if the arrn 63 is forcibly returned from the position shown in Fig. 8 to the position shown in Fig. 4, the sprocket 67 is effective to draw more of the chain 6l around the sprocket 65 than is being delivered from the sprocket 60. Consequently, during the return of the arm 68 from the position shown in Fig. 8 to the position shown in Fig. 4, the sprocket 65, and consequently the feed roll 50 will rotate at a faster speed than the normal speed created by the sprocket 60. Therefore, during the return of the arm 68 from the position shown in Fig. 8 to the position shown in Fig. 4 the sprocket 65 and consequently the feed roll, will be rotated at aspeed faster than normal to make up for the lost time or dwell period during which the wire was halted to be cut. After the arm 68 returns to the position shown in Fig. 4, sprocket 65 and consequently the feed roll 50 will be driven at normal speed In association with thisl countershaft there is a pinion 76 which meshes with a gear 77 that'is on the shaft 69.

The gear 77 is keyed to a bushing 78 that is loose on the shaft 69 and this bushing is pinned as by a pin 79 to the armature 8G of a magnetic clutch 81 that is keyed to the shaft 69. The pinion 73, gear 74, the pinion 76, and gear 77 merely `form a speed-reduction gear drive between the shaft 19v and the shaft 69 so that the magnetic clutch 81 will be driven at a comparatively low speed. This magnetic clutch, when engaged, causes the shaft 69 to rotate at low speed and to return the arm 68 from the position shown in Fig. 8 to the position shown in Fig. 4.

The arm 68 has an arm 82 rigid therewith, the end of which indicated at 83, is engageable with the end of a latch 84 that is pivoted on a pivot 85. This latch is engageable with an adjustable stop 86 which limits its rotary movement in one direction about the pivot under the action of a compression spring 87. The stop 86 is mounted on a lever 88 that is also pivoted on the pivot and which is connected to the core 89 of a solenoid 90. The arm 82 is equipped with two opposed adjustable stops 91 and 92 that are engageable with a finger 93 on a lever 94. This lever is pivoted at 95 and carries a mercury switch 96. The end 83 is normally engaged by the latch 84 to hold the arm 82 and consequently the arm 68 in the position shown in Fig. 4. However, whenever the solenoid is energized to attract the core S9 and swing the link 88 downwardly, the latch 84 will be caused to release or disengage the end 83 of the arm 82 and thus permit arm 68 to swing from the position shown in Fig. 4 to the position shown in Fig. 8, and thus cause the halt or dwell of the wire.

As the arm 82 swings from the position shown in Fig. 4 to the position shown in Fig. 8, stop 92. will engage the finger 93, thus swingingthe lever 94 and tilting the mercury switch 96. The mercury switch 96 controls the magnetic clutch 81 and when the mercury switch is in the tilted position shown in Fig. 8, the electric circuit through the magnetic clutch is closed, energizing this clutch and causing the shaft 69 to be rotated from the position shown in Fig. 8, back to the position shown in Fig. 4. During this return movement, the end 83 merely passes beneath the latch 84 swinging this latch upwardly until it may reengage the end 83 and as this occurs, the stop 91 will engage the nger 93 on the lever 94 returning the mercury switch 96 to therposition shown in Fig. 4- and opening the circuit through the magnetic clutch, thus effecting a release of the clutch and allowing all parts to be latched in the position shown in Fig. 4 until such time as the solenoid 9) is again energized.

