WINDING OF CONTINUOUS-CURRENT ARMATURES 255 



The Alioth German Patent, D.RP. 34,783, of 17th March 1885, 

 is amongst the first on record showing a short, uniformly-shaped, 

 counterpart, form-wound coil; and although there have been 

 numberless modifications devised by others since that date which 

 decrease the cost of winding and insulation, the mean length of 

 turn of the coil obtained by this Alioth winding has not since been 

 appreciably decreased by any other method. 



Fio. 290. Alioth Form-wound Coils. 



Figs. 290 and 291 show the coils shaped according to the Alioth 

 method of form winding. Fig. 292 shows the arrangement of a 

 winding form for shaping the coils. 



In reference to the shortest possible length of coil, one of the 

 authors took out a patent in 1901 (British Patent No. 17,489) for 

 a coil shape which is illustrated in Fig. 293. This coil is based 



Fro. 291. Alioth Form-wound Coils. 



on the idea that the shortest coil would have its end connections 

 formed on the principle of an equilateral triangle bent out of 

 its original plane, and with the corners rounded off or otherwise 

 modified to adapt it to joining the two corresponding face con- 

 ductors by an essentially three-sided equilateral end connection. 

 For a two-layer winding the coil would be conveniently formed to 

 the shape shown at the top of Fig. 293, and afterwards spread to 

 the shape shown in place on the armature in the lower views. 

 The Eickmeyer coil (English Patent 2246, 6th April 1888) 



