Citizen Watch Company, Ltd.

Nissin Machine Works, Ltd.

Masakazu Miyashita

Akira Kanai

Toshikazu Hatsuse

Koichi Koizumi

Junichi Yoshioka

Sosaku Kimura

Kazuo Shiba

Mitsuyoshi Nagashima

Masami Shimizu

Michimasa Daito

Fukuo Hashimoto

Takashi Hasebe

A rotary table unit having a stationary base element and a table element rotatably mounted on the stationary base element is provided with hydrostatic and hydrodynamic bearing guides forming a composite bearing guide mechanism for enabling smooth and stable rotation of the table element under application of local load to the table element. The rotary table unit is also provided with a main drive motor for rotating the table element and an auxiliary drive motor for supplementing a drive force of the main drive motor in response to a change in load applied to the table element.

Rotary table unit

A direct-acting table mechanism in which tables are driven without any contact by use of a hydrostatic fluid for thrust-transmitting the tables in their sliding direction. The tables are hydrostatically supported on hydrostatic guides on a bed, and differential pressures are supplied to the hydrostatically supporting portions to control the attitude of the tables. This table mechanism is of high degree of accuracy uninfluenced by errors in the feed screw system, high rigidity and thus permits highly stable fine feed.

Table mechanism for controlling table attitude

A measuring device for oblique angle which is wide in the range of measurement and is high in measuring accuracy, wherein an oblique table is controlled in such a way that the oblique table static-pressure supported is subjected to servo-control so that a detection signal of an oblique angle detector is zero, and an oblique angle is measured by the control signal.

Measuring device for oblique angle

Disclosed is a method of producing a grinding wheel by electroplating. A part of the outer peripheral portion of a grinding wheel body is immersed in a plating solution. While rotating the grinding wheel body at a low speed, electric current is supplied to flow between an anode disposed in the plating solution and a cathode contacting the grinding wheel body, so that a pre-plating layer of uniform thickness is formed on the outer peripheral surface of the grinding wheel body. Plating operation is continued while adhering abrasive grains to the pre-plating layer to further cause a precipitation of a plating layer to temporarily fix the abrasive grains. The abrasive grains are then pressed by a pressing roller so as to be forcibly embedded into the pre-plating layer by making an effective use of plastic deformation of the pre-plating layer, thereby to obtain a uniform projection height of the abrasive grains from the surface of the grinding wheel. Then, a final plating is conducted to finally fix the abrasive grains. Disclosed also is an apparatus suitable for use in carrying out this method.

Method for producing a grinding wheel by electroplating

A servo control system which can automatically control a position of a hydrostatically supported member such as a table of a machine tool, rotary shaft or the like is disclosed. The system comprises a closed loop control system including a differential amplifier for effecting a subtraction operation between an amount of displacement of a member and an amount of reference signal and a servo amplifier delivering a control signal and a servovalve for supplying operating pressure upon receipt of the control signal to the member, whereby the position of the member is controlled by the pressure applied thereto.

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Kokubunji, Japan

Masakazu Miyashita