Abstract: A safety lightbulb includes a base, a glass envelope connected to the base, and electrical contacts extending from the base into the glass envelope and electrically connected to a filament for producing light in the glass envelope when current is supplied to the electrical contacts from a power source to which the base is connected. A safety arrangement in the base automatically electrically disconnects the electrical contacts from the power source when the glass envelope is broken, and includes an electrical contact member in the base and a moving/restraining arrangement in the base for moving the electrical contact members out of electrical contact with the power source and the electrical contacts, when the glass envelope is broken.

Abstract: An underwater safety lighting device for lighting water beneath a surface (4) of the water in a swimming pool is provided. A water-tight light housing (1) is disposable beneath the surface (4) of the water in the pool and has a lens (5) removably attached to a front side (6) of the light housing (1), a light-emitting source (12) is secured within the light housing and a concaved light reflector (9) is secured within the light housing. The light-emitting source (12) is disposed above a conjugate axis (21) of the concave light reflector (9). An aperture (20) is disposed entirely in an upper one-half (21) of the light reflector (9) for receiving the light-emitting source (12). A control housing (2) is disposable out of the water of the pool and has a control device (26). An elongated connector (3) having a lower connector end (28) connects with a light housing connection portion (22) and an upper connector end (29) connects with a support of the pool.

Abstract: A portable electric lamp suitable for use in hazardous locations includes a fixture which is purged continuously with air during operation. Pressurized air is introduced at an input end of the fixture, through a plenum which establishes a generally laminar flow of air through the fixture during purging. To insure that the fixture is satisfactorily purged before power is applied to the lamps, differential pressure is measured over a precision orifice at the discharge end of the lamp, and total flow is determined. During the start-up cycle, pressure within the fixture must exceed a predetermined minimum threshold; but following start-up, the operating pressure may drop lower than the initial minimum pressure, as long as a positive pressure is maintained within the fixture.

Abstract: A portable electric lamp suitable for use in hazardous locations has the fixture purged with breathable air a predetermined time before power is coupled to energize the lamps. The fixture is continuously purged during operation. If the internal pressure falls below a predetermined minimum level, or exceeds a predetermined maximum during operation, power to the lamps is shut off, and the complete start cycle, including the time delay, must be undertaken before the lamps can be re-started. All leads and components are either potted or operated at an intrinsically safe power level.

Abstract: An explosion proof light comprising a shatter-resistant, fluid tight, light transmissive case and a fluid tight light source sealed within the case in at least partial spaced-apart relation thereto. An effective quantity of electrically non-conductive fluid extinguishant such as Halon 2402 is sealed within the space between the case and the light source under positive pressure for suppressing sparks resulting from damage to the light causing penetration to the light source and exposure of sparks and intense heat to the environment. An outer housing may preferably be positioned over the case to add further protection.

Abstract: A video inspection system for hazardous environments is provided, comprising a housing, sealable so as to contain a pressurized gas therein, having a view opening therein and further including a valve for introducing pressurized gas into the housing, connected to the housing; and a transparent lens, sealingly affixed across the view opening; a camera for recording visual images through the view opening, mounted within the housing; and a power supply, for powering the camera, mounted within the housing and operatively connected to the camera. A method for operating the above system is also provided, including the steps of substantially purging undesirable gases from the interior of the housing; sealing the housing, eliminating external connections thereto; introducing non-flammable gas to the interior of the housing until the pressure in the housing reaches a desired level; and operating the camera within the housing.

Abstract: A video inspection system for hazardous environments is provided, comprising a housing, sealable so as to contain a pressurized gas therein, having a view opening therein and further including a valve for introducing pressurized gas into the housing, connected to the housing; and a transparent lens, sealingly affixed across the view opening; a camera for recording visual images through the view opening, mounted within the housing; and a power supply, for powering the camera, mounted within the housing and operatively connected to the camera. A method for operating the above system is also provided, including the steps of substantially purging undesirable gases from the interior of the housing; sealing the housing, eliminating external connections thereto; introducing non-flammable gas to the interior of the housing until the pressure in the housing reaches a desired level; and operating the camera within the housing. The system may also be operated as a portable lighting system without the camera.

Abstract: A light radiator for effectively diffusing and radiating light rays outside of the optical conductor cable through which they were transmitted. The light radiator comprises a transparent cylinder, an optical conductor for guiding light rays into the cylinder, an optical means movably accommodated inside of the cylinder for reflecting the light rays guided into the cylinder and radiating outside of the cylinder, and a driving means for moving the optical means along the axis of the cylinder. The optical means is constructed with a cylindrical transparent member, a surface of one side on which the light rays impinge being formed on a plane and another surface of the other side being formed in a V-shaped concave surface.

Abstract: This invention is an improvement to safe electrical systems which have a hermetically enclosed space containing an electrical circuit member wherein means are provided for connecting and disconnecting the electrical circuit member to a power source in response to pressure changes within the hermetically enclosed space and for altering the volume within the hermetically enclosed space to effect a pressure change therein.

Abstract: An electrical lighting fitting for a remotely hazardous area comprises two enclosures. The lamp itself is disposed in one enclosure and the control equipment for the lamp is disposed in the other around the axis of the fitting. The two enclosures are thermally insulated from each other and at least the one containing the lamp is maintained at a pressure other than ambient. A pressure switch is associated with this enclosure so that should a break occur in the enclosure this can be sensed and the electrical supply to the lamp removed. The thermal insulation enables the lamp to be run in temperatures which would not otherwise be possible. The enclosure housing of the lamp may be fixed to the remainder of the lamp by springs to enable lamp maintenance without the use of tools.