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. 09, 2017
Filed:
Mar. 21, 2013
Hitachi Power Solutions Co., Ltd., Ibaraki, JP;
Hitachi Construction Machinery Co., Ltd., Tokyo, JP;
HITACHI POWER SOLUTIONS CO., LTD., Ibaraki, JP;
HITACHI CONSTRUCTION MACHINERY CO., LTD., Tokyo, JP;
Abstract
A pantograph device of a trolley-type truck includes: a base frame; a bottom frame rockably attached to the base frame; a top frame rockably attached to the vicinity of the top end portion of the bottom frame through a connecting shaft; a collector shoe rockably supported in proximity to the top end portion of the top frame; a hydraulic cylinder for raising and lowering the bottom frame, attached to the base frame; and a spring which acts so as to rotate the top frame upward through the connecting shaft. By erecting the bottom frame by the hydraulic cylinder, the tensile force produced in the spring is increased and the top frame is rotated upward through the connecting shaft. This makes it possible to obtain a wide movable range without use of a long and strong spring and enhance the followability to overhead wires without increasing pressing force.