USRE28582E - Lead forming method - Google Patents

Abstract

A method of attaching the leads of coils wound onto a slotted armature with the leads wrapped at least partially around the shaft of the armature and then connected to selected commutator hooks circumferentially spaced from the slots in which the coils are laid, which method is characterized by the fact that a pair of concentric sleeves shield the commutator to prevent engagement of the wire with the hooks during winding of the coils; and upon completion of a pair of simultaneously wound coils, rotation of the concentric sleeves both in unison and relative to one another, first in one direction and then the other, exposes the selected hooks and wraps the wire lead about them.

Description

United States Patent Dammar Reissued Oct. 28, 1975 [5 LEAD FORMING METHOD 3,212,170 10/1965 Marshall 29/598 3,309,548 3/1967 Gou h et al. 310/234 [75] Inventor: E Dammar Mmneapolls 3,395,448 8/1968 Moo re 29/596 3,395,449 8/1968 Moore 29/596 [73]. Assigneez Possis Corporation, Minneapolis, 3,448,311 6/1969 Mommsen et ai. 310/234 Minn. FOREIGN PATENTS OR APPLICATIONS [22] Filed 1972 121,253 4/1966 Netherlands 29/597 21 App]. No.: 280,037

Related U.S. Patent Documents Primary Examiner 'carl Hall Reissue of:

[64] Patent No.: 3,636,621 [57] ABSTRACT Issued: Jan. 25, 1972 PP N05 ,832 A method of attaching the leads of coils wound onto a Filed: Aug. 26, 1968 slotted armature with the leads wrapped at least par- 21 Division of Ser. No. 565,291, July 14, 1966. tially around the shaft of the armature and then con- 1 1 nected to selected commutator hooks circumferentially spaced from the slots in which the coils are laid, I 1 Cl 29/205 which method is characterized by the fact that apair 2 21: 2 2/ of concentric sleeves shield the commutator to pre- 310/234 vent engagement of the wire with the hooks during [51] Int. Cl.2 02K 15/00 winding of the oils; and upon completion of a pair of Field 05 Search 29/596, 598, 205 R, simultaneously wound coils, rotation of the concentric 29/205 CM; 140/92.1;242/7.03,7.05 B; sleeves both in unison and relative to one another, 310/234 first in one direction and then the other, exposes the selected hooks and wraps the wire lead about them. [56] References CIted UNITED STATES PATENTS 3,169,301 2/1965 Fletchen et al 29/205 )4 4 Claims 31 Drawing Figures 3,191,269 6/1965 Moore 29/598 Reissued Oct. 28, 1975Sheet 1 of7 Re. 28,582

I N VEN TOR. RA YMON l1. DA MMAR B Y JW,M W w A7- TORNE Kr Reissued Oct. 28, 1975Sheet 2 of7 Re. 28,582

m d QN [N VENTOR. AA YMON H. DA MMAR A7- TORNEYJ' Reissued 0m. 28, 1975 Sheet 4 of7 Re. 28,582

1N VENTOR. IFAYMoN/iDAA/IMAR Reissued Oct. 28, 1975Sheet 5 of7 Re. 28,582

INVENTUR. RA YMo/v ILDA MMAR .WN E

Reissued Oct. 28, 1975 Sheet 6 of7 Re. 28,582

QM r k INVENTOR. AA YMON H. DAMMAI? ,filwddocg ATrok/VEKY Reissued Oct. 28, 1975Sheet 7 of7 Re. 28,582

QM k M E 1 N VEN TOR. AA YMON h. DA MMAI? BIG $946M Ar TORNEYJ LEAD FORMING METHOD Matter enclosed in heavy brackets appears in the original patent but forms no part of this reissue specification; matter printed in italics indicates the additions made by reissue.

This application is a division of the copending application Ser. No. 565,291, filedJuly 14, 1966, now US. Pat. No. 3,474,515. I

This invention relates to a method of attaching the leads of coils wound onto a slotted armature core, to the hooks or tangs of the commutator of the armature, and has as its purpose to expeditiously produce armatures that are free'from objectionable crossover loops and undesirable bridging.

