US3575218A

US3575218A - Machines for forming windings for use in dynamo electric machines

Info

Publication number: US3575218A
Application number: US726802A
Authority: US
Inventors: Kenneth Preece
Original assignee: Lucas Industries Ltd
Current assignee: ZF International UK Ltd
Priority date: 1968-05-06
Filing date: 1968-05-06
Publication date: 1971-04-20
Anticipated expiration: 1988-04-20

Abstract

A machine for forming a wave-wound winding from conductive strip includes a forming station having a first set of fingers engageable with one axial end of a substantially helically wound coil of conductive strip at equiangularly spaced points around the coil. The turns of the coil are insulated from one another, and a second set of fingers is engageable with the other axial end of the coil at points equiangularly spaced from one another and from the points at which the coil is engaged by the first set of fingers. The fingers of each set are urged apart from one another by resilient means to positions in which they can engage the coil, and means is provided for moving the sets of fingers relatively towards or away from one another in the direction of the axis of the coil to bend the coil to form a wave-wound winding. The fingers of each set are mounted so as to permit inward movement of each finger against the action of said resilient means as the coil is bent, and the machine further includes means for returning the sets of fingers to their original position when the winding has been formed.

Description

United States Patent Continuation-impart of application Ser. No. 628,054, Apr. 3, 1967, now abandoned which is a continuation-in-part of application Ser. No. 443,821, Mar. 30, 1965, now Patent No. 3,328,617.

MACHINES FOR FORMING WINDINGS FOR USE IN DYNAMO ELECTRIC MACHINES 26 Claims, 19 Drawing Figs.

US. Cl 140]], 72/142, 72/385 Int. Cl. 1321f 3/04, B2lf 45/00 Field of Search 72/142,

[56] References Cited UNITED STATES PATENTS 2,400,008 5/1946 Korte 29/605 2,947,652 8/1960 Burr 140/1 Primary Examiner-Lowell A. Larson AtrorneyI-Iolman & Stern ABSTRACT: A machine for forming a wave-wound winding from conductive strip includes a forming station having a first set of fingers engageable with one axial end of a substantially helically wound coil of conductive strip at equiangularly spaced points around the coil. The turns of the coil are insulated from one another, and a second set of fingers is engageable with the other axial end of the coil at points equiangularly spaced from one another and from the points at which the coil is engaged by the first set of fingers. The fingers of each set are urged apart from one another by resilient means to positions in which they can engage the coil, and means is provided for moving the sets of fingers relatively towards or away from one another in the direction of the axis of the coil to bend the coil to form a wave-wound winding. The fingers of each set are mounted so as to permit inward movement of each finger against the action of said resilient means as the coil is bent, and the machine further includes means for returning the sets of fingers to their original position when the winding has been formed.

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SHEET 1 4 OF M IVIACIIINES IIGR FORMING WINDINGS FOR USE IN DYNAMO ELECTRIC MACHINES This application is a continuation-in-part of my application No. 628,054 filed Apr. 3, I967 and entitled: METHOD OF AND MEANS FOR MANUFACTURING A FIELD WINDING, now abandoned, which in turn is a continuationin-part of application Ser. No. 443,821, filed Mar. 30, 1965, entitled STA'IOR ASSEMBLIES FOR DYNAMOELECTRIC MACHINES, now U.S. Pat. No. 3,328,617.

In my said earlier application I have disclosed a machine for bending a helically wound coil of conductive strip to form a wave wound winding. The present application relates to the machine generally as disclosed in my earlier application and in addition discloses a further part of the machine wherein the helically wound coil is wound from conductive strip prior to being bent to form the wave wound winding.

One example of the invention is illustrated in the accompanying drawings wherein:

FIG. I is a front elevational view of a forming station of a machine for forming windings of the kind specified.

FIG. 2 is a part sectional view in the direction of arrow A in FIG. I,

FIGS. 3 and 4 are views showing the forming station of the machine in two operative positions respectively,

FIG. 5 is an enlarged view in the direction of arrow A in FIG. 3, but showing the sizing sleeve,

FIG. 6 is an enlarged view on the line 6-6 in FIG. I,

FIG. 7 is an enlarged view of part of FIG. I,

FIG. I is a perspective view of a coil prior to a forming operation,

FIG. 9 is a perspective view of a fonned winding priorto its assembly into a dynamoelectric machine,

FIG. III is a sectional view of a dynamoelectric machine having the winding shown in FIG. 9 assembled therein,

FIG. II is a sectional view on the line I M 1 in FIG. 10.

