CHAPTER XI 



THE WINDING OF CONTINUOUS-CURRENT ARMATURES, AND THE 

 DESIGN AND CONSTRUCTION OF WINDING FORMS 



THE coils of continuous-current armatures are now practically 

 always wound on formers. Form-wound coils are less universally 

 employed in alternating-current machinery, with which we shall 

 deal in Chapter XII. 



The original Siemens drum type of armature was generally 

 hand wound, taking the wire directly from the reel. When wound, 



FIG. 288. Winding Bobbin. FIG. 289. Winding Shuttle. 



the ends of the coils project a considerable distance along the 

 shaft, and are so interwoven that the repair or replacement of a 

 coil is a troublesome matter. 



The old Gramme ring type of armature construction was of the 

 hand-wound variety, and a wooden bobbin or shuttle (Figs. 288 and 

 289) for holding the wire was about the only implement necessary. 

 But with the advent of form-wound coils, a demand was created 

 for winding forms for facilitating the winding of interchangeable 

 coils. It has been customary for each manufacturer to devise and 

 construct his own winding forms according to his requirements, 

 and, as a rule, forms are being built to-day which are good for only 

 one type and size of machine, thereby necessitating a multiplicity 

 of winding forms which, on account of possible future repairs, must 

 always be kept in stock ready for these emergencies. 



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