US2726819A

US2726819A - Winding method and machine

Info

Publication number: US2726819A
Application number: US186476A
Authority: US
Inventors: Waldo H Zander; Fred D Zander; Delbert I Wilson
Original assignee: McGraw Electric Co
Current assignee: McGraw Electric Co
Priority date: 1950-09-20
Filing date: 1950-09-20
Publication date: 1955-12-13
Anticipated expiration: 1972-12-13

Description

Dec. 13, 1955 w. H. ZANDER ETAL 2,726,819

WINDING METHOD AND MACHINE Filed Sept. 20, 1950 16 Sheets-Sheet l INVENTORS Waldo H.jander Fred Djander BY Delbert 1. Milan i -R g 1955 w. H. ZANDER ET AL 2,726,819

WINDING METHOD AND MACHINE Filed Sept. 20, 1950 16 Sheets-Sheet 2 INVENTORS Waldo H jander Fred D-janqler BY Delbert I. Malian Dec. 13, 1955 w. H. ZANDER ETAL 2,726,819

WINDING METHOD AND MACHINE Filed Sept. 20, 1950 16 Sheets-Sheet 3 IN V EN T 0R5 Waldo H jandcr I A m Dec. 13, 1955 w. H. ZANDER ETAL 2,726,819

WINDING METHOD AND MACHINE Filed Sept. 20, 1950 16 Sheets-Sheet 4 INVENTORS Waldo H.,3ander Fred BJanqler B Delbert LWLlson Dec. 13, 1955 w. H. ZANDER ETAL 2,726,819

WINDING METHOD AND MACHINE I Filed Sept. 20, 1950 16 Sheets-Sheet 5 INVENTORS Waldo H. Jamie! Fred B. ander Delbert W1 lson, QM W 1955 w. H. ZANDER ETAL WINDING METHOD AND MACHINE l6 Sheets-Sheet 6 Filed Sept. 20, 1950 IN VEN TORS Waldo H j ander Fred. Djander Delbert 1. Wilson W. H. ZANDER ETAL WINDING METHOD AND MACHINE Dec. 13, 1955 16 Sheets-Sheet 7 Filed Sept. 20, 1950 E EEE! IN V EN TORS jamaler jamdm EEEEEI E Waldo H. Fred 0. D bert a IIII Dec. 13, 1955 w. H. ZANDER ETAL 2,726,819

WINDING METHOD AND MACHINE Filed Sept. 20, 1950 16 Sheets-Sheet 8 lull/III] INVENTORS Waldo H jander Fred Aljanqler BY Delbert I. Mlson a. ag

Dec. 13, 1955 w. H. ZANDER ETAL WINDING METHOD AND MACHINE l6 Sheets-Sheet 9 Filed Sept. 20, 1950 u Li L J n u L ILIIIIIIIIFII INVENT OR ande' Waldo H. 5

Fred D. gander BY Delbert Wilsm;

Dec. 13, 1955 w. H. ZANDER ETAL WINDING METHOD AND MACHINE 1s Sheets- Sheet 10 Filed Sept. 20, 1950 5 er ander .Jand

:i F E I K "L E INVENTOR Waldo H Fred DJ Delbert I @Mkf' MN HQ.

Dec. 13, 1955 w. H. ZANDER ETAL 2,726,819

WINDING METHOD AND MACHINE Filed Sept. 20, 1950 16 Sheets-Sheet 11 INVENTORS Waldo H. Jared-er Fred D. Janoler Delbert. I. lllilson L7 an Dec. 13, 1955 w. H. ZANDER ETAL 2,725,819

WINDING METHOD AND MACHINE Filed Sept. 20, 1950 1a Sheets-Sheet 12 INVENTORS Waldo H. gander Fred 0. anqler Delber' I. 1160" agy.