FIG. I2 is a front elevational view of a further part of a machine for forming windings of the kind specified,

FIG. I3 is a front elevational view of a still furtherpart of the machine,

FIG. I I is a sectional view of the part of the machine shown in FIG. I3,

FIG. I5 is a plan view of a wire severing component associated with the part of the machine shown in FIG. I3,

FIG. I6 is a sectional view of the component shown in FIG. I5,

FIG. I7 is a sectional view of a transfer mechanism of the machine,

FIG. 1b is a fragmentary front elevational view of the mechanism shown in FIG. I7, and,

FIG. I9 is a plan view of the mechanism shown in FIG. 17, various operative positions of the mechanism being indicated in chain dotted lines.

Referring first to FIGS. 1' to II of the drawings the machine includes a forming station 10 having a vertically extending frame II which constitutes an integral part of the frame of the whole machine. Pivotally engaged with the frame II and at the lower end thereof is a pair of vertically extending generally parallel fingers I2. The fingers I2 are arranged to pivot towards and away from the frame II and are of quadrant shaped cross section at their free ends. Slidable vertical on the frame II above the fingers I2 is a carriage I3, movement of which is controlled by an hydraulic ram I4. Pivotally engaged with the carriage for movement in a plane at 90 to the plane of movement of the fingers I2 is a second pair of fingers 15.. The fingers I5 extend downwardly towards the fingers I2 and are also quadrant shaped cross section at their free ends. The fingers I2 are urged apart by a spring I6, a similar spring 17 being interposed between the fingers I5 and urging the fingers I5 apart. The arcuate surface of the free end of each of the fingers I2,I5 includes a projection 18,181: respectively in the shape of the pole piece around which the winding to be formed will extend when in use in a dynamoelectric machine.

Moreover, each of the

projections

18,18a includes a limb I9,I9a respectively which extends parallel with its respective fingers I2,I5 to define with the free end thereof a slot 21.

Surrounding the fingers 12 is a cylindrical sizing sleeve 22 which is vertically movable on a carriage 23 slidable on the frame II. The carriage 23 is movable through the action of a hydraulic ram 24.

An inclined shute 25 is positioned adjacent the

fingers

12,15 and is movable to a position between the

fingers

12,15 during the operation of the forming station.

The operation of the forming station I0 is as follows:

At the commencement of an operating cycle the parts of the forming station III are in the position shown in FIG. I. A cylindrical coil 26 (FIG. 8) of flat aluminum strip wound to helical form and wrapped in insulating paper is engaged with the free ends of the fingers 12 so as to lie in the slots 21 in contact with the upper ends of the respective projections 18.

The ram M is then actuated to move the carriage I3 and consequently the fingers I5 downwardly. The free ends of the fingers I5 pass inside the coil 26 while their respective limbs I9a pass outside the coil. Thus the coil 26 is now supported at two diametrically opposite points by the projections 18 of the fingers I2 (FIG. 6) and is urged downwardly at a further two diametrically opposite points, spaced from the first diametrically opposite points by by the projections 18 of the fingers 15. Further movement of the carriage l3 downwardly now bends the coil 26 to form the winding substantially as shown in FIG. 9. As the coil bends, the fingers I2 are moved towards each other against the action of the spring 16, the fingers 15 being similarly moved against the action of the spring 17. Moreover, as the pairs of

fingers

12,15 are moved the free ends of the four fingers interdigitate so as to constitute a solid cylindrical bar when the carriage 13 reaches the lower limit of its travel. When the

fingers

12,15 have interdigitated a latch 27, associated with the pair of

fingers

12,15 closes to lock the fingers 12 together in their closed position and a similar latch 28 (FIG. 7) closes to lock the fingers I5 together.

Upon reaching the lower limit of its travel the carriage 13 actuates a microswitch which initiates operation of the ram 24. The ram 24 moves the carriage 23 and consequently the sizing sleeve 22 upwardly towards the point at which the fingers I2,I5 are interdigitated. The sleeve 22 tapers internally from a maximum diameter at its upper end to a minimum diameter part way along the length of the sleeve, the minimum diameter being slightly smaller than the inner diameter of the yoke of the dynamoelectric machine in which the winding is to be utilized. Associated with one of the fingers I5 is an extractor catch 29 (FIG. 5) which is operated as the sleeve 22 encompasses the interdigitated parts of the fingers, to engage the partly formed winding thereby securing it to the fingers 15. The sleeve 22 performs an upward stroke and is then returned to its original position, and in so doing forms the outside diameter of the partly formed winding to that required, thereby completing the forming of the winding. As the carriage 23 reaches its uppermost position it actuates a limit switch which initiates return movement of the carriage 23 to its original position. Upon reaching its original position the carriage 23 operates a microswitch which initiates return movement of the carriage l3 and therefore the fingers 15 towards the upper limit of travel of the carriage 13. Since the catch 29 is engaged with the winding the formed windingwill be carried upwardly with the fingers 15. During the return movement of the carriage 13 the carriage 13 operates a microswitch which halts the carriage 13 in its upward movement and initiates operation of a pneumatic cylinder to move the chute 25. When the chute 25- has fully retracted, chute 25 has moved between. the

fingers

12,15, a cam 25a thereon operates a microswitch and resumes the upward movement of the fingers 15. A cam 32 on the frame 11 coacts.

