Safety arrangement for a hand-held, power-driven portable tool

US4543723A · kind A · utility

Assignee

• Andreas Stihl AG & Co. KG · DE

Inventors

• Manfred Bortfeld · Unterschleißheim, DE
• Eberhard Schieber · Backnang, DE
• Gunter Dietzsch

Key dates

• Filing date: May 2, 1983
• Grant date: Oct 1, 1985
• Expiry date: May 2, 2003

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S83/01
• WIPO field: Electrical machinery, apparatus, energy
• WIPO sector: Electrical engineering

Abstract

The invention is directed to a safety arrangement for a power-driven portable tool such as a motor-driven chain saw or the like. The portable tool has a housing equipped with two handles both of which are grasped by the operator to hold and guide the tool during use thereof. One of the handles is a bail handle mounted at the forward part of the housing. The safety arrangement includes two switches associated with respective ones of the handles. The switches are operatively connected to the motor so as to cause the same to be operative only when both switches are closed. At least a portion of one of the contacts of the bail handle switch is displaceable from a first position whereat the bail handle switch is open to a second position whereat the switch contacts come into mutual contact and the bail handle switch is closed. An elastic body associated with the bail handle acts on the one contact to effect the displacement to the second position in response to pressure applied to the elastic body by the operator of the tool when grasping the bail handle.