Manufacturing method for a plastic element

Abstract

The present invention relates to a method and a mould for manufacturing plastic element as well as a plastic element having oppositely arranged eye parts where oppositely one eye part in relation to a substantially centrally placed stem is arranged a recess on the opposite side, where the manufactured plastic elements for example are chain links or a conveyor belt, and where the mould comprises two mould halves, where each part comprises protruding core parts and further a plastic element manufactured by the mentioned method of manufacture in the mentioned mould, where in the eye parts are provided through-going openings in the chain links with respect to the travel direction. It is the object of the invention to simplify moulds and the molding process as well as reduce the requirements for the size of the molding machine. This is achieved by a method where the mould comprises two halves with offset and side placed core parts, which create recesses between side placed eye parts on one side and cavities on the oppositely arranged eye parts, where the ultimate ends of the core parts on one mould half is brought into contact with side places interior parts of the core parts on the other mould part by closing the two-part mould. In this manner, pin bolts which until now have shaped the openings in the third dimension become superfluous.

What is claimed as new and to be desired by Letters Patent of the United States is:  
     
         1 . Method for manufacturing of plastic elements having oppositely arranged offset eye parts, wherein there oppositely to an eye part on one side of a stem is arranged a recess on the opposite side; where the manufactured plastic elements for example are chain links for a conveyor belt and where the method comprises; 
 that the mould for the molding process comprises two halves with protrusions/core parts which are moved into a position where the protrusions/core parts are arranged in a side-by-side manner prior to injecting the molding material;    that the protrusions/core parts on one mould half create the recesses between neighboring eye parts on one side and the cavity inside the oppositely arranged eye parts on the other side of the stem;    that the ultimate ends of the protrusions/core parts on a first mould half during closing/injection are brought into contact with the side-by-side arranged interior ends of the protrusions/core parts on the other mould part, and    that the mould halves after injection of mould material are withdrawn, whereby a through-going aperture through the eye parts in the chain links' width direction is created.    
     
     
         2 . Method for manufacturing of plastic elements by plastic molding according to  claim 1 , wherein the mould halves are shaped such that the elements are molded having the closing direction of the mould halves parallel to the elements' longitudinal direction/conveyor belt's transport direction.  
     
     
         3 . Mould for manufacturing elements in a plastic molding machine according to  claim 1  and/or  2 , wherein the mould comprises two mould halves, where each half comprises protruding mould parts, where the mould parts have a taper and wherein the core parts in a first mould half are offset in relation to the other mould part such that the core parts have corresponding ultimate side ends which during molding are in engagement.  
     
     
         4 . Mould for manufacturing elements in a plastic molding machine according to  claim 3 , wherein the ultimate side edges on the protrusions/core parts on a first mould half in the mould's closed position correspond to offset interior side surfaces on the protrusions/core parts on the other mould half.  
     
     
         5 . Element manufactured by a plastic molding process in a two-part mould according to any of claims  1 - 4 , where the element is a chain link, which chain link can be assembled with other corresponding or identical chain links and thereby create a flexible conveyor belt, where the chain link comprises a stem on both sides of which perpendicular to the transport direction of the chain link eye parts are provided such that directly opposite an eye part on the other side of the stem is arranged a corresponding recess such that two identical chain links can be pushed together and thereby have overlapping eye parts and where in the eye parts are arranged through-going apertures in the chain links with direction, wherein the stem is broken through such that from a recess on one side of the stem is created an opening into the oppositely arranged eye part on the other side of the stem.