Abstract: A butt mounted riser hinge has a plastic cam assembly mounted in two metallic cylinders so that their camming surfaces do not rub against the metallic cylinders and become readily worn. The cam assembly includes a male member with bevelled end that is rotatably received in a cup-shaped female member. The hinge further includes a spring and shell assembly in sliding arrangement with one of the metallic cylinders.

Abstract: A hinge for rotatably mounting a barrier member to a structural member. The hinge comprises a first hinge assembly which comprises a first hinge bracket attachable to the structural member, a second hinge bracket attachable to the barrier member, a first hinge member mounted for rotation with the second hinge mounting bracket and a second hinge member mounted for rotation with the first hinge member. Both hinge members have correspondingly configured engaging surfaces which permit staged rotation between the hinge members. This facilitates a staged rotation of the barrier member in predetermined sequential increments as determined by the engaging surfaces. This first hinge assembly connects a lower portion of the barrier member to the structural member and is responsible for bearing substantially all of the weight of the barrier member. The invention further comprises at least a second hinge assembly for providing rotational alignment between an upper portion of the barrier member and the structural member.

Abstract: A gravity door hinge in which a cam is inserted non-rotatably into the lower half of a socket provided in a fixed member, the upper end of an axial rod is inserted non-rotatably into an axial bore hole provided in a rotational member, a cam follower is fitted rotatably around the middle of the axial rod by inserting the axial rod through a central hole bored in the cam follower, the lower half of the axial rod is inserted rotatably into an axial hole formed by hollowing out the center of the cam, the cam follower is fitted rotatably into the upper half of the socket, on top of the cam housed in the lower half of the socket so that an inclined cam surface formed on the lower end of the cam follower comes into close contact with an inclined cam surface formed on the upper end of the cam, and the base of the socket is completely closed.

Abstract: A fence line is provided including a pair of spaced posts between which a fence opening is defined and wherein a cattle guard is substantially centered in the opening and spans considerably less than the width of the opening. A pair of edge upstanding panel-like wing closure members are provided at opposite sides of the opening between the posts and the adjacent sides of the cattle guard and pivot structure pivotally mounts first corresponding upstanding base edge portions of the closure members at the opposite sides of the opening for angular displacement about upstanding axes and with the closure members including second free swinging upstanding edge portions opposite the first edge portions swingable toward and away from closed positions with the second edge portions at least closely adjacent the opposite sides of the cattle guard and an upstanding plane containing the fence line opening.