Dec. 13, 1955 w. H. ZANDER ETAL 2,726,819

WINDING METHOD AND MACHINE Filed Sept. 20, 1950 16 Sheets-Sheet 13 INVENTOR Waldo H. Jamie? Fred ajanqler BY Delbert I. Wdson Dec. 13, 1955 w. H. ZANDER ETAL 2,7Z6819 WINDING METHOD AND MACHINE Filed Sept. 20, 1950 16 Sheets-Sheet 14 INVENTORS Walda Hjander Fred D jander y Delberi 1. Wilson Dec. 13, 1955 w. H. ZANDER ETAL 2,726,319

WINDING METHOD AND MACHINE Filed Sept. 20, 1950 16 Sheets-Sheet l5 INVENTORS 101 150 DH. jagoler re n er Delbert f wil son.

A TO F SHOW VARIOUS WINDING PO6IT10N$,AND

aTOb SHOW CORRESPONDING POINTS OF ENGAGEMENT OF WINDING RIBBON WITH MICA BLANK. BASED ON FIGURES ITO I6.

Dec. 13, 1955 Filed Sept. 20. 1950 W. H. ZANDER ETAL WINDING METHOD AND MACHINE l6 Sheets-Sheet l6 INVENTORS Waldo Hl jander Fred DJahgler Delbert 1. Wilson wINniNG tvmrr-ron are) Machine:

Application September 24), 195%, Serial No. 186,476

47 Claims. (Cl. 242-9) This invention relates to wire heating coils of the fiat type having strai ht windings all located on one face of afiat form and anchored by notched edges of the form, such as are commonly employed as heating elements in electric toasters. The invention includes both a new winding method for making the coils and a winding machine operating according to the method.

The single heatin face fiat coils described have heretofore been wound by hand by a slow, two-handed technique involving awkward manipulation in anchoring the wire at the notched edges of the flat form of sheet mice or other insulating material. Usually fiat resistance wire ribbon is employed for the coils, and, because of its fiat shape, inherent stifiness and resilience, it is difficult to manipulate, particularly at the anchoring points and, further, it tends to accidental twisting in the course of winding. For these reasons winding of the ribbon from a supply roll heretofore has been impractical and the practice has been to use cut lengths of ribbon for winding the single heating face coils.

A primary object of the invention is to provide an improved winding method for the described fiat heating coils with single heating faces adapted to ribbon and other shapes of wire involving a new technique for obtaining proper engagement of the wire with the notched edges of the supporting forms.

Another object of the invention is to provide a method of Winding fiat heating coils with single heating faces according to which the wire is wound from front to back through an edge notch of a fiat form, drawn to a surplus length at the back of the form then directed forwardly to form a large loop inthe surplus length and drawn to the front of the form through an adjacent notch to contract the loop into tight engagement with the back of the form between the notches.

Another object of the invention is to provide a method of winding fiat coils with single heating faces from wire ribbon with local twists in the ribbon at the anchoring notches on the forms. It is found that such twists serve to provide tight engagement of the ribbon with the notched edges.

A further obiect of the invention is to provide a method of winding the described flat coils of wire ribbon which avoids twisting of the ribbon along its supply path and adapted to supply the ribbon from rolls of any size. According to the method the ribbon is held against twisting in the course of feeding, but drawn through one edge notch of the flat form to a surplus length at the back of the form and then manipulated forwardly without twisting and drawn through the next notch to the front of the form to cause a local twist to develop in the ribbon against the back of the form between the notches.

Another object of the invention is to provide a new method for winding fiat coils on a mounted fiat form with a wire feeding holder by effecting oscillating arcuate winding movement about a fixed axis of one of such 'ice members relative to the other and moving zone of such members also along a feed path lengthwise.

Another object of the invention is to provide a new method for winding single faced flat coils employing mechanical wire manipulating and guiding devices for effecting tight anchoring of the wire at the notched-edges of a flat form and for locating the wire in the notches.

Another object of the invention is to provide a new method of winding the described flat heating' coils eniploying coil holding and wire handling mechanical eevices adapted for relative winding and feeding movements which can be effected through .p'ower mechanism or by manual manipulation of the devices.

Another primary object of the invention is to provide winding machine for mechanically winding heating coils on one face of flat forms.

