Manufacturing process for forming a chair back

摘要

An improved chair back is formed of a molded construction uses multiple mold shots of mold materials to develop different performance characteristics in selected areas of the chair back. The chair back has the appearance of a unitary molded panel, but is formed from multiple mold shots which preferably are performed at multiple stations on a mold tool. By providing multiple mold shots and selected materials to form different areas of the chair back, different performance characteristics are generated including the provision of a peripheral frame providing structural rigidity to the chair back, a lumbar support panel which provides localized support to the lumbar region of the chair occupant, and a thin sheet-like support panel extending between the frame and enclosing the interior region defined between the peripheral frame to provide a more flexible and pliant surface providing more comfortable contact with the occupant's back.

主权项

1. A manufacturing process for forming a chair back with a molding operation wherein said chair back has a generally rectangular shape and integrally includes two, downwardly projecting uprights which are configured to pivotally connect to a chair structure, said uprights rigidly supporting the chair back along the opposite left and right side edges thereof, and said chair back further comprising a sheet-like support panel extending between the uprights at the side edges, which said support panel is vertically enlarged and configured to support the chair back of the occupant, the method comprising the steps of:
performing a first mold shot to construct right and left structural components as a first step in forming a back frame, said left and right uprights providing structural rigidity to the left and right sides of the back frame; performing a second mold shot wherein the left and right uprights are overmolded with a second material to build up an overmolded layer on the left and right sides of said back frame to form vertical left and right frame sections as well as form upper and lower integrated cross members extending between said left and right frame section, said second mold shot generally forming an annular shape for said back frame that is defined by the overmolded uprights and the integrated cross members which surround an open interior of the chair back; after the second mold shot is completed, performing third and fourth mold shots wherein said third mold shot forms an encapsulating wall around the left and right frame sections and the upper and lower cross members to define a finished surfaces for these structures, and said fourth mold shot forms a thin sheet across the open interior which said thin sheet extends from an inner boundary of the third shot, said thin sheet of said fourth shot defining a relatively thin, sheet-like interior panel that encloses the open interior, and provides a support region which has greater flexibility in comparison to the back frame.