Auxiliary propane fuel tank system for vehicles

• US 6,279,612 B1
• Filed: 08/10/1999
• Issued: 08/28/2001
• Est. Priority Date: 06/24/1998
• Status: Expired due to Fees

• Current Assignee: Spare Tank LLC
• Original Assignee: Spare Tank LLC
• Inventors: Warth, Mitchell W.
• Primary Examiner(s): Chambers, A. Michael
• Assistant Examiner(s): MCSHANE, THOMAS
• Application Number:
  US09/371,228
• Time in Patent Office: 749 Days
• Field of Search: 137/899, 137/351, 137/266, 137/255, 280/834
• US Class Current: 137/899
• CPC Class Codes: B60K 15/013 of gas conduits
• CPC Class Codes: B60K 15/06 characterised by fuel reserve systems
• CPC Class Codes: B60Y 2200/15 Fork lift trucks, Industrial trucks
• CPC Class Codes: B66F 9/07518 Fuel or oil tank arrangements
• CPC Class Codes: Y10T 137/4673 Plural tanks or compartments with parallel flow
• CPC Class Codes: Y10T 137/4857 With manifold or grouped outlets
• CPC Class Codes: Y10T 137/6855 Vehicle
• CPC Class Codes: Y10T 137/6881 Automotive

Abstract

An auxiliary fuel tank system includes a permanent pressure tank for natural gas or propane is mounted on a vehicle such as a fork lift truck. The auxiliary tank is connected through fuel lines to a replaceable portable tank which supplies fuel to the auxiliary tank through check valves and a valve mechanism which may be turned on and off. The auxiliary tank is filled upon initial attachment of the portable tank to the fuel line for the truck. After filling the auxiliary tank, the valve mechanism is closed only to be reopened upon exhaustion of fuel from the portable tank. Fuel lines connect the respective tanks to the engine thereby permitting operation of the engine, even upon exhaustion of fuel from the portable, replaceable tank.

Claims

1. A pressurized propane or natural gas fuel tank system having an auxiliary fuel source for a vehicle having an internal combustion engine, said vehicle from a group comprising fork lift trucks, prime movers, automobiles, trucks and buses, said system comprising, in combination:

a replaceable tank of pressurized fuel removably mounted on the vehicle;

a fuel line from the replaceable tank connecting to the engine of the vehicle;

a first tee in said fuel line having an inlet and two outlets, one of said outlets connected to the fuel line to the engine;

an auxiliary fuel tank permanently mounted on the vehicle;

an auxiliary fuel line from the other outlet of the tee to the auxiliary tank;

a valve mechanism in the auxiliary fuel line operable to open and close the auxiliary fuel line;

a check valve in the lines on each outlet from the tee;

a second auxiliary line connecting from the first auxiliary line intermediate the check valve on the auxiliary line and the valve mechanism; and

at least one check valve in the fuel line from the replaceable tank to prevent flow back of pressurized gas into the replaceable tank whereby the valve mechanism is operable to simultaneously allow fuel flow to the engine and auxiliary tank from the replaceable tank to at least partially fill the auxiliary tank, and subsequently isolate the auxiliary tank, said valve mechanism being further operable to connect the auxiliary tank to the engine when the fuel in the replaceable tank is exhausted.

2. The system of claim 1 further including a second tee having a single outlet to the engine and a first inlet from the one outlet of the first tee and a second inlet from the second auxiliary line.

3. The system of claim 1 wherein the valve mechanism includes a valve in the second auxiliary line.

4. The system of claim 1 including a fuel pressure regulator in the fuel line to the engine.

5. The system of claim 1 wherein the valve mechanism is manually operable.

6. In a fork lift truck of the type including an internal combustion engine which uses pressurized propane or natural gas fuel, said truck including a removable fuel tank mounted on a simultaneously closed, and then being opened upon depletion of fuel in the main tank to allow fuel to flow to the engine from the auxiliary tank.

7. A fork lift truck auxiliary, pressurized gas fuel tank system for a fork lift truck of the type having a main, removable, pressurized propane gas or natural gas tank, and an internal combustion engine comprising, in combination:

a main fuel tank line from the main tank to the engine;

a tee connection in the main line with an inlet from the main tank, a first outlet to the engine, and a second outlet;

an auxiliary line from the second outlet;

an auxiliary pressurized fuel tank mounted on the fork lift connected to the auxiliary line;

a check valve in the main line between the main tank and tee inlet to preclude gas flow into the main tank; and

a valve mechanism in the auxiliary line between the second outlet and the auxiliary tank

whereby when the main tank is connected, the valve mechanism is initially open to fill and pressurize the auxiliary tank with fuel, then subsequently closed to retain auxiliary fuel and then opened again to provide auxiliary fuel through the second tee outlet and thence the first tee outlet to the main fuel line.

8. A fork lift truck auxiliary, pressurized gas fuel tank system for a fork lift truck of the type having a main, removable pressurized propane or natural gas fuel tank and an internal combustion engine, comprising, in combination:

a main fuel tank line from the main tank to the engine;

a tee connection in the main line with an inlet from the main tank, a first outlet to the engine, and a second outlet;

a first check valve in the main line from the first outlet to permit fuel flow to the engine;

an auxiliary tank inlet line from the second outlet to a pressurized gas fuel auxiliary tank;

a second check valve in the auxiliary tank inlet line to permit fuel flow to the auxiliary tank; and

a secondary fuel source line to the engine from the auxiliary line connected intermediate the second check valve and a valve mechanism the valve mechanism in the secondary fuel source line to open and close the line to the engine;

whereby the auxiliary fuel line and tank are filled when a filled, pressurized main tank is connected to the main line to thereby fill the auxiliary tank, said valve mechanism being simultaneously closed, and then being opened upon depletion of fuel in the main tank to allow fuel to flow to the engine from the auxiliary tank.

9. The system of claim 8 further including a tee connection between the secondary fuel source line, the main fuel source line and the engine.

10. The system of claim 9 including a fuel pressure regulator in the line to the engine.

11. A system for automatically storing in a spare pressurized fuel tank a reserve of pressurized propane or compressed natural gas from a removably mounted main pressurized fuel tank for later use, the spare tank being permanently mounted to a vehicle having an internal combustion engine, the system comprising:

a first pressurized fuel line from the main tank;

a first tee having an inlet connected to the fuel line from the main tank and first and second outlets;

a second pressurized fuel line connected to the first outlet of the first tee, coupled to the engine, including a first check valve for allowing unidirectional flow of pressurized fuel from the main tank to the engine and a second tee, the second tee having

an inlet coupled to the outlet of the first check valve,

an inlet coupled to the outlet of a valve mechanism, and

an outlet coupled to the engine;

a third pressurized fuel line connected to the second outlet of the first tee, coupled to the spare tank, including a second check valve for allowing unidirectional flow of pressurized fuel from the main tank to the spare tank and a third tee having

an inlet coupled to the outlet of the second check valve,

an outlet/inlet coupled to the spare tank, and

an outlet coupled to the inlet of the valve mechanism such that

the second check valve allows pressurized fuel to flow automatically from the main tank to the spare tank when the pressure in the main tank exceeds the pressure in the spare tank,

the valve mechanism and the second check valve contain the pressurized fuel in the spare tank while the valve mechanism is closed,

the valve mechanism allows pressurized fuel from the spare tank to flow to the engine when the valve mechanism is open, and

the first check valve prevents pressurized fuel from the spare tank from flowing back to the main tank when the valve mechanism is open.

12. The system of claim 11 wherein the valve mechanism is manually operable.