CROSS REFERENCE TO RELATED APPLICATIONS
ARMATURE WINDING MACHINE, Ser. No. 401,153, and WIRE CUTTER FOR ARMATURE WINDING MACHINE, Ser. No. 401,150, both filed on an even date herewith.
BACKGROUND OF THE INVENTION
In a conventional form of machine for winding aramture cores, a chuck is provided to engage the shaft of an armature core and hold it in a winding position, and a pair of flyers, mounted for rotation about axes perpendicular to the axis of the armature core, lay coils of wire in slots running longitudinally of the armature core. To direct the wire into the proper armature core slots, wire guide forms are provided which engage the core and cover all but the slots into which the wire coils are being laid.
For example, U.S. Pat. No. 3,713,598 discloses an armature winding machine of the general construction described above. In this machine the wire guide forms have sloping surfaces which tend to guide the wire down into the slots in the armature core. However, forms of this general type consist of several, generally planar surfaces which necessarily intersect at fairly sharp corners.
As a result, as the wire slides across the surface of the wire guide form it must pass over these corners. This necessarily results in additional stresses being imposed on the armature wires, sets up irregularities in the flow of wire onto the core and restricts winding speeds.
Additionally, while wire forms of this type are adapted to accommodate armature cores within a certain range of sizes, no provision is made for adapting the forms to cores varying appreciably in size from the size for which the forms were specifically designed.
Also, each time the armature core is indexed the forms must be moved away from the core and then moved back into contact with the core before the next coil is wound. These additional operations obviously decrease winding speeds.
SUMMARY OF THE INVENTION
The present invention provides a wire guide form of substantially hemispherical shape having a smooth, convex surface facing the core winding position of the armature winding machine and having a core-receiving channel extending across the convex surface.
The smooth hemispherical shape of the wire guide form results in an even, smooth flow of wire around the form and into the proper armature slots without irregularities in feed rates and permits higher winding speeds to be attained than in prior art structures.
Additionally, the winding forms are constructed of a pair of split base portions which can be separated and provided with shims to accommodate cores of different stack heights, and the forms themselves can be changed quickly to accommodate different lamination configurations.
Preferably each of the base portions is provided with a relieved section receiving a segment of the form and the outer surfaces of the segments and the base portions combine to define the generally convex surface. That portion of the core-receiving channel extending through the base portions of the form has a substantially greater radius of curvature than that portion of the channel extending through each of the segments. As a result, the segments have surfaces positioned adjacent opposite ends of the core and restrain the core against movement longitudinally thereof.
In a preferred embodiment of the invention a spring loaded pawl is carried by a base portion of one of the forms and projects outwardly into the core receiving channel to engage a slot in the core. This provides a positive stop against which the core can be reversed indexed at the beginning of a winding operation to position the core properly for further indexing operations.
The configuration of the winding guide forms allows them to be positioned in noncontacting relationship to the armature core during winding operations without danger of the wire being laid in the wrong core slots. Since it is unnecessary to retract and advance the forms out of and into contact with the core before and after each indexing operation, winding times can be appreciably decreased.
Additionally, the curved configuration of the forms directs the wire inwardly, so that it wraps the commutator shield often associated with armature winding machines. Therefore, when the shield is actuated to expose a selected commutator tang, the wire automatically engages the tang, thereby eliminating separate mechanism for moving the wire into tang engagement.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view from the right front of an armature winding machine incorporating the forms of the present invention;
FIG. 2 is a plan view of the machine of FIG. 1 with portions omitted for clarity;
FIG. 3 is a front elevational view of a portion of the machine of FIG. 1;
FIG. 4 is an enlarged view of a winding form and associated flyer with parts in section;
FIG. 5 is a plan view of the apparatus of FIG. 4 with parts in section;
FIG. 6 is a view of one base portion of a winding guide form in accordance with the present invention;
FIG. 7 is an end view of an armature core positioned between portions of winding guide forms in accordance with the present invention;
FIG. 8 is a perspective view from the left rear side of an armature winding machine incorporating winding guide forms in accordance with the present invention;
FIG. 9 is a perspective view of an individual winding guide form;
FIG. 10 is an exploded view thereof;
FIG. 11 is a top view of a winding guide form incorporating a shim, and
FIG. 12 is a partially exploded perspective view showing a shim interposed between base portions of a form.
