GB2095810A - Explosion-proof lamp - Google Patents

Explosion-proof lamp Download PDF

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Publication number
GB2095810A
GB2095810A GB8108508A GB8108508A GB2095810A GB 2095810 A GB2095810 A GB 2095810A GB 8108508 A GB8108508 A GB 8108508A GB 8108508 A GB8108508 A GB 8108508A GB 2095810 A GB2095810 A GB 2095810A
Authority
GB
United Kingdom
Prior art keywords
lamp
housing
explosion
coolant
proof
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
GB8108508A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
OSWIETLENIOWEGO POLAM
ZAKLADY SPRZETU
Original Assignee
OSWIETLENIOWEGO POLAM
ZAKLADY SPRZETU
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by OSWIETLENIOWEGO POLAM, ZAKLADY SPRZETU filed Critical OSWIETLENIOWEGO POLAM
Publication of GB2095810A publication Critical patent/GB2095810A/en
Withdrawn legal-status Critical Current

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V25/00—Safety devices structurally associated with lighting devices
    • F21V25/02—Safety devices structurally associated with lighting devices coming into action when lighting device is disturbed, dismounted, or broken
    • F21V25/04—Safety devices structurally associated with lighting devices coming into action when lighting device is disturbed, dismounted, or broken breaking the electric circuit
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V25/00—Safety devices structurally associated with lighting devices
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F21—LIGHTING
    • F21V—FUNCTIONAL FEATURES OR DETAILS OF LIGHTING DEVICES OR SYSTEMS THEREOF; STRUCTURAL COMBINATIONS OF LIGHTING DEVICES WITH OTHER ARTICLES, NOT OTHERWISE PROVIDED FOR
    • F21V25/00—Safety devices structurally associated with lighting devices
    • F21V25/10—Safety devices structurally associated with lighting devices coming into action when lighting device is overloaded, e.g. thermal switch

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Arrangement Of Elements, Cooling, Sealing, Or The Like Of Lighting Devices (AREA)

Abstract

An explosion-proof lamp has a housing 1 filled with an insulating liquid coolant 5. A float switch 6 cuts off the power supply to the lamp bulb 2 if the coolant level falls. A thermal switch 7 cuts off the power if the temperature rises excessively. Cooling fins 8 transfer heat from the coolant 5 to the surrounding atmosphere. <IMAGE>

