Continuous molding machine

Claim 1

Apparatus for continuously producing a rigid foam synthetic resin product of three dimensionally configured uniform cross section throughout its indefinite length, comprising: at least two substantially opposed highly flexible endless belts having a relaxed cross sectional configuration, transverse to the belts, that corresponds to the three dimensionally configured surface to be formed on the product; means guiding said belts for travel in respective desired endless paths lying generally in a common plane, with opposed generally rectilinear molding runs closely adjacent each other forming therebetween a molding tunnel, with return runs, and with transitional curved protions between said runs for each belt; said belts being of a material sufficiently resilient to bend without permanent deformation toward a planar configuration when traversing said transitional curved portions; support means including a rigid endless backup coveyor for each of said belts traveling in an endless path generally within the path of its respective belt and generally in said common plane; each of said rigid endless backup conveyors comprising a plurality of plates serially connected together by hinge means in an endless chain traveling in a path having a generally rectilinear belt backup run closely adjacent and parallel its respective belt molding run, a return run, and opposite end transitional curved runs spaced considerably from said belt transitional curved portions; each of said rigid endless backup conveyors having a plurality of metal blocks respectively corresponding in number to and integrally secured to the surface of said plates facing said its associated belt; each of said blocks being of identical cross section transverse to the conveyor length, and being of a width substantially equal to the corresponding width of said plates; the adjacent plates of at least one of said rigid endless conveyors being pivotally connected together for substantial limited lost motion transverse to said common plane; saId resilient belt associated with said one conveyor, at one side generally overlaping the adjacent belt and movable into abutting engagement with each other in one transverse direction when moved parallel to the pivoting connection of the adjacent plates in the molding zone, and at the other side having sliding engagement with the adjacent belt in the same transverse direction; backup guide means for moving said rigid endless conveyors toward each other with a predetermined spacing between the opposed plates of said rigid endless conveyors at the entrance of said molding zone and maintaining said spacing throughout the length of said molding zone; and said backup guide means further shifting successive plates of said one conveyor in said transverse direction downstream from said entrance for a substantial transverse distance to tightly clamp the adjacent abutting belt surfaces at said one side and to provide wiping sliding contact for the belt sliding surfaces at said other side, and further maintaining said shifted position throughout the remaining portion of said molding zone.