Back to results
US 4,527,769 AGranted
Apparatus for moving a controlled member to a predetermined position
AssigneeXomox Corporation
InventorsClarence H. Stogner, David J. Koerner
Life of this patent
Estimating the term…
Abstract
A fail-safe actuator of the type which permits cycling of a control member during normal operation without encumbrance from a return mechanism includes a link having a slot. A pin secured to a crankshaft coupled to the controlled member is slidably disposed within the slot. The slot permits rotation of the crankshaft within a range defined by the slot length. Upon system failure, a fluid pressure is moved to a predetermined position by a biasing spring to force the crankshaft to a fail-safe position.
Claims22
A fail-safe actuator, comprising:
- (a) a housing;
- (b) a reciprocally movable member movable between first and second positions within said housing;
- (c) means for biasing said reciprocally movable member toward said first position;
- (d) means for selectively moving the reciprocally movable member toward said second position against said biasing means;
- (e) a link secured relative to said reciprocally movable member for common movement therewith, said link having a slot;
- and
- (f) a force transmitting element moveable throughout a range adapted for transmitting force to a controlled member, said force transmitting element including a pin movably disposed within the slot of the link, the link being operative to move the force transmitting element to a predetermined position within said movement range through contact with the pin when the reciprocally movable member is in the first position while permitting movement of the pin within the slot when the reciprocally movable member is in the second position the movement of the pin within the slot permitting the force transmitting element to be moved throughout said movement range independently of movement of the reciprocally movable member whenever the reciprocally movable member is in the second position.
4 more elements
An actuator comprising:
- (a) a housing;
- (b) a fluid pressure member reciprocally movable between first and second positions along a rectilinear path within said housing;
- (c) a spring having linear force-displacement characteristics and operative to bias said fluid pressure member toward said first rectilinear position, said spring being displaced by said fluid pressure member as said fluid pressure member is moved toward said second rectilinear position;
- (d) means for introducing and exhausting a pressurized fluid into and out of said housing said fluid pressure member being selectively moved toward the second rectilinear position against the bias of said spring upon introduction of said pressurized fluid, said spring being operative to return said fluid pressure member to said first rectilinear position upon exhausting of said pressurized fluid from said housing;
- (e) a shaft rotatable between first and second rotatable positions about a rotational axis, said shaft being adapted for transmitting torque to a controlled member;
- (f) a crank arm rigidly secured to said shaft and rotatable therewith, said crank arm including a pin;
- and
- (g) a link pivotally attached relative to both said fluid pressure member and said rotatable shaft to transmit the biasing force of the spring along a line of action, said link having a slot for receiving said pin with said pin being movable within said slot, said link being operative to move the crank arm and the shaft to a predetermined position through contact with the pin when said fluid pressure member is in its first position while permitting rotation of the crank arm and the shaft between the first and second rotatable positions independently of movement of the pressure member whenever said fluid pressure member is in said second rectilinear position, the link-shaft attachment being offset relative to the rotational axis so that the link-shaft attachment travels along an arcuate path as the shaft is rotated between the first and second angular positions, the perpendicular distance between the rotational axis and the line of action being coordinated with the force displacement characteristics of the spring so as to produce a maximum spring generated torque intermediate the first and second rotational positions of the shaft.
5 more elements
Dependencies are inferred from the claim text.