Abstract: A method and apparatus for producing prestressed coil springs whereby the wire is fed about a rotating spindle and taken up or drawn in with a predetermined spacing from the front end of the coils and guided to a point ahead of the front end of the coils in the form of an expanded helix. A stop block is movable along the spindle, fixed against rotation and provided with a plurality of wire grooves at different angles of inclination so that the wire passes beneath the already formed coil as it passes through one of the grooves to produce the desired stress.

Abstract: A bedstead is disclosed including crossheads between which a woven mat support is stretched. The mat is made of spring steel wire, preferably plastic coated and includes longitudinal wire members having U-shaped ends. Hook rails are carried by the crossheads and have adjacent recesses between which they define V-shaped hook members. One of the hook rails is adjustable so as to tension the mat support. A U-shaped clamping bar is provided into which the U-shaped ends of the longitudinal wire members are fitted. A resilient intermediate layer is positioned between the clamping bar and the U-shaped ends of the longitudinal wire members. The clamping bar is positioned in the V-shaped hook members of the adjustable hook rail such that a clamping force is exerted on the U-shaped ends of the longitudinal wire members by the clamping bar in proportion to tension force applied to the mat support by the adjustable hook rail.

Abstract: A platform conveyor having two laterally adjacent, interconnected rows each having a plurality of flat panel members of plastic material hingedly connected together along transversely extending edges thereof, the upper surface of the interconnected panel members forming a load supporting surface, a plurality of integrally formed eyes along each transversely extending edge of each of the panel members and being aligned to receive an interconnecting transverse bar member which connects both rows of the panel members together to form the conveyor belt, the eyes on one transversely extending edge of each panel being staggered relative to the eyes on the opposite edge thereof, the transverse bar member extending to a stop at one side of a panel member forming one edge of the conveyor belt, and at the other edge of the conveyor belt being retained by a pin inserted through a transverse aperture in the eye, and at least one hook attached to one side of the panel members which engages a web at the edge of the lateral