CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation-in-part of pending U.S. Application Serial No.
922,152 filed on October 23, 1986.
BACKGROUND OF THE INVENTION
[0002] The present invention relates generally to lighting apparatus, and more particularly
provides a uniquely constructed heat-dissipating light fixture for use with tungsten-halogen
lamps.
[0003] The vast majority of lights currently used in retail and exhibition display applications
are incandescent flood lamps which range in power from 100 watts to 300 watts. Despite
the prevalence of its use, incandescent display lighting is subject to several well
known disadvantages and limitations. For example, the efficiency of incandescent lamps
is limited to approximately eight to eleven percent, which results in high electrical
power consumption compared to the useful light obtained. Additionally, the spectrum
of the light generated by incandescent display lamps is heavily weighted toward the
infrared portion of the spectrum. This results in relatively poor color balance of
the displayed objects.
[0004] Moreover, heat that is generated by the infrared component of incandescent display
lamps is projected forwardly, thereby potentially creating undesirably high temperatures
on the illuminated merchandise. This last point is particularly relevant where bright
lighting is required for expensive or irreplacable objects such as clothing, furs,
jewelry, or paintings. It is well known that concentrated infrared energy can significantly
deteriorate the object at which it is directed. As an example, infrared energy can
change the molecular structure of diamonds and other precious stones, thereby significantly
decreasing their value. Additionally, watches are particularly sensitive to heat,
and are easily damaged under incandescent lighting.
[0005] As an alternative to high wattage, low efficiency incandescent lighting, dichroic,
tungsten-halogen low voltage lamps have recently been utilized in display applications
and potentially offer several distinct advantages over incandescent lighting systems.
For example, the efficiency of tungsten-halogen low voltage lamps is approximately
ten times that of incandescent lamps. At 12 volts, a 75 watt tungsten-halogen lamp
produces essentially the same amount of usable light as a much higher wattage incandescent
lamp, and produces more of the light output in the visible spectrum. This, of course,
represents a significant energy savings. Additionally, the life of a tungsten-halogen
lamp is approximately 2.5 to 3 times that of an incandescent lamp due to the "halogen
cycle" which re-deposits evaporated tungsten on the lamp's filament, preventing blackening
of the lamp envelope and also prolonging the life of the tungsten filament.
[0006] The color spectrum of the light produced by tungsten-halogen lamps provides a truer
color representation for illuminated objects due in part to the high "white hot"
temperature that the tungsten filiment is heated to, and to the special dichroic coating
on the lamp reflector which reflects visible light and absorbs other transmitted frequencies
such as infrared. Finally, projected heat from a tungsten-halogen lamp is significantly
reduced by its dichroic reflector which absorbs approximately 70 percent of the infrared
radiation (as well as ultraviolet) resulting in a safe light for illuminating delicate
merchandise.
[0007] It can be seen that these advantages inherent in tungsten-halogen lamps make them
a very desirable light source for many retail and other commercial applications. However,
the conventional fixtures in which these tungsten-halogen lamps are typically housed
significantly shorten the useful life of such lamps. This is due primarily to the
inability of conventional fixtures to adequately dissipate the intense heat produced
at the rear of the lamp by the high temperature tungsten filament and by the reflector-absorbed
infrared energy. A typical method of installing a tungsten-halogen lamp in the conventional
light fixture is simply to plug the connecting prongs of the lamp into a connector
fitting disposed within the fixture. Other than allowing the heat from the lamp base
portion to be somewhat dissipated by convective transfer to air within the fixture
surrounding the lamp, no adequate heat dissipation mechanism has heretofore been incorporated
in these fixtures.
[0008] This deficiency in conventional fixture design leads to premature lamp failure in
three primary modes due to excessive heat buildup in the lamp. First, the seal portion
of the lamp often fails, thereby allowing the halogen gas within the glass envelope
to escape, due to interior seal temperatures exceeding 350°C. The lamp seal is typically
made of electrically conductive strips such as molybdenum, pressed between the quartz
envelope. Due to the high filament temperature and high current (6.25 amps at 75w)
flowing through the strips they often reach very high temperatures. Additionally,
if the reflector temperature is allowed to exceed approximately 350°C, the reflector's
dichroic coating can deteriorate. Finally, the connector fitting within the fixture
can also be caused to fail due to the high temperature transmitted from the lamp base
to the connector pins. Excessively high temperature can result in increasing resistance
and eventual breakdown of the connector pin and of the power supply connection thereto.
[0009] It can be seen from the foregoing that a need exists for an improved light fixture
for use with tungsten-halogen lamps which eliminates or substantially minimizes above-mentioned
and other lamp heat buildup problems and limitations. Accordingly, it is an object
of the present invention to provide such a fixture together with associated lamp
heat-dissipating methods.
SUMMARY OF THE INVENTION
[0010] In carrying out principles of the present invention, in accordance with a preferred
embodiment thereof a uniquely constructed heat-dissipating light fixture is provided
for use with tungsten-halogen lamps to significantly prolong their operating life
by preventing excessive heat buildup in such lamps. The fixture comprises a heat conductive,
externally finned metal body in which a cavity is formed for receiving a tungsten-halogen
lamp, the cavity opening outwardly through the exterior surface of the fixture body.
Operatively disposed within the cavity is an electrical connector which is connected
to suitable external power wiring and has a pair of openings formed therein for receiving
the connector prongs which extend outwardly from the base portion of the lamp.
[0011] Also disposed within the fixture body cavity is a metal heat shield which engages
around its periphery the interior surface of the cavity and is positioned adjacent
the electrical connector. A socket opening is formed through the heat shield and is
adapted to receive the base portion of the lamp so that the reflector portion of the
lamp is disposed on one side of the heat shield and the electrical connector is disposed
on the other side. The lamp is operatively connected to the electrical connector by
passing the lamp base portion through the socket opening until the lamp connector
prongs are received in the corresponding openings in the electrical connector.