Another object of the invention is to provide a .niachine for winding coils on flat forms having variations in the spacing of the anchoring notches in the .form edges.

Another object of the invention is to provide a cdil winding machine embodying power operated oscillating coil winding mechanism and power operated feed mechamsm.

Another object of the invention is to provide :a power operated flat coil winding machine adapted to high speed production of coils.

Still another object of the invention is to provide an automatically operated and controlled fiat coil winding machine.

Still another object of the invention is to provide for the winding of electric heating elements with single heating faces suitable for electric toasters.

Both the inventive method and machine and their .advantages may be understood by reference to' the accompanying drawings and the detailed description thereof to follow.

In the drawings:

Fig. :1 is an end view at the start of winding a flat formed wire ribbon heating coil according to a preferred adaptation of the new method, and showing a supporting holder for the fiat form, a dual roller wire feeding holder and devices coactive with the wire and opposite notched edges of the form;

Fig. 2 is a fragmentary perspective front view, Fig. 3 an end view and Fig. 4 a fragmentary perspective rear view of the parts shown in Fig. l at the second winding stage;

Figs. 5 and 6' are corresponding fragmentary rear and cross sectional views of certain detailed parts coact'ing with the wire and notched edges of the form;

Fig. 7 is an end view showing a further winding stage;

Figs. 8 and 11 are views similar to Fig. 6 but showing later. winding stages;

Fig. 9 is an end view and Fig. 10 a corresponding fragmentary perspective rear view, and Figs. 12 through 16 are end views illustrating still further stages to complete one winding cycle; 7

Fig. 17 is a front elevation of a new flat heating coil winding machine designed to mechanically perform the novel winding method illustrated in Figs. I to 16, and incorporating many novel structural features;

Fig. 18 is a top view of the same machine";

Fig. 19 is a right end view thereof;

Fig. 20 is a sectional elevation looking fromth front taken on line 2020 of Fig. 18, and showing the main parts of the winding mechanism;

Fig. 21 is a cross sectional view taken at line 21'21 of Fig. 20, showing parts of the manually operated mechanism for securing a coil form in the for'r'n hdlder and also showing the form holder oscillating drive and other driving parts;

line 23-23 of Fig. and showing the feed carriage. V and parts ofthe reduction gear drive for the drum cam;

Fig. 24 is a fragmentary vertical cross sectional view taken at line 24-24 of Fig. 20 and showing parts of the reduction gear drive for the drum cam notshown in Fig. 23;

Fig. 25 is a longitudinal view taken on line 25-25 of Fig. 20 showing the form locking mechanism on the form holder and actuating parts therefor actuatable by the manual control shown in Figs. 1 and 21;

Fig. 26 is a transverse view, partly in section and partly in end elevation,'taken on line 26-26 of Fig. 20 and showing the coil holder and associated parts of the winding mechanism; 7

Fig. 27 is a perspective view, partly in section and partly diagrammatic, of all the principal operating parts of the winding machine;

J Fig. 28 is a front view of the form holder and associated parts of the winding mechanism;

Fig. 29 is a view corresponding to Fig. 28 but with the form holder reversed to show the back side thereof;

Fig. 30 is a perspective view of the coil winding mechanism at an intermediate stage of coil winding;

Fig. 31 is a fragmentary rear elevation of a fiat coil showing the twists produced in the wire ribbon along the notched edges of the supporting form;

Fig. 32 is a rear perspective view of the coil winding mechanism and the wire ribbon delivery mechanism;

Fig. 33 is a left end view of the wire ribbon delivery mechanism;

1 Fig. 34 is a vertical sectional view taken on line 34-64 of Fig. 33;

Fig. 35 is a further vertical sectional view taken on line 35-35'of Fig. 33;

Fig. 36 is a horizontal sectional view taken'on line 36-36 of Fig. 33; V

Fig. 37 is a schematic view showing the development of the cam drum;

Fig. 38 is a schematic view showing the oscillatory path of the coil form holder according to the winding method illustrated in Figs. 1 to 16;

Fig. 39 is a diagrammatic view of automatic control electrical and pneumatic circuits for the winding machine;

Fig. 40 is a top view of one of the wire ribbon guides;

Fig. 41 is a vertical view, partly in section and partly in elevation, taken at line 41-41 of Fig. 40; and

Fig. 42 is a vertical view, partly in section and partly in elevation, taken at line 42-42 of Fig. 40.

