Timed contact switch
AssigneeHoneywell Inc.
InventorsJames P. Miller, Ronald G. Cox, John E. Wardrop
Life of this patent
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Abstract
A timed contact switch apparatus has a conventional pushbutton placing a main switch in an actuated state when the pushbutton is depressed. A timing circuit is activated by the pushbutton to provide power to activate an electromechanical latch which holds the main switch in its actuated state while the timing circuit times out. Preferably the timing circuit operation is initiated by output of a Hall sensor which is controlled by a magnet whose position is mechanically linked to the position of the pushbutton.
Claims10
In a timed contact switch apparatus of the type receiving DC power from an external source, and including a housing, a manually actuated pushbutton mounted on the housing for movement between first and second positions, a spring urging the pushbutton toward its first position, and a main electrical switch within the housing whose conduction state is controlled by an actuator thereon having first and second positions, said actuator biased by an actuator spring toward its first position, and said actuator further in operative communication with the pushbutton and urged toward its second position by movement of the pushbutton toward its second position, said main switch changing conduction state as the actuator moves between its first and second positions, the improvement comprising:
- a) an electrically activated latch including a winding and a ferromagnetic armature, said armature interposed to transmit force from the pushbutton to the actuator and having first and second positions corresponding to the pushbutton's first and second positions, said winding providing responsive to a latch current in the winding, magnetic attraction for the armature sufficient to maintain the armature and the actuator in their second positions and to overcome the actuator spring force biasing the actuator to its first position;
- b) an auxiliary switch having first and second conductive states, and mechanically controlled by the pushbutton to its first and second states corresponding to the first and second positions of the pushbutton, and electrically receiving a DC voltage from the external source and providing a first output voltage level responsive to the auxiliary switch first conductive state and a second output voltage level otherwise;
- and
- c) a latch operating circuit receiving DC power from the external source and having a power control element gating latch current from the external source to the latch's winding responsive to a closure signal, and a timing element receiving the output voltage levels from the auxiliary switch and providing the closure signal to the power control element for a predetermined time period responsive to and beginning with the appearance of the second output voltage level from the auxiliary switch.
Dependencies are inferred from the claim text.