Abstract: A rigid plastic enclosure is made from flat blanks. The enclosure is particularly well suited for use as an electrical or electronic component enclosure. The top, bottom, back, and side walls of the enclosure are parts of a structure made by cutting and/or routing a sheet of plastic which can be folded into an open-faced, box-shaped structure. A cover or face plate can be fastened to the structure to complete the enclosure. Because the enclosure is constructed from plastic, holes can be easily drilled into its walls, eliminating the need for providing knockout holes at predetermined locations.

Abstract: A rigid plastic enclosure is made from flat blanks. The enclosure is particularly well suited for use as an electrical or electronic component enclosure. The top, bottom, back, and side walls of the enclosure are parts of a structure made by cutting and/or routing a sheet of plastic which can be folded into an open-faced, box-shaped structure. A cover or face plate can be fastened to the structure to complete the enclosure. Because the enclosure is constructed from plastic, holes can be easily drilled into its walls, eliminating the need for providing knockout holes at predetermined locations.

Abstract: The invention relates to the method of making a hinge joining rigid plastic pieces at least one fourth inch thick and includes machining a series of hinge knuckles along straight edges of first and second pieces of rigid plastic, machining keyhole shaped passages perpendicular to and across the width of hinge knuckles of the pieces, the keyhole shaped passages each having a tubular central portion and an outwardly extending slot of narrower width on one side of each knuckle, each hinge knuckle having a width less than the space between adjacent knuckles so that the knuckles of each of the two pieces may be assembled by interleaving the hinge knuckles, and inserting a hinge pin through the aligned tubular central portion to hinge together the first and second pieces. The invention also relates to the hinge structure as so manufactured.

Abstract: A rigid plastic enclosure made from flat blanks which is particularly well suited for use as an electrical or electronic component enclosure. The top, bottom, back, and side walls of the enclosure are parts of a unitary structure made by cutting and/or routing a single sheet of plastic which can be folded and locked into an open-faced, box-shaped structure. A cover or face plate can be fastened to the folded and locked structure to complete the enclosure. Because the enclosure is constructed from plastic, holes can be easily drilled into its walls, eliminating the need for providing knockout holes at predetermined locations. The invention is lighter than steel enclosures, and can be shipped and stored in a flat configuration, thereby saving space and allowing for lower shipping and handling costs.

Abstract: In the method an apparatus engages pre-cut lengths of heated thermoplastic pipe against a pair of eccentric wiper arms bending the pipes into elbows. The eccentric wiper arms have an eccentric portion and a constant radius portion. A bending form has an arcuate die adapted to hold a pre-cut length of pipe. Four such bending forms are radially connected to a rotation shaft which is journalled at each end to a support frame. A continuous supply of pre-cut lengths of pipe are transported through a heating chamber by a set of endless chains. Each pipe is then transferred to a bending form which is rotated by the shaft so that the cold end portions of each pipe engages the spaced apart and substantially parallel eccentric wiper arms. The wiper arms urge the end portions of each pipe length slightly beyond the outer edges of each arcuate die to compensate for the effect cooling has on each pipe length. Once the pipe is bent, the rotation of the bending form causes the pipe to drop into a tank of water.

Abstract: An apparatus engages pre-cut lengths of heated thermoplastic pipe against a pair of eccentric wiper arms bending the pipes into elbows. The eccentric wiper arms have an eccentric portion and a constant radius portion. A bending form has an arcuate die adapted to hold a pre-cut length of pipe. Four such bending forms are radially connected to a rotation shaft which is journalled at each end to a support frame. A continuous supply of pre-cut lengths of pipe are transported through a heating chamber by a set of endless chains. Each pipe is then transferred to a bending form which is rotated by the shaft so that the cold end portions of each pipe engages the spaced apart and substantially parallel eccentric wiper arms. The wiper arms urge the end portion of each pipe length slightly beyond the outer edges of each arcuate die to compensate for the effect cooling has on each pipe length. Once the pipe is bent, the rotation of the bending form causes the pipe to drop into a tank of water.

Abstract: An apparatus and method for the manufacture of plastic couplings for joining together two lengths of plastic pipe. The couplings are manufactured from blanks of plastic material, such as polyvinyl chloride, which are heated to the thermoplastic state. The blanks are expanded between two mandrels which come together inside the ends of the blank. The mandrels have an outer member with a thin walled section and a nosepiece inside of that section which collapses at the end of the inward stroke of the mandrels so that the center shoulder of the coupling is not as wide as that of the prior art coupling. This results in a coupling which is shorter and lighter than the prior art coupling and yet is the full equivalent of the prior art coupling.

Abstract: A riser assembly of rigid conduit is provided for an electrical cable which is adjustable. The riser assembly includes first and second rigid conduits having a telescoping interconnection at an elongated enlarged diameter lower end of the second conduit. This permits the upper end of the second conduit to be connected by a threaded fitting to a meter box and to have the lower end of the first conduit extend below grade to receive an electrical cable. Settling of the ground or thermal expansion is readily accommodated by the telescoping adjustment without any strain on the threaded fitting connection to the meter box.

Abstract: A method and an apparatus are presented for forming couplings from blanks made from lengths of extruded plastic pipe, to join pipe together. The blank is cut from the length of extruded pipe and heated to the thermoplastic point. The heated blank is mounted between two mandrels which have a slight taper toward the ends, which are beveled. The ends of the mandrels are brought together inside the blank at a uniform rate and force. The pressure between the ends of the mandrels causes a bulge in the blank. A split die clamps around the blank at about the bulge, causing the bulge to collapse and forming a ridge in the inside surface of the blank. Coolant circulates in the mandrels and cools the inside surface of the blank. The mandrels are then withdrawn, leaving the formed blank in the split die.

Abstract: A method is presented for forming couplings from blanks made from lengths of extruded plastic pipe, to join pipe together. The blank is cut from the length of extruded pipe and heated to the thermoplastic point. The heated blank is mounted between two mandrels which have a slight taper toward the ends, which are beveled. The ends of the mandrels are brought together inside the blank at a uniform rate and force. The pressure between the ends of the mandrels causes a bulge in the blank. A split die clamps around the blank at about the bulge, causing the bulge to collapse and forming a ridge in the inside surface of the blank. Coolant circulates in the mandrels and cools the inside surface of the blank. The mandrels are then withdrawn, leaving the formed blank in the split die.

Abstract: An electrical switch or receptacle box for mounting in a wall, ceiling or the like, including a pair of opposite side walls having retaining studs of triangular or wedge-shaped configuration molded integrally therewith, and terminating rearwardly from the open forward side of the box. The box further includes a pair of integrally molded cover plate flanges which flank the opening at the forward side of the box. Each of the flanges carries a metal insert-receiving lug on the rear side thereof, and each of these lugs is slotted to engage an apertured metal insert which is positioned to receive through an aperture therein, a mounting screw extended through the respective flange and used to mount a cover plate carrying a switch or electrical receptacle on the box.