PATTEKN MAKING 



61 



When the cope and drag have been separated, the upper half A 

 of the pattern is taken out, and the cope is returned to its place 011 

 the drag. The whole flask is now turned over, and the drag lifted 

 off the cope, when the ring of green sand Z, Fig. 124, will rest on 

 the cope sand and the part of the pattern is taken out. We thus 

 have two partings of the sand mould, but only one parting of the 

 flask. 



I*-TTV V ' 2,'- 'Kj^"^^^^^v\C'v^^t\v^^^K^'s^\g^ r '' : ''^'''' ',?* * 



Fig. 124. 



i 



Many other examples might be given, as the case of the 

 common two-flange pulley, which, when small, is often moulded in 

 this way. 



Pig. 127. 



It is frequently the case that parts of the pattern will over- 

 hang so that the pattern cannot be removed from the sand in any 

 direction, even if parted. In such cases the overhanging parts arc; 

 fastened loosely to the main part of the pattern by wires or wooden 

 pins. An example of such a casting is shown in the slide, Fig. 

 125. A cross-section of the pattern for this slide is shown in 

 Fig. 126, in which the two overhanging parts are held in posi- 

 tion by the use of pins. After being rammed up, the part A is 



