280 



A RMA TURK CONSTR UCTION 



various stages the process which has already been referred to 

 on p. 262 and Fig. 303. 



TRIPLE-COIL WINDING FORMS. 



I. The windings in the present case, as in many classes of 

 tramway armature, consist of three separate coils, which in 

 most cases are wound singly, and afterwards assembled together 

 during the insulating process. These coils, being all wound on 

 the same form, require a fair amount of skill and care in 

 assembling the component parts so that they fit well together. 

 In order to avoid these difficulties, and to cheapen the labour 



FIG. 332. Section through Armature of 10 h.p. Motor. 



costs, it is desirable to wind these three coils simultaneously, 

 and Figs. 333 to 339 illustrate a practical way devised by H. 

 W. Turner in 1897. 



Fig. 333 shows the winding form attached to the head of the 

 winding lathe, with the three wires attached ready for winding. 

 The reel of wire is seen on the left, and the method of tension in.u r 

 is shown the wire being clamped between two blocks, and the 

 tension adjusted by the tightness of the clamping bolts. 



Fig. 334 shows the form in a position after the first turn 

 has been made, and the method of applying the V-shaped coil 

 separator in the slot portion of the coil. This will be seen as the 

 strip of insulation embracing the middle wire of the three, and 

 thus insulating the middle layer from the outers. 



