Patent ID: 6253723
Filing Date: 2001-07-03
Classification: F01L

Abstract:
An automatic valve for reducing compression during start of a two-stroke internal combustion engine, comprising a movable valve (25) adapted to control a gas flow through an opening (16) in a wall of the combustion chamber of the engine, a resilient means (27) for moving said movable valve (25) to an open position, and a driver actuated by an underpressure and adapted to move said movable valve (25) to a closed position against the action of said resilient means (27), wherein the driver comprises a cylinder (18) and a piston (19), said piston being movable in said cylinder (18) and connected to said movable valve (25), a conduit (22) connects said cylinder (18) to a source of underpressure, a one-way valve (23) is provided in said conduit (22) for allowing air flow in a direction away from said cylinder (18) and for preventing air flow in a direction toward said cylinder, and a leak passage (30) adapted to allow a small flow of atmospheric air into said cylinder (18) to facilitate opening of said movable valve (25) when the operation of the engine has been stopped.