1922. ] Automatic “ make and break.” 223 
Suppose now that setpepee state II is just over and it is 
necessary to ‘ make” the c 
The following pate Rae occur :— 
The lever M is raised by one of the teeth on the wheel A 
(minute-hand axis, period 1 hour). The axis 00’ is however 
still held in check. by the catch N!; 5 seconds afterwards, 
under the influence of the teeth of the, wheel B (period 20 
seconds) N releases C and allows rotation of the axis through 
60°; then re-engages with C? and stops the motion; after 
another 5 seconds a new tooth in B causes N to release C 
again, allowing a further rotation of 60° and no more. 
After still another 5 second interva] N prepa ) a third 
time, sabteben a third rotation of 60° and no mo 
this stage after rotation of 3 x 60°= 180° the lever M 
dein ss into the slot r’ and stops the axis for 5 minutes. 
this stoppage to occur at the right moment, A must be correctly 
adjusted on its axis 
Pig. RF 
Lea 
rat =z 
e 3 connections D, E and F all being ‘‘ made” the 
Coolidge “runs”? for 5 minutes, At the end of 5 minutes 
M again rises and catch N actuated by B proceeds to permit 
three 60° revolutions as before, during which, the cam P raises 
F and breaks the coil primary; the contact piece e actuates 
the peed (Fig. 3) and peer ee 220 volt circuit; the cam 
“<Q” breaks the heating circu 
As before there are 5 ee intervals between the three 
operations. 
‘ Finally, : descends into slot r again and stops the motion 
for [0 minu 
The airvalte are now all‘ off” and the Coolidge cools. 
The process is then repeated automatically. 




: ig. 2. The catch K rigidly ene to N is pushed aside by 
B iebiw in fig. 1) actuating the arm the direction of the arrow 
a to - A ie s oss wheel C, ote permed bo K from the pin p (on 
Stop-pin = 