[0012] A compliant, heat conducting material, such as a suitable graphite foil, is secured
to the reflector side of the heat shield and has a portion which projects into the
socket opening. When the lamp is plugged into the connector through the socket opening,
a portion of the graphite foil is bent inwardly into the socket opening and is compressed
between the lamp base portion and an interior surface portion of the socket opening.
The slightly compressed portion of the foil provides an efficient heat conduction
flow path between the exterior surface of the lamp base portion and the interior surface
of the socket opening in the heat shield.
[0013] During operation of the tungsten-halogen lamp, the heat shield interposed between
the electrical connector and the reflector portion of the lamp functions to intercept
infrared radiation transmitted from the reflector toward the connector. The infrared
radiation intercepted by the foil-faced heat shield is absorbed therein and transferred
therethrough by conduction to the metal fixture body which serves as a conductive
heat sink. Additionally, heat within the lamp base (adjacent the lamp seal portion)
is very efficiently conducted through the compressed foil portion into the heat shield
and, again by conduction, into the fixture body heat sink. The external fins on the
fixture body enhance the dissipation of heat conducted thereto by means of radiation
and convection to the surrounding ambient air.
[0014] In this unique manner, both the reflector and base portions of the lamp, and the
electrical connector portion of the fixture, are protected from excessive heat buildup
in a manner maintaining the temperature of the connector and the lamp base below acceptable
limits to thereby significantly prolong the useful life of the lamp. Typically, a
lamp seal temperature reduction of approximately 30% is achieved compared to seal
temperatures of tungsten-halogen lamps housed in conventional fixtures.
[0015] In an alternate embodiment of the light fixture, the finned body portion thereof
is inexpensively formed from a tubular metal inner section and a series of metal discs.
Central circular portions of the discs are punched out, provided with appropriate
openings therethrough and then press-fitted into the interior of the tubular section
to form the heat shield and connector support structure within the body. The remaining
annular portions of the discs are axially press-fitted onto the tubular section to
form the external cooling fins on the light fixture body.
[0016] According to another aspect of the present invention, a specially designed cooled
lamp connector assembly is provided which may be utilized, in retrofit applications,
to replace the existing electrical lamp connector within the outer housing of a conventional
light fixture. The improved connector assembly is preferably formed from two extruded
aluminum sections which are suitably intersecured to form a hollow, externally finned
cooling body section of the assembly. This body section, at the front end thereof
has a socket opening which extends inwardly into an enlarged cavity within the body.
[0017] Captively retained within this enlarged internal cavity is a uniquely configured
lamp connector structure which comprises two stacked pairs of metal blocks that are
positioned in a side-by-side relationship, and are encapsulated within and separated
by a silicon insulating material that is highly resistive to the flow of electricity
therethrough, but has relatively good thermal conductivity. A pair of electrical power
leads are each connected to one of the metal block pairs. A forwardly facing opening
is formed in the silicon insulation material and communicates with the socket opening
formed in the cooling body. A back portion of the cooling body has suitably secured
thereto a connecting bolt by means of which the body may be mounted in the interior
of an existing light fixture housing.
[0018] With the cooling body mounted within the light fixture housing, the base of the
fixture's lamp is inserted into the socket opening formed in the cooling body so that
the lamp base pins enter a pair of pin openings formed along the junctures of the
stacked metal block pairs. The pairs of such blocks are resiliently held in engagement
by the silicon insulation material which encapsulates and separates them. As the
lamp base pins enter the pin openings in the blocks, each pair of the blocks is slightly
separated against the resilient force of the encapsulating insulation material. This
provides a desirable "pin wiping" action in the connector which is inexpensively
achieved due to its unique construction.
[0019] With the lamp base secured to the internal connector in this manner, a forward end
portion of the cooling body defines a heat shield which is interposed between the
reflector portion of the lamp and the captively retained connector structure disposed
within the cooling body. In a manner similar to that previously described, a graphite
foil sheet is held by the cooling body and is compressed between the lamp base and
the inner surface of the socket opening formed in the body.
[0020] During operation of the lamp, rearwardly directed radiant heat from its reflector
portion is intercepted by the integral heat shield portion of the cooling body. The
absorbed heat is dissipated by the finned portion of the body into the interior of
the light fixture housing to thereby shield the internal lamp connector, and the lamp
base and its internal seal elements, from such heat. The compressed portion of the
graphite foil sheet forms a conductive heat path from the lamp base to the cooling
body to thereby further protect the internal seal elements from excessive heat.
[0021] The metal block structure which defines the interior portion of the lamp connector
structure functions as a heat sink to absorb further heat transmitted to the connecting
pins from the lamp base. Heat received in these metal blocks from the connector pins
is conducted outwardly to the silicon encapsulating material, into the cooling body,
and is then dissipated into the interior of the light fixture housing through the
finned portions of the body, and is further conducted into the light fixture housing
through a rear end portion of the cooling body that is bolted to the light fixture
housing. In this manner, the improved connector assembly provides additional protection
against excessive heat buildup in the connecting pins to further prolong the life
of the lamp.
[0022] In an alternate embodiment of the cooled lamp connector assembly, its externally
finned cooling body is formed from two aluminum extrusions which are positioned in
a spaced, side-by-side relationship. The two extruded metal body sections are encapsulated
within and separated by a silicon insulation material similar to that previously
described. A pair of electrical power leads are each connected to one of the extruded
metal sections.
[0023] The cooling body has a lamp base socket formed in a forward end portion thereof and
is provided at its rear end with a suitable connecting bolt for connecting the body
to the interior of an existing light fixture housing.
[0024] At the inner end of the socket opening each of the extruded sections is split along
a rearwardly extending cut line which terminates somewhat forwardly of the rear end
of the extrusion. At the section junctures defined by this cut line are formed a pair
of lamp base pin openings. The non-split rear portions of the extruded sections function,
in effect, as spring portions of the sections to resiliently resist separation of
the split portions thereof.
