A button press has an indexable turntable on which are mounted a plurality of alternating lower forming die asseblies and crimping die assemblies. The lower die assemblies are positioned beneath an upper die assembly as the turntable is indexed. The upper die assembly is reciprocated towards and away from the lower die assemblies to first form a cover sheet and display sheet about a metal button front and then to join that subassembly to a metal back having a pin. The indexing of the turntable and the vertical reciprocation of the upper die assembly are provided by a single electric motor. The motor drives a sprocket which is mounted on a shaft leading to a right angle drive mechanism which converts the continuous rotation of the shaft into incemental rotary motion of the turntable. A vertical linkage extends from a face of the sprocket to one end of a walking beam whose other end is connected to a ramrod that mounts the upper die assembly. A control for the electric motor allows continuous or intermittent incremental operation and includes switches that sense the position of the turntable to insure that the lower die assemblies are aligned beneath the upper die assembly when a press operation is to occur.

An indexing apparatus includes a casing, an indexing unit, a gripping unit, a dynamic unit and a driving unit. The indexing unit includes a connecting rod journalled in the casing and having a top portion extending out of the casing, an indexing disc sleeved rigidly on the connecting rod, and several circumferentially equidistant limiting devices provided along the periphery of the indexing disc. The gripping unit slides along the periphery of the indexing disc and can engage with one of the limiting devices so as to prevent the gripping unit from sliding relative to the indexing disc. The dynamic unit supplies power to the indexing unit. The driving unit transfers motion of the dynamic unit to the indexing unit so as to rotate the indexing disc. In a case where the gripping unit is engaged with one of the limiting devices, the movement of the dynamic unit disengages the gripping unit from the limiting device so as to rotate the indexing disc until the gripping unit engages with the next limiting device.

Angular regions (A, B) for turning a trunk body (12) of an industrial robot can be changed in accordance with an operation of the industrial robot by setting movable stoppers (18, 20). Turning movement can be stopped by an electrical means (LS1, LS2, LS3, LS4, LS5) to protect a drive motor and a drive mechanism, just before a stopper (22) fixed on the trunk body collides with mechanical stoppers (14, 16, 18, 20). An accident based on an error operation of the movable stoppers can be prevented by disposing proximity detectors (PS1, PS2, PS3, PS4).

An indexing table having a mounting plate, a support plate and a base. The indexing table further has a lifting piston, locating pistons and clamps for clamping the support plate. The indexing table additionally provides a valve to carry out the specific operations.

An index head provided with a long rack and a short rack which are slided alternatively towards an index table by the movement of a pinion of a piston rod. The long rack which is characterized to move at a speed twice a forwarding speed of the piston rod, gives to the index table a revolution corresponding to desired divisions. Immediately upon the completion of said revolution of the index table, the short rack which becomes then movable at a speed twice the forwarding speed of the piston rod, brings about, in cooperation of the rotary movement of the pinion, the engagement of the piston rod with the index table, whereby inertia given to the index table through its revolution by the long rack is prevented so as to attain accurate divisions.