124 



PATTERN MAKING 



avoid excessive weight, the box is made in the form shown in Figs. 

 227 and 228. In this form all unnecessary metal is removed and 

 the connecting iron dowel pins are placed in lugs or thin outside 

 projections as indicated. 



Fig. 229. 



Fig. 230. 



Fig. 231. 



Fig. 229 illustrates the pattern for the stuffing box and bonnet 

 of the valve, with core print turned on each end, which, like the main 

 pattern of the valve must be parted, or made in two halves. Two 

 core boxes are necessary to make the core for this part of the valve. 

 From Fig. 230 it will be seen that the core box for the lower 

 end of the core can be turned out on the lathe by 

 using a template of the reqiiired shape. For the 

 upper part or stem, the half box shown in Fig. 231, 

 is all that is necessary. By examining the two core 

 boxes, Figs. 230 and 231, it will be seen that here 

 again we have recourse to the tenon and socket 

 form of construction for uniting the two parts of 

 the core which are shown pasted together in the 

 completed core, Fig. 232. The nut for the bonnet 

 is shown in Fig. 233, and the pattern, which is 

 Fig. 232. hexagonal, should be so made as to form its own 



core, as indicated by the dotted lines in the drawing. Fig. '2'.\ \ 

 shows the pattern for the valve and also the pattern for the valve 

 nut, each of which will fonn its own core, and Fig. 23.") is an illus- 

 tration of the pattern for the valve spindle. 