with the catch 29 during the further upward movements of the fingers I5 to release the catch 29 and simultaneously the projection 18a of one of the fingers I5 passes between stops 33 on the frame 11 which engage the formed winding 36 and strip it from the fingers 15. The formed winding 36 drops into the chute 25 and rolls down the chute 25 into a storage bin. (not shown). Upon reaching its uppermost position the carriage 13 actuates a further microswitch which causes the chute 25 to be returned to its original position, and also operates a pair of

pneumatic rams

34,35 which release the

latches

27,28 respectively. Release of the latch 27 allows the fingers 12 to move apart under the action of the spring 16 until they engage stops on the frame 11 which position .the arms 12 in preparation for a further operating cycle. Release of the latch 28 similarly allows the fingers to move apart until they engage stops 40 (FIG. 7) on the carriage which serve to position the anns 15 for the further operating cycle.

In use the formed winding 36 is bound with tapes 37 and is provided at its ends respectively with a screw threaded portion 38 and a pair of brushes 39 with their associated leads 41 (P16. 9). The winding 36 is then inserted into the yoke. 42 of a dynamoelectric machine so that two of its curved end portions 360 are engaged with the rounded ends of a pair of diametrically opposite pole pieces 43 integral with the yoke 42. A further pair of pole pieces 44 are then inserted in the yoke 42, the winding 36 being trapped between the yoke 42 and integral flanges 45 on the

pole pieces

43,44.

It will be appreciated that the coil 26 need not be cylindrical. Satisfactory windings 36 have been produced by the machine described starting from coils of generally square and generally elliptical cross section.

it will further be appreciated that the

fingers

12,15 could be modified to engage the coil in such a manner that they could be moved away from one another rather than towards one another to bend the coil to form the wave-wound winding.

The manufacture of the blank coil 26, from which the winding 36 is formed will now be described with reference to FIGS. 12 to 16.

Aluminum wire in the form of a continuous strip 51 of rectangular cross section, passes from a supply station (not shown), between sets of vertical and horizontal straightening rollers 52, to an insulating station 53. In the insulating station 53, the strip 51 passes onto a plate 54, and a continuous strip 55 of insulating paper is led from a supply reel 56 between the strip 51 and the plate 54. The plate 54 is formed with an aperture, through which projects one edge of a roller 57 having therein a circumferentially extending channel. A further roller 58 engages in the channel of the roller 57 and the strip 51 and the paper strip 55 pass between the

rollers

57,58. The width of the paper strip 55 is equal to the circumference of the strip 51 and the strip 51 is positioned on the strip 55 so as to extend along the longitudinal center line of the strip 55. Thus as the

strips

51,55 pass between the

rollers

57,58 the strip 55 is bent to a U-shape, with the strip 51 lying between the limbs of the U.

Beyond the

rollers

57,58, a plate 59 is positioned parallel with and above the plate 54, the plate 59 being formed with a V-shaped slot extending from one edge thereof. The

strips

51,55 pass between the

plates

54,59 and the walls of the slot in the plate 59 bend the limbs of the U-shaped strip 55 into contact with the upper surface of the strip 51 so that the strip 51 is enclosed by the insulating paper strip 55. A continuous strip 61 of adhesive tape is fed from a supply reel 62 onto the top surface of the strip 55 to secure the two limbs of the strip 55 in contact with strip 51. The strip 61 is pressed into place by passing the

strips

51,55 and the strip 61 between a pair of

rollers

63,64, the roller 63 being coated with resilient material, for example rubber, to ensure that a firm even pressure is applied to the strip 61. The

strips

51,55 and 61 are guided in their paths from the respective supply stations by further guide rollers which are shown in the drawings but which are not described in detail.

The covered strip hereinafter designated 65 now passes on to a winding station 66 wherein the blank coil 26 is wound. The winding station 66 includes a substantially cylindrical fonner 67 having an outwardly directed peripheral flange 68 at its lower edge. The former 67 is secured to the upper end of a vertically extending shaft 69 which is journaled for axial and angular movement in the frame of the machine. An air spring 71 acts through a forked lever 73 which engages a collar 74 on the shaft 69 to urge the shaft 69 and the former 67 upwardly. The end of the shaft 69 remote from the former 67 is formed with splines 75 which engage corresponding splines in the upper end of a drive shaft 76. The shaft 76 is driven by an electric motor through a two speed gear arrangement and a reduction gear box 77. The shaft 76 carries a pair of

cam discs

78,79 which rotate with the shaft 76 and which operate microswitches controlling rotating of the former and an electromagnetic brake 81 which is operable to arrest rotation of the shaft 76 and consequently the former 67.

