PIN-TYPE RATCHET ESCAPEMENT MECHANISM

Weight Q applies a torque that tends to rotate pin-type ratchet wheel 1 clockwise about fixed axis A. Wheel 1 carries pins a located in two concentric circles. There are the same number of pins in each circle; they are equally spaced around each circle; and the pins of one circle are displaced from those of the other circle by one half pitch. Pawl 2 oscillates about fixed axis B and alternately engages pins a of the two circles so that wheel 1 has intermittent rotation.
$2662$RG,3L$