Signaling device and method of alerting a work machine operator to a predetermined condition using same

• US 20070103327A1
• Filed: 11/09/2005
• Published: 05/10/2007
• Est. Priority Date: 11/09/2005
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: Zimmermann, Daniel
• Granted Patent: US 7,508,315 B2
• Time in Patent Office: Days
• US Class Current: 340/652
• CPC Class Codes: G01R 31/54 Testing for continuity
• CPC Class Codes: G08B 21/185 Electrical failure alarms
• CPC Class Codes: H02H 3/24 responsive to undervoltage or no-voltage H02H3/207 takes precedence

Abstract

A signaling device includes an electrical circuit which discharges an electrical energy storage device through an electrically powered alert mechanism via a biased open transition switch upon disruption of electrical power in an electrical system of a work machine. A work machine is further provided having an alert device coupled with a normally closed electrical power circuit, the alert device being activated upon opening of the normally closed electrical circuit via a transistor switch. An associated method includes using the signaling device to alert a work machine operator to a predetermined condition by closing a normally open electrically switch to connect an electrical energy storage device with an electrically powered alert mechanism, via an electronic controller or via interruption of electrical power in a normally closed electrical circuit of a work machine.

Claims

1. A signaling device comprising:

a housing;

a portion of an electrical circuit configured to connect with an electrical power supply and being disposed at least partially within said housing, said portion of an electrical circuit including an alert mechanism, an electrical energy storage device and an electrical switch operable to selectively connect said alert mechanism with said electrical energy storage device and having an open/closed state based at least in part on an electrical power supply voltage.

2. The signaling device of claim 1 wherein said electrical switch comprises a biased open electrical switch.

3. The signaling device of claim 2 wherein said electrical switch comprises a transistor switch, and further comprising a switch biasing resistor operable to bias open said transistor switch and configured to connect with first and second input/output lines of the electrical power supply.

4. The signaling device of claim 3 wherein said transistor switch comprises a p-channel FET.

5. The signaling device of claim 2 further comprising first and second electrical connection leads for connecting with first and second terminals of said electrical power supply, said electrical switch comprising a transistor switch having a gate/base coupled with said first electrical connection lead.

6. The signaling device of claim 5 wherein said first electrical connection lead is a positive terminal connection lead.

7. The signaling device of claim 6 further comprising:

a circuit breaker coupled with said portion of an electrical circuit and operable to interrupt electrical communication between said electrical energy storage device and said electrical power supply;

a zener diode disposed between said first and second electrical connection leads to control a voltage in said portion of an electrical circuit; and

a Schmitt trigger disposed between the gate/base of said transistor switch and said first electrical connection lead.

8. The signaling device of claim 5 further comprising a normally closed power supply circuit that includes said portion of an electrical circuit and having positive and negative terminals coupled with said first and second electrical connection leads, respectively.

9. The signaling device of claim 8 wherein said electrical energy storage device comprises a capacitor configured to store electrical energy supplied via said power supply circuit.

10. The signaling device of claim 9 wherein said alert mechanism comprises an audible alert mechanism.

11. A work machine comprising:

an electrical system; and

a signaling device operably coupled with said electrical system and including an electrical energy storage device, an alert mechanism and a normally open electrical switch disposed between said electrical energy storage device and said alert mechanism, said electrical switch having an open/closed state based at least in part on an electrical system voltage.

12. The work machine of claim 11 wherein:

said electrical system comprises a power supply including first and second input/output lines coupled with said signaling device; and

said electrical switch comprising a biased open transistor switch having a gate/base coupled with one of said input/output lines and being configured to close upon de-coupling from said power supply.

13. The work machine of claim 12 wherein:

said electrical energy storage device comprises at least one of a battery and a capacitor; and

said electrical switch comprises a p-channel FET disposed between said electrical energy storage device and said alert mechanism.

14. The work machine of claim 13 further comprising at least one pre-determined condition monitor and an electronic controller in communication therewith, said electronic controller being configured to selectively de-couple said signaling device from said power supply based on a control signal or a control signal failure between said electronic controller and said at least one pre-determined condition monitor.

15. The work machine of claim 13 wherein said electronic controller includes a startup diagnostic algorithm operable to temporarily de-couple the power supply from the signaling device during initialization.

16. The work machine of claim 11 wherein:

said electrical system comprises a normally closed electrical circuit having first and second input/output lines including a positive terminal and a negative terminal;

said electrical switch is a normally open transistor switch having a gate/base coupled with said positive terminal and maintained at a normally positive voltage thereby.

17. The work machine of claim 16 further comprising an electronically controlled/monitored redundant work machine steering system coupled with said normally closed electrical circuit, wherein said transistor switch is configured to close upon opening of said normally closed electrical circuit.

18. A method of alerting a work machine operator to the occurrence of a predetermined condition of a work machine comprising the steps of:

supplying electrical power to a normally closed electrical circuit in an electrical system of the work machine; and

closing an electrical switch in a signaling device to electrically connect an electrically powered operator alert device with an electrical energy storage device, if a disruption in electrical power in the normally closed electrical circuit occurs.

19. The method of claim 18 wherein the electrical switch is a transistor switch, the step of closing an electrical switch comprising a step of adjusting a voltage at a gate/base of the transistor switch, if the normally closed electrical circuit is opened.

20. The method of claim 19 comprising the steps of:

monitoring/controlling at least one work machine operating parameter at least in part via an electronic controller; and

opening the normally closed electrical circuit of the signaling device via a control signal from the electronic controller, if the at least one work machine operating parameter meets a predetermined criterion.