Overflow prevention mechanism for liquid transfer systems

• US 6,584,997 B1
• Filed: 03/30/1998
• Issued: 07/01/2003
• Est. Priority Date: 03/30/1998
• Status: Expired due to Fees

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Blichmann, John R., Kloeblen, Scott A.
• Primary Examiner(s): Walton, George L.
• Application Number:
  US09/050,688
• Time in Patent Office: 1,919 Days
• Field of Search: 417/36, 417/41, 417/44.1, 417/44.4, 417/44.11, 417/45, 137/392, 137/454, 141/198, 123/198.D, 123/510, 123/511, 307/118, 361/178
• US Class Current: 137/392
• CPC Class Codes: F02D 33/003 Controlling the feeding of liquid fuel from storage containers to carburettors or fuel-injection apparatus control of electrical fuel pumps F02D41/3082, controlling fuel flow to a common rail F02D41/3845; Failure or leakage prevention; Diagnosis or detection of failure; Arrangement of sensors in the fuel system; Electric wiring; Electrostatic discharge
• CPC Class Codes: F02M 37/007 characterised by its use in vehicles, in stationary plants or in small engines, e.g. hand held tools
• CPC Class Codes: F02M 37/0088 Multiple separate fuel tanks or tanks being at least partially partitioned
• CPC Class Codes: G05D 9/12 characterised by the use of electric means
• CPC Class Codes: Y10T 137/7306 Electrical characteristic sensing

Abstract

An overflow prevention mechanism for use in association with liquid transfer systems of the type including an electrically controllable flow control device such as a pump connected between a source of liquid and a liquid tank, the mechanism including a backup liquid level sensor and a shunt trip breaker or other normally-closed switching device. The backup liquid level sensor senses if the level of liquid within the tank reaches an extreme high level. When the liquid level within the tank reaches the extreme high level the backup liquid level sensor produces an output indicative of the liquid having reached such extreme high level. The shunt trip breaker is connected between the source of electrical energy and the flow control device. The shunt trip breaker is operatively connected to the backup liquid level sensor so as to respond to the production of the backup liquid level sensor output by opening, thereby disconnecting the flow control device from the electrical energy source when the liquid level within the tank reaches the extreme high level.

Claims

1. A liquid transfer system for repeatedly transferring a liquid from a main liquid source to a container while preventing overflow of the container, the system comprising:

a liquid path fluidly connecting the main liquid source to the container;

an electrically controllable flow control device positioned along the liquid path for enabling controlled delivery of liquid through the liquid path from the main liquid source to the container along the liquid path;

a first liquid level sensor operatively positioned relative to the container for sensing when the level of liquid within the container rises to a predetermined high level;

a second liquid level sensor operatively positioned relative to the container for sensing when the level of liquid within the container rises to a predetermined extreme high level;

a normally-closed switching device electrically connected between a source of electrical energy and the electrically controllable flow control device; and

a normally-open switching device electrically connected between the normally-closed switching device and the electrically controllable flow control device;

the second liquid level sensor being operatively connected to the normally-closed switching device for effecting the opening thereof when the level of liquid in the container reaches the predetermined extreme high level.

2. The liquid transfer system, as set forth in claim 1, wherein the liquid level sensor responsively produces an output indicative of the level of liquid within the container having risen to the predetermined extreme high level, the system further comprising:

a controller connected to the liquid level sensor for receiving the extreme high level indicative output therefrom, the controller connected to the normally-closed switching device and responsively applying a control signal to the normally-closed switching device upon receipt of the extreme high level indicative output, the control signal effecting the opening of the normally-closed switching device.

3. The liquid transfer system, as set forth in claim 2, wherein the liquid level sensor is operable to produce an output signal having a parameter which varies as the level of fuel in the fuel tank varies, and the controller is operable to apply the control signal to the normally-closed switching device when the output signal parameter reaches a predetermined level.

4. A fuel transfer system for repeatedly transferring fuel from a main fuel source to a fuel tank and preventing overflow of the fuel tank as a result of such fuel transfer, the system comprising;

a fuel path fluidly connecting the main fuel source to the fuel tank;

an electrically controllable flow control device positioned along the fuel path for enabling controlled delivery of fuel through the liquid path from the main fuel source to the fuel tank along the fuel path;

a normally-open switching device electrically connected between a source of electrically energy and the electrically controllable flow control device;

a normally-closed switching device electrically connected in series between the source of electrical energy and the normally-open switching device;

a fuel level sensor operatively positioned relative to the fuel tank for sensing a level of fuel within the fuel tank and producing an output indicative of such level;

an electronic controller electrically connected to the fuel level sensor for receiving the output therefrom, the normally-open switching device for controlling the closing and opening thereof, and the normally-closed switching device for controlling the opening thereof, the controller being operative to open the normally-closed switching device when the controller receives the output from the fuel level sensor, the opening of the normally-closed switching device removing the source of electrical energy from the normally-open switching device.

