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:
Jul. 28, 1992
Filed:
Sep. 07, 1989
Rudolf Schneider, Reinach, CH;
Niklaus Liechti, Reinach, CH;
Erowa AG, Reinach, CH;
Abstract
The driving apparatus for the rotation of the spindle or the work piece pallet of an electroerosive machining device comprises two electric motors which drive e.g. the spindle to a rotational movement by means of two gear boxes and a plurality of gear wheels. In order to avoid any backlash in the gear box and any clearance between the gear wheels and to compensate the elasticity of the gear transmission, the two electric motors are always operated to rotate in opposite directions and/or to yield different values of torque. Thus, the entire transmission assembly is always subjected to a certain bias force so that a precise positioning of the spindle is possible by means of simple and inexpensive driving elements.