The two speed gear arrangement includes a two part first shaft which is driven by an electric motor through a V belt drive. The first shaft is coupled to the reduction gearbox and a first electromagnetic clutch is operable to interconnect the two parts of the first shaft so that the reduction gearbox is driven through the first shaft. The first part of said first shaft carries a gear wheel which is engaged with a gear wheel on the first part of a two part lay shaft. Moreover the second part of said first shaft also carries a gear wheel which is engaged with a gear wheel on the second part of said lay shaft. A second electromagnetic clutch is operable to interconnect the two parts of the lay shaft. Thus when the motor is operative, the first clutch is inoperative, and the second clutch is operative, then the motor will drive the reduction gearbox through the lay shaft. The sizes of the four gear wheels are so chosen that the reduction gearbox will be driven at lower speed through the lay shaft than through said first shaft. In use, the motor is operative constantly and the rotation of the former 67 is controlled by said microswitches through said first and second clutches and the brake 81.

Associated with the former 67 is a layering roller 82 which is movable vertically on a carriage 83. slidable on the machine frame, into engagement with the flange 68 of the former 67. The movement of the carriage 83 is by means of a pneumatic ram 84. The roller 82 is in the form of a rigid disc and the rotational axis of the roller 82 is offset from, and inclined relative to the axis of the former 67. The carriage 83 also carries a downwardly extending pin 85, the purpose of which will be explained later.

Pivotally mounted on the flange 68 of the former 67 is a clamping finger 86 which in use serves to clamp the end of the strip 65 to the former 67. The finger 86 is coupled to a toggle linkage 87 carried by the former 67, and the toggle linkage 87 is operable to move the finger 86 in a clamping direction by a first control arm on the frame of the machine, and is operable to move the finger 86 in a release direction by a second control arm on the frame of the machine. The first and second control arms do not rotate with the former and are only moved to their operative positions when the former is stationary, moreover the linkage 87 is such that when the finger 86 is moved to either of its positions, then the finger is maintained in that position by the linkage 87 until the linkage 87 is actuated by the appropriate control arm.

Associated with the winding station 66 is a strip severing component 88, which is operable to sever the wound coil 26 from the remainder of the strip 65 at the tennination of a winding operation. The component 88 includes a slide 89 which is mounted on the frame of the machine, and which carries an anvil 91. Pivotally mounted on the slide 89 adjacent the anvil 91 is a cutter blade 92 movable towards and away from the anvil 91. The blade 92 is moved by the actuation of a pneumatic ram 93, through a linkage 93a, and the arrangement is such that in use actuation of the ram 93 first moves the slide 89 from a rest position to an operative position, wherein the strip 65 is positioned between the anvil 91 and the blade 92, without moving the blade 92 relative to the anvil 91. The slide 89 is arrested in its operative position by a stop on the body of the machine, and further actuation of the ram 93 serves to move the blade 92 towards the anvil 91 to 95a, secured to the machine frame, for rotational movement,

and for axial movement in a vertical direction. At its lower end the column 95 has secured thereto a large diameter gear wheel 96, the gear wheel 96 and the column 95 being coaxial. A piston 97 is engaged in the bore in the column 95 and above the piston 97 the bore in the column 95 is closed. A piston rod 90 is secured to the piston 97 and extends from the lower end of the column 95 and is 'secured at its end remote from the piston 97 in a bracket 99 secured to the frame of the machine. The lower end of the column 95 is sealed and so a pair of chambers 101,102 are defined within the column 95, on opposite sides of the piston 97 respectively. The chamber 101 is connected through a passage 103 in the piston rod 90, and through a valve to a source of pneumatic pressure, and the chamber 102 is similarly connected to said source of pneumatic pressure through a flexible conduit 1 and a valve. Thus when the chamber 101 is placed in communication with said source the column 95 will be moved upwardly, and similarly when the chamber 102 is placed in communication with said source the column 95 will be moved downwardly, it being appreciated that the chamber 102 is opened to an exhaust when the column moves upwardly and the chamber 101 is similarly connected when the column 95 moves downwardly.

The gear wheel 96 meshes with a pinion 105 mounted on a shaft 106 adjacent, and parallel with the column 95. The pinion 105 has an axial length in excess of the permitted vertical movement of the column 95 so that throughout the vertical movement of the column the gear wheel 96 is engaged with the pinion 105. The gear wheel 96 and the pinion 105 are formed with axially extending teeth and so the pinion 105 serves to guide the lower end of the column 95 during vertical movement. At its lower end the shaft 106 carries the movable part of a brake 107, the fixed part of which is carried by the machine frame. The brake 107 is spring urged to a condition wherein it prevents rotation of the shaft 106, and therefore the column 95, and electrically operable means are provided for releasing the brake. The end of the shaft 106 remote from the brake 107 is coupled to a reversible electric motor and gearbox unit 100 through an electromagnetic clutch 109.