[0025] With the cooling body installed within the light fixture housing, the base of the
fixture's lamp is inserted into the socket opening of the body so that the lamp base
pins enter the pin openings. Entry of the pins into their associated openings slightly
forces the split portions of the extruded metal sections apart to thereby provide
the previously described automatic "pin-wiping" action. A graphite foil strip is secured
wtihin the socket opening and has portions which are compressed between the lamp base
and the interior surface of the socket opening as previously described.
[0026] As in the case of the previously described embodiment of the improved connector assembly,
a forward end portion of the cooling body defines a heat shield interposed between
the lamp reflector and the portion of the assembly which receives the lamp base pins.
Intercepted radiant heat, and heat within the lamp base and its connecting pins are
absorbed within the extruded metal sections, and dissipated by the body fins into
the interior of the light fixture housing, as well as being conducted from the metal
extrusions into the light fixture housing through the encapsulating silicon material.
[0027] In this latter embodiment of the improved connector assembly, no separate internal
connector structure is required. The cooling body itself integrally defines such structure
in addition to performing its various cooling and heat dissipation functions.
[0028] While the improved connector assembly apparatus described above is particularly well
suited for retrofit applications in which the existing connector is removed from
a light fixture and replaced with an embodiment of the improved connector assembly,
it will be appreciated that such improved assembly could also be used as original
equipment in a newly manufactured fixture if desired.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029]
Fig. 1 is a perspective view of a heat-dissipating light fixture which embodies principles
of the present invention and may be advantageously used in conjunction with a tungsten-halogen
lamp to efficiently illuminate various display objects;
Fig. 2 is an enlarged scale cross-sectional view taken through the light fixture along
line 2-2 of Fig. 1;
Fig. 3 is an exploded perspective view, partially in section, of the light fixture;
Fig. 4 is a cross-sectional view, similar to that in Fig. 2, illustrating an alternate
embodiment of the light fixture;
Fig. 5 is a reduced scale front elevational view of a metal disc used to form one
of the external housing fins on the light fixture of Fig. 4, and also to form a portion
of the lamp connector heat shield and support structure therein;
Fig. 6 cross-sectionally depicts a heat dissipating retrofit connector assembly which
embodies principles of the present invention operatively installed within an existing
lamp fixture and having a lamp connected thereto;
Fig. 7 is a front elevational view of the connector assembly, with the lamp being
removed therefrom, taken generally along line 7-7 of Fig. 6;
Fig. 8 is a fragmentary cross-sectional view, similar to that in Fig. 6, illustrating
an alternate embodiment of the connector assembly installed in an existing light fixture
housing; and
Fig. 9 is a cross-sectional view through the connector assembly of Fig. 8 taken along
line 9-9 thereof.
DETAILED DESCRIPTION
[0030] As illustrated in Figs. 1-3, the present invention provides a uniquely constructed
heat-dissipating light fixture 10 adapted for use with a conventional tungsten-halogen
lamp 12 comprising a glass reflector housing 14 and a tungsten-halogen bulb 16. The
reflector housing 14 has a forwardly disposed reflector portion 18 whose inner surface
is provided with a dichroic reflective coating 20, and a rearwardly disposed hollow
base portion 22 which is tapered along its length and has a generally rectangular
cross-section. The back end of the bulb 16, which contains its critical seal portion
23 (Fig. 2), is extended rearwardly through the hollow lamp base 22 and is secured
therein by a suitable ceramic potting material 23
a which encapsulates the bulb within the base 22. The back end of the bulb 16 is provided
with a pair of connecting prongs 24 (Figs. 2 and 3) which project rearwardly from
the lamp base 22.
[0031] During operation of the lamp 12, the dichroic reflector coating 20 reflects visible
light from the bulb 16 forwardly (i.e., leftwardly) from the reflector portion 18,
while a large portion of the infrared radiation from the bulb is absorbed by the reflector
coating 20 and radiated rearwardly (i.e., rightwardly) from the reflector portion
18. When a tungsten-halogen lamp such as lamp 11 is installed in a conventional light
fixture, by simply plugging the connector prongs 24 into an electrical connector disposed
within the fixture, the combination of the intense tungsten filament heat in the bulb
16 and the rearwardly generated infrared radiation tends to overheat the lamp base
22, thereby rather rapidly deteriorating the internal seal 23 within the bulb 16,
the connector prongs 24, and the electrical connector which receives these prongs.
Additionally, the intense heat generated by the bulb 16, which is absorbed by the
reflector housing 14, can cause deterioration of the reflector coating 20. These overheating
problems are eliminated in a novel manner by the light fixture 10 which will now be
described.
[0032] Fixture 10 includes a hollow cylindrical aluminum body 26 having a front end 28 and
a back end 30. A cavity is formed within the body 26 by cylindrical bores 32, 34 and
36 extending axially therethrough. Bore 32 extends inwardly from the back end 30 of
the fixture body 26 and inwardly communicates with the smaller diameter bore 34. Bore
36 extends inwardly from the front end 28 of the housing body and has a conically
flared forward end portion 38 as best illustrated in Fig. 2.
[0033] The bores 34 and 36 are separated by a cylindrical internal dividing wall 40 formed
integrally with the balance of the fixture body 26. Extending centrally through the
wall 40 is a rectangularly cross-sectioned socket opening 42 whose height and width
are just slightly larger than the height and width of the lamp base 22.
[0034] A front end portion of the fixture body 26 is externally threaded, as at 43, and
has secured thereto an annular, internally threaded aluminum cap 44 having at its
forward end an annular, radially inwardly projecting lip 46. Extending between the
inner end of the externally threaded portion 43 and the back end 30 of the fixture
body is an axially spaced series of radially outwardly projecting annular cooling
fins 48 which are formed integrally with the balance of the fixture body.
[0035] The light fixture 10 may be operatively connected to a conventional lighting power
track disposed above the fixture by means of an elongated hollow cylindrical support
rod 50 having a threaded upper end portion 52. A lower end portion of the support
rod 50 is extended into the bore 32 through a slot 54 formed downwardly through a
rear end portion of the fixture body 26 and the series of cooling fins 48. The lower
end portion of the support rod 50 is also received within a radially inwardly extending
slot 56 formed in a cylindrical bearing cap 58 which is disposed within the bore 32.