Description

SPECIFICATION Explosion-proof lamp This invention relates to explosion-proof electric lamps, intended in particular for use in environments preventing special explosion hazards.
Known explosion-proof lamps, for example as described in Polish Patent Specification No.
56548, use air cooling of the space around the light source. These present an explosion hazard if the lamp bowl or housing is broken, as well as because of danger resulting from the possibility of explosion of especially dangerous gas mixtures, for example acetylene, to expand outside.
Furthermore, if the lamp bowl or housing is broken, danger may arise from sparking at internal electrically contacts.
According to the present invention, the interior of an explosion-proof lamp is filled with an insulating liquid coolant which is chemically and physiologically inactive. The coolant is preferably a silicone oil.
The lamp has control means for example a float switch responsive to the liquid coolant level, and a thermal switch immersed in the coolant, to cut off the electrical supply to the light source if the coolant level falls or the temperature rises excessively.
The lamp housing preferably has a side surface shaped as a radiator or heat sink with internal and external fins.
The present lamp ensures adequate transfer of heat from the light source to the environment, and eliminates the risk that sparking at internal contacts might affect an external explosive atmosphere. The lamp is versatile and can be used in many fields for example mining, tanker ships, chemical plant and underwater operations.
An embodiment of the invention is shown by way of example in the accompanying drawing, which shows the lamp partly in longitudinal section.
The illustrated lamp has an explosion-proof housing 1 comprising a transparent bowl. An electric incandescent light bulb 2 is mounted in a bulb holder 3 fixed to a supporting insulator 4 in the housing. The housing has substantially conventional electrical connections for the bulb holder, and a suitable cable entry.
The interior of the explosion-proof housing Is filled with an insulating liquid coolant 5, preferably a silicone oil, which covers the bulb, bulb holder and supporting insulator. The liquid surface level is monitored by a float switch 6 consisting of a movable float carrying a permanent magnet, and a reed relay switch unit attached to the insulator 4. A thermal switch 7 is immersed in the liquid. These switches are connected in series with one another and with the bulb holder.
The sides of the housing form a heat sink or radiator 8, with internal and external fins to transfer heat from the liquid coolant to the surrounding atmosphere. The bowl of the housing is protected by a cage or net 9. The liquid coolant and the fins provide efficient heat transfer from the lamp bulb to the surroundings. The housing is sealed by gaskets made of silicone rubber so as not to react with the silicone oil used as the liquid coolant.
If the housing is damaged so that the coolant can escape, the drop in the coolant level is detected by the float switch 6 which cuts off the power supply to the bulb holder. This eliminates the risk of explosion due to sparking inside the lamp housing.
The thermal switch 7 immersed in the coolant cuts off the power supply when a predetermined temperature is exceeded, for example during a developing fire, thus allowing gradual evacuation.
Claims
1. An explosion-proof lamp comprising a housing, means for mounting an electrical light source in the housing, and an inert electrically insulating cooling liquid in the housing.
2. A lamp as claimed in Claim 1 including control means for the light source responsive to the liquid level in the housing and arranged to deenergize the light source on loss of liquid.
3. A lamp as claimed in Claim 2 further including control means for the light source responsive to the temperature in the housing and arranged to de-energize the light source when the temperatlJre exceeds a predetermined value.
4. A lamp as claimed in Claim 3 in which the control means are a float switch and a thermal switch connected in series with one another and with the light source.
5. An explosion-proof lamp guarded by a protective net and comprising an electric circuit consisting of a light source and two cut-outs connected in series, characterized by an explosion-proof housing of which the interior is filled with an insulating liquid coolant, with a float voltage switch located on the coolant surface and a thermal voltage switch situated at any depth of the coolant.
6. A lamp according to Claim 5, characterized in that the side surface of the explosion-proof housing is shaped as a radiator having internal and external fins.
7. A lamp as claimed in any of Claims 1 to 6, in which the said liquid is a silicon oil.
8. An explosion-proof lamp substantially as herein described with reference to the accompanying drawing.
**WARNING** end of DESC field may overlap start of CLMS **.

