Patent ID: 7575426

Claim:
A clamping device for selectively clamping a first die set or a second die set, each die set including a stationary die, a movable die, and parting surfaces formed between the dies, the clamping device comprising: a stationary platen unit to which the stationary die of the first die set or the stationary die of the second die set is attached; a movable platen unit to which the movable die of the first die set or the movable die of the second die set is attached; a plurality of tie bars stretched between the stationary platen unit and the movable platen unit and arranged parallel to one another at respective outer peripheral portions of the platen units; and a pressure mechanism which presses the stationary platen unit and the movable platen unit toward each other, at least one of the stationary and movable platen units including a platen body configured to be pressed by the pressure mechanism, a load transmission portion having a pressure surface projecting toward the die set from a central part of a platen body region which is surrounded by the tie bars, a die fixing plate located on the pressure surface and having a die fixing surface wider than the load transmission portion, a space portion formed around the load transmission portion and between the platen body and the die fixing plate, and a backup member disposed in the space portion between the platen body and the die fixing plate, the backup member being configured to move between a first position in which the backup member is in contact with both the platen body and the die fixing plate and a second position in which the backup member is separate from the platen body or the die fixing plate, and the backup member being situated in the first position when the first die set with the parting surfaces wider than the pressure surface is attached to the die fixing plate and being moved to the second position when the second die set smaller than the first die set is attached to the die fixing plate.