Bearing cap 58 is secured to the housing body by means of a pair of screws 60 which
extend through openings 62 in the cap 58 and are threaded into an annular shoulder
64 defined between the bores 32, 34 within the fixture body 26.
[0036] The fixture body 26 is pivotally connected to the lower end of the support rod 50
by means of an elongated pivot pin 66 which extends transversely through the lower
end of the rod 50 as best illustrated in Fig. 3. The outwardly projecting end portions
of the pin 66 are received in small resilient bearing sleeves 68 which are in turn
received in arcuately cross-sectioned radial slots 70 formed in the inner end surface
72 of the bearing cap 58. The sleeved pin 66, together with the bearing cap 58, pivotally
connects the fixture body 26 to the support rod 50, thereby permitting the light fixture
10 to be pivotally adjusted in a counterclockwise direction from the position of the
light fixture illustrated in Figs. 1 and 2.
[0037] By selectively tightening or loosening the bearing cap screws 60 the bearing sleeves
68 may be compressed to a predetermined degree between the bearing cap slots 70 and
the pivot pin 66 to thereby frictionally maintain the light fixture in its pivotally
adjusted position.
[0038] Suitable power wires 74, 76 are extended downwardly through the interior of the support
rod 50 and into the interior of the bore 34 through a small slot 78 (Fig. 3) formed
through a lower end of the forwardly facing sidewall surface 80 of the support rod.
The inner ends of the power wires 74, 76 are operatively connected to a rectangular
ceramic electrical connector 86 disposed within the bore 34.
[0039] Screws 82, 84 are respectively extended through suitable mounting holes 88, 90 formed
in the connector 86, and are additionally extended through mounting holes 92, 94 formed
through the internal wall 40 and corresponding mounting holes 96, 98 formed through
a graphite foil disc 100 disposed in the bore 36 and having a diameter generally equal
to that of the internal wall 40. Retaining nuts 102, 104 are threaded onto the outer
ends of the screws 82, 84 to thereby clamp the connector 86 to the rear end surface
of the wall 40 over the socket opening 42, and clamp the foil disc 100 to the front
end surface of the wall 40 as best illustrated in Fig. 2.
[0040] The foil disc 100, which plays an important role in the present invention, has formed
through a central portion thereof an H-shaped cut 106 (Fig. 3) which forms in the
disc upper and lower tab portions 108, 110. With the cap 44 removed, the tungsten-halogen
lamp 12 is installed in the fixture 10 by pushing the tapered lamp base 22 rearwardly
through the foil cut area 106 and the socket opening 42 until the lamp connector prongs
24 enter prong-receiving openings 24
a (Fig. 3) formed in the forward end surface of the electrical connector 86. Insertion
of the lamp base 22 into the socket 42 in this manner bends the foil tabs 108, 110
rearwardly into the socket 42 so that the tabs respectively engage and are compressed
by the upper and lower side surfaces 112, 114 (Fig. 3) of the lamp base 22, the degree
of such compression varying along the lengths of the tabs (as illustrated in Fig.
2) due to the tapered configuration of the lamp base 22. Importantly, the tabs 108,
110 which are compressed between the lamp base 22 and the upper and lower interior
side surfaces of the socket 42, form a highly efficient heat conductive thermal flow
path between a substantial exterior surface portion of the lamp base 22 and the internal
wall 40 which circumscribes it.
[0041] The assembly of the light fixture 10 may then be completed by screwing the cap 44
onto the externally threaded forward end portion 43 of the fixture body 26. With the
cap 44 installed, the interior surface thereof engages and supports an annular, outwardly
projecting flange 112 on the front end of the lamp reflector portion 18, the flange
112 being spaced rearwardly from the cap lip 46 as best illustrated in Fig. 2.
[0042] If desired, a circular lens element 114 may be dropped into the cap 44 prior to its
installation on the fixture body so that the lens is captively retained between the
lamp 12 and the cap lip 46 as illustrated in Fig. 2. Additional lens elements, such
as "beam shaping" lenses may also be positioned between the lamp and the cap lip.
If needed, a circular anti-glare grid member 116 may be pressed into the interior
of the cap lip as illustrated.
[0043] The unique heat-dissipating characteristics of the light fixture 10 will now be described
in detail with particular reference to Fig. 2. As previously mentioned, during operation
of the lamp 12 the high intensity tungsten-halogen bulb 16 generates both visible
light and infrared radiation. The dichroic reflector coating within the reflector
portion 18 forwardly (i.e., leftwardly in Fig. 2) reflects the visible light toward
the display object (not shown) to be illuminated. However, a very substantial portion
of the infrared radiation is absorbed by the dichroic coating 20 (and thus the reflector
portion 18) and radiated rearwardly from the reflector portion toward the electrical
connector 86. A portion of the heat absorbed by the reflector portion 18 is also conducted
therefrom into the lamp base 22.
[0044] It can be seen in Fig. 2 that the foil-faced internal wall 40, which circumscribes
the lamp base 22, is interposed between the lamp reflector portion 18 and the electrical
connector 86. Because of this unique interposition of the internal wall 40, it functions
(together with a circumferential portion of the foil element 100) as heat shield means
117 for intercepting rearwardly directed infrared radiation emanating from the lamp
reflector portion 18, thereby shielding the electrical connector 86 from such radiation.
Radiation intercepted by the heat shield 117 is absorbed thereby, and heat from the
absorbed radiation is conducted radially outwardly through the heat shield into the
fixture body 26 which functions as a conductive heat sink. The cooling fins 48 function
to convectively and radiantly dissipate to the surrounding ambient air heat conducted
into the fixture body 26.
[0045] Heat conducted into the lamp base 22 from the lamp reflector portion 18 is very efficiently
conducted from the lamp base into the internal wall 40 through the highly conductive
foil tabs 108 and 110. Heat transmitted in this manner to the internal wall 40 is
also conducted therethrough into the fixture body 26 and convectively and radiantly
dissipated by the cooling fins 48.
