The time relay switches pump 1 to idle runninig after a preset time interval. Pump 1 delivers fluid to rotary directional valve 2 and, simultaneously, through port 7 and valve 9 to both ends of time relay 3. Plunger 4 of the time relay, moved to the left by spring 5, forces the fluid out of the left end of the relay into the right end. Throttle valve 6 enables the speed of return motion of plunger 4 to be regulated. After the plunger has moved to the left sufficiently to connect ports 7 and 8, pump 1 idles (delivering fluid back to the tank). To switch back to working operation, it is necessary to push the knob of plunger 4 again.
$4165$CHP,Dr$