Briefly, the method of this invention contemplates shielding the commutator of the armature and, more especially, its lead-receiving hooks or tangs, in the mouth of a pair of concentric relatively rotatable sleeves during the winding of the coils to prevent engagement of the wire with the hooks or tangs, and then -at the completion of each coil and with the wire held against the outer sleeve-carrying the wire around the armature shaft by rotation of the outer sleeve to a point just beyond a selected commutator hook. At this point, the selected hook is exposed by relative rotation between the sleeves and the wire drops behind the selected hook. Now, by rotation of the sleeves in unison, but in the reverse direction, the wire is carried around the hook, whereupon relative rotation of the sleeves frees the wire from the concentric sleeves so that winding of the next coil can commence.

It is a feature of this invention that, during the attachment of the wire lead to a commutator hook, the armature is not rotated. The only rotation imparted to the armature is that required to index it for the winding of successive coils.

With these observations and objectives in mind, the manner in which the invention achieves its purpose will be appreciated from the following description and the accompanying drawings, which exemplify the invention, it being understood that changes may be made in the precise method of practicing the invention and in the specific apparatus disclosed herein without departing from the essentials of the invention set forth in the appended claims.

The accompanying drawings illustrate one complete example of the physical embodimentof the invention constructed according to the best mode so far devised for the practical application of the principles thereof, and in which:

FIG. 1 is a plan view of an apparatus that can be employed to practice the method of this invention, illustrating an armature in position and being wound;

FIG. 2 is a side view of the apparatus shown in FIG. 1, partly in section;

FIG. 3 is a sectional view taken along the line 3-3 of FIG. 2; 1

FIG. 4 is a sectional view taken along theline 44 of FIG. 1;

FIG. 5 is a sectional view taken along the line 5-5 of FIG. 1;

FIG. 6 is an enlarged sectional view taken along theline 66 of FIG. 2;

FIG. 7 is an enlarged viewsimilar to FIG. 5 showing a detail of the drive control of the apparatus;

FIG. 8-is an enlarged sectional view taken along the line 8-8 of FIG. 1;

FIG. 9 is a fragmentary plan view of the structure shown in FIG. 8;

FIG. 10 is a sectional view taken along the line 10-10 of FIG. 9;

" FIGS. 11 and 12 are sectional views similar to F IG. 10 to illustrate how rotation of the outer sleeve carries the wire lead around the shaft;

FIG. 13 is a top view of the structure shown in FIG. 12 taken along line 13l3;

FIG. 14 is a sectional view similar to FIG. 10 showing the wire lead carried to the point at which it drops behind the selected commutator hook;

FIG. 15 is a fragmentary plan view taken along line 15-15 of FIG. 14;

FIG. 16 is an enlarged sectional view taken along the line 1616 of FIG. 14;

FIG. 17 is a sectional view similar to FIG. 10 showing how reverse rotation of the sleeves wraps the lead wire about the selected commutator hook;

FIG. 18 is a sectional view similar to FIG. 10 showing how during relative rotation of the sleeves in the reverse direction the lead wire is disnegaged from the inner member;

FIG. 19 is a plan view of the structure shown in FIG. 18;

FIG. 20 is a sectional view similar to FIG. 10 showing the situation as it obtains preparatory to the indexing of the rotor for winding the next coil;

FIG. 21 is a plan view of the structure shown in FIG. 20 with parts broken away to show the lead wrapped around the hook;

FIG. 22 is a sectional view similar to FIG. 20 showing the rotor indexed to the next coil receiving position; and

FIGS. 23 to 31 are diagrammatic views partly sectioned showing the sequential relationships between the driving control structure of the apparatus and the movable lead-carrying structure with respect to the lead receiving hook on the commutator.

Referring to the drawings there is shown in FIG. 1, a rotor for an electrical machine indicated generally at 35 positioned in working relation with a lead-attaching apparatus indicated generally at 44.Rotor 35 has a softiron armature core 36 formed with a plurality of circumferentially spaced longitudinal slots for receiving coils ofwire 37 forming electrically effective coil loops.

The coils of wire are wound or placed onarmature core 36 by a winding machine (not shown) havingmovable fliers 38 for directing the wire leads 39 into pairs of slots in the armature core. Axially spaced fromcore 36 is acommutator 41 mounted on ashaft 42 carryingarmature core 36.Commutator 41 has a plurality of circumferentially spaced conducting segments forming an outer cylindrical surface. Each segment of thecore 36 has a hook ortang 43 turned upwardly and axially away from the core to receive and hold leads 39 extended from the slots.