[0046] It can readily be seen that the internal wall 40 operates in conjunction with the
foil disc 100 to uniquely protect the connector 86, the lamp base 22 and the connecting
prongs 24 from excessive heat buildup which, in fixtures of conventional design, lead
to premature failure of the tungsten-halogen lamp. The novel conductive heat flow
path defined by the wall 40 and the foil disc 100 also reduces the operating temperature
of the dichroic foil coating 20 to prevent premature deterioration thereof. Because
of the reduced operating temperature of the electrical connector 86 provided by the
present invention, the power wiring to the connector is also protected from heat-induced
burn out.
[0047] It will be appreciated that the thermally conductive heat flow path provided between
the lamp base 22 and the internal wall 40 by central portions of the foil disc 100
may be alternately provided by other means if desired. For example, heat conductive
compliant materials other than graphite foil may be interposed between the lamp base
and the interior surface of the socket 42. While graphite foil has proven to be particularly
well suited for providing this conductive heat link ,other materials such as pliable
silicon elements could also be employed. Alternatively, a suitable heat conductive
grease could be used.
[0048] It will also be appreciated that the compliancy of the compressed foil tabs 108,
110 allows them to conform to and engage a substantial portion of the upper and lower
lamp base surfaces 112, 114 disposed in the socket 42. Alternatively, relatively non-compliant
conductive heat transfer elements could also be used. However, such non-compliant
elements would not be as thermally efficient since they normally would not contact
the upper and lower lamp base surfaces as uniformly and completely as a compliant
material would.
[0049] As previously described, the internal wall 40 is conveniently formed integrally
with the balance of the fixture body 26. If desired, however, the wall 40 could be
formed separately and internally connected to the fixture body, in heat conductive
communication therewith, in another suitable manner.
[0050] In the preferred embodiment of the light fixture 10 described above, the foil disc
100 is conveniently secured to and covers the front end surface of the internal wall
40 so that the heat shield means 117 are collectively defined by the wall 40 and a
radially outer portion of disc 100. However, a variety of other methods of attaching
the foil or other heat conductive element to the internal wall could be utilized so
that the front surface of wall 40 would not be covered by foil or other heat conductive
material. In such instance wall 40 would directly intercept infrared radiation from
the lamp's reflector portion and would by itself define the heat shield means 117.
[0051] Unlike conventional fixtures used to house tungsten-halogen lamps such as lamp 12,
the light fixture 10 of the present invention does not to any appreciable degree
rely on internal convection to dissipate heat from the lamp. Accordingly, the fixture
10 may be sealed (by, for example, the lens 114) to render the fixture suitable for
outdoor use. Moreover, since internal air cooling need not be employed in the fixture
10, auxiliary cooling fans are not required, and no "light leaks" through body cooling
openings are created.
[0052] Finally, while the fixture 10 of the present invention is particularly well suited
for use with tungsten-halogen lamps such as lamp 12, it could also be used with other
high intensity lamps having base portions which are prone to excessive heat buildup.
[0053] The body 26 of the light fixture 10 just described, together with its external cooling
fins 48, may be machined from a single block of aluminum to provide the fixture body
with a very pleasing exterior appearance unbroken by assembly joint lines. However,
this body fabrication technique results in a considerable amount of scrap metal which
normally must be discarded. Cross-sectionally illustrated in Fig. 4 is an alternate
embodiment 10
a of the light fixture 10 which is considerably less expensive to produce and generates
a significantly diminished amount of scrap metal. Components in the fixture 10
a similar to those in fixture 10 have been given the same reference numerals, but with
the subscript "a".
[0054] The body 26
a of fixture 10
a has an inner section defined by a length of aluminum tubing 120 which has a counterbore
122 extending axially into a forward end portion thereof, and an equal diameter counterbore
124 extending axially into a rear end portion thereof. Counterbores 122 and 124 respectively
define within the tubular body section 120 annular forwardly and rearwardly facing
ledges 126 and 128.
[0055] The external body cooling fins 48
a are formed from portions of a series of thin aluminum discs 130, one of which is
representatively depicted in Fig. 5. A central circular portion 132, having a diameter
slightly larger than those of the counterbores 122 and 124, is punched from each of
the discs 130 as indicated by the dashed punchline 134, leaving an annular disc portion
136 having an inner diameter somewhat smaller than the outer diameter of the tube
120. The annular disc portions 136 are axially press-fitted onto a rear portion of
the tube 120 to form the longitudinally spaced external cooling fins 48
a as indicated in Fig. 4.
[0056] To form the internal heat shield means 117
a within the fixture body 26
a, central rectangular openings are formed through three of the punched-out central
disc portions 132, and these three central disc portions are press-fitted into the
open forward end portion of the tube 120 until they abut the forward annular ledge
126. The rectangular openings in these three disc portions are appropriately aligned
to collectively define therein the lamp base socket opening 42
a. If desired, a greater or smaller number of the central disc portions could be used
to define the heat shield means 117
a, depending on the thickness of the individual central disc portions and the overall
thickness desired for the heat shield.
[0057] The open back end of the tube 120 is closed by a fourth central disc portion 132
which is press-fitted into the counterbore 124 until it abuts the rearwardly facing
annular ledge 128. A suitable circular opening 138 is formed in this disc portion
to define an outlet opening for the power leads (not illustrated) from the electrical
connector 86
a. Connector 86
a is supported within the body 26
a by means of bolts 82
a which extend through the heat shield 117
a, through the connector 86
a, and through the rearwardly disposed central disc portion 132. The connector 86
a is tightened against the rear surface of the heat shield 117
a by means of nuts 140 threaded onto the bolts 82
a. The graphite foil strip 100
a, which is interposed between the lamp base 22
a and the interior surface of the socket opening 42
a, is secured to the front surface of the heat shield 117
A by the heads of the bolts 82
a as illustrated.
[0058] The body cap 44
a, which holds the lens 114
a in place, is provided with a smooth interior surface 142 which may be slipped onto
the forward end of the tube 120 and held in frictional engagement therewith by means
of an O-ring member 143 carried in a suitable groove formed around the exterior periphery
of the forward end of the tube 120.
