Apparatus for securing a workpiece to be machined on a machine

Apparatus for securing and registering a workpiece with respect to a tool machine, comprising;

• a tool machine table having a plurality of openings;
• a workpiece support plate disposed on and parallel to the table and having a plurality of bores at locations matching those of the openings of the table;
• means for interchangeably securing the workpiece support plate to the table to secure a workpiece thereto, comprising, a plurality of locking pins each axially displaceable in one of the bores in the workpiece support plate and downwardly into and through one of the openings in the table and having a lower portion with an annular groove below the table, a spring for each locking pin disposed above the table to bias the pin upwardly;
• a locking plate for each locking pin, disposed below the table in the region of the respective opening, slanting in a predetermined direction relative to the table and having a slot extending in said direction whose edges can engage the annular groove of the locking pin, said slot having an enlarged portion adjacent the table for releasing the locking pin, each locking plate having slide means rigid therewith and disposed to guide the plate along the underside of the table, and a rod secured to said slide means, below the table for reciprocably sliding the plate in said direction between a first position in which the respective locking pin has its lower end in the enlarged portion of the slot and a second position in which the groove of the pin is engaged by the edges of the slot and the pin is drawn down against the bias of the spring;
• and
• actuator means lateral of the workpiece support plate for axially, reciprocably moving the rods to move the locking plates along the underside of the table, thereby to move the locking pins in directions through the workpiece support plate and thus to interchangeably secure the workpiece support plate to the table.