The lead-attachingapparatus 44 operates in conjunction with the winding machine to carry the ending leads which extend from the slots around the shaft and onto commutator hooks that are circumferentially spaced from the slots from which the leads emanate, in a manner which eliminates crossover loops and bridging of successive leads. As shown in FIG. 2, theapparatus 44 has a flat frame orbase plate 46 carrying a box shapedhousing 47.Frame 46 has a plurality of elongated openings adapted to receive bolts used to secure the frame to amachine support 45 or the like.Housing 47 has a longitudinal bore accommodating an elongated outertubular shaft 48.Ball bearing assemblies 49 and 51 rotatably mountshaft 48 inhousing 47. Concentrically positioned withintubular shaft 48 is aninner shaft 52.Sleeve bearings 53 and 54 located in the opposite end portions ofshaft 48 rotatably mountshaft 52 withintubular shaft 48.

Mounted on the forward end ofshafts 48 and 52 is a commutator shielding and lead moving and guidingunit 55 which is operable to move and guide each end ing wire lead which extends from the coil just wound, aboutrotor shaft 42 and around a selected commutator hook while at the same time shielding the entire commutator except the selected hook to thereby prevent other or previously attached leads from leaving their hooks. As shown in FIG. 16,unit 55 comprises an outer sleeve orcup member 56 telescoped over and secured to the end oftubular shaft 48 byscrews 57. Projected radially from the forward portion ofsleeve 56 are two diametrically opposite lugs orfingers 58 and 59. These fingers are identical in construction as shown in FIGS. 9 and 10, and they have front or leading faces which lie in a common plane that contains the axis of theshafts 48 and 52. The opposite trailing and outward side faces of the lugs are each inclined and converge to flat heads havingrearward projections 61. Axial recesses 62 are located in the bottom portions of the trailing faces. Located adjacent to the leading face offinger 58 is a triangular-shapedgroove 63 having aninclined plowing edge 64. A similartriangular groove 63A is located ad.- jacent to the leading face offinger 59 to provide aplowing edge 64A.

Concentrically disposed withinsleeve 56 is an inner sleeve which provides a thimble or inner cup member indicated generally at 65, the cylindrical interior of which forms achamber 66 for receiving and shielding theentire commutator 41.Cup member 65 has abase 67 and an outwardly projected cylindrical flange 68.

Base 67 is drivably connected with theinner shaft 52 by a radially disposedpin 69 which has its inner end portion fixed in a hole inshaft 52 and its outer end por tion received in anarcuate slot 71 inbase 67. The arcuate length of theslot 71 provides the connection between theinner shaft 52 and thecup member 65 with about 20 of lost motion.

A frictional driving connection between thecup member 65 and theouter sleeve 56 is provided by a plurality of circumferentially spacedshoes 72 located inradial recesses 73 inbase 67.Springs 74 positioned inrecesses 73 bias the shoes radially outwardly into frictional engagement with the inner surface ofouter sleeve 56.

As shown in FIG. 16, the forward end ofinner shaft 52 has an axial bore 76 to receive theshaft 42 of an armature to be wound. Bore 76 axially aligns the armature core with the lead moving and guiding unit to insure the location ofcommutator 41 within thechamber 66.

The cylindrical flange 68 of the shielding cup or thimble hasaxial slots 77 and 78 which open to the outer end ofmember 65 and are normally covered by theouter sleeve 56. When uncovered by relative rotation of the inner and outer sleeves theslots 77 and 78 are located immediately adjacent the leading ends of the plowing edges 64 and 64A respectively, and when so uncovered, theslots 77 and 78 receive the wire leads and allow them to be engaged over and around the commutator hooks.

As shown in FIG. 4, theconcentric shafts 48 and 52 are rotated by reciprocation of arack 79 which meshes with apinion gear 81 fixed with respect to theouter shaft 48. The rack extends transversely through an opening inhousing 47 and has its opposite ends secured topistons 82 and 83 operative incylinders 84 and 86 respectively. The inner ends of the cylinders are secured tohousing 47 and close theopening 80.Caps 87 and 88 secured to the outer ends of thecylinders 84 and 86 are coupled tolines 89 and 91 used to supply pressure fluid, preferably air, to selectively drive the pistons towardhousing 47. The top ofrack 79 rides on abearing plate 92 transversely positioned inhousing 47 and secured to the top ofhousing 47 bybolts 93. As shown in FIG. 2,plate 92 has an elongated rectangular guideway forracks 79 and maintains the teeth of the rack in meshing engagement with the teeth ofpinion gear 81.

