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. 22, 1979
Filed:
Aug. 16, 1977
Jerry W Allen, Greensboro, NC (US);
Herbert G Cooper, Charlotte, NC (US);
A. S. K. Elevator Service, Inc., Greensboro, NC (US);
Abstract
A hydraulically operable elevator having a vertically reciprocable cab suspended from an overhead structure by differential hydraulic piston systems which are responsive to introduction of hydraulic fluid to decrease the overall length of the differential pistons causing the cab to ascend, and which are responsive to withdrawal of hydraulic fluid from the piston assemblies to increase the overall length of the differential pistons, allowing the cab to descend. Only one differential piston assembly is required on each side of the transverse axis of the cab to increase its stability and to provide maximum cross-sectional area for the interior of the cab.