Abstract: An automatic lathe wherein the carriage for an indexible tool turret is biased against a stop and can be moved toward the work spindle by a rotary cam which is driven by a hydraulic motor and is arrested by a hydraulic brake when the carriage reaches a selected position. The motor is automatically decelerated to crawling speed prior to complete stoppage of the cam and the brake is applied subsequent to deceleration of the motor and simultaneously with opening of an arresting valve which connects the supply and return conduits for the motor. The supply conduit continues to receive some pressurized fluid while the motor is at a standstill. Abrupt acceleration of the motor is prevented by maintaining the arresting valve in open position after a motor valve increases the rate of fluid flow from a pump to the supply conduit and by closing the arresting valve simultaneously with disengagement of the brake.

Abstract: A hydraulic double acting chuck motor comprising a hollow cylinder and piston mounted at the rear end of a working spindle of a lathe operates a collet or chuck by pushing or pulling on a hollow operating shaft. The chuck motor is arranged in an enclosed housing attached to the rear end of the head stock of the lathe and which is fitted with a drainage connection. The hollow piston of the chuck motor is operatively controlled through a hollow cylinder extension attached to the cylinder and which is provided with a pair of fluid supply ducts, each of which communicates with a chamber of the chuck motor. The ducts open on the outer peripheral surface of the cylinder extension. A slidable annular collar surrounds the cylinder extension and defines therewith an annular space. The collar is connected by a conduit to a source of fluid under pressure and is axially shiftable by a control means into communication with one or the other of the openings to the ducts leading to the chambers of the chuck motor.