Abstract: Apparatus for the pressure-forming and curing of polymer products incorporates two moulds (1) and a forming device, the moulds (1) being sturdily linked to each other with provision for setting the separating distance as required and for revolving on a fulcrum pin (9) so that the material of a circular product can be wound therearound. The moulds (1) are semicylinders which face each other with their flat sides and are sturdily interlinked by two parallel plates (2) so as to form integrally therewith a sturdy building core having a contoured outside surface. The forming device is a girdling structure which embraces the semicylinders (1) and the plates (2) circumferentially and is made up of at least two elements at least one whereof is located with provision for radial displacement in the course of pressure-forming.

Abstract: A mold for making annular polymeric articles comprising a core having an outer contoured surface for placing a workpiece thereon, two half-molds with holes for discharging excess polymer embracing the contoured surface of the core and partially embracing end faces of the core in the course of radial displacement of the half-molds during press-forming of the article, and a means for pressure-sealing a forming cavity of the mold. The half-molds have in the area where they are joined a width equal to the length of the generating line of the core, whereas the pressure-sealing means includes two members rigidly affixed on one of the half-molds at the opposite sides thereof. Each member has at the side facing the half-molds the form of a closure embracing these half-molds in the area where they are joined, and by their shelves embracing part of the end faces of the half-molds and core during press-forming.