[0059] It can be seen that the light fixture 10
a is at least somewhat less expensive to produce than the previously described fixture
10 and generates less scrap in the fabrication process. Of the previously described
components used to fabricate the body 26
a of the fixture 10
a, the only portions that are discarded are the central disc portions 132 not used,
and the small amount of scrap material resulting from the formation of the counterbores
122 and 124. Further, with the exception of forming such counterbores, no machining
is required to form the body 26
a.
[0060] The foregoing portion of this description has focused upon the present invention's
provision of an entire light fixture assembly which uniquely functions to substantially
prolong the life of a lamp housed therein by significantly reducing the operating
temperature of portions of the lamp, and the conventional electric connector into
which it is plugged. However, as will now be described, the present invention also
provides unique retrofit apparatus which may be used to modify an existing light fixture
to incorporate therein the novel lamp heat dissipating principles incorporated in
the fixtures 10 and 10
a.
[0061] With reference now to Figs. 6 and 7, the present invention also provides a uniquely
designed heat dissipating lamp connector assembly 150 which may be used in retrofit
applications to replace the conventional ceramic connector (not shown) disposed within
the exterior housing 152 of a conventional light fixture 154 that utilizes a tungsten-halogen
lamp 156 having a reflector 158, a filament 160, a tapered base portion 162 having
seal strips 164 therein, and a pair of connecting pins or prongs 166.
[0062] The heat dissipating connector assembly 150 includes a hollow cooling body 168 which
is preferably formed from two extruded aluminum sections 170, l72 which have a series
of external cooling fins 174 formed on their upper and lower sides. The extruded sections
170, 172 are intersecured in a side-by-side contiguous relationship (Fig. 7) by a
pair of aluminum clamping panels or plates 176 which are held against opposite external
side surfaces of the two extruded sections by four connecting bolts 178 extending
through the sections 170 and 172 and the panels 176.
[0063] A forward end portion 180 of the cooling body 168 defines the heat shield means 117
a and has a rectangularly cross-sectioned socket opening 42
a extending rearwardly therethrough. Side edge portions 182 of a pair of rectangularly
shaped graphite foil elements 100
a are captively retained in a pair of upper and lower slots 184 formed in the interior
surface of the socket opening 42
a so that the remaining portions 186 of the foil elements 100
a are bendable into the socket opening 42
a as best illustrated in Fig. 6.
[0064] The cooling body 168 is also provided with an enlarged, rectangularly cross-sectioned
internal cavity 188 which is positioned rearwardly of and communicates with the socket
opening 42
a. Clamping plates 176 define opposite side wall portions of both the socket opening
72
aand the cavity 188.
[0065] Captively retained within the cavity 188 is a connector portion 190 of the assembly
150 which includes two pairs of vertically stack aluminum blocks 192 and 194 that
are positioned in a spaced, side-by-side relationship within the internal cavity
188. The stacked block pairs 192, 194 are encapsulated within and separated by a silicon
insulating material 196 which engages the interior surface of the cavity 188. The
insulating material 196 is highly resistive to electrical current flow therethrough,
but has a relatively high degree of thermal conductivity. Extending rearwardly through
the block pairs 192, 194, along their juncture areas 198 and 200, are a pair of connector
pin openings 202, 204. Secured to the rear end surface 206 of the cooling body 168
is a suitable connecting bolt 208 formed from an electrical insulating material. To
provide electrical power to the connector portion 190 of the assembly 150, a pair
of power lead wires 210 are suitably secured to the block pairs 192, 194 as best illustrated
in Fig. 7.
[0066] Prior to the installation of the improved heat dissipating connector assembly 150
in the existing light fixture 154, the base 162 of the lamp 156 is connected within
a conventional ceramic electrical connector (not shown) disposed within the housing
152. A forward end flange 212 of the lamp 156 is engaged and supported by spring clip
elements 214 (only one of which is illustrated in Fig. 6) that is carried by an annular
insert 216 which is frictionally received within the forward end of the housing 152
and also supports the fixture lens 218. Disposed forwardly of the insert 216 is a
representative louvered trim element 220 also frictionally received within the forward
end of the housing 152.
[0067] To install the new connector assembly 150 in the existing fixture 154, the lamp 156,
together with its supporting insert 216, the lens 218 and the trim element 220, are
removed from the housing 152. The existing ceramic connector is then disconnected
and also removed from the housing 152. The cooling body 168 is then secured to the
rear wall 222 of the housing 152 by extending the connecting bolt 208 outwardly through
an appropriate opening 224 formed in wall 222 and affixing a suitable nut 226 to the
outer end of the bolt 208. To improve the heat transfer from the cooling body 168
to the rear wall 222 of the housing 152, a layer of a suitable thermal grease is placed
between the rear surface 206 of the cooling body 168 and the interior surface of the
rear housing wall 222. Alternatively, if desired, a sheet of graphite foil may be
interposed between these two surfaces. Suitable power wiring connections are then
made to the retrofitted connector assembly 150.
[0068] With the assembly 150 installed in this manner within the housing 152, the balance
of the fixture 154 may be operatively reinstalled. During this re-installation process,
the lamp base 162 is inserted into the socket opening 42
a, and through a forward side opening 230 formed in the encapsulating insulation material
196, until the rear end of the lamp base 162 abuts the block pairs 192, 194 and the
connector pins 166 enter their associated pin openings 202, 204. Insertion of the
lamp base 162 into the socket opening 42
a bends the graphite foil portions 186 rearwardly within the socket opening, and compresses
them between upper and lower side surfaces of the lamp base 162 and the interior surface
of the socket opening. This compression of the foil element portions 186 compensates
for planarity irregularities in such surfaces, and forms a very efficient and uniform
thermal conductivity path therebetween.