There is also associated with the lever 68 an arm 97 carrying an adjustable stop 98 that is engageable with a microswitch 99. When the stop 98 is in engagement with the button of the microswitch 99 this switch is held open or in open circuit position, but when the arm 68 is swung from the position shown in Fig. 4 to the position shown in Fig. 8 and arm 97 descends from the position shown in Fig. 4, the microswitch 99 automatically closes or assumes closed circuit position. 99 is electrically connected to the solenoid 180 which controls a one-revolution clutch illustrated in Fig. 9 which forms a part of the punch press. The punch press is separately driven by a motor 1i131, and when the solenoid 160 is energized it operates the one-revolution `clutch to cause the die 53 to descend and to make a cut and thereafter to return to its elevated position. By having the solenoid 100 electrically connected to the microswitch 99 a positive assurance is provided that the punch' press will not be operated unless the dwell mechanisrn has functioned to stop rotation of the sprocket 65 and consequently the feed roll 50. In this manner, there is assurance that the wire traversing the anvil 52 The switch has come to rest while the punch press is being operated, it being quite important that the dwell mechanism function properly and cause the wire to halt so that no part of the die 53 will be broken by moving wire.

On the side of the punch press there is a microswiteh 102, the button of which is engageable by a pivoted lever 103 which, in turn, is actuated by a lug 104 on an endless chain 105. This endless chain is trained over sprockets 106 and 107. The sprocket 107 is on a shaft that is driven by an endless chain 108, see Fig. 5, o of the feed roll 50. The switch 102 and its lever 103 are mounted on a worm wheel 109 that can be rotatably adjusted about the shaft of the sprocket 107 by a manually adjustable worm 110. This rotary adjustment of the lever 103 and the microscwitch 102 is to enable proper timing of the halt in the movement of the wire so that it may be properly located with respect to the die 53 and the anvil. The microswitch 102 is electrically connected to the solenoid 90. By adding links to the chain 105 or subtracting links from this chain, the length of the wire cut can be adjusted or varied.

From an inspection of Figs. 6 and 7, it will be appreciated that the die cr punch 53 consists of a central pilot 111, and side pilots 112, 113, 114, and 115. The cutting portion of the die is indicated at 116 designed to cut off one of the curved ends of one of the convolutions while the wire is centered with relation to the die and anvil by the pilots. In Figs. 4 and 8 117 merely indicates a belt-driven oil pump which supplies lubricant to a force feed lubrication system, the details of which are unimportant to the present invention.

The operation of the above-described construction is substantially as follows:

Power is delivered from the main motor 11 to the gear 15 which causes the rack 26 to reciprocate in a transverse direction, thus rotating or oscillating the oscillator 22 back and forth through arcs of approximately 360. In conjunction therewith the shuttle 31 is caused to reciprocate laterally and as the wire is fed'through the shuttle to the oscillator, the bending pins becomel effective to convert the straight wire into sinuous Wire. This action is assisted by the restraining pin 41.

Thus, at this rst station of the machine sinuous Wire is being formed at a steady and constant rate although the wire may leave the oscillator with an intermittent motion.

In starting the machine, as the wire leaves the oscillator it tends to follow the curvature of the guide 49 and the leading end of the wire is directed initially against the descending rear teeth 51 on the feed roll 50. Whatever tooth on the feed roll engages the leading end of the wire causes this wire to be carried thereby around the under side of the feed roll and then to pass between the feed roll and the shoe 54. As the teeth 51 on the feed roll engage the lateral bars of the sinuous wire, the sinuous Wire is accurately fed thereby. At the same time, the wire is longitudinally arched by the shoe 54. From the feed roll the wire passes acros the anvil 52. As the feed roll 50 rotates the sprocket 107 will also rotate a commensurate amount, thus driving the chain 105 and ultimately causing the lug 104 to engage the lever 103 and close the microswitch 102. When microswitch 102 is momentarily closed by the lug 104 it energizes the solenoid 90 causing link S8 to lift the latch 84 and thus disengage the end 83 on the arm $2. The tension on the endless chain 61 between the

sprockets

65 and 60 causes the sprocket 67 to move from the position shown in 4 to the position shown in Fig. 8.'