Supported on the upper surface of the gear wheel 96 are two pairs of arcuatggamplates 110a, 11% and 1100, 110d each of which is'associated with a

respective microswitch

111, 112, 113, 114 carried by the frame of the machine. The plungers of the

microswitches

111, 112, 113, 11 1- are engaged with their respective cam plates 110 when the column 95 is in its raised position, and in conjunction with microswitches at the forming station 10 and the winding station 66, the

microswitches

111, 112, 113, 11 1 serve to control movement of the column 95. 1

Secured to the upper end of the column 95 and extending at right angles thereto is plate 115 having pivotally mounted thereon a pair of jaw members 116,117 respectively. The jaw members 116,117 extend beyond the free end of the plate 115 and are provided at their ends with respective arcuate gripping pieces 110,119, of inverted L-shaped cross section, the pieces 110,119 being presented to one another. At their ends remote from the pieces 118,119, the jaw members carry respective rollers 121,122, and between the rollers is a slidable wedge 123. The jaw members 116,117 are interconnected by a spring (not shown) which urges the rollers 121,122 into engagement with opposite faces of the wedge 123. The wedge 123 is movable by a pneumatic ram 124 and the arrangement is such that as the rollers 121,122 are moved apart by the wedge 123 the pieces 110,119 are mofIed towards one another.

The operation of the machine is as follows: assuming that the machine is switched off at the end of a cycle, that is to say that a coil 26 has been wound, severed from the strip 65, transferred to the formingstation, and then a winding has been formed and deposited in said storage bin, then the former 67 will not yet be in the correct position to start winding a further coil 26 since in this example the coil 26 is made up of 7% turns. When the signal is given to the machine to commence operation, the drive motor for the former 67 will start and the first clutch in the two speed gear arrangement will be deenergized, the second clutch in the two speed gear arrangement will be energized and the former 67 will be rotated at a relatively slow speed. When the former 67 has been rotated through one-fourth of a revolution it will be positioned at its start position and the cam disc 78 will operate an associated microswitch which causes the brake 81 to be applied, and said second clutch to be deenergized so that the former 67 is arrested at its start position. The microswitch which causes the former 67 to be arrested initiates operation of a pneumatic ram 125 (FIG. 12) which causes movement of rack 126. A pinion (not shown) is engaged with the rack 126, and as the rack 126 moves the pinion drives both the roller 57 and the roller 50 through a Spragg clutch, the

rollers

57,58 being driven in opposite directions. Since the

strips

51,55 are between the

rollers

57,58 the strips aremoved by the rollers 57, 50, and the arrangement is such that the strip 65 is moved onto the flange 60 of the former 67. At the completion of its movement the rack 126 operates a microswitch which causes operation of the ram 8 1 to move the carriage 83 and the layering roller 82 downwardly towards the former 67. The edge of the roller 82 urges the strip 65 against the flange 68 of the former 67 and the pin bends the free end of the strip 65 downwardly out of the plane of the flange 68. When the carriage 83 reaches its lowermost position the ram 84 is locked to hold the carriage 83 and the roller 82 in position, and a microswitch is closed to cause said first control arm to move the clamping finger 86 to clamp the strip 65 against the cylindrical surface of the former 67. The first control arm is operated by a pneumatic cylinder to move the finger 68 to its clamping position. Full extension of the cylinder closes a microswitch which initiates the return of the first control arm to a position clear of the former 67. The return of said first control arm to its rest position operates a further microswitch to release the brake 81 and energize said first clutch in the two speed gear arrangement so that the shaft 69 and the former 67 are rotated at a relatively fast speed. Since the free end of the strip 65 is clamped to the former, then as the former rotates the strip 65 will be pulled through the insulating station described above, and will be wound onto the former 67 to constitute the coil 26. The strip 65 is wound so that adjacent turns are in face to face rather than edge to edge contact. As described above, the free end of the strip 65 was bent downwardly by the pin 85 and so acts as a ramp to guide the second turn of the coil onto the surface of the first turn, the coil being compressed axially by the roller 82. It will be appreciated that since the roller 82 is locked in position relative to the frame of the machine, then the former 67 is moved downwardly against the air spring 71 in a series of steps as each turn is wound onto the former. The cam disc 79 is of course rotating with the former,.and a microswitch associated therewith operates a counting circuit associated with the control of the machine to count the number of complete turns wound onto the former. When a desired number of complete turns have been wound a part of a complete turn is still to be wound. The part of the turn is determined by the cam disc 78 which is also rotating with the former, and when the number of complete turns plus the part of the turn have been wound the brake 81 is applied and said first clutch is deenergized, the former 67 stopping virtually instantaneously.

