Intrinsically-safe roof hazard alert module

• US 6,469,619 B1
• Filed: 11/09/2000
• Issued: 10/22/2002
• Est. Priority Date: 04/20/1999
• Status: Expired due to Fees

• Current Assignee: The United States of America As Represented By The Secretary of Agriculture
• Original Assignee: United States Department Of Health And Human Services
• Inventors: Brautigam, Albert L., Mayercheck, William D.
• Primary Examiner(s): Hofbass, Jeffery
• Assistant Examiner(s): Nguyen, Tai T.
• Application Number:
  US09/673,595
• Time in Patent Office: 712 Days
• Field of Search: 340/331, 340/321, 340/953, 340/691, 340/825.34, 340/825.44, 340/573.1
• US Class Current: 340/331
• CPC Class Codes: E21F 17/18 Special adaptations of signalling or alarm devices for mine lifts B66B; gas-sensitive devices per se G01N
• CPC Class Codes: G08B 21/0213 System disabling if a separation threshold is exceeded disabling electrical appliances in case of unplugging G08B13/1409

Abstract

A light weight, self-contained, portable, intrinsically-safe warning device for providing warning to personnel of an unsafe condition is provided. This warning device is especially adapted for attachment to the roof of a mine to indicate unsupported roof conditions or other unsafe conditions. This intrinsically-safe warning device has (a) a case having side walls, a first end wall, and second end wall wherein the case has an internal cavity formed by the side walls and first and second end walls; (b) a low-voltage power supply within the case comprising one or more direct current batteries; (c) a switch in electrical contact with the low-voltage power supply to activate the module; (d) a light-emitting diode in electrical contact with the switch and the low-voltage power supply, and (e) a means to attach the module in close proximity to or in a hazard area having a potential hazard such that the light is directed towards the area from which personnel are likely to enter the hazard area, wherein the module is lightweight, portable, and intrinsically-safe; whereby, when the module is activated, the light-emitting diode emits a light to warn personnel in the area of the potential hazard and direct their attention to the potential hazard. This device is especially useful in underground mining operations in order to discourage miners from going into unsupported mine roof areas by rendering the attendant hazard more evident, directing the miner'"'"'s attention to an appropriate warning message on the device, and thus avoiding the hazard beyond the device.

Claims

1. An intrinsically-safe hazard alert module for warning personnel of a potential hazard, said module comprising:

(a) a case having side walls, a first end wall, and second end wall wherein the case has an internal cavity formed by the side walls and first and second end walls;

(b) a low-voltage power supply within the case comprising one or more direct current batteries;

(c) a switch in electrical contact with the low-voltage power supply to activate the module;

(d) a light-emitting diode in electrical contact with the switch could the low-voltage power supply operable to produce user visible light;

(e) a means to attach the module in close proximity to or in a hazard area having a potential hazard such that the light is directed towards the area from which personnel are likely to enter the hazard area;

(f) a decal describing the nature of the potential hazard, the decal being attached to the case such that the decal is visible to personnel entering the hazard area; and

(g) at least two rectifiers positioned in series between each battery and the switch;

wherein the module is lightweight, portable, and intrinsically-safe;

whereby, when the module is activated, the light-emitting diode emits a user visible light to warn personnel in the area of the potential hazard and direct their attention to the potential hazard.

2. A module as defined in claim 1, wherein the light-emitting diode is a flasher-type.

3. A module as defined in claim 2, wherein the low-voltage power supply contains at least two batteries of about 2 to 10 volts.

4. A module as defined in claim 2, wherein the light-emitting diode flashes at a rate of about 1 to 5 pulses per second.

5. A module as defined in claim 1, wherein the low-voltage power supply contains at least two batteries of about 2 to 10 volts.

6. A module as defined in claim 1, wherein the case is sealed to prevent the entry of water and/or dust into the case.

7. An intrinsically-safe roof hazard ale module for warning personnel of a potential hazard in an underground mine, said module comprising:

(a) a case having side walls, a first end wall, and second end wall wherein the case has an internal cavity formed by the side walls and first and second end walls;

(b) a low-voltage power supply within the case comprising one or more direct current disposable batteries;

(c) a switch in electrical contact with the low-voltage power supply to activate the module;

(d) a flasher-type light-emitting diode in electrical contact with the switch and the low-voltage power supply operable to produce user visible light;

(e) a means to attach the module in close proximity to or in a hazard area having a potential hazard such that the light is directed towards the area from which personnel are likely to enter the hazard area;

(f) a decal describing the nature of the potential hazard, the decal being attached to the case such that the decal is visible to personnel entering the hazard area; and

(g) at least two rectifiers positioned in series between each battery and the switch;

wherein the module is lightweight, portable, and intrinsically-safe;

whereby, when the module is activated, the light-emitting diode emits a user visible flashing light to warn personnel in the area of the potential hazard and direct their attention to the potential hazard.

8. A module as defined in claim 7, wherein the attachment means allows the module to be attached to a roof bolt.

9. A module as defined in claim 7, wherein the low-voltage power supply contains batteries of about 2 to 10 volts and wherein the light-emitting diode flashes at a rate of about 1 to 5 pulses per second.

10. A module as defined in claim 9, wherein the case is sealed to prevent the entry of water and/or dust into the case.

11. A hard alert module for warning personnel of a potential hazard in a hazard area, the module comprising:

a case having an interior cavity;

an electrical circuit comprising a low-voltage power supply, at least two rectifiers positioned in series, a resistor, a fuse, a light-emitting diode operable to produce user visible light and a switch;

wherein the rectifiers are operable to limit current flow in one direction, thereby avoiding damage to the light-emitting diode operable to produce user visible light and wherein the resistor limits current flow through the rectifiers; and

a decal describing the nature of the potential hazard, the decal being attached to the case such that the decal is visible to personnel entering the hazard area;

wherein the module is intrinsically safe to permit use of the module in an environment containing flammable material.

12. The module as defined in claim 11, wherein the case has an outer wall defining a recess, and an operator for the switch extending through the outer wall and positioned in the recess.

13. The module as defined in claim 11, wherein the case has an outer wall defining a recess, and the light-emitting diode extends through the outer wall and is positioned in the recess.

14. The module as defined in claim 11, further comprising a magnet for magnetically attaching the module to a structure.

15. A hazard alert module for warning personnel of a potential hazard in a hazard area;

the module comprising;

a case having an interior cavity and an outer wall defining a first recess;

a low-voltage power supply disposed with the cavity, the power supply comprising one or more direct current batteries;

a switch in electrical contact with the low-voltage power supply to activate the module, the switch being positioned in the recess;

a light-emitting diode in electrical contact with the switch and the low voltage power supply, the light-emitting diode being operable to produce user visible light;

a decal describing the nature of the potential hazard, the decal being attached to the case such that the decal is visible to personnel entering the hazard area; and

at least two rectifiers positioned in series between each battery and the switch;

wherein the module is intrinsically safe to permit use of the module in an environment containing flammable material.

16. The module as defined in claim 15, wherein the outer wall further comprises a second recess, the light-emitting diode being positioned in the second recess.

17. The module as defined in claim 15 further comprising a magnet for magnetically attaching the module to a structure.