Safety device for combined ventilator/light unit

• US 5,021,932 A
• Filed: 05/17/1989
• Issued: 06/04/1991
• Est. Priority Date: 05/17/1989
• Status: Expired due to Term

• Current Assignee: Marley Engineered Products LLC (SPX Corporation)
• Original Assignee: Fasco Industries, Inc. (Schneider Electric SE)
• Inventors: Ivey, Charles W.
• Primary Examiner(s): Lazarus, Ira S.
• Assistant Examiner(s): Hagarman, Sue
• Application Number:
  US07/352,895
• Time in Patent Office: 748 Days
• Field of Search: 362/96, 362/373, 362/294, 34/87, 98/40.07, 98/40.08
• US Class Current: 362/96
• CPC Class Codes: F21V 25/10 coming into action when lighting device is overloaded, e.g. thermal switch
• CPC Class Codes: F21V 29/503 of light sources cooling arrangements structurally associated with gas-discharge or vapour-discharge lamps H01J61/52; cooling arrangements structurally associated with electric incandescent lamps H01K1/58; cooling arrangements structurally associated with light-emitting diodes H01L33/64
• CPC Class Codes: F21V 29/67 characterised by the arrangement of fans
• CPC Class Codes: F21V 33/0088 Ventilating systems lighting fixtures combined with outlets for air treatment systems F24F13/078
• CPC Class Codes: F24F 13/078 combined with lighting fixtures

Abstract

Two thermal protectors or thermostatic sitches are mounted on the outside of the housing of a combination ventilator/lamp unit to sense any heat build-up in the housing during operation of its lamp. One switch is normally open and is connected between the lamp and the motor for the ventilator fan; and the other switch, which is normally closed, is connected in series with the fan motor and lamp. The normally open switch is set to close automatically when the temperature in the housing reaches a first value above room temperature, thereby to energize the fan motor to cool down the housing. If the normally open switch and/or the fan motor fails the normally closed switch is set to open at a temperature above that at which the normally open switch closes, and functions as a safety switch to disconnect both the fan motor and lamp from the power supply.

Claims

1. A safety device for a combination ventilator/light unit of the type having a housing containing in its lower end a lamp, and in its upper end a ventilator fan and electric motor therefor, comprising

a first normally closed, temperature responsive switch mounted on said housing,

means for connecting said first switch across a power supply in series with said lamp and said motor, and operative automatically to disconnect both said lamp and said motor from said power supply when the temperature in said housing exceeds a first predetermined value,

a second, normally open, temperature responsive switch mounted on said housing in communication with the interior thereof between said lamp and said fan to sense the temperature in said housing adjacent said lamp,

means connecting said second switch between said fan motor and said lamp, said second switch being operative, when said lamp is energized, automatically to close and energize said fan motor when the temperature in said housing exceeds a second predetermined value lower than said first predetermined value,

said second switch comprising a thermostat mounted in a metal container extending at one end through a hole in one exterior wall of said housing and having thereon on its opposite end a mounting flange secured against the outside surface of said one exterior wall of said housing,

said one end of said container being closed to prevent access to the wire leads of said thermostat from the interior of said housing,

a pair of wire plug receptacles mounted in said one wall of said housing adjacent said thermostat, and

a cover removably secured to said outside surface of said one wall of said housing and overlying and covering said thermostat and said plugs.

2. In the combination of a combined ventilator/light unit of the type having a housing containing in one end thereof a lamp and in its opposite end an exhaust fan and electric motor for driving said fan, and a circuit including a pair of mutually operable switches connected in series with said lamp and said fan motor, respectively, and operable selectively to connect said fan and said motor to a power source for selective operation of the lamp and motor independently of each other, means for preventing undesirable overheating of the housing, comprising

first heat sensing means mounted intermediate its ends in an opening in one external wall of said housing to extend at one end externally of said housing, and to extend at its opposite end into said housing between said lamp and said motor,

said first sensing means including a temperature responsive, normally open switch connected to said lamp and said motor, and operable, when closed, to supply power to each of said lamp and said motor through one of said manually operable switches when the latter is closed, and

second heat sensing means mounted on said one wall of said housing and including a normally closed, temperature responsive switch connected in series with said lamp and said motor,

said normally open switch being set automatically to close when the temperature in said housing between said lamp and said motor reaches a first predetermined temperature above room temperature, and

said normally closed switch being set to open when the temperature in said housing between said lamp and said motor exceeds said first predetermined temperature.