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:
Apr. 26, 2016
Filed:
Sep. 11, 2013
Abb Technology Ltd, Zurich, CH;
Per Krainer, Ludvika, SE;
Harald Hedsten, Grängesberg, SE;
ABB TECHNOLOGY LTD, Zurich, CH;
Abstract
An actuator for a tap changer of an electrical transformer, including: a piston, being hollow to define a piston space; a cylinder arranged around the piston such that the piston is arranged to be movable axially into and out of the cylinder; a piston ring fixed to the outside surface of the piston such that a cylinder space is formed between the piston and the cylinder and delimited by the piston ring, the cylinder space having a variable volume which is configured to vary with axial movement of the piston; and a spring engaging both the piston and the cylinder such that the spring is able to be compressed and elongated, respectively, with axial movement of the piston. The piston space is connected to the cylinder space via at least one hole through the hollow piston. The piston space is connected to an outside of the piston.