During the winding of the coil 26 the rack 126 was returned to its rest position, said Spragg clutch ensuring that the rollers 57,511 were not rotated in a direction to pull the strip 65 off the former 67. Moreover by virtue of the Spragg clutch the rollers 57,50 free wheel when the rack 126 is stationary and the strip 65 is being wound onto the former.

The application of the brake 81 at the end of the winding operation causes operation of the ram 84 in a manner to raise the carriage 83 and consequently the roller 82. As the roller 82 is raised the former 67 is raised with it under the action of the air spring 71, but the movement of the roller 82 is greater than the permitted movement of the former 67 so the roller 82 is moved clear of the former 67.

During the winding operation, the column 95 of the transfer mechanism 94 is in a raised position, and is disposed angularly in a first waiting position with the jaw members 116,117, open, and adjacent the former 67. Moreover, since the column 95 is in its raised position the

microswitches

111, 112, 113, and 114 are operable by their

respective cam plates

110a, 110b, 1100 and 110d respectively. In the first waiting position the

microswitches

111, 113, 114 are closed by their respective cam plates but the cam plate 11% is such that the microswitch 112 is open. The arrangement is such that when the microswitch 112 is open then the column 95 cannot be rotated to move the jaw members 116,117 into alignment with the former 67 in the absence of a signal that the roller 82 is clear of the former 67. At the termination of its upward movement the carriage 83 operates a microswitch which supplies the necessary signal to the transfer mechanism 94 thereby releasing thebrake 107 and energizing the clutch 109 so that the unit 108 rotates the column 95, through the pinion 105 and the gear wheel 96 to position the open jaw members 116,117 above the former 67. Upon reaching the position wherein the jaw members 116,117 are above the former 67, a microswitch on the frame of the machine is opened by a plate 115a carried by the plate 115 to apply the brake 107 and deenergize the clutch 109 to arrest the column 95. The operation of the microswitch on the frame of the machine also causes pneumatic pressure to be applied to the chamber 102 in the column 95 to lower the column 95 so that the gripping pieces 118,119 of the jaw members 116,117 are positioned on opposite sides of the wound coil on the former 67. As the column 95 is lowered the

cam plates

110a, 110b, 1100 and 110d are moved away from their respective microswitches and the gear wheel 96 operates a microswitch 127 which signals the position of the column 95, initiates the operation of the severing component 88, and reverses the polarity of the motor 108 so that the next time the motor 108 rotates the column 95 the rotation of the column 95 will be in the opposite angular direction.

The severing component 88 operates as described above to sever the coil 26 from the remainder of the strip 65. The material of the strip 65 has, of course, some inherent resilience, and since the gripping pieces 118,119 are not engaged with the coil 26, then when the coil 26 is parted from the remainder of the strip 65, the coil 26 will unwind until the severed end of the coil 26 engages one of the pieces 118,119. This slight unwinding of the coil 26 is sufficient to allow the coil 26 to expand so that it is no longer tightly gripping the former 67. When the severing component 88 has severed the coil 26 from the strip 65 a microswitch in the component 88 is operated which initiates operation of the ram 124 in the mechanism of the jaw member 116,117. Operation of the ram 124 pushes the wedge 123 between the rollers 121,122 and thereby causes the pieces 118,119 to grip the coil 26. The operating arm of the microswitch on the machine frame, which is engaged by the plate 115 includes a roller which is engaged by a hardened steel plate on ihe side of the plate 115, so that the roller guides the plate 115 in its vertical movement. Moreover, the column 95 and its associated bearings are formed with coacting guide means which guide the column 95 during its vertical movement. The column 95 is rotated only in its raised condition and said coacting guide means is such that it serves to support the column 95 in its raised position during rotation.

A pressure switch is included in the supply line to the ram 124 and as the pieces 118,119 grip the coil 26 the pressure in said supply line increases. When the pressure in said supply line rises above a predetermined amount the pressure switch is operated to cause said second control arm to release the clamping finger 86 so that the coil 26 is free of the former 67, and to return the severing component 88 to its original position. The release of the finger 86 operates a microswitch which causes pneumatic pressure to be applied to the chamber 101 in the column 95 to lift the column 95 and thereby lift the coil 26 from the former 67, the coil 26 being held in its wound configuration by the gripping pieces 118,119. As the column is raised the cam plates e, 110d operate their respective microswitches 113,114 to release the brake 107 and energize the clutch 109 so that the column 95 is rotated. The rotation of the column 95 is now in a direction to carry the coil 26 towards the forming station 10.

