Low density spring assembly and method of making low density spring assemblies

Abstract

A method of making low density spring interior assemblies having rectangular arrays of spring positions, some of which are occupied by individual coil springs and some of which are empty, is provided. Preferably, the array is formed of rows of alternating springs and empty positions laced to similar rows offset from each other in a staggered arrangement so that spaces and springs alternate both transversely and longitudinally. Preferably the springs are unknotted. The assemblies are automatically formed on a system that includes at least one coil former, at least one conveyor, a transfer station or mechanism and a spring interior assembly machine. A coil former forms and loads springs individually onto a conveyor. The transfer station transfers rows of coils to the assembly machine, which laces rows of coils together in the array. The coil formers, conveyors, transfer station and assembly machine may be conventional, with at least one controlled to create empty positions and determine the relative locations of springs and empty positions. In some embodiments, coils may be placed at spaced locations on a conveyor to create the empty positions, either by controlling the timing of the coil former or controlling the indexing of the conveyor, while in other embodiments, the transfer station or assembler may space the springs prior to transfer or lacing. One or more of the elements of the system may be controlled to stagger the rows, either before, during or after transfer to the assembler. One or multiple conveyors may be timed or arranged so that different rows are presented to the transfer station in different offset positions.

Dependencies are inferred from the claim text.