Time delay relay
OwnerTim Hasenour, David Parker +1inventors
InventorsTim Hasenour, David Parker, Kurt Zarbock
Life of this patent
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Abstract
A time delay relay includes a coil having a longitudinal axis therethrough and an armature proximate an end of the coil. The armature is movable between an energized position and a de-energized position. A tube is positioned within the coil. The tube has a longitudinal axis that is substantially coincident with the axis of the coil. A metallic core is disposed within the tube. The core is movable along the longitudinal axis of the tube in response to a magnetic field in the coil to induce movement of the armature to the energized position. A time delay occurs between the onset of the presence of the magnetic field and the movement of the armature to the energized position.
Claims22
1-19. (canceled)
A method for controlling an electric power tool to provide a soft start, comprising:
- providing a power tool, having a motor and a motor circuit, the motor circuit including a current limiting element that limits current to the motor;
- coupling a time delay relay in the motor circuit to bypass the current limiting element when the time delay relay is energized to provide full power to the motor after a time delay, the time delay relay comprising a coil having a longitudinal axis therethrough;
- an armature proximate an end of said coil, said armature being movable between an energized position and a de-energized position;
- a tube positioned within said coil, said tube having a longitudinal axis that is substantially coincident with said axis of said coil;
- and
- a metallic core disposed within said tube, said core being movable along said longitudinal axis of said tube in response to a magnetic field in said coil to induce movement of said armature to said energized position, wherein a time delay occurs between the onset of the presence of the magnetic field and the movement of said armature to said energized position.
A method for controlling an electric power tool to provide a soft start comprising:
- providing a power tool with a motor and a motor circuit, the motor circuit having a current limiting element that limits current to the motor;
- providing a relay having a metallic core that is movable from a de-energized position to an energized position to provide a mechanically controlled time delay represented by the time required for the core to move from the de-energized position to the energized position and for contacts in the relay to close;
- and
- coupling the relay in the motor circuit so that the current limiting element is bypassed after the core moves from the de-energized position to the energized position so that full power is available to the motor.
Dependencies are inferred from the claim text.