Abstract: An apparatus is provided for indicating a level of a fluid in a reservoir and comprises a first multi-strand fiber optic cable with one end of the strands being disposed for receiving light from a light source for transmission to the second ends. A second multi-strand fiber optic cable having the same number of strands is disposed for receiving light from the second ends of the strands in the first cable. The second ends of the second cable are arranged for indicating the presence of light received by respective ones of the first ends of the second cable. A detector detects the level of the fluid in the reservoir, and an interrupter is disposed between the second ends of the first multi-strand fiber optic cable and the first ends of the second multi-strand fiber optic cable for interrupting the transmission of light between corresponding pairs of strands of the first and second fiber optic cables.

Abstract: An automatic recirculation valve is disclosed which utilizes three valve elements to accomplish particularly smooth and nondisruptive switching of fluid flow between main fluid flow and recirculation fluid flow. A unique back pressure control valve provides close control over changes in fluid pressure relative to fluid flow rate and functions to suppress erosion and cavitation of the bypass valve.

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 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 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 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.

Abstract: There is disclosed herein a toolholder for use in machine tools, particularly those of the type having means for automatically changing tools according to a predetermined plan, the toolholder being transported from a tool rack to a spindle for use and being returned to the tool rack when it has served its purpose. The toolholder has two flanges forming two annular grooves, one groove shaped to receive holding means on the tool rack and the other groove shaped to receive the edges of a socket in the tool transporting means; one flange having a single peripheral keyway to receive a key on the tool rack to maintain the circular orientation of the toolholder and tool therein when being stored on the rack and the other flange having two usually diametrically placed slots, one to engage a driving key on the spindle with which the tool is used, and the other to be engaged by a key on the carrier by which the tool and toolholder is transported to and from the spindle, said keys serving to maintain the desired 360.