A partially completed heating element of the type to be produced according to the invention is shown in Fig. 30, the same comprising a mica or other suitable insulating flat form EF wound on one face with successive windings of electrical resistance wire ribbon R. The ribbon windings are anchored along opposite edges of the form by passing from the front side of the form through notches N and held at the back side by support ing legs L, as best shown in Fig. 31.

The heating element is shown in Fig. 30 supported for winding with its notched side edges horizontal, and with its bottom vertical at the right. The winding of the ribbon is shown as being progressive from bottom to top. As conventionally, the windings are relatively close together near the bottom of the form and their holder FH comprising a rigid plate adapted to support the back of the somewhat flexible mica form and pro vide reinforcement therefor during winding. As shown in Fig. 4, such holder is narrower than the heating element form EF so that the notched side edges of the form are spaced outwardly at the lengthwise horizontal edges of the holder.

The form is removably retained on form holder FH in any suitable manner. We prefer to provide V-shaped retaining notches in the opposite edges of 'the form located at the ends of the holder to engage retaining fingers on the holder. In Fig. 2 the edge of the form a at the right engages the inner end of raised portion 5-8 ,on the holder from which projects inwardly a V-shaped retaining finger 51 interfitting with one of the form notches. a

The wire ribbon R is fedfrom a ribbon holder RH comprising interfitting grooved and ribbon feed rolls 52 and 53. Winding on form-EF is accomplished by oscillating either the ribbon holder RH or the form holder FH relative to the other about a fixed axis. Preferably, and as shown, the form holder is the oscillating member, being suitably supported to oscillate about its horizontal medial axis. The ribbon holder is supported in fixed spaced relation to such axis a short distance outwardly of the arcuate path of oscillation about such axis of the ribbon notches N of the horizontally extending edges of the heating element form EF mounted on the form holder FH. The alternative procedure comprehended within the new method of oscillating the ribbon holder while supporting the form holder against turning, is

feasible.

RH. As the preferred alternative, the ribbon holder 7 is suitably mounted for such feed movement axially.

In a simple adaptation of the new method the feed movement just referred to can be effected manually with out the aid of mechanical guides. It is further preferred to provide guides to bring the ribbon into registry with the notches N of the heating element form, such guides being mounted for feed movement along the edges-of the form simultaneously with the ribbon holder RH and oscillating with the form and form holder PE in the course of winding. A similar pair of such ribbon guides RG and R6 are variously shown in Figs. 1-16 as embracing the opposite horizontally extending notched edges of the form EF.

Ribbon guide RG provides a channel of V-shape and open at its bottom adapted to guide the ribbon into successive form notches when the ribbon is wound from front to back and also when the winding is from back to front. This ribbon guide has a bottom recess accommodating the notched edges of the form and the thickness of the ribbon at both faces of the form. An undercut and/or groove parallel to the edge of the form to accommodate the thickness of the ribbon between notches at the back of the form is provided in the guide and adjoins the main recess. In the particular forms shown part 55 of the guide is of generally triangular shape with a sloping face defining one side 'of the channel. part is undercut at the front to overlie the edge of the form as is shown in Figs. 2 and 4. At the other side of the channel is a front plate56 undercut to accommodate the thickness of the form and of the ribbon at the front of the form, as shown in Figs. 1 and 6 and having a.

sloping inner edge bounding the channel. Such edge is rounded in its lower portion. Back of the plate facing the channel is a sloping faced part 57 terminating in a Such rounded lower end as shown in Fig. 5 above the lower area of the form notches.

Parts

56 and 57 are secured on a supporting part 58 mounted on a common base 59 with part 55 on the opposite side of the channel as shown in Fig. 4.

