312 W. P. White — Switch for Thermoelement Work. 



Fig. 2a. 



,Thermoelement busbars 



Locking bar 



Fig. '26. 



-Locking bar 



Thermoelement bus bars 



Fig. 2, a and 6. Top view and section of the whole switch. In the view, 

 above, the second pair of thermoelement lead terminals and the lower aux- 

 iliary-connecting frame, X 2 , are pushed back (to the right) by an operating 

 rod, and thus put in circuit. In the section below, the fixed auxiliary-con- 

 necting frame, FX, is making contact, but the circuit is open at the thermo- 

 element terminals. Scale, -^f full size. 



Copper strips are shown full black; other metal and wood, shaded: cellu- 

 loid insulation, C, clear white. The lettering is otherwise explained in the 

 text. 



