Abstract: A machining tool is provided with an electric discharge truing/dressing apparatus comprising a spindle stock for containing and supporting a workpiece spindle which is driven for rotation while holding a workpiece or an electrode; a tool rest which moves parallel and perpendicular to the spindle of the spindle stock and holds an electrode machining tool and a grinding wheel; a feed electricity means disposed between a workpiece supporting portion of the spindle and the tool rest; a magazine disposed at an outside area of a machining area of the tool rest and adapted to store the workpiece and the electrode; and a loading device disposed between the magazine and the spindle. The grinding wheel on the tool rest is subjected to truing/dressing by feeding the electrode from the magazine to the spindle stock.

Abstract: A jig has a main body. The main body is provided with a rotatable engaging shaft. The engaging shaft is provided with a main body fixing portion actuator and a workpiece clamping portion actuator. The main body fixing portion actuator is provided with a main body fixing portion drivable by the main body fixing portion actuator. The workpiece clamping portion actuator is provided with a workpiece clamping portion drivable forward and backward by the workpiece clamping portion actuator. When the engaging shaft is rotated, attachment and detachment of the main body and clamping of a workpiece can be performed.

Abstract: A casing is rotatably and stoppably held on tool supporting means, a rotary tool spindle is rotatably supported on the casing so as to have a shifted rotary center with respect to the rotary center of the casing, power transmission means is rotatably supported on the casing, and the power transmission means and the rotary tool spindle are engaged through eccentric engagement means. The movement of the rotary tool in the Y-axis direction is performed by integrally rotating the casing and the rotary tool spindle. The machining is performed by rotating the power transmission means in the state where the casing is held stationary, thereby to rotate the rotary tool with respect to the stationary casing through the eccentric engagement means.

Abstract: A method of grinding a workpiece for shaping it into a cam by imparting a rotary motion and a rocking motion, which conforms to the profile of a master cam, to the workpiece. In the first rough grinding step, a grinding wheel is rapidly entered into the workpiece while the workpiece is rotated at a low velocity. In the second rough grinding step, the grinding wheel is rapidly entered into the workpiece while the workpiece is rotated at a velocity greater than the low velocity. In the third rough grinding step, the wheel is rapidly entered into the workpiece while the workpiece is rotated at a high velocity. Each of the three steps includes a step for removing the portion left uncut in such a state that the infeed of the wheel is ceased. The depths of cut in the three steps DS.sub.1, DS.sub.2 and DS.sub.3, respectively, are so set that the following relation holds:DS.sub.1 >DS.sub.2 >DS.sub.

Abstract: A device for detecting grinding wheel life is provided including a truing tool wear detection device for detecting a total wear amount of a truing tool after every truing operation and an arithmetic and judgement circuit arrangement. The circuit arrangement compensates for the total wear amount by a theoretic in-feed amount through which the truing tool has to have been in-fed from its original position when the grinding wheel is worn down to a predetermined limit. Further, the circuit arrangement calculates an actual in-feed amount of the truing tool and by comparing the actual in-feed amount with the compensated theoretical in-feed amount, judges whether or not the grinding wheel has been worn down to a predetermined limit.

Abstract: A feed safety apparatus for a movable member slidably supported on a stationary bed of a machine tool. A feed device moves the movable member at various speeds. A hydraulic cylinder is fixedly mounted on the movable member and includes a piston slidably received therein. A reference plate member is secured to the bed and operatively connected to the piston for permitting bodily movement of the hydraulic cylinder and the piston within a predetermined distance, but restraining movement of the piston beyond the predetermined distance to cause relative movement between the hydraulic cylinder and the piston. A fluid flow regulating device is disposed between the pair of cylinder chambers of the hydraulic cylinder for restrictively controlling relative movement between the hydraulic cylinder and the piston.

Abstract: A feed control apparatus wherein a servomotor control device responsive to feed pulses distributed from a numerical controller controls a d.c. servomotor to advance a grinding wheel carriage of a grinding machine through the rotation of a feed screw successsively at a speed-up feed rate, a rapid feed rate, a slow-down feed rate and a grinding feed rate. A detection device is provided, which outputs a velocity checking signal to an abnormality confirmation device when the carriage reaches a velocity checking point defined within a slow-down feed range. When confirming that the feed rate of the carriage has exceeded a reference feed rate lower than the rapid feed rate, the abnormality confirmation device applies a stop signal to an emergency stop control circuit in response to the velocity checking signal, so that the rotation of the servomotor is immediately discontinued.