Lamp Cooling System

The lamp cooling system inserts into a standard socket and receives a lamp bulb. The lamp cooling system has a fan and cooling fins therein for cooling the lamp and electronics.

Lamps generate heat and, in some cases, the heat limits lamp life. In other cases, the generated heat prevents utilization of a lamp of the required luminosity because overheating of the system occurs. Thus, the installation of lamp bulbs is often limited by the cooling capacity of the environment. In many cases, additional cooling is required in order to permit the utilization of a lamp of the desired luminosity.

In order to aid in the understanding of this invention, it can be stated in essentially summary form that it is directed to a lamp cooling system wherein the system includes a housing which has a lamp socket therein and which can be installed in a lighting system. The lamp is inserted into the lamp socket, and the housing contains fins to dissipate heat from the lamp socket and contains a motor-driven fan to move air over the lamp and fins. The housing may contain electronics for powering the fan motor and/or the lamp.

It is thus a purpose and advantage of this invention to provide a lamp cooling system which permits the installation of a high-power lamp bulb in a socket location which would not otherwise permit it due to lack of adequate cooling.

It is another purpose and advantage of this invention to provide a lamp cooling system wherein high-power lamps can be employed to permit illumination at a higher level than would be permitted if ordinary cooling were to be relied upon.

It is another purpose and advantage of this invention to provide lamp cooling systems one of which can utilize a standard screw-in bulb base, while another one permits the insertion of a lamp having a plug-in base, both of which systems have forced cooling of the lamps.

It is another purpose and advantage of this invention to provide lamp cooling systems which can be employed in an ordinary retrofit by screwing it into a standard threaded socket, and yet permit a lamp of higher luminosity because its base is force-cooled.

Other purposes and advantages of this invention will become apparent from a study of the following portion of the specification, the claims and the attached drawings.

FIG. 1 is a side-elevational view of the first preferred embodiment of the lamp cooling system of this invention which utilizes a lamp bulb with a screw base.

FIG. 2 is a substantially center line section therethrough.

FIG. 3 is a side-elevational view of a second preferred embodiment of a lamp cooling system in accordance with this invention which utilizes a plug-in lamp.

FIG. 4 is a substantially center line section therethrough.

The first preferred embodiment of the lamp cooling system of this invention is generally indicated at 10 in FIGS. 1 and 2. The system comprises a housing 12 which carries a threaded plug 14 on its lower end. The threaded plug 14 is of standard dimensions to screw into a bulb socket. It has a metal threaded sheath 16 and a separate insulated nose 16 to make contact at the two electrical potentials in the socket.

Housing 12 is generally cylindrical and tubular. It has a series of ventilation openings 20 adjacent the plug 14. Interiorly of the housing, the housing is provided with a series of steps 22, 24 and 26. These steps are successively of larger diameter in the upward direction away from the plug 14 to permit assembly. The second step 24 carries fan support board 28. Motor 30 is mounted in the center of the fan support board. Fan blades 32 are supported by the motor, are wrapped around the motor, and rotate with the motor. Shroud 34 surrounds blades to increase air delivery efficiency. Fan support board 28 is provided with air flow holes 36 to permit the fan to blow air, preferably downward, toward the threaded plug 14.

It is contemplated that the threaded plug be screwed into a socket which is supplied with 120 volt AC electric power. It is difficult to manufacture a motor 30 sufficiently small for such an application when it is to be powered by 120 volt AC. Accordingly, the motor 30 is of lower voltage and may be a direct current motor. Therefore, motor power supply 38 is provided. The power supply may be a transformer plus a diode bridge plus a condenser to provide a 12 volt DC output for the fan motor. Then the motor power supply is mounted on power supply board 40, which rests upon step 22. Holes 42 around the power supply permit air flow downward through the housing. The fan support board 28 and power supply board 40 may be dielectric and are secured in place by a convenient means such as molded-in resilient stops above the boards or by adhesive attachment. The output of the power supply 38 is connected to fan motor 30.

The top step 28 supports heat sink platform 44. The heat sink platform also has holes 46 therethrough to permit downward flow of air. The heat sink platform carries a socket 48 into which screws lamp bulb 50, in conventional manner. The lamp bulb has a standard threaded plug the same size as plug 14. The socket is firmly mounted on the heat sink plate 44 so that heat is conducted from the plug of the lamp bulb to the socket 40 and thence to the heat sink platform 44. The heat sink platform is made of metal such as aluminum and carries metal fins 52 which extend upward from the platform, as seen in FIG. 2. In addition, surrounding the socket 48, metal fingers 54 extend upward. These fingers are resilient and engage to the collar 56 on the bulb envelope. Quite often, the standard PAR light bulbs have such a collar thereon. When no such collar is present, the fingers 56 can engage on the neck of the bulb envelope above the base. Fingers 58 are also mounted on the heat sink.

