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:
May. 28, 2002
Filed:
Apr. 26, 2000
Joel H. Baum, Potomac, MD (US);
David A. Baker, Hillsboro, OR (US);
Credence Systems Corporation, Fremont, CA (US);
Abstract
A test head manipulator for a semiconductor integrated circuit tester includes a support frame, a vertical guide attached to the support frame, a carriage mounted on the vertical guide and movable vertically therealong, a manipulator arm attached to the carriage and projecting therefrom, a counterbalance assembly mounted to the support frame for vertical movement relative thereto, a drum mounted to the support frame for rotation about a horizontal axis, a flexible tension member trained over the drum and having one end connected to the carriage and an opposite end connected to the counterbalance assembly whereby upward movement of the carriage is accompanied by downward movement of the counterbalance assembly and downward movement of the carriage is accompanied by upward movement of the counterbalance assembly, a hand operated power input element at a fixed height relative to the drum, and a force transmission mechanism which couples the power input element to the drum for transmitting manual effort from the power input element to the drum for raising or lowering the carriage.