[0069] According to an important feature of the improved connector assembly 150, the pin
openings 202, 204 formed in the block pairs 192, 194 are provided with diameters just
slightly smaller than those of the connector pins 166 which they receive. Accordingly,
when the pins 166 are operatively inserted into the pin openings 192, 194 the metal
blocks in each stacked pair thereof are caused to slightly separate against the resilient
force of the encapsulating insulating material 196. This creates a frictional force
between the block pairs and the lamp base pins inserted therebetween to thereby create
a very desirable "pin-wiping" action within the connector assembly 150. In conventional
connector assemblies, this pin-wiping action is often provided by means of a rather
complex system of internally spring-loaded contact members which are resiliently biased
into engagement with the lamp base pins. In the present invention, however, this pin-wiping
action is achieved in a significantly more reliable and less expensive manner.
[0070] During operation of the retrofitted light fixture 154, rearwardly directed radiant
heat from the lamp reflector 158 is intercepted and absorbed by the integral heat
shield means 117
a of the cooling body 168. The absorbed radiant heat is convectively dissipated to
the interior of the fixture housing 152 by means of the external cooling fins 174
on the cooling body 168. Lamp base heat, from the lamp base itself and from heat radiated
by the seal strips 164, is transferred to the graphite foil elements 100
a and conducted to the cooling body 168 for further dissipation into the interior of
the housing 152.
[0071] Additional heat from the lamp base 162, and the connecting pins 166, is conducted
to the metal block pairs 192, 194 and then transmitted through the thermally conductive
insulating material 196 into the cooling body 168. This pin and lamp base heat initially
conducted to the relatively massive internal heat sink defined by the metal block
pairs is dissi pated into the interior of the fixture housing 152 by the cooling
fins 174, and is also conducted to the rear housing wall 222 through the thermal grease
228.
[0072] In these various manners, lamp base heat, seal element heat, and connecting pin heat
is uniquely sinked away from the lamp by the improved heat dissipating connector assembly
150 to thereby significantly reduce the lamp operating temperature, and accordingly
extend its operating life far beyond that normally occurring when the lamp is installed
in conventional fixtures. The unique lamp heat dissipating abilities provided by
the present invention may thus be easily and inexpensively incorporated in a variety
of existing light fixtures.
[0073] Illustrated in Figs. 8 and 9 is an alternate embodiment 240 of the heat dissipating
connector assembly 150. Connector assembly 240 comprises a cooling body 242 defined
by a pair of extruded aluminum sections 244, 246 having a series of external cooling
fins 248 formed on their upper and lower side surfaces. The metal sections 244 and
246 are encapsulated within and laterally separated by a silicon insulating material
250 (similar to the previously described encapsulating insulating material 196) which
is highly resistive to electrical current flow, but also has a fairly high degree
of thermal conductivity.
[0074] A forward end portion 252 of the cooling body 242 defines the heat shield means 117
a and has formed therein a rectangularly cross-sectioned socket opening 254 having
a rear end surface 256. Side edge portions of a pair of rectangularly shaped graphite
foil elements 258 are captively retained within suitable slots 260 formed in the interior
surface of the socket opening 254 so that the remainder 262 of each of the foil ele
ments may be bent rearwardly into the socket opening 254 as best illustrated in Fig.
8. Positioned rearwardly of the socket end surface 256, and slightly forwardly of
the rear end surfaces 264 of the metal sections 244, 246, are a pair of vertically
centered rectangular openings 266 which are formed through the metal sections.
[0075] The cooling body 242 is vertically split along a cut line 268 which extends rearwardly
from the forward end 252 of the cooling body to the openings 266 so that the vertically
split portions of the cooling body 242 are joined only along relatively thin, insulation
covered metal portions 270 positioned immediately behind the openings 266. A pair
of pin openings 272, 274 are formed through the split metal sections 244, 246 along
the cut line 268, and are of slightly smaller diameters than those of the lamp base
connector pins 166. Suitable power lead wires 276, 278 are respectively connected
to the split metal sections 244, 246.
[0076] To secure the connector assembly 240 within the existing fixture housing 152, a connecting
bolt 280, formed from a suitable electrical insulating material, is secured to the
rear end of the cooling body 242, is extended outwardly through a suitable opening
282 formed through the rear end wall 222 of the fixture housing, and is provided at
its outer end with a retaining nut 284. A layer of thermal grease 286, or a suitable
heat conductive foil element or the like, is positioned between the rear end of the
cooling body 242 and the inner surface of the housing rear wall 222.
[0077] When the connector assembly 240 is secured in this manner within the fixture housing
152, the lamp 156 is secured to the connector 240 by inserting the lamp base 162 into
the socket opening 254 until the rear end of the lamp base 162 abuts the rear surface
256 of the socket opening, and the connector pins 166 are received in their associated
pin openings 272 and 274. Entry of the lamp base 162 into the socket opening 254 rearwardly
bends and compresses the foil portions 262 within the socket opening as previously
described. Entry of the pins 166 into the pin openings 272, 274 causes the vertically
separated portions of the metal sections 244, 246 to slightly pivot (as indicated
by the arrows 288) about and against the resilient restoration force of the thin rear
metal portions 270 to maintain a desirable pin-wiping force on the connector pins
166.
[0078] During operation of the retrofitted light fixture 154 depicted in Fig. 8, rearwardly
directed radiant heat from the lamp reflector 158 is intercepted by the heat shield
means 117
a, which is interposed between the reflector and the portion of the cooling body 242
that receives the connector pins 166, is absorbed within the cooling body, and is
then convectively dissipated via the cooling fins 248 to the interior of the fixture
housing 152. Heat from the lamp base 162, the seal elements 164 and the connecting
pins 166 is transferred (directly and through the foil elements 258) into the relatively
massive internal heat sink defined by the split, metal sections 244, 246. Heat transferred
into such internal heat sink is convectively dissipated via the cooling fins 248
into the interior of the housing 152, and is further conductively transferred to the
rear endwall 222 of the housing via the thermal grease 286. This transferred heat
is then dissipated to ambient via the walls of the housing 152.
[0079] In a manner similar to that described in conjunction with the connector assembly
150, the assembly 240 uniquely functions to significantly lower the operating temperature
of the lamp 156 to thereby greatly prolong its operating life.
