Document Type and Number:
Japanese Patent JPS4971056
Kind Code:
A
Abstract:
Plastic is foamed in a pressure tunnel portion of a molding conveyor formed by opposed endless conveyor runs with side pieces defining the product cross section. One or both employed the endless runs, preferably the bottom conveyor run is laterally split into at least two separate endless shiftable conveyors respectively carrying the side pieces forming the sides of the pressure tunnel, which shiftable conveyors are laterally movable, with respect to the conveying or molding direction, at the tunnel entrance and the tunnel exit for clamping and unclamping respectively, that is for bringing the side pieces horizontally toward each other transverse to the molding direction to form the final configuration for the tunnel cross section and away from each other at the molding tunnel exit to release the sides of the molded product. This clamping and unclamping of the side pieces is particularly important with molded sheets having a configured edge so that the side pieces may be constructed with a corresponding configuration. Preferably, the two shiftable endless conveyors are constructed of a series of plates having pivotal connections therebetween to form a chain, which connections will allow additional sliding or shifting of the plates with respect to each other within a limited range, preferably under the control of guide means on the individual plates and stationary support structure. Preferably, the guide means are rollers on the plates engaging within stationary tracks. A flexible cover endless belt may be employed to bridge the joint between the shiftable endless conveyors and form the entire bottom surface for the tunnel portion. After the lower shiftable conveyors have been moved toward each other to their final tunnel configuration, a flexible endless belt may be tightly brought into contact with the tops of the side pieces and clamped by the upper rigid endless conveyor, so that through the unsupported tunnel portion, the upper belt will be tightly held at its opposite ends and not subject to sagging while forming a smooth continous upper wall for the molding pressure tunnel.
Application Number:
JP10555473A
Publication Date:
July 09, 1974
Filing Date:
September 20, 1973
Export Citation:
International Classes:
B29C47/00; B29B7/00; B29C39/00; B29C39/16; B29C39/20; B29C39/26; B29C44/30; B29C48/90; B29D1/00; (IPC1-7): B29D27/04
Domestic Patent References:
| JPS4815976A |