Traction type press

Traction type press comprising a rigid framework and at least two plates having work surfaces, of which is a mold assembly disposed between the work surfaces, said mold assembly comprising two mold halves each carried by one of the plates, said mold halves being provided with their own self positioning means;

• one of the plates being movable with respect to the rigid framework and to the other plate, said other plate being fixed with respect to the framework,
• the movable plate having at least one side for moving along a bearing surface of the framework,
• wherein translational movement of the movable plate takes place from an endmost open position, in which the tool assembly is open wide, to an endmost closed position in which the component parts of the tool assembly cooperate closely,
• wherein the closure of the press takes place in two steps, a first step for bringing the plates together and a second step for applying clamping force,
• wherein the press uses separate means for carrying out the first and second steps, the press having an approach means providing rapid movement over a large distance but without a high force to accmplish the first step, and a clamping means providing movement over a short distance and developing the clamping force to accomplish the second step, press:
• and wherein the action of the clamping means is retransmitted from one of the plates to the other by at least one clamping structure which consists substantially of a rigid substantially rectangular frame of inner dimensions sufficient for passing with play about the fixed and movable plates, said frame comprising longitudinal members each situated on one side of the press and two transverse beams situated behind the fixed and movable plates where said transverse beams form bearing element with the fixed movable plates,
• each clamping structure being attached to one of the plates
• by a pivoting means, the press further comprising a means for controlling swinging of the clamping structure so as to free a corresponding bearing element from the opposite plate and allow opening of the press,
• and wherein the clamping means bears directly on one of the plates and on the bearing element of the transverse beam situated behind said one of the plates.