Apparatus for multiple sheet line molding
AssigneeLear Corporation
InventorRichard P. McCorry
Life of this patent
Estimating the term…
Abstract
Apparatus for compression molding thermoplastic backed carpeting in deep draft molds wherein carpeting is precut into sheets, heated, positioned between the mold parts, clamped at selected locations around its periphery, differentially prestretched by tensioning actuators, compression molded, cooled and removed from the mold. Tensioning actuators draw the sheet material downwardly into the deep draft of the mold and further stretch the material in the region of shallow draft, uniformly thinning the material. Stretching of the material by the mold during the compression molding step is minimized in this method. Prestretching allows sheets to be precut to a smaller size than the mold for more efficient use of material and provides control of product thickness independent of mold draft.
Claims14
Apparatus for compression molding of sheet material into a molded product, comprising:
- a mold having a draft and comprising interengagable mold parts, the draft of said mold being greater at a first predetermined location than at a second predetermined location, said mold parts being relatively movable between an open, disengaged position and a closed, interengaged position;
- means for positioning said sheet material between said mold parts when said mold parts are in said open position;
- first sheet tensioning means operatively connected to said positioning means for selectively differentially prestretching and drawing said sheet material from said second predetermined location into said first predetermined location prior to interengagement of said mold parts;
- a frame surrounding said mold, said frame including elongated support members extending along the mold perimeter, and means mounting said sheet tensioning means at preselected locations on said elongated support members;
- said sheet tensioning means comprising a plurality of devices for pretensioning said sheet material at preselected locations around the perimeter of said sheet material;
- said means mounting each of said pretensioning devices comprising a positioning fixture slidably supported on said elongated support members, said positioning fixture having second means for locking said positioning fixture at preselected locations on said support member;
- said means mounting each of said pretensioning devices further comprising an upright holding fixture, said upright holding fixture including an elongated channel section having a pair of spaced flanges and an open side, said channel section fitting over and slidably engaging said elongated support members, said channel section having said second locking means for fixing said channel section at preselected locations on said elongated support members, said upright holding fixture having means for vertically positioning said pretensioning device comprising:
- a first plate fixed to said upright holding fixture, said first plate having a plurality of apertures vertically spaced at a plurality of predetermined heights;
- and
- a second plate fixed to said pretensioning device, said second plate having a stud projecting perpendicularly from the surface thereof for selectively mating with one of said vertically spaced apertures in said first plate, said plates overlapping when said stud mates with said one aperture of said vertically spaced apertures.
Dependencies are inferred from the claim text.