The second guide RG' is similar in construction to guide RG. While not so shown, except in figures hereafter to be described, guides RG and R6 are rigidly interconnected for common feed movement along the opposite notched side edges of form and are alined for correct registry with the opposite form notches. It is also to be understood that ribbon holder RH is mounted to move with the guides and in vertical alineruent with the channels therein.

In Fig. 1 form holder FH is shown in its starting position tilted on its axis relative to ribbon holder RH. The ribbon has been secured in any suitable manner to the lower edge of form EF. The form holder is now turned forwardly to the position shown in Fig. 3 to wind ribbon R across the front of the form and through guide RG into the first notch. The parts are shown in their relative position at the end of such movement in Figs. 2, 3 and 4, form holder FH now being reversely tilted relative to the ribbon holder at one extremity of its path of oscillatory movement. It will be observed that a substantial length of ribbon has been drawn between the edge of the form and the ribbon holder.

The ribbon holder is again turned clockwise from the position shown in Fig. 3 in continuous movement through the position shown in Figs. 7, 9 and 12 to the opposite limit of its oscillatory path as shown in Fig. 13. In the position shown in Fig. 3 or shortly after such movement has begun the ribbon guides and ribbon holder are advanced along the form into alinement with the next pair of notches at opposite side edges of the form. The guide is shown in partially advanced position in Fig. 5 and is in registry with the next notch in Fig. 8. When movement has reached the position shown in Fig. 7 the length of ribbon previously drawn assumed the form of a large slack loop which is readily guided by part 57 of the guide into the next notch N. In the position shown in Figs. 9 and 10 the slack loop has been drawn down into close engagement with the back of the leg portion of the form intervening between the first two notches as will be understood from Fig. 11. Continuing through the position shown in Fig. 12 the second winding of ribbon is laid across the front of form EH. By the time it has reached its second limit position shown in Fig. 13 the ribbon has been guided by ribbon guide RG' into the notch in the second side edge of the form. In reaching the position shown in Fig. 13 also a length of ribbon has been drawn between the second edge of the form and ribbon holder RH similar to that shown in Fig. 3.

The next movement of the form is in a counterclockwise direction from the position shown in Fig. 13 through the positions shown in Figs. 14 and 15 to a tilted stop position, shown in Fig. 16 which is the same as the starting position shown in Fig. 1. In the position shown in Fig. 13 or shortly after movement therefrom has started ribbon guides RG and RG' and ribbon holder RH are advanced to the third notch along the form EF. The large slack loop which has been formed from the excess length of ribbon as shown in Fig. 14 is readily guided by guide RG' into the third notch at the second edge of the form by the time the form has turned to the position shown in Fig. 15 and the excess loop has been drawn tightly against the back of the leg portion of the form between the second and third notches. Further turning movement to position 16 merely completes the first winding cycle in which two lengthsof ribbon have been laid across the front of the form and anchored at the backs of. the opposite notched side edges. The cycle is repeated by the oscillatory turning movement of theforrn and the advance of the ribbon guides and the ribbon holder from notch to notchis repeated, as will be under- 6 stood from Fig. 30 until the desired number of windings have been put on the form.

By reference to Figs. 11 and 31 it will be observed that a twist has been formed in the ribbon at the back of the form between the notches. This is considered desirable in securing tight engagement of the ribbon withthe form and results from the fact that the ribbon holder holds the ribbon against twisting but a twist is necessarily formed as the loop shown in Figs. 7 and 1-4 is drawn against the back of the form. It may be noted the twists formed at the opposite notched side edges of the form are in reverse vdirections, this being due to the diiference in the directions of movement ofthe form relative to the ribbon holder.

The oscillating winding cycle just described is further explained in Fig. 38 wherein the movements of the form holder FH are illustrated. Line A represents the starting and stopping position of the form holder as in Figs. 1 and 16. Line B represents the first limit position of the path of movement as in Fig. 3 and line E represents the second limit position of such path. The three stages of movement of the form holder are: first, counterclockwise from A to B; and, second, clockwise from B through line D, corresponding to Fig. 12, to E; and, third, again counterclockwise from E back'to A.

