Punch press with tool changer

A method of operating an N/C punch press to produce a programmed pattern Of punched apertures in a workpiece using a plurality of selectively mountable tool sets in a work head, the work head having a Y-axis servo for indexing thereof, and a back table with work clamps for the workpiece and an X-axis servo for indexing the workpiece along a back rail, the method comprising the steps of:

• gripping the workpiece in the work clamps attached to the back table for indexing along the back rail;
• providing a plurality of tool sets for selection by the work head, mounting the tool sets in tool holders along the back table for translation along the X axis only along with translation of the workpiece;
• for each punched aperture, performing an N/C control of the X axis servo to move the workpiece and the Y axis servo to move the work head to select X, Y positions on the workpiece;
• and
• for each tool change operation, performing an N/C control of the X axis to position a tool and the Y axis to index the work head to enter and leave a tool change position at the back rail with respect to a selected tool holder for a tool exchange.

A numerically controlled punch press comprising in combination:

• a bed adapted to support a workpiece;
• a back rail along the back of the bed and having a back table carrying work clamps adapted to clamp the workpiece;
• a first single axis servo drive for the back rail for translating the back table with work clamps to position the workpiece along the X axis;
• a work head including a punch holder and a die holder for accepting a tool set, a second single axis servo drive for positioning the work head along a Y axis whereby the first and second servo drives combine for X, Y positioning of the tool set with respect to the workpiece;
• a plurality of tool cartridges carried by the back table for translation therewith along the X axis, the tool cartridges releasably holding tool sets for transfer to the work head;
• and
• the numerical control including means for translating the back table along the back rail to index the cartridge of a selected tool set along the X axis to a tool changing position, and to index the tool head along the Y axis to the tool changing position for transferring the selected tool set between the work head and the selected tool carrier.