Patent GB-190626538-A (GB)
Title: Improvements in Methods of Winding Dynamo-electric Machines with Semi-closed Slots
Inventor: CREEDY FREDERICK
Filed: 1906-11-22
Granted: 1907-10-24
Abstract: 26,538. Creedy, F. Nov. 22. Armatures.-Consists in bending up the ends of former-wound coils and so modifying the section of the active coil-members at the points of flexure that the coils may be inserted in partly-closed slots without disarrangement of the component conductors. Fig. 7 shows a coil held by bars and clamps b on a former c, one flange of which has been removed to allow the ends a of the layers to be bent up. The layers are separated by fibre or similar strips f which prevent binding, and they may be bent around a cylindrical movable bar d which is secured on the slotted part of the former by a nut and screw. The layers are kept intact during the bending by metal clips h, which may be put on during the winding. When the coil is removed from the former, the portions a, which lie in parallel planes, are bent into a common plane for introduction into the slots, as shown in Fig. 9. A sheet-metal or similar lining having a flared opening is placed in the slot, or in both slots in cases where both sides of the coil are inserted together. The active members of the coil are then surrounded with the slot insulation, where this is used, and the bent-up parts a are introduced so as to protrude from the liner. A pin a<1> is inserted to prevent the insulation and coil from leaving the liner, and the coil is then drawn into position by pulling the handle on the other end of the liner The bent-up ends, shown in Fig. 11, are then straightened again, and bent to their final position by band, or in the case of heavy coils, by metal clips which are tightened on to the coils by clamps. Fig. 12 shows a coil a of which all the layers have been bent up together ; by inserting wide packing between the layers at either end before bending, the bent-up parts may be drawn past one another, as shown at b, Fig. 12, in order to be brought subsequently into one plane to enter the slot opening. A similar effect may be obtained by deforming the coils before bending, so that the end members are horizontal when bent up, as shown in Fig. 13. Fig. 14 shows a former for producing coils ready for introduction into the slots without bending. Each turn is carried up through a slot a and down a similar one c, the pitch of these being equal to the winding-pitch of the machine. The rind-part of the end member is wound vertically against two bobbins b, so as to give a coil, as shown in Fig. 15, ready for insertion. The bent ends are straightened and bent down on the machine, as described above. The outer members a<1>, c', Fig. 14, of the former slots may be omitted. Allowance for the obliquity of the active coil-members, as shown in Fig. 11, is made in the case of large coils by distorting them either duriog or after winding on the former. Fig. 16 shows a coil made up of a number of coils, each of which may be made as above described and bent down after insertion. The method is also applicable to coils which are wound with their active members long enough to be reflexed and laid in two or more slots. Where clearance for drawing the rotor in two directions is not required, the bending-down of the inserted coils is omitted. In the case of wide pitches, the coil is distorted from the form shown at a, Fig. 5, to that of b, Fig. 5, so that one side may be introduced before the other. To avoid asymmetric overlapping of the end connexions in machines having more than one range of coils, after the first coil 1, Fig. 3, has been inserted and bent down, the coil 5 of the adjacent slot is not inserted, but the coils 2, 3, 4 are first placed to complete the initial range. The range starting with the coil 5 is then completed to clear the first range all round.