As shown in FIGS. 2 and 3, a clamp unit comprising asleeve portion 94 and aclamp portion 96 located inhousing 47 is attached toouter shaft 48 bybolts 97.Sleeve portion 94 has a radial flange surroundingouter shaft 48 and accommodatingbolts 98 securingpinion gear 81 tosleeve portion 94 so that on rotation ofpinion gear 81 the outer shaft is rotated.Outer shaft 48 rotates approximately as determined by a pair oflimit switches 99 and 101 mounted on opposite sides ofhousing 47 as shown in FIG. 1. These switches have forwardly projectedactuators 102 and 103 which control suitable valves (not shown) for directing the pressure fluid tocylinders 84 and 86 respectively.Actuators 102 and 103 are controlled by the angular positions of a pair ofcollars 104 and 106 adjustably mounted onouter shaft 48. The collars have radially directedarms 107 and 108 respectively which engageactuators 102 and 103 to determine the clockwise and counterclockwise stop positions ofouter shaft 48.

Rotational movement ofouter shaft 48 with respect toinner shaft 52 is regulated by a drive control indicated generally by 109 in FIGS. 1,2,5 and 7.Drive control 109 comprises aradial arm 1 11 having a bifurcated inner end clamped about the end ofinner shaft 52 with abolt 112. Arm 111 is engaged by a rearwardly projectedpin 113 secured to acollar 114. A fastening means 115, as a setscrew, adjustably mountedcollar 114 onouter shaft 48 to provide a positive driveconnection betweencollar 114 andouter shaft 48. Acoil spring 116 concentrically disposed about the rear end ofinner shaft 52 provides a resilient driving connection betweenpin 113 and arm 111.Spring 116 has one end hooked overpin 1 13 and its opposite end hooked about the inner edge ofarm 1 11 so as to resiliently urge arm 111 into engagement withpin 1 13.

On rotation ofouter shaft 48 in response to the application of fluid pressure tocylinder 84, theouter shaft 48 andinner shaft 52 rotate together by reason of the friction drive established byshoes 72. The rotatinginner shaft 52 carriesarm 1 11 toward and into engagement with anadjustable stop 117. As shown in FIG. 7, when arm 111 engages thestop 117inner shaft 52 is prevented from further rotation, but theouter shaft 48 continues to rotate theinner cup member 65 an amount equal to the lost motion ofpin 69 inangular slot 71. During thismovement pin 113 moves away from arm 111 against the biasing force ofspring 116.

On reversing the direction of the movement ofrack 79 by applying fluid pressure tocylinder 86 theouter sleeve 48 rotates in a reversedirection moving pin 113 back into engagement with the arm 111.Spring 116 holds arm 111 into engagement withstop 117.Inner cup member 65 rotates withsleeve 56 until the lost motion provided by theslot 71 is taken up. At thistime sleeve 56 rotates relative tocup member 65 overriding the friction drive ofshoes 72 untilpin 1 13 engages arm 111. Arm 11 1 is then carried back to its initial position bypin 113 allowingcup member 65 to be moved withsleeve 56 back to their starting positions.

In use,rotor 35 is held by the winding machine in an indexed position with itsshaft 42 in bore 76 of the lead moving, guiding and shieldingunit 55. Theentire commutator 41 is positioned incylindrical chamber 66 with the ends of itshooks 43 close to flange 68 to prevent applied leads from coming off the hooks and shielding the hooks from the wire as it is wound oncore 36.Movable fliers 38 of the winding machine wind the wire leads 39 in separate pairs of core slots aroundcore 36 to form thecoils 37. As shown in FIG. 1, ending leads 39 fromcoils 37 extend from the core 36 adjacent to the top and bottom portions ofouter sleeve 56. The following description is directed to the movement of theleft lead 39 located under thesleeve 56 and engageable withfinger 59. The opposite or right lead is moved and hooked in a similar manner and engagesfinger 58.

