Patent ID: 7059016

Claim:
A device for checking rotation of a hinge pin, comprising: an outer cone comprising a flange containing at least three ball bearings and at least one cam plate upwardly extending locking member opening; an inner cone having at opening therein for receiving a hinge pin such that when said hinge pin is rotated, said inner cone rotates within said outer cone; a cam plate positioned between said inner and outer cones, said cam plate comprising depressions corresponding to the positions of said ball bearings and at least one upwardly extending locking member positioned within said at least one opening in said outer cone flange, said opening sized to allow movement of said upwardly extending locking member between lock and release positions wherein the rotation of said cam plate is limited by the engagement of said upwardly extending locking member with said outer cone flange; and a friction disc between said cam plate and an inner cone flange upper surface, wherein said inner cone is movable between a locked position wherein said ball bearings are located in said depressions and said outer and inner cones are engaged and a release position wherein upon rotation of said inner cone said friction disc causes said cam plate to rotate so that the interaction of said ball bearings with said cam plate causes said outer cone to disengage said inner cone.