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. 19, 1991
Filed:
Mar. 30, 1990
Shuji Ohta, Kariya, JP;
Toshiyuki Takeuchi, Kariya, JP;
Kabushiki Kaisha Toyoda Jidoshokki Seisakusho, Kariya, JP;
Abstract
A hydraulic control circuit arrangement for a single-acting cylinder provided with bottom and rod chambers separated by a piston having a piston rod extending the rod chamber, the arrangement including a directional control valve for controlling a supply of an operating oil from a hydraulic pump to the bottom chamber and an evacuation of the operating oil from both the bottom and rod chambers, a first pilot-operated valve for controlling the type of operation of the single-acting cylinder from a ram type to a piston type, and vice versa, in response to a change in an extent of a load applied to the single-acting cylinder during the lifting thereof, a short-circuiting conduit arranged between the bottom and rod chambers of the cylinder to short-circuit a flow of the operating oil from the bottom to rod chamber, and vice versa, a second pilot-operated valve located in the short-circuiting conduit to control the short-circuiting of the flow of operating oil, and a flow control valve for generating a pressure in the bottom chamber of the single-acting cylinder to thereby promote the short-circuiting of the flow of operating oil from the bottom to rod chamber of the single-acting cylinder during the lowering of the cylinder.