Patent · US Expired

Portable handheld motor tool having a one-piece fan housing

US4970993A · kind A · utility

7Cited by

3References

8Claims

0Family size

Assignee

Andreas Stihl AG & Co. KG · DE

Inventors

Hermann Weiss · Hamburg, DE
Siegfried Frank · Bergstadt Bad Grund, DE
Wolfgang Kirtz · Winnenden, DE
Luise Stephani · Bad Marienberg, DE

Key dates

Filing date	Mar 15, 1990
Grant date	Nov 20, 1990
Priority date	—
Expiry date	Mar 15, 2010

Classification

Technology area (CPC F)Mechanical Engineering; Lighting; Heating
CPC primaryF02B2075/025
WIPO fieldEngines, pumps, turbines
WIPO sectorMechanical engineering

Abstract

The invention relates air-cooled combustion engine powered handheld tool. A fan screen has radial struts and tranverse walls which together define windows. The effective intake suction area of the fan is less than the area of the screen. Wood chips and the like are kept out by the size of the windows and the reduced air flow velocity through the screen.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.