Patent ID: 6051948
Filing Date: 2000-04-18
Classification: G05B

Abstract:
A positioning actuator for positioning at least a part of a movable load at selected positions in a range of available positions in response to corresponding provisions of electrical energy of selected polarities between a pair of power terminals, said positioning actuator comprising:a first range terminator comprising a limit switch, normally closed by having a pair of electrical contacts therein forcibly positioned against one another, electrically connected between first range terminator first and second terminals to allow, when closed, electrical current to be conducted from said first range terminator first terminal to said first range terminator second terminal, said first range terminator limit switch being positioned with respect to at least said part of said moveable load so as to be opened by that part of said moveable load forcibly separating said electrical contacts in said limit switch when reaching positions in a corresponding first portion of said range of available positions, said first range terminator first terminal being electrically connected to a corresponding one of said power terminals;a drive motor having an output effector connected to at least said part of said moveable load and having a pair of motor terminals through which sufficient electrical current provided in either direction therethrough will cause said output effector to move in a corresponding one of two alternative directions to thereby move at least said part of said moveable load to corresponding positions in said range of available positions, said first range terminator second terminal being electrically connected to one of said pair of motor terminals and with that other of said pair of motor terminals being electrically connected to that said power terminal opposite that one of said pair of power terminals electrically connected to said first range terminator first terminal; anda capacitor electrically connected between said motor terminals of a capacitance sufficient to force said drive motor to cause said output effector thereof to move at least said part of said moveable load sufficiently to provide a selected assurance gap between said first range terminator limit switch electrical contacts following an initial separation thereof forced by said moveable load.