Prior to reaching a position wherein the coil 26 is at the forming station the column 95 reaches a second waiting position wherein the microswitches 111,112 and 114 are closed by their respective cam plate but wherein the microswitch 113 is opened by its respective cam plate 1100 and in the absence of a signal from the forming station, that the forming station is ready to accept the coil 26, the column 95 will not progress beyond the second waiting position. It will be appreciated that because three separate functions are involved in the machine, that is to say, winding, transferring, and forming, then it is necessary to have the first and second waiting positions, since the three functions do not necessarily take the same length of time.

The signal that the forming station 10 can receive the coil 26 is given by the return of the chute 25 and the return of the carriage 13 to their original positions, and upon receipt of the signal the column 95 rotates to a position wherein the coil 26 is between the

fingers

12,15 of the forming station 10. When the column 95 reaches said position a further microswitch on the frame of the machine is opened by a plate 1l5b carried by the plate of the gripping mechanism and the microswitch 114 is opened by its respective cam plate 110d. The opening of the microswitch on the frame of the machine applies the brake 107 and deenergizes the clutch 108 to arrest the column 95 and further causes the column 95 to be lowered to engage the coil 26 with the fingers 12 of the forming station 10. As the column 95 is lowered the gear wheel 96 again operates the microswitch 127 which again signals the position of the column 95, again reverses the polarity of the motor 108 and releases the pressure in the supply line to the ram 124 so that the gripping pieces 118,119 release the coil 26, the coil 26 now being held in its wound configuration by the limbs 19, of the fingers 12 in the forming station 10.

The release of the pressure in the supply line to the ram 124 allows said pressure switch to open whereupon the column 95 is raised and returned to its first waiting position.

The operating arm of the further microswitch on the machine frame, which is operated by the plate 115 of the gripping mechanism also includes a roller which is engaged by a further hardened steel plate on the plate 115 and so guides the plate 115 and the gripping mechanism during the latter described vertical movement. Moreover the column 95 is guided during said latter movement by said coacting guide means on the column 95 and the bearing 95a.

The machine is provided with safety cutouts which switch off the machine in the event of failure of components such as the gripping finger 86, and when any of the supply stations for the

strips

51,55, 61 are exhausted.

Although the machine has been described, for the sake of clarity, as controlled solely by microswitches, the preferred form of machine includes a control unit which includes three uniselectors, one each for the winding, transferring and forming stations of the machine. Each movement of each of the parts of the stations in monitored by a respective switch and the signals from the switches are fed to the respective uniselector which then initiates the appropriate subsequent operation. Thus the machine can be run continuously but can be stopped and restarted at any point in the cycle, and need not be stopped only at the end of a cycle.

lclaim:

l. A machine for forming a wave-wound winding from conductive strip including a forming station having a first set of fingers engageable with one axial end of a substantially helically wound coil of the conductive strip at equiangularty spaced points around the coil, the turns of the coil being insulated from one another, a second set of fingers engageable with the other axial end of the coil at points equiangularly spaced from one another and from the first set of fingers, mounting means for said set of fingers, resilient means urging said fingers outwardly to positions at which said fingers can engage said coil, and means for moving said sets of fingers relatively towards or away from one another in the direction of the axis of the coil to bend the coil to form a wave wound winding, said mounting means permitting inward movement of each finger against the action of said resilient means as the coil is bent, and the machine further including means for returning the sets of fingers to their original position when the winding has been formed.

2. A machine as claimed in claim 1 wherein the sets of fingers move towards one another to bend the coil.

3. A machine as claimed in claim 2 wherein each finger includes a convex portion which engages the respective axial end of the coil, said relative axial movement of the fingers causing the coil to be bent around said convex portion.

4. A machine as claimed in claim 3 wherein each finger includes a first axially extending portion which engages the inner surface of the coil when the convex portion of the finger engages the respective axial end of the coil, the axially extending portions of the fingers serving to support the coil against inward collapse during bending of the coil.

5. A machine as claimed in claim 4 wherein each finger further includes a second axially extending portion which engages the outer surface of the coil when the first portion of the respective fingers engages the inner surface of the coil, the second axially extending portions of the fingers supporting the coil against outward collapse during bending of the coil.

6. A machine as claimed in claim 4 wherein said first portions of the fingers are so shaped that at the termination of the bending of the coil said first portions interdigitate to constitute a solid cylinder, the machine further including a sleeve coaxial with the sets of fingers, and means mounting said sleeve for axial movement relative to the fingers to engage said winding thereby shaping said winding to conform to the inner diameter of the yoke of the dynamoelectric machine in which the winding is utilized, said solid cylinder serving to support the winding during said shaping.

7. A machine as claimed in claim 1 further including a sleeve coaxial with the sets of fingers, and means for moving the sleeve axially relative to the sets of fingers, after the coil has been bent to form said winding, said sleeve shaping the winding to conform to the inner diameter of the yoke of the dynamoelectric machine in which the winding is to be utilized.

