Abstract: A machine tool having a spindle assembly associated with an indexing tool storage rack on which a number of distinct tools are stored, and a transport or tool carriage for conveying a selected tool between the storage rack and the spindle assembly; and including a control circuit for sequencing the operation of the various component parts of the machine tool for either manual or automatic operation. The spindle assembly includes a variable speed motor drive for rotating a spindle having a drawbar for releasably securing a tool adaptor with the tool to the end of the spindle and which is associated with a push rod operable to control the release of the tool adaptor during a tool changing operation. A spindle gear shifting assembly is operatively connected to the spindle for shifting of the spindle between direct high speed drive and back gear low speed drive or to a neutral position in which the spindle is disengaged from the variable speed motor drive.

Abstract: There are disclosed herein methods for transporting a toolholder between a tool storage rack and a machine tool spindle which include the steps of, in one continuous operation, causing a tool carrier to remove a toolholder from said storage rack and transport the toolholder to the position of the machine tool spindle, causing the tool carrier to be raised to and deposit the toolholder in the spindle, causing the tool carrier while still raised to disengage the toolholder and return to a position remote from the spindle. After the work has been performed by the toolholder, in one continuous operation, advancing the tool carrier to the spindle to engage the toolholder, causing the tool carrier to descend to withdraw the toolholder from the spindle, then be raised and return the toolholder to the storage rack, said reverse operations being caused by reversing the direction of operation of means for supplying power to said tool carrier.

Abstract: There is disclosed a spindle unit for machine tools in which the spindle is rotated by a change speed mechanism comprising a drive sleeve splined and slidable axially in the spindle and a gear shift sleeve slidable with the drive sleeve and having a bull gear adapted in one position to engage a driving gear driven by a motor and in another axial position to cause a clutch element to engage a companion clutch element connected to a pulley also driven by the motor. There are pneumatic means for moving the sleeve to cause the bull gear to disengage said drive gear to free the spindle for independent hand rotation when setting up or adjusting the mechanism. The spindle driving means includes gear shift means to cause the drive sleeve and spindle to selectively rotate at high speed, low speed or be in neutral.

Abstract: There is disclosed a spindle unit for machine tools in which there is a spring operated drawbar in the spindle having finger hooks for engaging the adapter of a toolholder for drawing the latter into a tapered socket at the nose of the spindle with means for locking the finger hooks in engagement with the toolholder adapter and automatically operated means for relieving the pressure of the hooks against the toolholder adapter and providing push rod means to cause the finger hooks to move clear of the adapter and apply a force to the toolholder so that the latter, with the tool carried thereby, may be removed from the spindle socket. The spindle is advanced toward the work and retracted therefrom by a tubular quill provided with a helical groove to cooperate with a ball-nut means formed integrally with a pulley which is connected by a timing belt driven by a pulley on the shaft of a stepper motor, the advancement of the spindle depending on the number of step-like movements of the motor.

Abstract: There is disclosed a tool storage and changing mechanism comprising a rotatable table tool rack having radial sockets to removably hold toolholders, a horizontal arm, forming a track between the tool rack and the machine spindle, carries a mechanical hand having a forked end to receive from the rack and hold a selected toolholder and carry it to and from the spindle. Assuming that the work with the toolholder has been performed, the empty hand travels to the spindle where, without vertical movement of the arm, the hand grasps the toolholder in the spindle which then releases the toolholder. The arm and hand then descend to withdraw the toolholder from the spindle, after which the arm rises again and the carriage travels back to the rack and deposits the toolholder in its rack socket.