Indicator for monitoring linear activator position
AssigneeGraco Robotics, Inc.
InventorNorman Fender
Life of this patent
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Abstract
The present invention relates to an indicator for monitoring the position of a piston rod of a linear actuator utilized in robotic mechanisms. The indicator includes a precision toothed chain which is pulled by an extending piston rod and drawn in by a coil spring to maintain tension in the chain and a non-slipping relation with a sprocket wheel driven by the chain. A shaft encoder mounted on a shaft of the sprocket wheel delivers digitized quantities representative of the degree of rotation of the shaft and sprocket wheel and of the linear position of an actuating, linearly-movable end of the piston rod.
Claims5
An indicator for monitoring the position of a linear actuator having a relatively stationary cylinder housing and a piston rod with an actuating, linearly-movable end, comprising:
- (a) a rotatable shaft in a housing, said housing affixed to said stationary cylinder housing with said rotatable shaft positioned transverse to the direction of movement of said linearly-movable end;
- (b) a toothed sprocket mounted to said shaft;
- (c) a rotatable means coupled to said rotatable shaft, for generating signals representative of the position of said rotatable shaft;
- (d) a toothed chain having a first end affixed to said linearly-movable end, and engaged about said toothed sprocket, and having a second end;
- and
- (e) tension spring means for applying extensible tension to said toothed chain, said tension spring means having a first end connected to said cylinder housing and a second end connected to said toothed chain second end.
Dependencies are inferred from the claim text.