Electrical connections from the threaded plug 14 directly connect to the socket 48 so that, when the plug is energized, the socket is energized. In addition, the motor power supply 38 is also energized from that source. As a result, when a lamp bulb is screwed into the socket 48 and the plug 14 is screwed into a source of electric power suitable for the lamp bulb, the system is energized. The lamp bulb is illuminated and the motor is energized. Air is drawn past the lamp bulb, across the fins 52 and through the holes 46 in the heat sink platform 44. The energized fan blades then blow the air across the motor power supply 38 and out through the vent openings 20 in the bottom of the housing. In this way, the lamp bulb runs cooler and, thus, has a longer life. Alternatively, a larger lamp bulb can be installed and still operate within reasonable life design parameters. The system 10 is thus suitable for utilization of standard lamp bulbs, including lamp bulbs with built-in reflectors.

The lamp cooling system 60, shown in FIGS. 3 and 4, is similar to the lamp cooling system 10. However, it is configured to permit the utilization of a lamp bulb which does not incorporate its own reflector. Instead, the reflector is mounted on the housing. Housing 62 is formed in upper and lower housing portions 64 and 66 for purposes of assembly. The two housing portions are joined at a sleeve joint where the upper housing portion enters around the outside of tube 68 and engages against the stop face 70 adjacent tube 68. The lower end of the housing has a standard threaded plug 72 thereon for threaded engagement in a standard socket and electrical engagement therein. Shoulder 74 is formed interiorly of the lower housing portion 66, and printed wiring board 76 engages thereagainst. The printed wiring board carries suitable circuitry and discrete components for providing the conversion necessary for output voltage, frequency and current. The circuitry mounted on printed wiring board 76 is generally indicated at 78 and may include a transformer or other type of converter oscillator to generate a low voltage AC high current, together with rectifiers preferably arranged in a bridge circuit and condensers to smooth the output of the rectifiers to supply the necessary DC voltage for the fan.

Mounted against tube 68 is fan support board 80. Fan motor 82 is mounted on the fan support board, and fan blades 84 are mounted around the fan. Fan shroud 86 surrounds the fan blades and is mounted on the fan support board 80 to enhance fan efficiency. Openings 88 in the fan support board, openings 90 in printed wiring board 76, and openings 92 in the lower housing portion permit air to be driven by the fan downward over the electronics and power converter on the board 76.

Heat sink baseplate 94 has openings 96 therein and has fins 98 thereon. The heat sink baseplate and its fins are preferably made in one piece of low thermal resistance metal such as aluminum or are connected with low thermal resistance therebetween so that heat is readily transferred. The configuration of the fins is generally radial from the upright center line of the baseplate so that the fan draws air downward across the fins, as indicated by the arrows in FIG. 4. It should be noted that the fins 98 extend upward along a portion of the bulb length, but not as far as the filament in the top of the bulb. A portion of the fins extends up into the lower portion of the lamp cover around the lamp bulb.

Lamp bulb socket 100 is directly mounted on a heat sink post 102, which forms an integral part of or is directly attached to the heat sink baseplate. The radial fins are preferably also attached to the heat sink post below socket 100.

In the present preferred embodiment, the lamp bulb 104 mounted in the socket 100 is a halogen lamp. Such halogen lamps require 12 volts AC, and this is also supplied from the power converter 78. Appropriate connections are made from the power converter to the lamp socket 100 and, when rectified, to the fan motor.

Collar 106 is screw-threaded onto the top of housing 62 on screw threads 108. The collar has ventilation openings 110 therein to permit a continuous air opening through the housing, including past the fins, through the fan and support boards and out of the housing. Collar 106 carries lamp cover 112, which has a front substantially transparent lens 114 and a reflector surface 116 around the lamp bulb 104. The reflector surface 116 is preferably configured so that the lamp bulb is at a focus so that substantially parallel light rays are delivered toward the lens 114. While a parabolic reflector together with a forward lens is shown as the preferred embodiment, the configuration of the lamp cover 112 can be as desired. For example, it may be globular or may have a decorative configuration. Furthermore, the lamp cover can be frosted, partly frosted, or partly reflectorized depending upon the application and the manner in which illumination is desired. The configuration of the lamp cooling system permits a halogen lamp to be force-cooled and powered in an ordinary socket.

This invention has been described in its presently contemplated best embodiments, and it is clear that it is susceptible to numerous modifications, modes and embodiments within the ability of those skilled in the art and without the exercise of the inventive faculty. Accordingly, the scope of this invention is defined by the scope of the following claims.