Points a, b, c, d and 2 represent the points of engagement of the ribbon with the edges of the form in the position represented by lines A, B, C, D, E. Thus the ribbon is anchored in the first notch of the second edge of the form in starting position A, such anchoring having been done manually. At b the ribbon is at the first edge, having been drawn from front to back through the first notch in such edge in the initial movement of the form holder from A to B. At points 0 and d the ribbon is still at the first edge but by the time it reaches D it is in the second notch thereof. At point e, the ribbon is again at the second stage of the form since while the first edge moved from D to E below the ribbon has been drawn from front to back through thesecond notch in the second edge in the corresponding movement of the second edge from B (Fig. 12) to A (Fig. 13) at the top.

Line C is directly below the position of the ribbon holder RH. Line F is likewise, with a are between C and F. Not only must the first limit position at B be at an angle to C but in such position the form holder must be suiiiciently inclined to the ribbon holder RH that the ribbon is drawn well down into the notch in the first edge and extends backwardly'to the ribbon holder at an abrupt angle (see Fig. 3) clear of inter fering with the subsequent advance of the ribbon guide RG to the second notch. Similar considerations apply to the location of the second limit position at E when the ribbon extends backwardly through the notch in the second edge and ribbon guide RG is ready for advance (see Fig. 13).

The actual angles of the limit position at B beyond C and of limit position E beyond F are not critical and depend in part upon the distance between the location of ribbon holder RH and the form. By way of example, angles in the range of 30 to 40 have proved satisfactory. With such angles beyond 180 the form will oscillate through an overall arcuate path in the range of 240 to 260.

The method which has been described for winding fiat heating elements with single heating faces can be carried out by manually turning the form holder FH and by manually advancing the ribbon guides RG and RG' and the ribbon holder RH from notch to notch alongthe form EF. As so practiced the method is a marked advance over prior hand winding since the hands arenot required to manipulate the ribbon at any stage of Wind'- ing and merely anchor it to the heating element'form at the start of winding and severing the ribbon after winding has been completed.

The machine The general construction of the machine is shown in Figs. 17, 18 and 19. In the specific form to be described the machine operates to wind electric heating elements with twenty windings of varying spacing on a single heating face and suitable for electric toasters. Since two windings, in opposite directions can be obtained with each completeoscillatory winding cycle, and with feed advance each half cycle, according to the description of by electric motor EM through a rotary to oscillatory motion translating drive. The ribbon guides RG and RG are oscillated in the same manner but are mounted independently ofthe form holder together with the ribbon holder RH, by a feed carriage FC for feed advance along the axis of the form holder. 'Advance of the feed carriage is controlled by a rotary cam drum CD having twenty cam steps of varying dimension conforming to the changing spacing of the notches along the edges of the coil forms (see Fig. so that the feed carriage advances notch by notch along each side edge of the form each half oscillating cycle of the form holder to provide exact registry of the ribbon guides and the ribbon holder with the notches.

Cam drum CD is also driven by electric motor EM, through a rotary speed reducing drive to make one complete revolution for each complete coil Winding operation of ten oscillating cycles of the form holder, such L rotary drive being in a 1:10 ratio to the oscillating drive of the form holder.

The advance of the feed carriage FC, ribbon guides RG and RG and ribbon holder RH is effected under control of the cam drum by a separate motor, pneumatic motor PM.

Through an appropriate automatic control circuit each heating element may be wound in a continuous operation and the machine reset and then stopped for replacement of the completed heating element by a new form for winding.

The specific machine operation just mentioned is merely exemplary. The invention involves the machine in its basic construction, since the same may be adapted to produce coils on fiat forms of any desired size and with I any desired number of windings for electric toasters, or for other uses.

In the description to follow some structural details, such as various bearings, are omitted from mention where they are unimportant to a proper understanding of the inventive machine.