DESCRIPTION OF THE PREFERRED EMBODIMENT
An armature winding machine 10 in accordance with the present invention may be of the same general type as that disclosed in the above noted application, ARMATURE WINDING MACHINE, although the winding guide forms of the present invention find application in armature winding machines generally and are not limited to the specific arrangement described in the present application and the above noted related application.
Thus, for purposes of illustration the armature winding machine 10 is shown as including a pedestal 12 mounting a pair of DC motors 14 driven through any suitable control circuit. Upper and lower lead traps 16 and 18, respectively, (see also FIG. 8), may be provided for engaging the lead and terminal ends of wire wound on the armature core during the initial and terminal portions of the winding process. The lead traps per se form no part of the present invention and for a more detailed description thereof reference is had to the above noted related application, ARMATURE WINDING MACHINE.
Similarly, a commutator shield 20 is provided having a notched forward edge, as at 22, for exposing preselected tangs on a commutator associated with an armature core being wound. Such shield may be, if desired, of the rotatable type or, alternatively, a two-piece commutator shield may be utilized as disclosed in U.S. Pat. No. 3,713,209. With the rotatable type commutator shield a rack 24 and pinion 26 drive arrangement is utilized powered by a piston and cylinder 28 to rotate the shield 20 about its axis to expose preselected tangs on the commutator.
Additionally, the end of the armature core adjacent the commutator may be gripped in a collet disposed within the shield 20 and operated by a piston and cylinder 30. Suitable indexing means may also be provided for rotating the armature core about its axis to align preselected slots thereof in the proper position to receive coils of armature wire. In this regard the collet drive 29 may have mounted thereon a pulley 32 wrapped by a belt 34 which also wraps a pulley 36 on a stepping motor 38.
Associated with each of the motors 14 are flyers 40, which, as best seen in FIG. 3 of the drawings, are rotated in opposite directions and are displaced approximately 180° from each other. Each of the flyers has a passageway, as indicated at 42 in FIG. 4 of the drawings, through which wires, indicated somewhat schematically at 44 in FIG. 1, are trained from a suitable source and thence around pulleys 46 and 48.
Mounted on an extension 50 of each of the flyers by means of a bearing 52 is a collar 54, to which is attached by means of screws or the like 56, winding forms 60 and 62. Considering first the right hand winding form 62, it will be seen particularly from FIGS. 5, 6 and 9 through 12 of the drawings, that it includes a pair of base portions 64 and 66 having relieved sections 68 and 70, respectively, which receive segments 72 and 74, respectively.
The base portions 64 and 66 are provided with openings 76 therethrough with the openings in the portion 66 being somewhat smaller in diameter than those in the portion 64 and receiving a pair of relatively short pins 78 which are press fitted therein. Those portions of the pins 78 projecting outwardly of the planar face 80 of the section 66 are received in the somewhat larger diameter openings in the portion 64.
The openings 76 are shown as extending completely through the base portions 64 and 66 even though the pins 78 are relatively short in length and extend through only a portion of the opening 66. This has been found convenient for manufacturing purposes, although it will be apparent that relatively short, blind bores could be formed into the portions 64 and 66 from the face 80 of the section 66 and the opposing face of the section 64.
To lock the base portions 64 and 66 together bolts or the like 82 are provided which extend through openings 84 in the portion 64 and are threadably received in threaded openings 86 in the portion 66.
It will be particularly noted from FIGS. 6 and 10 of the drawings that the inner face 80 of base portion 66 is provided with a cut-out section 88 receiving a pawl mounting block 90. A pawl 92 is pivotally mounted in block 90, as at 94, and has a tooth 96 thereof urged outwardly through a slot 98 by means of a spring 100. The pawl mounting block 90 is retained and positioned within the base portion 66 by means of opposing set screws 102.
The segments 72 and 74 are each attached to their respective base portions 64 and 66, respectively, by means of bolts or the like 104 which pass through openings 106 in the segments and are threadably received in openings 108 in the base portions.
Each of the base portions 64 and 66 is provided with a substantially semi-circular channel 110 extending across its face. Similarly, each of the segments 72 and 74 are provided with channels 112 which are also substantially semi-circular but of lesser radius than the channels 110. It will also be noted that each of the segments 72 and 74 is provided with a shoulder portion 114 of approximately the same radius as the radius of the channel 110 in the base portions 64 and 66. As a result shoulders 116 are provided at each end of the channel through the base portions and will be disposed opposite the ends of the armature stack to restrain it against movement longitudinally of the armature axis.
