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:
Nov. 22, 1994
Filed:
Dec. 31, 1992
Shozo Imanishi, Sagamihara, JP;
Toshihiko Arai, Shiroyama, JP;
Aida Engineering, Ltd., Kanagawa, JP;
Abstract
An apparatus for operating feed bars to move a workpiece between stages of a pressing machine includes cylinder devices. Each of the cylinder devices serves to move the feed bars linearly and each has a respective absolute encoder. The cylinder devices include a feed cylinder device which is responsive to hydraulic pressure to linearly advance and return the feed bars. First and second clamp cylinder devices are responsive to hydraulic pressure to move the feed bars linearly so as to clamp and unclamp the workpiece between the feed bars A hydraulic pressure supply circuit is connected commonly to each of the cylinder devices. Hydraulic pressure is applied to the cylinder devices through respective servo valves of a hydraulic valve arrangement. The servo valves are selectively actuatable to apply the hydraulic pressure from the hydraulic pressure supply circuit to drive the associated cylinder device, and thus the feed bars, with a predetermined stroke and at a predetermined speed in response to a feedback signal from the absolute encoder of the associated cylinder device. A driver control device controls the hydraulic valve arrangement so that the servo valves are actuated in a predetermined sequence. In this way, the feed bars are actuated directly for linear movements with minimum energy.