8. A machine as claimed in claim 1 including latch means preventing said resilient means from moving the fingers outwardly during return movement of said sets of fingers to their original positions.

9. A machine as claimed in claim 1 wherein one of the sets of fingers includes releasable catch means securing said winding to said one set of fingers during return movement of the sets of fingers to their original positions.

10. A machine as claimed in claim 9 further including a chute, and means for releasing said catch means during said return movement of the sets of fingers so that the winding can drop into the chute.

11. A machine as claimed in claim 10 in which the sets of fingers move in a vertical plane, the machine including means for moving said chute to a position beneath said one set of fingers during said return movement of the sets of fingers.

release of saidcatch means.

13. A machine as claimed in claim 12 wherein said stripping means comprises a stop engaged by said winding during said movement of the set of fingers to strip the winding from the 14. A machine as claimed in claim 1 wherein one of said sets of fingers is fixed.

15. A machine as claimed in claim 1 including a winding station adjacent said forming station, for winding said helically wound coil from said conductive strip with the turns of said coil insulated from one another, and a transfer mechanism for transferring said wound coil from said winding station to said fonning station.

16. A machine as claimed in claim 15 wherein said forming station and said winding station operate at differing speeds, and said transfer mechanism is so controlled that it cannot transfer a wound coil to the forming station until the forming station is clear.

17. A machine as claimed in claim 15 wherein the conductive strip passes through an insulating station wherein the strip is provided with an insulating sheath prior to entering the winding station.

18. A machine as claimed in claim 17 wherein during a winding operation the strip is initially fed into the winding station, and thereafter is drawn through the insulating station by the winding operation.

19. A machine as claimed in claim 15 wherein said transfer mechanism includes means for gripping the coil in such a manner that the coil cannot unwind during a transfer operation.

20. A machine as claimed in claim 15 wherein the winding station includes means operable after the coil has been wound, for severing the wound coil from the remainder of the strip.

21. A machine as claimed in claim 15 wherein said winding station includes a generally cylindrical, rotatable, former and said former includes means for gripping the free end of said strip so that rotation of the former winds said strip onto said former to constitute said coil.

22. A machine as claimed in claim 21 wherein said former includes a peripheral outwardly extending flange with which the first turn of the coil is engaged as the coil is wound and the former has associated therewith a roller which serves to compress the coil axially as the coil is wound.

23. A machine for forming a wave wound winding from conductive strip, including, a winding station having a generally cylindrical, rotatable former, means on the former for gripping an end of said strip so that rotation of said former winds said strip onto said former to constitute a helically wound coil adjacent turns of which are insulated from one another, and severing means associated with said winding station for severing the wound coil from the remainder of the strip, wherein said former moves axially as the coil is wound so that the strip adjacent the former is maintained in the same plane relative to the frame of the machine throughout the coil winding operation.

24. A machine as claimed in claim 23 wherein said former includes a peripheral outwardly extending flange with which the first turn of the coil is engaged as the coil is wound, and the former has associated therewith a roller which serves to compress the coil axially as said coil is being wound.

25. A machine as claimed in claim 24 wherein said roller is fixed relative to the frame of the machine during the winding operation so that said former is moved axially as the axial length of the coil increases during the winding operation.

26. A machine as claimed in claim 25 wherein the fon'ner is moved axially against resilient means.

Claims

1. A machine for forming a wave-wound winding from conductive strip including a forming station having a first set of fingers engageable with one axial end of a substantially helically wound coil of the conductive strip at equiangularly spaced points around the coil, the turns of the coil being insulated from one another, a second set of fingers engageable with the other axial end of the coil at points equiangularly spaced from one another and from the first set of fingers, mounting means for said set of fingers, resilient means urging said fingers outwardly to positions at which said fingers can engage said coil, and means for moving said sets of fingers relatively towards or away from one another in the direction of the axis of the coil to bend the coil to form a wave wound winding, said mounting means permitting inward movement of each finger against the action of said resilient means as the coil is bent, and the machine further including means for returning the sets of fingers to their original position when the winding has been formed.

12. A machine as claimed in claim 11 further including a stripping means associateD with said one set of fingers for aiding removal of the winding from the set of fingers upon release of said catch means.

13. A machine as claimed in claim 12 wherein said stripping means comprises a stop engaged by said winding during said movement of the set of fingers to strip the winding from the fingers.

14. A machine as claimed in claim 1 wherein one of said sets of fingers is fixed.

15. A machine as claimed in claim 1 including a winding station adjacent said forming station, for winding said helically wound coil from said conductive strip with the turns of said coil insulated from one another, and a transfer mechanism for transferring said wound coil from said winding station to said forming station.

26. A machine as claimed in claim 25 wherein the former is moved axially against resilient means.