# US 5,706,776 A · Fuel tank backfilling system for vehicles

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- Number: US 5,706,776 A
- Document ID: US5706776A
- Status: Granted
- Kind: A
- Application number: 08/802,480
- Filed: 1997-02-20
- Granted: 1998-01-13
- Earliest claimed: 1997-02-20
- Inventors: Elmer L. Luehring
- Web page: https://patentgrep.com/patent/US5706776A

## CPC

- B60K 15/035: characterised by venting means
- B60K 2015/03381: {for preventing explosions}
- B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES

## Abstract

A backfilling system for a liquid fuel tank of a vehicle using engine exhaust gas to prevent the accumulation of explosive vapors in the fuel tank. Exhaust gas is cooled, filtered and regulated in pressure before entering the fuel tank.

## Claims

### Claim 1

An apparatus for moving a load from place to place comprising:
a. a rigid tank containing a liquid fuel that is delivered to an internal combustion engine, said engine producing by-product exhaust gas incapable of supporting combustion and wherein said tank having a vent; and
b. a duct that can carry exhaust gas at near atmospheric pressure from a vented chamber supplied with said gas from said engine exhaust whereby said exhaust gas occupies space created by depletion of liquid fuel used by said engine.

### Claim 2 (depends on 1)

The apparatus according to claim 1 wherein said duct is a tube.

### Claim 3 (depends on 1)

The apparatus according to claim 1 wherein said duct further including a filtering means for removing particulate matter from the exhaust gas.

### Claim 4 (depends on 1)

The apparatus according to claim 1 wherein said duct further including a pressure regulating system for controlling the pressure of the exhaust gas as it enters said fuel tank and a pressure relief system for venting excess fuel vapor.

### Claim 5 (depends on 2)

The apparatus according to claim 2 wherein said tube is made of metal.

### Claim 6 (depends on 3)

The apparatus according to claim 3 wherein said filter is composed of a porous ceramic element.

### Claim 7 (depends on 2)

The apparatus according to claim 2 wherein said tube is of a length whereby the exhaust gas is effectively cooled to the ambient temperature of said fuel tank.

### Claim 8 (depends on 3)

The apparatus according to claim 3 wherein said filter is composed of a porous metallic element.

### Claim 9 (depends on 3)

The apparatus according to claim 3 wherein said filter is a fibrous element.

### Claim 10

A fuel tank backfilling system for an internal combustion engine comprising:
a. a fuel tank;
b. a combustion engine producing exhaust gas, wherein said exhaust gas is provided to said fuel tank which is emptying during use of said engine;
c. a gas duct; and
d. a vented chamber, wherein said vented chamber receives said exhaust gas from said internal combustion engine and said gas duct receives said exhaust gas from said vented chamber, wherein said vented chamber designed to minimize the difference in pressure between the atmosphere and said gas duct under varying operating conditions of said engine and wherein said exhaust gas passes through said gas duct from said vented chamber to said fuel tank.

### Claim 11

A fuel tank backfilling system comprising:
a. an internal combustion engine producing by-product exhaust gas;
b. a fuel tank, wherein said fuel tank supplying liquid fuel to said internal combustion engine;
c. an atmospheric vented duct chamber;
d. a duct, wherein said atmospheric vented duct chamber provides pure exhaust gas at near atmospheric pressure to a cooling duct from said internal combustion engine;
e. a filter; and
f. a regulating valve, wherein said cooling duct carrying said exhaust gas to said filter and said regulating valve and then to top of said fuel tank that contains the liquid fuel supplying said internal combustion engine and wherein said fuel tank being separately vented at the top by a pressure relief valve.