Control panel power enabling and disabling system for aerial work

Abstract

A control panel enabling and automatically disabling system is coupled between a source of electrical power and a plurality of motion controls on an aerial work platform. Upon activation of a pushbutton type power enabling switch, power is coupled to all the motion controls for a predetermined fixed time period which when activated will couple power to a respective motion producing mechanism such as a boom actuator. If none of the motion controls are activated by an operator within this time period, a timer times out and the panel thereafter becomes inactive by interrupting the electrical power. However, if a motion command is effected by actuation of any one of the motion controls during this time period, the timer is automatically reset to zero time and held thereat until all motion commands cease, at which time the timer is restarted. The enabling switch cannot be defeated by a continuous activation thereof. The enabling switch must be released and pushed again to start a new cycle. Further if a motion command is generated by inadvertent movement of one of the motion controls prior to the power enabling switch being activated, the system will not activate. All motion commands must cease before operation of the enabling switch can activate the timer and energize the system.