Abstract: A power actuator for rotating and reversing a high power radio frequency switch is disclosed. The actuator uses a motor drive and a delay cam means to enable the transmitter's interlock switches to be opened or closed before the radio frequency switch is rotated. A manual drive means is provided to manually rotate the radio frequency switch and the interlock switches if desired. The delay cam includes a first cam means mounted on the shaft which drives the radio frequency switch. A second cam means which rotates freely on the same shaft is driven by a remotely controlled motor. The two cams are engaged, in the first embodiment, by an elongated pin which is fixed in the second cam and extends through an arcuate slot in the first cam. In the second embodiment, the arcuate slot cam means is replaced by a single pin which extends transversely through the first cam means drive shaft. This pin alternately engages at 90.degree.

Abstract: This invention relates to a coupling device and especially a coupling device operable by a dead-man's handle on a lawnmower. When used in a lawnmower the coupling device couples the motor shaft to the cutting blade. A spool has a hole in it that surrounds the shaft. A rotary connecting device normally couples the spool to the shaft so that the spool and shaft rotate together. A disconnect element and brake are operated when the dead-man's handle is released to disconnect the spool from the shaft and subsequently stop the spool. The cutting blade has a central hole through which the spool passes. The blade is in frictional contact with the flanges of the spool and is rotated thereby.