PURPOSE: To make release possible when set time adjustable with timer expired after rush is charged by combining timer, electromagnetic clutch, limit switch and others.

CONSTITUTION: When rush is charged, its weight lowers lever 1, turns limit switch 2 on, and turns timer 3 on. When set time expired, current is let flow to electromagnetic clutch 4, whose engagement causes rotation of speed reducer 5 and crank 6. By arm 7 connected to the crank 6, release arm 12 lifts, tilts and slides rush down, then returns to the original position. By placing limit switch 8 at the end portion after a revolution of the crank 6, this senses to cut off current for the electromagnetic clutch 4, and together return the timer 3 to its original state. When rush is charged again, the above operation is repeated.