Abstract: A novel back stop gauge for determining accurate and safe positioning of work piece material in a machine tool, such as a press brake, wherein a linear stop has an axially stiff, but transversely flexible coil spring intermediate end portions, one end portion being engaged by work piece material and the opposite end portion being anchored to a cooperating support. Misplacement of work material either over or beneath the stop, while normally destructive of the work piece upon closure of the press brake, does not result in damage to the machine tool or the press because of the flexible nature of the back stop, which permits movement of the stop out of the path of the machine tool.

Abstract: A multi-piece die section for a press brake installed rotary bending tool in which a forming anvil is positioned in a holder in accordance with the thickness of material to be bent so that the rotary bender and press brake operate on the same center line. In one version of the holder a forming anvil is adjustably positioned relative to the center line of the rotary bender and in a second version thereof the forming anvil is precision sized in accordance with the thickness of the work material whereby to eliminate the need for shims and readjustment of press ram stroke as required by the first version.

Abstract: A rotary bending tool holder, particularly useful in a press brake type press, which embodies a two piece holder, namely a main body and clamp; usually attached to the moveable ram of the press brake. A rotary bending tool used with the holder is provided with elongated rectangular keyway slots along opposite sides which are aligned to received opposing tabs or keys engageable with such slots. One key is formed on the clamp of the holder while the other key is formed on the main body of the holder. Once positioned in the holder, the clamp is tightened to engage its associated key in one of the slots of the bending tool. This action causes the other key on the holder body to engage the other slot of the bending tool. At the same time opposing surfaces on the holder body and bending tool, located at the same distance from the center line of the tool holder engage to precisely align the center of the rotary head on the center line of the holder and press head.

Abstract: A compensating bolster and die holder combination for use with the bed of a press brake to provide vertical adjustment and compensating camber to the die holder supported thereby. The die holder is vertically moveable in an open channel of an underlying elongated bolster fitted to the bed of the press; with plural wedge members, moveable transversely of the die holder, serving to adjustably position and support the latter. Each wedge member has joined thereto an indicator pin extending through one side of the bolster which operates to visually indicate the adjusted position of its wedge member; while the several indicator pins cooperate to show the relative adjusted positions of the several wedge members and the consequential adjusted elevation of the die and die holder.