PATTERN MAKING 



109 



at e cut away to the same curve as />, giving the same results as 

 in the former method. 



The pattern for the 2-iiich elbow, Fig. 190, is another illustra- 

 tion of how such work may be simplified, and time saved, by 

 doing the greater part of 

 the work in the lathe. 



As these elbows are 

 usually cast in large num- 

 bers, the pattern should be 

 made double as shown in 

 Fig. 191. To construct the 

 double pattern, a ring is 

 first turned like Fig. 192, a cross-section of which is a semicircle 

 as shown in the lower right-hand corner of the drawing. This ring 



Fig. 188. 



is cut into quarters, and the four pieces e, e, e and e make the 

 quarter turns for the two halves of the double pattern. 



The ends, including the core prints and connecting tenons, are 



Fig. 189. 



Fig. 190. 



turned in one piece as shown in Fig. 193, the stock for which is 

 prepared, with the inserted dowel pins all iji position in the same 

 manner as described for the tee pattern, Fig. 188. The quarters, e, e, 