Referring to FIG. 8, 9 and 10,core 36 is in an indexed position with thecoils 37 wound on the core in substantially vertical planes bymovable fliers 38.Bottom lead 39 extends fromcoil 37 rearwardly around the flier pulley adjacent the bottom ofsleeve 56 forwardly offinger 59. Whencoil 37 is completed the winding machine sends a signal which actuates a valve (not shown) to supply fluid under pressure tocylinder 84driving piston 82 to the left as shown in FIG. 4. The consequent movement ofrack 79 positively rotatesouter shaft 48 and by virtue of the frictional driving connection, theinner shaft 52 is likewise turned. Since thesleeve 56 is fixed to the outer shaft, it too is positively rotated, and in so doingmoves finger 59 into engagement with endinglead 39 carrying the lead in an upward direction as shown byarrow 118 in FIG. 11. As thesleeve 56 continues to rotatelead 39 falls intogroove 63A in the outer edge ofsleeve 56 adjacent the forward side offinger 59. As shown in FIGS. 12 and 13, lead 39 is moved circumferentially around theshaft 42 and retained ingroove 63A by the tension on the lead from the winding machine.

FIGS. 23, 24 and 25 showouter sleeve 56 rotated in the clockwise direction withfinger 59 moved upwardly along with the arm 111 of thedrive control 109. FIG. 25 compares with FIG. 12. In this position arm 111 engages stop 117 thereby preventing further rotation ofinner shaft 52. Theinner cup member 65 continues to rotate withouter sleeve 56 by reason of the friction drive established by theshoes 72 as shown in FIG. 6 and the lost motion ofslot 71 andpin 69.Cup member 65 continues to rotate withouter sleeve 56 untilpin 69 engages the opposite wall ofslot 71 as shown in FIGS. 7 and 26. Continued rotation ofouter shaft 48 then movesouter sleeve 56 relative tocup member 65 untilslot 78 is in alignment withgroove 63A as shown in FIGS. 15, 16 and 27. In thisposition finger 59 has carried endinglead 39 approximately aroundshaft 42. The tension onlead 39 maintained by the winding machine moves the lead forwardly intoslot 78. The depth ofslot 78 is sufficient to allow the lead to move to the far side ofhook 43 ofcommutator 41. As shown in FIG. 16, lead 39 is inslot 78 and is positioned below and forwardly of the end of the hook.

At thispoint arm 108 engagesactuator 103 ofswitch 101 and thereby terminates the flow of pressure fluid intocylinder 84 and actuates a valve (not shown) by which the pressure fluid is directed tocylinder 86 thereby reversing the direction of rotation ofouter shaft 48. As shown in FIGS. 27 and 28, arm 111 is held in engagement withstop 117 during the initial reverse movement of theshaft 48 byspring 1 16interconnecting arm 1 11 withpin 113. In FIG. 27,slot 78 is adjacent the forward side ofhook 43. On initial reverse rotation ofouter sleeve 56cup member 65 moves withsleeve 56 withslot 78 aligned withgroove63A carrying lead 39 underhook 43 as shown in FIG. 17.Slot 78 andgroove 63A move together because of the lost motion ofpin 69 inangular slot 71.Pin 69 holdscup member 65 from further reverse relative rotation with respect toinner shaft 52 thereby fixing the angular location ofslot 78.

Theouter sleeve 56 continues to rotate because of its positive drive connection withouter shaft 48.Spring 116 holds arm 111 in engagement withstop 117 thereby preventing rotation ofinner cup member 65.Sleeve 56 rotates in a reverse direction relative tocup member 65 since the force ofspring 1 16 is greater than the friction drive ofshoes 72 onsleeve 56. This relative rotation between theouter sleeve 56 andcup member 65 moves the inclined plowing edge orsurface 64A acrossslot 78 forcing thewire lead 39 out of the slot and onto the end ofsleeve 56 thereby moving the wire lead in a backward direction adjacent the rear side ofhook 43. This completes the placement of the lead abouthook 43 and places the hook in a shielding position withinchamber 66. FIGS. 18 and 19 show how the plowing edge orsurface 64A moves thewire lead 39 aroundhook 43 out ofslot 78.

As shown in FIG. 29,pin 113 is moved into engagement with arm 111 whereby theouter shaft 48 drivesinner cup member 65 andsleeve 56 together back to their initial positions. As thesleeve 56 continues to rotate back to its initial position theopposite finger 58 engageslead 39 as shown in FIGS. 20 and 21. The lead is retained on the finger as it falls intorecess 62 on the trailing side of the lug. As shown in FIG. 30,pin 113 is in contact with arm 111 establishing a positive drive connection between'the outer shaft and the inner shaft.Cup member 65 is in frictional drive relationship withouter sleeve 56 sincepin 69 engages the trailing side ofslot 71. This location ofpin 69 inslot 71 is maintained during the indexing of the rotor to the next position for receiving additional coils of wires as shown in FIG. 31. FIG. 22 shows the position of the trailing portion of the last wound coil lead located approximately 180 aroundshaft 42 and aroundcommutator hook 43. The commutator has been indexed to the next position for receiving additional coils in adjacent pairs of slots. During the indexing of the rotor thefingers 58 and 59 are not rotated as-therotor shaft 42 is free to turn in bore 76.

