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:
Aug. 15, 1989
Filed:
Jun. 23, 1988
Sigurd V Seld, Hamburg, DE;
Joh. Friedrich Behrens AG, Ahrensburg, DE;
Abstract
Pneumatically operated driving tool for fasteners comprising a working cylinder, a working piston within the working cylinder connected to a driver of the like, a stop in the working cylinder limiting the working stroke of the working piston, a control valve adapted to be actuated by a trigger, a working space above the working piston when the piston is in its upper dead point position, the control valve being adapted to alternatingly connecting the working space with a pressurized air source or with atmosphere, respectively, a piston return chamber surrounding the working cylinder and connected thereto by a first opening adjacent the stop, and a second opening spaced from the stop, the working piston having a smaller diameter than the working cylinder. An annular piston is sealingly displaceably located on the driver and sealingly engages the wall of the working cylinder. The annular piston also sealingly engages the working piston in its upper dead point position, the proportion of the effective areas and the masses of the working piston and the driver blade on one side and of the annular piston on the other side being such that the acceleration of the annular piston during the working stroke is not larger than that of the working piston.