The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 25, 1991
Filed:
Aug. 28, 1989
Hiroshi Narushima, Konan, JP;
Okuma Machinery Works, Ltd., Nagoya, JP;
Abstract
A feed-screw support structure is adapted to absorb thermal expansion of a feed screw in a machine tool. It comprises a main-body member, a bearing-holder at the one end of the feed screw slidably arranged in the main-body member, a clamping member provided between the bearing-holder member and the main-body member and adapted to fix these members, and a device for operating the clamping member in accordance with factors and matters related to heat generation in the feed-screw. The bearing-holder member being normally held in a stationary condition by the clamping member, the feed screw being allowed to relieve thermal expansion by temporarily releasing the stationary condition when heat generation in the feed screw takes place to a relatively large degree. Alternatively, the structure may comprise a main body member, piezoelectric elements, a bearing case at the one end of the feed screw arranged between the piezoelectric elements and restricted in the axial movement by the bracket of the main-body member, and a device for measuring factors related to heat generation in the feed screw, fine adjustment of the bearing in the axial direction being effected by varying the voltage of the piezoelectric elements.