Each succeeding terminating lead for each of the coils wound on the core is moved circumferentially around a portion of the shaft located between the core and the commutator and around the commutator hook y from the far side in the manner described untilthe desired number of coils have, been wound on the core.

During the winding of any coil all of the leads already connected to commutator hooks are sheil'ded by the cup-shapedmember 65. This prevents the leads from becoming unhooked from the commutator hooks and 1 unit. With the commutator shielded one or more coils I of wire are placed in separate circumferentially spaced slots of the slotted core. When the coils are completed the terminating leads which extend from the slots are located adjacent to the shielded commutator in engage ment with the lead moving and guiding unit. The terminating lead of each coil is carried circumferentially around the shaft carrying the core by rotation of the lead moving and guiding unit. This places the lead ex tended from the core close to the shaft and eliminates bridging of successively applied leads. The leads are then placed about selected hooks with all hooks except the selected hooks remaining shielded. This is done by moving the leads in axial directions away from the core adjacent the farm forward side of the selected commutator hooks; The leads are then carried a short distance back in a circumferential direction under the selected hooks, and then moved in axial directions toward the core adjacent the rear side of the hooks thereby placing the leads around the selected commutator hooks. The selected hooks are only unshielded during the time the leads are carried circumferentially back to locate the leads under the hooks.

Those skilled in the art will appreciate that the invention can be embodied in forms other than as herein disclosed for purposes of illustration.

The invention is defined by the following claims:

1. A method of winding an armature having a core with circumferentially spaced coil-receiving slots, a

commutator having segments with lead-receiving hooks to which leads from coils that are wound into pairs of the slots are attached, and a shaft on which the core and the commutator are mounted in axially spaced relation, said method comprising the steps of:

A. shielding the entire commutator by inserting the same into an open end portion of the inner one of a pair of concentric sleeve members that are rotatable together and with respect to one another;

B. winding a coil in a pair of circumferentially spaced slots of the armature core while the commutator is thus shielded;

C. upon completion of the coil; holding the ending lead thereof taut and" alongside the portion of the armature shaft between the core and the commutator and adjacent to the shielded commutator;

D lby rotation of the outer sleeve member in one direction, moving said lead circumferentiallyabout the axis of the armature into tangential engagement with said portion ofthe armature shaft and into jux taposition to a selected' commutator hook that is Reqzassg circumferentially spaced from the coil slot from which the lead emanates;

E. by relative rotation between the sleeve members, exposing only the selected hook and placing the lead in position to be engaged with said hook;

F. by rotation together and relative to one another of both sleeve members in the opposite direction,

completing engagement of the lead with the hook, reshielding said hook, moving the lead which now extends from said hook [circumferentially about the axis of the armature into position to enter directly into the first of the next pair of coil-receiving slots;

G. with all of the hooks of the commutator again shielded and with the armature indexed to bring said next pair of slots into winding position, placing the lead directly into the first of said pair of slots to begin the next coil and completing the winding of said next coil; and

H. repeating the aforesaid steps until all coilreceiving slots have had coils wound into them.

2. The method ofclaim 1, wherein the lead is moved circumferentially around the axis of the armature between and 270 from the coil slot from which it emanates in being brought into juxtaposition to the selected commutator hook,

3. The method ofclaim 1, wherein during the first movement of the lead circumferentially about the axis of the armature, the lead is placed adjacent to one side of the selected hook,

and wherein during the second movement of the lead [circumferentially about the axis of the armature] the lead is carried under and placed at the opposite side of the selected hook.

said selected hook being unshielded only during the time the lead is carried under said hook.

4. The method ofclaim 1, wherein a pair of coils are simultaneously wound in two pairs of coil slots,

and wherein the ending leads from the two coils are simultaneously engaged with selected commutator hooks, while all of the other hooks remain shielded.

