US 4,696,264 A · Two-stroke engine

Abstract

A two-stroke engine is disclosed which is controlled by a carburetor throttle valve and has a crankcase subjected to continuously alternating overpressure and underpressure. A pneumatic control member responsive to a signal dependent on the rotational speed of the engine is in pressure communication with the inner chamber of the crankcase via a valve. The output member of the pneumatic control member is connected with the throttle flap of the carburetor. The valve provided between the crankcase and the pneumatic control member is responsive to a signal for controlling the pressure in the pneumatic control member. This valve can be configured as a resonance control valve fixedly mounted to the housing of the engine. The resonance control valve has a mass oscillator which, at a correspondingly high engine speed and as a result of the vibration frequency associated therewith, acts upon a sealing diaphragm in the resonance control valve to open a pass-through opening communicating with the pneumatic control member.

Claims9

Dependent claims

A two-stroke engine equipped with a control device to control an operating condition of the engine, the engine comprising:

a crankcase subjected to continuously alternating underpressure and overpressure conditions;
an output actuator connected to said control device for adjusting said operating condition;
pneumatic actuating means responsive to a change in pressure therein for acting on said output actuator so as to cause the latter to adjust said control device to control said operating condition;
pressure connecting means for connecting said pneumatic actuating means to said crankcase;
and,
resonance valve means connected into said pressure connecting means for opening the latter in response to a predetermined resonance frequency thereby subjecting said pneumatic actuating means to one of said pressure conditions and causing a pressure change therein.

3 more elements

A two-stroke engine having a predetermined resonance frequency and being equipped with a carburetor controlled by a throttle flap, the engine comprising:

a crankcase subjected to continuously alternating underpressure and overpressure conditions;
an output actuator connected to said throttle flap of the engine for adjusting the speed thereof;
pneumatic actuating means responsive to a change in pressure therein for acting on said output actuator so as to cause the latter to adjust the position of said throttle flap thereby changing the speed of the engine;
pressure conduit means for connecting said pneumatic actuating means to said crankcase;
and,
resonance valve means connected into said pressure conduit means for opening the latter in response to a predetermined resonance frequency thereby subjecting said pneumatic actuating means to one of said pressure conditions and causing a pressure change therein.

3 more elements

Dependencies are inferred from the claim text.

Two-stroke engine

Life of this patent

Two-stroke engine

Life of this patent

Abstract

Claims9