COTTON-SPINNING 



977 



Four fluted drawing portions are usually mounted in one drawing frame, which are 

 set a-going or at rest together. 



560 



A drawing frame usually consists of three heads or portions, each similar to the 

 other. The cotton passes once through each head, and in order to save the labour of 

 carrying the cans from one side to another of the frame, the centre head is set in a 

 direction contrary to the other two. By this alternate arrangement, the work goes 

 on without interruption. 



The fast pulley u, fig. 561, by which the whole machine is driven, derives its motion 

 from the main shaft of the mill by means of the band w. The similar pulley z, which 

 sits loose upon the axis, and turns independently of it, is called the loose pulley. When 

 the operative desires to stop the machine, he transfers the band from the fast to tho 

 loose pulley by means of a lever bearing a fork at its end, which embraces the band. 

 This arrangement of fast and loose pulley is common to all machines used in cotton 

 manufacture. Upon y, four pulleys such as x are fixed, each of which sets in motion 

 a drawing head, by means of a band like to going round the pulleys x and u. The 

 toothed wheel-work, by which the motions are communicated from the backmost fluted 

 roller to the middle and front ones, is seen in Jig. 561. 



The more frequently the drawing process is repeated, the more perfectly will its 

 object be accomplished. The fineness of the appearance of the sliver after the last 

 draught depends upon the number of doublings conjointly with the original fineness 

 and number of drawings. By changing the wheels which drive the back roller, for 

 others with a different number of teeth, the speed of the roller may be increased or 



562 



S 



diminished, and thus the fineness of the sliver may bo modified in any desired degree ; 

 for, when the subsequent processes of tho mill remain tho same, the finer the drawings 

 VOL. I. 3 B 



