Machine tool head having nutating spindle

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NEW PATENTS This Sectioncontainsabstracts and, where appropriate, illustrationsof recentlyissued United States patents and published patent applications filed from over 30 countries under the Patem Cooperation Treaty. This information was obtained from recent additionsto the Pergamon PATSEARCH®online database in accordance with interest profiles developed by the Editors. Furlher information about Pergamon PATSEARCH®can be obtained from Pergamon International Information Corporation, 1340 Old Chain Bridge Road, McLean, Virginia 22101 U.S.A. Copies of complete patents announcedin this Sectionare availablefrom PergamonInternationalInformationCorporation for $8 per copy. Paymentwith order is required. Orders outside North America add $2 for air postage. Order by patent number from Pergamon International only. 4417379

A machine tool head having a spindle nutatable about a center at the front of the spindle and at or closely adjacent to the front face of the machine tool head so that the radial reaction to the cutting forces is transmissible from the spindie to the machine-tool head essentially in the plane of the front face of the machine tool head.

is used with power-operated chucks and provides reliable and effective compensation for the effect of centrifugal force, which otherwise tends to reduce gripping force on the workpiece. The control includes a static adjust signal generator, for establishing the desired level of gripping force upon the workpiece, and a rotation speed responsive signal generator, for generating a signal which is a function of the square of the rotational speed. These two signals are combined and serve to actuate a servo valve to control hydraulic pressure delivered to the power operated chuck. Hydraulic pressure increases with increased rotational speed, in order to maintain chucking force at a constant level. A feedback circuit detects the level of hydraulic pressure and compares to the combined signals, developing a fault signal where the output hydraulic pressure does not agree with the signal delivered to the controlling servo valve. The circuit includes a redundant, parallel system for generating static and dynamic signals, cornbiningthem and comparing them to the primary combined signals. The redundant system prevents an unintended loss of chucking force in the event of failure of any of the primary signal generating components.

4414871

4414732

CHUCK FORCE MODULATOR SYSTEM FOR ROTARY TYPE MACHINE TOOL

MACHINE TOOL WITH AUTOMATIC TOOL CHANGE FUNCTION

MACHINE

TOOL

NUTATING

HEAD HAVING SPINDLE

Keith F Goode assigned to The Ingersoll Milling Machine Company ~,

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David Trout assigned to White Consolidated Industries Inc

Tamaki Tomita, Yoshikaz Sano, Kunimichi Nakashima, Okazaki, Japan assigned to Toyoda Koki Kabushiki Kaisha

The disclosure relates to an improved chuck force control and compensating means for rotary machine tools, such as lathe. The control

In a machine tool with an automatic tool change function, a rotatable tool spindle carries a key 71