The left hand winding guide form 60 is in all respects identical to the right hand guide 62 except that rather than utilizing a base portion 64 and a base portion 66 carrying a spring loaded pawl, a pair of identical base portions 64 are used.
With the above construction it will be seen that an unwound armature core is received in the armature winding machine with the collet 29 gripping the armature shaft adjacent the commutator and the commutator tang shield 20 covering all but selected commutator tangs. The opposing winding guide forms 60 and 62 are moved inwardly to a position in closely spaced relationship to the armature stack as shown in FIG. 7 of the drawings. This is accomplished by means of the piston and cylinder assemblies 120, attached to depending portions 122 of the motor mountings, the motor mountings being slidable along trackways 124. Adjustable stops 125 are also provided to obtain the desired spacing between the forms and the armature core stack.
The indexing motor 38 is then actuated to reverse index the armature core in a clockwise direction, as seen in FIG. 7, until an edge of an armature slot, as at 118, is engaged by the outwardly projecting tooth 96 of the spring loaded pawl 92 in the right hand winding guide form 62. This positions the slots in the armature, as shown in FIG. 7, in a position to receive armature wire in the subsequent winding operation and serves as a reference point for future indexing operations.
Once the armature core is positioned as shown in FIG. 7 and a loop of wire is hooked about a preselected starting tang on the commutator, the flyers 40 are rotated by the motors 14 in the direction indicated by the arrows in FIG. 3 of the drawings. The flyers 40 and 42, as they are rotated by the motors 14, wind the wire in selected slots in the armature core. Thus, with reference again to FIG. 7 it will be seen that the right hand flyer 40 will apply a coil of wire in the upper and lower slots 126 and 128 while the left hand flyer applies wire to the upper and lower slots 130 and 132.
During the winding operation the winding guide forms 60 and 62 cover all but selected slots in which wire is being deposited. In this regard the substantially hemispherical shape of the winding guide forms provide a smooth surface about its entire periphery over which the wire may flow at an even rate and under substantially constant tension. As a result, not only are higher winding speeds attainable, but the length of wire extending between the upper and lower slots at the ends of the armature stack is substantially decreased. Since this portion of the wire serves no function in the motor in which the armature is eventually utilized, it is desirable to minimize the amount of wire at this point on the armature.
As noted above, the curved configuration of the forms also insures that the wire engages selected tangs during the winding process without requiring additional means for moving the wires into tang engagement. Thus, the curved forms direct the wire around the commutator shield so that when the shield is actuated to expose the selected tang, the wire automatically engages the tang.
As noted above, the winding guide forms, in their innermost positions are in closely spaced nongripping relationship to the armature core stack. This is contrary to the practice in some prior art winding machines, where the forms actually engage the armature core stack to prevent wire from entering the wrong slots. Because of the unique configuration of the winding guide forms of the present invention, the wire is guided into the proper slots without the necessity of a gripping contact between the forms and armature. As a result it is unnecessary to release the forms before each indexing operation and then reengage them before winding the next coil, resulting in an increase in machine speed.
The winding guide forms as described above are capable of handling armature cores having different size stacks within certain limits. When these limits are exceeded the wire forms may be modified slightly to accommodate larger stacks. Thus, as best seen in FIGS. 11 and 12, a shim 134 of the desired thickness may be positioned between the opposing base portions 64 and 66 in the case of the right hand form 62 or between a pair of identical but opposite base portions 64 in the case of the left hand form 60. The shim 134 is of course suitably apertured as at 136 and 138 to accommodate the pins 78 and bolts 82, respectively.
Should modifying the winding guide forms through the use of shims be inadequate to accommodate an armature core to be wound, it will also be noted that in accordance with the present invention a new pair of larger forms may be incorporated in the armature winding machine by simply removing the fasteners 52 connecting the forms to the collar and replacing the forms with larger guide forms.
From the above it will be seen that the present invention provides a uniquely configured winding guide form which provides a smooth even wire flow onto an armature core, permitting higher winding speeds and decreasing the amount of wire needed and also a form which is adaptable to armature core stacks of varying sizes.
While the form of apparatus herein described constitutes a preferred embodiment of the invention, it is to be understood that the invention is not limited to this precise form of apparatus, and that changes may be made therein without departing from the scope of the invention.