US Patent 7891641 Manual disengaging and self-engaging clutch

A clutch mechanism (75) for use with a machine to disengage the machine until normal operation thereof is commenced. The clutch mechanism (75) includes a clutch engaging member (130) movable into engagement with a notch (77) of the ring gear (76) of a planetary gear stage (70) to engage the clutch, and movable out of engagement with the ring gear (76) to disengage the clutch mechanism (75). The clutch engaging member (130) is spring biased to a position in which the clutch mechanism is engaged. A manually-operated handle (120) moves the clutch engaging member (130) via a link (128) and clutch actuator (122) from a clutch engaging position to a clutch disengaging position. An over-center position of the link (128) and clutch actuator (122) maintains the clutch in a disengaged condition, until normal operation of the machine is commenced, whereupon a protrusion (256) on the clutch actuator (122) is struck and the clutch actuator (122) is forced back to the engaged position, thus self engaging the clutch on commencement of normal machine operation.