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:
Jun. 06, 1989
Filed:
Dec. 19, 1986
Applicant:
Inventors:
Assignee:
Other;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
E21B / ;
U.S. Cl.
CPC ...
1731621 ; 74603 ;
Abstract
A handheld portable tool has a drive unit connected to the handle via damping elements. The drive unit includes an internal combustion engine having a crankshaft. To reduce the vibration transmitted by the drive unit to the handles, a static or dynamic imbalance of defined position and quantity is provided on the crankshaft of the engine, as a result of which vibration in the handles is considerably reduced. An imbalancing weight may for instance be provided in the fan wheel, so that the crankshaft and its elements are manufactured and balanced in the same manner as before, and only the fan wheel has to be structurally modified.