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. 30, 1991
Filed:
Mar. 29, 1990
Robert Messinger, Palmerton, PA (US);
Other;
Abstract
This invention provides improved body length adjustment value structure for a vacuum powered lifting system of the type that embodies a variable length lifting body responsive to the differential of pressure inside that body with atmospheric pressure to resolve critical manual control problems. Thus control is provided by proportional movement of a control member over a substantially linear range producing a smooth progressive movement of the lifting mechanism. This permits non-critical lowering and release of a work load object by unskilled operators. Thus, an air injection valve with an air release port, is positioned within the lifting body having an elongated slot operable over a control range proportionately change the body length by release of a progressively increasing flow of air into the body to increase air pressure and body length over the critical range of lowering and releasing the work load object in response to a corresponding substantially linear movement of the control member. Variable adjustment value structure establishes a known upper lift limit by control of the length of the body both under loaded and unloaded conditions, and provisions are made to keep a vacuum responsive work object grasping mechanism continuously operable.