5. The fuel transfer system, as set forth in claim 4, further comprising a second fuel level sensor, and a third fuel level sensor, the second and third fuel level sensors being connected to the electronic controller, the third fuel level sensor is operable to produce an output indicative of the level of fuel within the tank having fallen to a third predetermined level, the second fuel level sensor is operable to produce an output indicative of the level of fuel within the tank having risen to a second predetermined level which is higher than the third predetermined level, and wherein the fuel level sensor comprises a first fuel level sensor operable to produce an output indicative of the level of fuel within the tank having risen to a first predetermined level which is higher than the second predetermined level.

6. The fuel transfer system, as set forth in claim 4, wherein the fuel level sensor produces an output signal having a parameter which varies as the level of fuel within the fuel tank varies.

7. The fuel transfer system, as set forth in claim 4, wherein the normally-closed switching device comprises a shunt trip breaker and the normally-open switching device comprises a relay.

8. The fuel transfer system, as set forth in claim 4, wherein the main fuel source comprises a bulk fuel tank.

9. The fuel transfer system, as set forth in claim 4, wherein the electrically controllable flow control device comprises a pump which is operated by a motor.

10. The fuel transfer system, as set forth in claim 4, wherein the fuel tank is connected for providing fuel to an internal combustion engine.

11. An overflow prevention mechanism for use in association with a fuel transfer system, the fuel transfer system including a pump fluidly connected between a source of fuel and a fuel tank which may be filled with fuel from the source of fuel by operation of the pump, the pump controlling delivery of fuel through a liquid path between the source and fuel tank, a relay electrically connected between a source of electrical energy and a pump motor which operates the pump, and a fuel level sensor operatively positioned relative to the fuel tank for sensing when the fuel level within the fuel tank reaches a predetermined high level at which it is desired to stop further fuel transfer thereto, the fuel level sensor operatively connected to the relay to effect control thereof, the overflow prevention mechanism comprising:

a backup fuel level sensor for sensing if the level of fuel within the fuel tank reaches an extreme high level which is higher than the predetermined high level and corresponds to a overfilling condition, the backup fuel sensor operable to produce an output when the fuel level within the tank reaches the extreme high level; and

a shunt trip breaker electrically connected in series between the source of electrical energy and the relay, the shunt trip breaker operatively connected to the backup fuel level sensor so as to respond to the production of the backup fuel level sensor output by opening, thereby disconnecting the pump motor from the source of electrical energy when the fuel level within the fuel tank reaches the extreme high level.

12. The overflow prevention mechanism, as set forth in claim 11, further comprising:

a controller; and

wherein the backup fuel level sensor is connected to the controller and the controller is connected to the shunt trip breaker, the controller responsive to the backup fuel sensor extreme high level indicative output to provide a control signal to the shunt trip breaker which effects the opening thereof.

13. The overflow prevention mechanism, as set forth in claim 11, wherein a control input of the shunt trip breaker is directly connected to the backup fuel level sensor.

14. The overflow prevention mechanism, as set forth in claim 11, wherein the fuel tank is connected to provide fuel to an internal combustion engine.

15. A material transfer system for repeatedly transferring a material from a main source to a container while inhibiting the occurrences of undesirable material levels in the container, the system comprising:

a material path physically connecting the main source to the container for delivery of material between the main source and the container;

an electrically controllable flow control device positioned along the material path for enabling controlled delivery of material through the material path from the main source to the container along the material path;

a first material level sensor operatively positioned relative to the container for sensing when a level of material within the container reaches a first predetermined material level;

a second material level sensor corresponding to a second predetermined material level;

a third material level sensor corresponding to a third predetermined material level;

a normally-closed switching device electrically connected between a source of electrical energy and the electrically controllable flow control device; and

a normally-open switching device electrically connected between the source of electrical energy and the electrically controllable flow control device, the normally-open switching device being in series with the normally-closed switching device;

the first material level sensor being operatively connected to the normally-closed switching device for effecting the opening thereof when the level of material in the container reaches the first predetermined material level,

the second and third material level sensors being connected to the electronic controller, the third material level sensor being operable to produce an output indicative of the level of material within the tank having fallen to a third predetermined material level, the second material level sensor being operable to produce an output indicative of the level of material within the tank having risen to a second predetermined material level which is higher than the third predetermined material level, and the first material level sensor is operable to produce an output indicative of the level of material within the tank having risen to the first predetermined material level which is higher than the second predetermined material level.