gizes the solenoid 100 on the punch press, causing' the one-revolution clutch of the punch press to be actuated and the die 53 to descend. As the die descends its pilots center the wire properly with relation to the anvil and a cut is made following which the die 53 is lifted. This cutting operation occurs while the mechanism is moving from the position shown lin Fig. 4 to the position shown in Fig. 8, in which position the mercury switch 96 is tilted into the position which will cause the magnetic clutch 8l to be energized and to engage. The magnetic clutch serves to return parts from the position shown in Fig. 8 to the position shown in Fig. 4, after which the magnetic clutch is deenergized. During this return the movement of the sprocket 67 about shaft 69 as a center causes the sprocket to be temporarily driven at faster than normal speed to make up for the lost time occasioned by the halt or period of dwell of the wire. After this has been made up sprocket 65 and consequently the feed roll. 50 rotate at normal speed until such time as the lug 104 causes the microswitch 102 to again close. When this occurs a cycle of operation is repeated.

It will thus be appreciated that the improved mechanism is such that although wire or strip-like material is being delivered at a iirst station at the oscillator 22 at a uniform rate whereas at the second station, namely at the punch press, the wire is temporarily halted while a. cut is being made, that the mechanism is so designed as to cause the overall or average rates at which the wire passes these two stations to be the same. Consequently, the punch press and the oscillator can be closely coupled in a single machine.

In the apparatus disclosed, the sprocket 65 may be regarded as the -driven sprocket driven by the driving sprocket 60. This driven sprocket, in turn, drives the feed roll 50 so that the feed roll will have a peripheral speed which at the normal speed of rotation, will be equal to that at which the wire is supplied from the oscillator. This feed roll receives the wire from the oscillator in a non-slack condition, and during the period of halt or dwell, while the cutting means or punch press is effecting a cut, the sinuous wire is temporarily compressed or shortened in a lengthwise manner. This compression or holding back of the wire occurs only during a relatively short period of time, and at the conclusion of the dwell, the wire is immediately lengthened out to its normal or natural length by the faster-than-normal speed of rotation of the feed roll.

The sprockets 67 and 70 which are arranged between the driving and driven roll, in effect, form an S-shaped loop or bend in the endless chain 61 and the swinging of the sprocket 67 about the center of sprocket 70 as a cente merely straightens out or renders more acute this S-shaped bend. As the S-shaped bend is straightened the driven sprocket 65 is caused to halt and as the S-shaped bend is made more acute the driven sprocket, and consequently the feed roll, are driven at a fasterthan-normal speed to gain back the time lost during the halt or dwell of the wire on the punchV press.

Various changes may be made in the details of construction without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

l. A feed means for feeding strip material between two stations at one of which the material passes at a constant rate and at the other of which the material must periodically halt but move at an overall rate equal to said constant rate, comprising feed means engageable with the strip material, and means for driving the feed means comprising a driven sprocket, a drive sprocket, means for rotating the drive sprocket at a constant rate, a chain trained over the sprockets, two sprockets between the driven and drive sprockets over which the chain is trained, one of said two sprockets being swingable about the other as a center, means for releasably holding said one of said two sprockets against swinging movement, means for effecting its release for swinging movement and means for restoring it to its initial position whereby the driven sprocket will be driven at normal speed by the drive sprocket, then caused to halt, and then driven at a fasterthan-normal speed during the period of restoration and then returned to normal speed.

2. A feed means for feeding strip material between two stations at one of which the material passes at a constant rate and at the other of which the material must periodically halt but move at an overall rate equal to said constant rate, comprising feed means engageable with the strip material, means for driving the feed means comprising a driven sprocket, a drive sprocket, means for rotating the drive sprocket at a constant rate, a chain trained over the sprockets, two sprockets between the driven and drive sprockets over which the chain is trained, one of said two sprockets being swingable about the other as a center, means for releasably holding said one of said two sprockets against swinging movement, means for effecting its release for swinging movement, means for restoring it to its initial position whereby the driven sprocket will be driven at normal speed by the drive sprocket, then caused to halt, and then driven at a fasterthan-normal speed during the period of restoration and then returned to normal speed, and a spring urged idler sprocket over which the chain is trained for taking up slack in the chain when the mentioned sprocket is released for swinging movement.

