PATTERN MAKING 



123 



readily seen, allows the core to be easily removed when the box 

 is opened. The lower part d, Fig. 224, of the core is made in the 

 box shown in Fiu;. 'l'l'-\. The part c has a square tenon which fits 

 into the mortise in the part d. This mortise is made in the core by 

 means of the print marked Y in Fig. 223, and as will be seen by 

 Fig. 224, this core tenon and mortise will bring the two parts of the 

 core into perfect alignment when they are pasted together. 



In Fig. 225, we have an outside view of the completed core and 

 in Fig. 226 a sectional view through the middle of the core, 

 lengthwise ; from which the necessity for the tenon and mortise 



PDowel 



Inside view of 

 upper part.V. 



Fig. 227. 



Fig. 228. 



connection will be readily understood, this being the only connection 

 between the two parts of the core. In working out the core boxes 

 it is well to use templates which can be formed and made from the 

 drawings furnished. The templates will aid in getting the proper 

 shapes, and leaving a uniform amount of metal in all parts of 

 the case. 



Figs. 222 and 223 illustrate the common wooden core box, but 

 to insure uniformity, and because of the necessary wear and 

 fragile character of wood for boxes of this kind, these core boxes 

 should be made of metal. The wooden pattern for the metal core- 

 box must then have an allowance for double shrinkage, and to 



