Patent · US Active

Handheld work apparatus

US8662047B2 · kind B2 · utility

1Cited by

8References

15Claims

0Family size

Assignee

Andreas Stihl AG & Co. KG · DE

Inventors

Predag Ostojic · Bietigheim, DE
Andreas Lingen · Backnang, DE
Michael Schmid · Bern, CH
Jörg Amann · Walheim, DE

Key dates

Filing date	May 6, 2008
Grant date	Mar 4, 2014
Priority date	—
Expiry date	Aug 11, 2031

Classification

Technology area (CPC F)Mechanical Engineering; Lighting; Heating
CPC primaryF02D2400/06
WIPO fieldEngines, pumps, turbines
WIPO sectorMechanical engineering

Abstract

A handheld work apparatus has an internal combustion engine (9, 9′, 9″) and a starter device (8). The internal combustion engine has a piston (10, 10″) which has at least one piston ring (37, 38). In order to avoid a delay when starting the engine, at least one recess is provided in the cylinder bore (26) which bridges the at least one piston ring (37, 38) in at least one position of the piston (10, 10′) and which has a distance (n, o, p) to all function openings of the engine (9, 9′, 9″) configured in the cylinder bore (26). To reduce the compression in the combustion chamber (25), the piston (10′) has only one piston ring (37) or two piston rings (37, 38) are provided having respective piston ring gaps (39, 40) defining an angle (β) which is up to approximately 45°.

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