# US 5,701,856 A · Separate oiling type two cycle engine

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- Number: US 5,701,856 A
- Document ID: US5701856A
- Status: Granted
- Kind: A
- Application number: 08/755,898
- Filed: 1996-12-02
- Granted: 1997-12-30
- Earliest claimed: 1995-12-28
- Assignees: Fuji Jukogyo Kabushiki Kaisha
- Inventors: Toshihiro Nagano; Yoshiaki Sato; Jun Nishimori; Fusao Tachibana
- Web page: https://patentgrep.com/patent/US5701856A

## CPC

- F01M 3/00: Lubrication specially adapted for engines with crankcase compression of fuel-air mixture or for other engines in which lubricant is contained in fuel, combustion air, or fuel-air mixture (separating lubricant from air or fuel-air mixture before entry into cylinder F01M11/08)
- F02M 17/04: having fuel inlet valve controlled by diaphragm
- F02B 2075/025: {two}
- F01M: LUBRICATING OF MACHINES OR ENGINES IN GENERAL; LUBRICATING INTERNAL COMBUSTION ENGINES; CRANKCASE VENTILATING
- F02M: SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
- F02B: INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL (gas-turbine plants F02C; hot-gas or combustion-product positive-displacement engine plants F02G)

## Abstract

A separate oiling type two cycle engine having a diaphragm type float-less carburetor including a metering chamber and a needle valve comprises a fuel reservoir for reserving fuel, a fuel supply port provided at the fuel reservoir for supplying fuel into the fuel reservoir, a fuel passage for connecting the fuel reservoir with the needle valve, a venturi provided immediately upstream of the needle valve, an oil discharge port provided adjacent to the inlet of the venturi for discharging lubricating oil therethrough so as to mix lubricating oil with fuel, and a fuel return port provided at the higher position than the fuel supply port for returning fuel to a fuel tank. Since lubricating oil is supplied to almost all major components of the carburetor, carburetor components such as a choke valve, a throttle valve, fuel passages, jets, metering needles, nozzles and the like can be prevented from being corroded, rusted or clogged by salt water contained in fuel.

## Claims

### Claim 1

A separate oiling type two cycle engine having a diaphragm type float-less carburetor, a fuel tank and a fuel pump, said carburetor including a metering chamber for metering fuel, a needle valve for regulating a fuel flow into said metering chamber and a diaphragm for operating said needle valve, comprising:
a fuel reservoir for reserving a fuel;
a fuel supply port provided at said fuel reservoir for supplying said fuel into said fuel reservoir;
a fuel passage for connecting said fuel reservoir with said needle valve;
an oil discharge port provided adjacent to the inlet of said needle valve for discharging a lubricating oil therethrough so as to mix said lubricating oil with said fuel; and
a fuel return port provided at a higher position than said fuel supply port for returning said fuel to said fuel tank.

### Claim 2

A separate oiling type two cycle engine having a diaphragm type float-less carburetor, a fuel tank and a fuel pump, said carburetor including a metering chamber for metering fuel, a needle valve for regulating a fuel flow into said metering chamber and a diaphragm for operating said needle valve, comprising:
a fuel reservoir for reserving a fuel;
a fuel supply port provided at said fuel reservoir for supplying said fuel into said fuel reservoir;
a fuel passage for connecting said fuel reservoir with said needle valve;
a venturi provided immediately upstream of said needle valve;
an oil discharge port provided adjacent to the inlet of said venturi for discharging a lubricating oil therethrough so as to mix said lubricating oil with said fuel; and
a fuel return port provided at the higher position than said fuel supply port for returning said fuel to said fuel tank.