Machine tools

A machine tool in which small easily distorted workpieces such as hollow pins, studs and the like disposed in a supply channel are advanced from a ready position therein to a pair of clamping jaws at loading station and from there to a work station, the latter located on a predetermined first center line, where a tapping, drilling, facing or like operation involving torque is performed thereon, comprising:

• a pair of opposed workpiece clamping jaws for clamping a workpiece at the work station;
• a first one of the jaws disposed slidably in a first jaw holder on one side of the work station and a first detent spring biasing the first jaw toward the second jaw at the work station;
• the second jaw disposed in a second jaw holder on the other side of the work station and biased by a second detent spring toward the opposed jaw at the work station, the opposing free faces of the jaws presenting a recess substantially complemental to the workpiece to clamp the workpiece at the work station;
• a feed finger reciprocal along a second center line at a loading station displaced to one side of said first center line and operating in a guide channel which intersects the supply channel at a point of confluence;
• reciprocal means to actuate the second jaw holder in an advancing direction laterally toward the work station thereby to cause the second jaw to push the first jaw toward the first center line against its spring and cooperate with the first jaw effectively to dispose and clamp a workpiece to be machined at the first center line against the torque of the tool and to withdraw the second jaw holder in a return direction toward the second center line, the spring bias on the first jaw causing it to slide in its holder to follow the second jaw during return movement so both jaws hold the machined workpiece by detenting during return movement of the first jaw holder to the second center line, whereby a workpiece is translated back and forth between the stations while clamped between the jaws;
• the recess presented by the jaws being disposed substantially at the second center line when the second jaw is returned by the reciprocal means thereby enabling the feed finger to load a fresh workpiece, located at the point of confluence, into and between the free faces of the spring-biased jaws for transfer to the work station when such reciprocal means is next advanced toward the first center line, the machined workpiece being ejected from the recess concurrently with loading the jaws with a fresh workpiece.