Neutral start switch and backup alarm switch, and method of assembling the same for a manual displacement control for a hydrostatic transmission

摘要

A manual control for hydrostatic transmission has a body member having a first cavity exposed to hydraulic pressure into which a manually operated input shaft extends. The body member has a second cavity with a passage intersecting the first cavity and a shaft and O-ring seal in therebetween. The second cavity is free of hydraulic pressure and has an electrical switch extending thereinto. Switch has an actuating member cable of electrically and individually actuating at least two separate circuits. Cam are operatively connected to the input shaft and positioned to contact the electrical switch such that a first of the cam caused by the input shaft will open one of the circuits and a second increment of movement of the cam will close the other of the circuits. Switches normally in a neutral and closed position with respect to one circuit. The method of assembling the aforementioned structure involves providing a torsional spring to interconnect the body member, the cam, and the shaft to normally maintain the switch in a neutral position wherein one circuit is closed and the other is opened. The cam plate of the cam is released from spring connection to the shaft. The cam plate is devised so that it will maintain the switch in its neutral position. The cam plate is then fixed in a position with respect to the input shaft and the switch.