3. In a spring forming machine, means for forming sinuous wire at a constant rate, cutting means for cutting the wire into lengths, a feed roll engageable with the wire between the forming means and the cutting means, means for driving thefeed roll so as to cause the Wire to be fed toward the cutting means, halt, then feed the wire at a rate which will make up the time lost by the halt, means -for causing the cutting means to cut the wire during the period of halt, and means for preventing the cutting means effecting a cut unless the feed roll has caused the wire to halt.

4. Means for driving a driven shaft by a constantly rotating drive shaft periodically with a substantial period of dwell between periods of rotation comprising sprockets on the driving and driven shafts, an endless chain trained over said sprockets, a third sprocket over which the chain is trained, a frame swingable about the axis of rotation of the third sprocket, a fourth sprocket rotatably mounted on the frame and movable therewith about the axis of rotation of the third sprocket, a yieldable chain tightener engageable with the chain between the driving and driven sprockets, means for releasing the frame for swinging movement about the axis of the third sprocket whereby the rotation of the driven sprocket may stop, and means for restoring the frame to its initial position.

5. Means for driving a driven shaft by a continuously rotating drive shaft periodically with a substantial period of dwell between periods of rotation comprising sprockets on the driving and driven shafts, an endless chain trained over said sprockets, a third sprocket over which the chain is trained, a frame swingable about the axis of rotation of the third sprocket, a fourth sprocket rotatably mounted on the frame and over which the chain is trained, a chain tightener between the driving and driven sprockets, means for releasably holding the frame against rotation about the axis of the third sprocket, means for releasing the frame for rotation about the axis of the third sprocket, and means for restoring the frame to its initial position.

6. Means for driving a driven shaft by a continuously rotating drive shaft periodically witha substantial period of dwell between periods of rotation comprising Sprockets on the driving and driven shafts, an endless chain trained over said sprockets, a third sprocket over which the chain is trained, a frame swingable about the axis of rotation of the third sprocket, a fourth sprocket rotatably mounted on the fralme and over which the chain is trained, a chain tightener between the driving and driven sprockets, means for releasably holding the frame against rotation about the axis of the third sprocket, means for releasing the frame for rotation about the axis of the third sprocket after variable time intervals, and means for restoring the frame to its initial position.

7. Means for driving a driven shaft by a continuously rotating drive shaft periodically with a substantial period of dwell between periods of rotation comprising sprockets on the driving and driven shafts, an endless chain trained over said sprockets, a third sprocket over which the chain is trained, a frame swingable about the axis of rotation of the third sprocket, a fourth sprocket rotatably mounted on the frame and over which the chain is trained, a chain tightener between the driving and driven sprockets, means for releasably holding the frame against rotation about the axis of the third sprocket, a timing chain driven by the driven shaft, means operable by the timing chain for periodically releasing the frame for rotation about the third sprocket, and means for restoring the frame to its initial position after the frame has rotated about the axis of the third sprocket a predetermined distance.

8. Means for driving a driven shaft by a continuously rotating drive shaft periodically with a substantial period of dwell between periods of rotation comprising sprockets on the driving and driven shafts, an endless chain trained over said sprockets, a third sprocket over which the chain is trained, a frame swingable about the axis of rotation of the third sprocket, a fourth sprocket rotatably mounted on the frame and over which the chain is trained, a chain tightener between the driving and driven sprockets, means for releasably holding the frame against rotation about the axis of the third sprocket, a timing chain driven by the driven shaft, means operable by the timing chain for periodically releasing the frame for rotation about the third sprocket, and means for restoring the frame to its initial position after the frame has rotated about the axis of the sol third sprocket, a predetermined distance, said timing chain being adjustable as to length so that the period of time that the driven sprocket is rotated by the releases of the frame may be varied.

References Cited in the file of this patent