The form holder The holder PH, as best shown in Figs. 20, 26, 28 and 29, comprises a solid rigid plate, as in Fig. 1, adapted to support a heating element'form for winding. At one end the plate is provided with an extension 600 .of reduced width to which is secured a stub shaft 61 having a bearing journal in a supporting post 62 upstanding from the right I end of the machine casing CS.

Rigid with the other end of the form holder is a hub '63 split longitudinally on one side and threaded, and

clamped by a screw through its split side (see Fig. 25), rigidly to the end portion of a long oscillatable drive shaft 64 which extends lengthwise of the machine. Shafts 64 8 and 61 have a common axis extending along the medial line of form FH.

The opposite end of shaft 64 is journalled in the inner end wall 65 of the upstanding portion of the casingat the leftend of the machine. integral flange 66, and threaded on the shaft near the flange is a nut 67. Bearing 68, secured in wall 65by a flanged retaining ring 69 is clamped between the shaft flange and the nut to support shaft 64 against axial movement.

Form locking mechanism A readily releasable mechanism is provided which will lock a form on the form holder in proper position for winding and which is quickly adjustable to facilitate Withdrawal and replacement of a'fortn after winding. Referring first to Figs. 28 and 29, together with Fig. 25, on extension 669 of form holder FH is a raised element 59 adapted to engage one edge of a form and. provided with a projecting retaining finger 51 in the same manner as in the form holder shown in Fig. 2 and adapted, as earlier explained, to engage a retaining V-shaped notch provided in the form for the purpose.-

At the opposite end of the form holder is a retractable undercut bar 79 forming with the surface of the form holder a slot adapted to'receive the opposite edge of a form and having a retaining finger 71 adapted to engage a further V-shaped form notch. 72 in the form holder slidably mounts a flat extension '73 of a hub 74. Bar is secured to the hub extension at the front face of the form holder. A plate 75 is secured to the hubextension to slidably engage the back of the form holder and hold bar 7t) against the form holder. for movement lengthwise of the form to move bar 70 between locking and retracted positions relative to a form on the holder. 7

The form holder oscillating shaft 63 is hollow and through it extends a slidable shaft 76 anchored to hub 74. The opposite end 'of shaft 76 extends beyond shaft 63, as seen in Figs. 2 5, 27, 20 and 21, and through a bore in a cylinder 77 into a larger counterbore. A bearing 79 is adapted to journal shaft 76 for turning oscillation with shaft 63 without turning movement of cylinder 77. End portion 78 of shaft 76 is of reduced diameter, providing a shoulder, and a nut 80 is threaded to hold the bearing against the shoulder. Bearing 7 9 is secured in the cylinder counterbore so that the cylinder and shaft are adapted to conjoint axial movement.

Cylinder 77 is mounted for axial movement in bore 81 of an interior boss 82 integral with the casing. A crossbore 84 extends inwardly from the front casing wall to meet bore 81 and terminates beyond in a reduced inner end portion 85. Housed in the cross-bore is a shaft 86 housing an integral gear 87 coacting with ratchet teeth 88 on theunderside of cylinder 77. 89 of the shaft is reduced to provide a shoulder which engages a retaining ring 90 supported by a removable cover plate 91 and holding the shaft against axial movement. A lever 92 is secured to the projecting reduced shaft portion 89 at the outside of the casing.

Turning of lever 92 results in axial movement of cylinder 77, shaft 76, hub 74 and form locking bar 70. Turning of the lever in one direction moves bar 70 inwardly lengthwise on the form holder FH to look a form on the holder in contact with element 50 and

fingers

51 and 71. Reverse turning of thelever retracts the locking bar to free a form for removal from the holder.

Oscillating form holder drive The form holder FH is oscillated in its'winding path by a drive from motor EM shown in Fig. 27. Only portions of such drive are shown in Fig. 20 for reasons of clarity but the portions omitted therein are shown in Figs. 21 and 22.

Through reduction gearing the motor drives Near its end the shaft has an A rectangular opening Hub 74 is independent of hub 63 and is designed The outer end ortion