Abstract: Pivot rods tend to move from a preferred resident working axial position in modular link conveyor belts because of load forces tending to flex the rods, movement of belts around curves and other conditions encountered. This invention provides for pivot rod receptacle apertures in modular link ends which are elongated and contain detenting structure for holding the pivot rod in a bistable position in either end of the elongated apertures. Thus, the edge of links or belts have only one of the ends of the apertures occluded so that rods may be inserted and removed in a slack non-working bistable position and then the rods are moved with a force overcoming the detent into a tension working bistable position where they are confined in their resident working position. A preferred detenting structure in resilient plastic belt modules comprises reduced width waist structure intermediate the two ends of the elongated apertures in one or more of the link ends.

Abstract: Apparatus and a method for permanently joining integrally formed plastic screw conveyor modules is disclosed. A support means supported by a base supports a multiplicity of previously joined modules. A holding means also mounted to the base supports a single module to be joined to the already joined modules. The holding means supports the single module such that the axial member of the single module is aligned with the axial member of the multiplicity of modules. A melting means such as a heating plate is placed in firm contact between the ends of the modules to be joined until the plastic begins to melt. The heating plate is then removed and the modules while being supported firmly along their axis are pressed together and maintained in such a position until the melted plastic begins to solidify and thereby joining or bonding the single module to the already joined modules.

Abstract: Apparatus for bonding or joining confronting edges of flights of adjacent integrally molded screw conveyor modules is disclosed. The apparatus comprises means for supporting a plurality of the modules in axial alignment and with confronting edges of the module flight members in confronting relationship. Also included is a clamping means for enclosing and maintaining the confronting edges in a fixed position. The clamping means includes at least one passage extending from outside the clamp to a position inside the clamp between the confronting edges. A heated gas such as nitrogen is provided through the passage to the confronting edge to heat the edges substantially to the melting point of the plastic modules. Subsequent to heating the edges with the hot gas, a liquid plastic material under selected temperature and pressure is injected through the clamp passage and into the space between the confronting flight edges to fill the space between the edges and to bond the flights together.