[5. In the winding of an armature having a core circumferentially spaced slots, into pairs of which coils are successively wound, a commutator having segments with books onto which leads from the coils are attached, and a shaft on which the core and the commutator are mounted in axially spaced relation, the improvement by which crossover loops and undesirable bridging of leads of are eliminated and which improvement is achieved by:

A. shielding the commutator hooks;

B. with the commutator hooks shielded, winding a coil of wire into a pair of circumferentially spaced core slots;

C. upon completion of the coil, holding the ending lead of the coil taut and alongside the portion of the armature shaft between the core and commutator;

D. effecting relative motion between the tautly held lead and the armature about the axis of the armature to bring the lead into tangential engagement with said portion of the shaft;

E. with the tautly held lead bearing tangentially against sa-id portion of the shaft, rendering accessible'a selected commutator hook that is circumferentially spaced from the coil slot from which the lead emanates and effecting relative motion between the lead and the armature to produce engagement of the lead with said selected hook,

F. reshielding the selected commutator hook;

G. again effecting relative motion between the tautly held lead and the armature about the axis of the armature to thereby engage the lead around the selected commutator hook;

H. with the armature indexed to dispose the pair of slots into which the next coil is to be wound in winding position, carrying the lead directly into the first of said pair of slots with said stretch of the lead that extends from the engaged commutator hook bearing tangentially against said portion of the armature shaft, and resuming the winding operation; and

l. repeating the aforesaid steps until all of the core slots have coils wound therein.

[6. In the winding of an armature, the improvement set forth inclaim 5, wherein said relative motion between the tautly held lead and the armature is PK duced by impartingg motion to the tautly held lea while the armature remains stationary.

7. The method of claim 6, wherein during said fir: relative motion, the tautly held lead is moved in one d. rection around the axis of the armature beyond the se lected commutator hook so that the lead engages be hind the hook, and

wherein said second relative motion is in the revers direction to carry the lead around the hook.]

I 8. The method of the claim 6, wherein the shield ing of the commutator hooks is done by placing the en tire commutator in a cup-shaped chamber, and

wherein the relative motion between the tautly helc lead and the armature is effected by establishing 2 connection between the lead and the side of saic chamber and rotating the chamber around the commutator.

Claims (4)

1. A method of winding an armature having a core with circumferentially spaced coil-Receiving slots, a commutator having segments with lead-receiving hooks to which leads from coils that are wound into pairs of the slots are attached, and a shaft on which the core and the commutator are mounted in axially spaced relation, said method comprising the steps of: A. shielding the entire commutator by inserting the same into an open end portion of the inner one of a pair of concentric sleeve members that are rotatable together and with respect to one another; B. winding a coil in a pair of circumferentially spaced slots of the armature core while the commutator is thus shielded; C. upon completion of the coil; holding the ending lead thereof taut and alongside the portion of the armature shaft between the core and the commutator and adjacent to the shielded commutator; D. by rotation of the outer sleeve member in one direction, moving said lead circumferentially about the axis of the armature into tangential engagement with said portion of the armature shaft and into juxtaposition to a selected commutator hook that is circumferentially spaced from the coil slot from which the lead emanates; E. by relative rotation between the sleeve members, exposing only the selected hook and placing the lead in position to be engaged with said hook; F. by rotation together and relative to one another of both sleeve members in the opposite direction, completing engagement of the lead with the hook, reshielding said hook, moving the lead which now extends from said hook (circumferentially about the axis of the armature) into position to enter directly into the first of the next pair of coil-receiving slots; G. with all of the hooks of the commutator again shielded and with the armature indexed to bring said next pair of slots into winding position, placing the lead directly into the first of said pair of slots to begin the next coil and completing the winding of said next coil; and H. repeating the aforesaid steps until all coil-receiving slots have had coils wound into them.

2. The method of claim 1, wherein the lead is moved circumferentially around the axis of the armature between 90* and 270* from the coil slot from which it emanates in being brought into juxtaposition to the selected commutator hook.

3. The method of claim 1, wherein during the first movement of the lead circumferentially about the axis of the armature, the lead is placed adjacent to one side of the selected hook, and wherein during the second movement of the lead (circumferentially about the axis of the armature) , the lead is carried under and placed at the opposite side of the selected hook(.) , said selected hook being unshielded only during the time the lead is carried under said hook.

4. The method of claim 1, wherein a pair of coils are simultaneously wound in two pairs of coil slots, and wherein the ending leads from the two coils are simultaneously engaged with selected commutator hooks, while all of the other hooks remain shielded.

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