Motor chain saw having a guide bar clamped between the housing and a clamping piece

US4999918A · kind A · utility

Assignee

• Andreas Stihl AG & Co. KG · DE

Inventors

• Harald Schliemann · Waiblingen, DE
• Michael Wissmann · Markgröningen, DE

Key dates

• Filing date: Dec 11, 1989
• Grant date: Mar 19, 1991
• Expiry date: Dec 11, 2009

Classification

• Technology area (CPC F): Mechanical Engineering; Lighting; Heating
• CPC primary: F16B5/02
• WIPO field: Mechanical elements
• WIPO sector: Mechanical engineering

Abstract

The invention relates to a motor chain saw having a guide bar clamped between the housing and a clamping piece. The chain saw has a drive motor arranged in a housing and the drive motor drives a saw chain running on a guide bar. The guide bar is clamped to the housing at one end between the housing and a clamping piece with the clamping being transverse to the plane of the guide bar. For tensioning the saw chain, the guide bar is displaceable in the longitudinal direction thereof by means of a chain tensioning device when the clamping piece is loosened. If high forces act on the guide bar, then the latter slips toward the sprocket wheel in the longitudinal direction notwithstanding the fact that the guide bar is clamped to the housing. Accordingly, the saw chain must be again tensioned by means of the chain tensioning device. According to a feature of the invention, at least one of the surfaces between the end of the guide bar and the housing or between the clamping piece is treated to increase friction whereby higher forces can act on the clamping connection for the same clamping force without effecting a displacement of the guide bar. It then becomes unnecessary to retension the …