Abstract: A coupling system for selectively locking a tool to a toolholder, in which the locking mechanism carried by the toolholder has a cross-sectionally compact structure and provides release assist when the tool is being removed from the toolholder. The body of the toolholder has an axial drawbar bore in which a drawbar selectively slides. The forward end of the drawbar bore in combination with the forward end of the drawbar form a tool profile cavity which is contoured to seatably receive a tool profile of the tool. The drawbar is hollow and is provided with a pair of apertures. The locking mechanism within the drawbar comprises a pair of locking fingers which are pivotally mounted on a common pivot pin connected with the body. Each locking finger may rotate so as to be retracted within the drawbar or erupt out of the apertures in the drawbar. Rotation of the locking fingers is effected by interaction between the apertures and the locking fingers as the drawbar is axially moved in the drawbar bore.

Abstract: A tapered drawback collet which engages a conically tapered collet chamber in chuck body. A collet extension is axially displaced through high reduction gearing including a worm gear and threaded feed ring acting on a sleeve having only axial contact with the collet extension and therefore is free of any radial loading.

Abstract: An indexable slot cutting tool for narrow widths having both head and base members with adjacent opposed cutting faces. An axially oriented sleeve with right hand differential pitch threading engages the head and base members to effect axial movement of the cutting faces for slot adjustment.

Abstract: Adjustable cutting tool bit support, usable as in a stump cutter body, including adjustable jack for variable registration depth of cutting bit, a differential screw engaging differential threads in the body and jack for adjusting the jack position, a wedge clamp for locking engagement of the body and tool bit in adjusted position and a differential screw engaging differential threads in the respective wedge clamp and jack for positively moving said wedge clamp into an effective clamping engagement.