Claims (8)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Explosion-proof lamp This invention relates to explosion-proof electric lamps, intended in particular for use in environments preventing special explosion hazards. Known explosion-proof lamps, for example as described in Polish Patent Specification No. 56548, use air cooling of the space around the light source. These present an explosion hazard if the lamp bowl or housing is broken, as well as because of danger resulting from the possibility of explosion of especially dangerous gas mixtures, for example acetylene, to expand outside. Furthermore, if the lamp bowl or housing is broken, danger may arise from sparking at internal electrically contacts. According to the present invention, the interior of an explosion-proof lamp is filled with an insulating liquid coolant which is chemically and physiologically inactive. The coolant is preferably a silicone oil. The lamp has control means for example a float switch responsive to the liquid coolant level, and a thermal switch immersed in the coolant, to cut off the electrical supply to the light source if the coolant level falls or the temperature rises excessively. The lamp housing preferably has a side surface shaped as a radiator or heat sink with internal and external fins. The present lamp ensures adequate transfer of heat from the light source to the environment, and eliminates the risk that sparking at internal contacts might affect an external explosive atmosphere. The lamp is versatile and can be used in many fields for example mining, tanker ships, chemical plant and underwater operations. An embodiment of the invention is shown by way of example in the accompanying drawing, which shows the lamp partly in longitudinal section. The illustrated lamp has an explosion-proof housing 1 comprising a transparent bowl. An electric incandescent light bulb 2 is mounted in a bulb holder 3 fixed to a supporting insulator 4 in the housing. The housing has substantially conventional electrical connections for the bulb holder, and a suitable cable entry. The interior of the explosion-proof housing Is filled with an insulating liquid coolant 5, preferably a silicone oil, which covers the bulb, bulb holder and supporting insulator. The liquid surface level is monitored by a float switch 6 consisting of a movable float carrying a permanent magnet, and a reed relay switch unit attached to the insulator 4. A thermal switch 7 is immersed in the liquid. These switches are connected in series with one another and with the bulb holder. The sides of the housing form a heat sink or radiator 8, with internal and external fins to transfer heat from the liquid coolant to the surrounding atmosphere. The bowl of the housing is protected by a cage or net 9. The liquid coolant and the fins provide efficient heat transfer from the lamp bulb to the surroundings. The housing is sealed by gaskets made of silicone rubber so as not to react with the silicone oil used as the liquid coolant. If the housing is damaged so that the coolant can escape, the drop in the coolant level is detected by the float switch 6 which cuts off the power supply to the bulb holder. This eliminates the risk of explosion due to sparking inside the lamp housing. The thermal switch 7 immersed in the coolant cuts off the power supply when a predetermined temperature is exceeded, for example during a developing fire, thus allowing gradual evacuation. Claims
1. An explosion-proof lamp comprising a housing, means for mounting an electrical light source in the housing, and an inert electrically insulating cooling liquid in the housing.
2. A lamp as claimed in Claim 1 including control means for the light source responsive to the liquid level in the housing and arranged to deenergize the light source on loss of liquid.
3. A lamp as claimed in Claim 2 further including control means for the light source responsive to the temperature in the housing and arranged to de-energize the light source when the temperatlJre exceeds a predetermined value.
4. A lamp as claimed in Claim 3 in which the control means are a float switch and a thermal switch connected in series with one another and with the light source.
5. An explosion-proof lamp guarded by a protective net and comprising an electric circuit consisting of a light source and two cut-outs connected in series, characterized by an explosion-proof housing of which the interior is filled with an insulating liquid coolant, with a float voltage switch located on the coolant surface and a thermal voltage switch situated at any depth of the coolant.
6. A lamp according to Claim 5, characterized in that the side surface of the explosion-proof housing is shaped as a radiator having internal and external fins.
7. A lamp as claimed in any of Claims 1 to 6, in which the said liquid is a silicon oil.
8. An explosion-proof lamp substantially as herein described with reference to the accompanying drawing.
GB8108508A 1980-03-27 1981-03-18 Explosion-proof lamp Withdrawn GB2095810A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PL22309380A PL223093A1 (en) 1980-03-27 1980-03-27

Publications (1)

Publication Number Publication Date
GB2095810A true GB2095810A (en) 1982-10-06

Family

ID=20002184

Family Applications (1)

Application Number Title Priority Date Filing Date
GB8108508A Withdrawn GB2095810A (en) 1980-03-27 1981-03-18 Explosion-proof lamp

Country Status (4)

Country Link
DD (1) DD157625A5 (en)
FR (1) FR2479415A1 (en)
GB (1) GB2095810A (en)
PL (1) PL223093A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3412395A1 (en) * 1984-04-03 1985-10-10 CEAG Licht- und Stromversorgungstechnik GmbH, 6800 Mannheim LAMP

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1918223A (en) * 1931-04-18 1933-07-11 Koehler Mfg Co Mine lamp
GB371614A (en) * 1931-05-04 1932-04-28 Gen Electric Co Ltd Improvements in electric lamp fittings
DE2215614A1 (en) * 1972-03-30 1973-10-11 Heribert Kampmann THERMAL SECURED LIGHTING EQUIPMENT

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3412395A1 (en) * 1984-04-03 1985-10-10 CEAG Licht- und Stromversorgungstechnik GmbH, 6800 Mannheim LAMP

Also Published As

Publication number Publication date
DD157625A5 (en) 1982-11-24
FR2479415A1 (en) 1981-10-02
PL223093A1 (en) 1981-10-02

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Legal Events

Date Code Title Description
WAP Application withdrawn, taken to be withdrawn or refused ** after publication under section 16(1)