A multi-station apparatus for drilling closely-spaced holes in a plurality of workpieces while individually supported by a turntable. A frame supports the turntable with their axes of rotation extending vertically such that two of the turntables lie within one of two spaced-apart vertical planes and the two remaining turntables lie within the other vertical plane. Parallel line shafts extend horizontally below the turntables and carry bevel gears that mesh with other bevel gears secured to the turntables. The line shafts are interconnected by a train of spur gears that are, in turn, rotated by a handwheel having a pin extending into an indexing plate for locking the gear drive and thereby holding the turntables in a desired adjusted position. The vertical columns extend above the turntables at horizontally-spaced locations such that the turntables lie between the columns. Each column carries a radial arm with its extended end carrying pairs of drill means, one for each turntable. Piston and cylinder assemblies advance the drill means toward a workpiece while supported on the turntable and stops are provided to limit displacement of the drill means.
A numerically controlled transfer machine comprises a rotary index table having thereon a plurality of jig tables for holding workpieces, and a plurality of working units are disposed in spaced relation around the index table so that rotary indexing of the index table successively positions the jig tables opposite different ones of the working units. Each working unit includes a positioning feed mechanism for controlling the feeding and return movements of the working unit to enable a working operation to be carried out on the workpieces. Each working unit has a position detector comprised of a microswitch mounted on a slide member slidably mounted on the working unit. A biasing spring urges the slide member in the direction of return movement of the working unit and a stopper comes into contact with and actuates the microswitch during the course of return movement to thereby feed an origin reference signal to the positioning feed mechanism to effect positioning of the working unit at a preselected origin return position. In the event of continued return movement past the origin return position, the stopper comes into contact with and pushes the slide member against the force of the biasing spring thereby preventing damage to the microswitch.
A double-spindle machine tool comprises two tool-holder spindles and two work holding fixtures allocated thereto. A work holding fixture comprises a work carrier plate which supports itself on an adjustable abutment. This abutment is adjusted by means of an adjusting device in dependence on changes in the distance of the axes of rotation of the tool-holder spindles.
