US 5,122,782 A · Misgrip sensor for a support member

Abstract

A misgrip sensor cooperates with a support member, the support member being of the type having an arm for supporting a workpiece during a plurality of forming operations. The sensor detects improper engagement of a workpiece by the support arm and includes a support housing, a contact rod journaled in the front and rear walls of the housing for rectilinear movement and having a collar mounted thereon, a proximity switch mounted on the housing adjacent to the rod for generating a signal indicating proper engagement of a workpiece by the arm, a sensor plate slidably mounted on the rod between the front wall of the housing and the proximity switch and first and second springs which act in opposition to urge the sensor plate against the contact rod collar at an equilibrium position coincident with a non-actuation position spaced from the proximity switch. Displacement of the contact rod toward a rear wall of the housing by a workpiece engaged by the support arm such that the collar is displaced between the actuation position and the rear wall enables the first spring to urge the sensor plate from the non-actuation position to an actuation position, and subsequent, relatively minor movements of the contact rod and collar do not displace the sensor plate from the actuation position so that false signals from the proximity switch are prevented. In a preferred embodiment, the sensor includes a stop, fixed to the housing, which holds the sensor plate a predetermined distance from the proximity switch in the actuation position.

Claims23

Dependent claims

For use with a workpiece holding member of the type having an arm for supporting a workpiece during a plurality of forming operations, a misgrip sensor for detecting improper engagement of a workpiece by said arm, comprising:

a support bracket;
means moveably mounted on said support bracket for contacting a workpiece engaged by said arm, said contact means having a shoulder fixed thereon;
a sensor plate mounted on said contact means and movable relative thereto;
means, fixed relative to said support bracket and responsive to displacement of said sensor plate from a non-actuation position to an actuation position adjacent thereto, for generating a signal indicating proper engagement when said sensor plate is in said actuation position;
means, fixed relative to said support bracket, for stopping movement of said sensor plate at said actuation position;
and
means for biasing said sensor plate and said shoulder against each other to an equilibrium position coincident with said non-actuation position, such that displacement of said contact means by a workpiece supported by said arm sufficiently to displace said shoulder toward said stop means enables said biasing means to urge said sensor plate against said stop means at said actuation position, thereby causing said signal means to generate a signal indicating proper workpiece engagement, and relatively minor displacement of said contact means do not enable said shoulder to displace said sensor plate from said actuation position, whereby false readings of improper engagement are prevented.

4 more elements

a support housing having a front wall for orientation proximate said workpiece and a rear wall at an opposite end of said housing;
a contact rod journaled in said front and rear walls and extending through said housing for rectilinear movement relative thereto, said contact rod having a collar fixed thereon;
a proximity switch mounted in said housing adjacent to said rod for generating a signal indicating proper engagement of a workpiece by said arm;
a sensor plate slidably mounted on said contact rod between said front wall and said proximity switch, and movable between a non-actuating position and an actuating position adjacent to said proximity switch wherein said switch generates a signal;
first resilient means, extending between said front wall and said sensor plate, for urging said sensor plate to said actuating position;
second resilient means, extending between said collar and said rear wall, for urging said collar against said sensor plate, said second resilient means having a force greater than that of said first resilient means such that said sensor plate assumes an equilibrium position at said non-actuating position;
whereby displacement of said contact rod toward said rear wall by a workpiece engaged by said arm such that said collar is between said actuation position and said rear wall enables said first resilient means to urge said sensor plate to said actuation position, and subsequent, relatively minor, movements of said contact rod and collar do not displace said sensor plate from said actuation position so that false signals from said proximity switch are prevented.

4 more elements

Dependencies are inferred from the claim text.

Misgrip sensor for a support member

Life of this patent

Misgrip sensor for a support member

Life of this patent

Abstract

Claims23