[0080] The connector assemblies 150 and 240 described above are very easy and relatively
inexpensive to manufacture and install in retrofit applications. They also advantageously
provide, in somewhat different manners, internal heat sinks which, compared to the
lamp bases and their connecting pins are relative massive to thereby quickly sink
away larger portions of the lamp heat ordinarily retained within the reflector, the
lamp base, its seal elements and the connecting pins. While the heat dissipating connector
assemblies 150 and 240 just described are particularly well suited for retrofit installation
applications, it will readily be appreciated that they could also be employed as original
equipment in a variety of light fixtures designed for operation in conjunction with
tungsten-halogen lamps or other similar lamp elements having high heat generation
characteristics.
[0081] The foregoing detailed description is to be clearly understood as given by way of
illustration and example only, the spirit and scope of the present invention being
limited solely by the appended claims.
1. Heat-dissipating light fixture apparatus comprising:
a hollow, heat conductive body;
electrical connector means, disposed within the interior of said body and being operatively
connectable to the base portion of a lamp having a reflector portion, for transmitting
electrical power from a source thereof to said lamp;
heat shield means, connected to the interior of said body and being interposable between
said electrical connector means and the reflector portion of a lamp whose base portion
is operatively connected to said electrical connector means, for intercepting radiant
heat generated by said reflector portion toward said electrical connector means, and
for conducting the intercepted radiant heat to said body; and
heat conducting means, interposable between said heat shield means and said base portion
of said lamp, for defining a conductive heat flow path between said base portion of
said lamp and said heat shield means.
2. The apparatus of Claim 1 wherein:
said heat shield means comprise wall means dividing the interior of said body into
first and second opposite portions, said electrical connector means being disposed
in said first interior portion adjacent one side surface of said wall means, and
said wall means have a socket opening extending therethrough and adapted to receive
said base portion of said lamp with said reflector portion of said lamp being disposed
adjacent the opposite side surface of said wall means.
3. The apparatus of Claim 2 wherein:
said heat conducting means comprise a compliant, heat conductive material interposable
between said base portion of said lamp and the interior surface of said socket opening
in said wall means.
4. The apparatus of Claim 3 wherein:
said heat conductive material is a graphite foil material.
5. The apparatus of Claim 2 wherein:
said heat conducting means comprise a foil element carried by said wall means and
having a portion bendable into said socket opening and adapted to be at least slightly
compressed between said base portion of said lamp and the interior surface of said
socket opening.
6. The apparatus of Claim 5 wherein:
said foil element is connected to said opposite side surface of said wall means.
7. The apparatus of Claim 6 wherein:
said foil element is of a graphite material.
8. A heat-dissipating light fixture for use with a tungsten-halogen lamp or the like
having a base portion adapted to receive electrical power from a source thereof, and
a dichroic reflector portion adapted to reflect visible light and absorb infrared
radiation generated by said lamp, said light fixture comprising:
a body having a cavity therein;
electrical connector means carried in said cavity and being connectable to said base
portion of said lamp for transmitting electrical power from a source thereof to said
lamp;
heat shield means disposed in said cavity for intercepting and absorbing infrared
radiation produced by said lamp and directed generally toward said electrical connector
means, and for conducting heat from the absorbed radiation to said body, said heat
shield means having a socket opening therein adapted to receive said base portion
of said lamp; and
heat conducting means for engaging said base portion of said lamp and conducting
heat therefrom to said body through said heat shield means.
9. The light fixture of Claim 8 wherein:
said heat shield means are formed integrally with said body.
10. The light fixture of Claim 8 wherein:
said heat conducting means are of a compliant material and are positioned and configured
to be at least slightly compressed between said base portion of said lamp and the
interior surface of said socket opening.
11. The light fixture of Claim 10 wherein:
said compliant material is a graphite foil material.
12. The light fixture of Claim 8 wherein:
said heat shield means comprise an internal wall within said body, said electrical
connector means being connected to one side of said internal wall, and said heat
conducting means are connected to the opposite side of said internal wall.
13. The light fixture of Claim 8 wherein:
said heat conducting means comprise a compliant member carried by said heat shield
means and having a portion bendable into said socket opening.
14. The light fixture of Claim 13 wherein:
said compliant member is of a graphite foil material.
15. The light fixture of Claim 8 wherein:
said body has external cooling fins formed thereon.
16. The light fixture of Claim 15 wherein:
said body has a generally cylindrical configuration.
17. The light fixture of Claim 16 wherein:
said body has a longitudinally extending slot formed therein, and said light fixture
further comprises a support rod having an end portion disposed in said slot, and
means for pivotally connecting said body to said end portion of said support rod.
18. A method of protecting the base portion of a tungsten-halogen lamp, and an electrical
connector to which the base portion is operatively attached, from excessive heat build-up
during operation of the lamp caused by absorbtion of heat from the reflector portion
of the lamp, said method comprising the steps of:
providing a conductive heat sink;
providing a heat shield;
utilizing said heat shield to intercept and absorb heat radiated from said reflector
portion toward said electrical connector;
conducting heat from said base portion to said heat shield;
conducting heat from said heat shield to said conductive heat sink; and
dissipating heat from said conductive heat sink.
19. The method of Claim 18 wherein:
said step of providing a conductive heat sink is performed by providing a hollow metal
light fixture body,
said step of providing a heat shield includes forming an internal metal wall within
said body and forming a socket opening through said wall, and
said step of conducting heat from said base portion to said heat shield includes
positioning a compliant, heat conductive material within said socket opening.
20. The method of Claim 19 wherein:
said step of conducting heat from said base portion to said heat shield is performed
by positioning a graphite foil material within said socket opening.
21. The method of Claim 20 wherein:
said step of dissipating heat from said conductive heat sink includes the step of
forming external cooling fins on said light fixture body.
22. The apparatus of Claim 2 wherein:
said body includes a tubular section onto which a series of annular exterior cooling
fins are secured, said cooling fins being formed from a series of disc-shaped elements
from which central portions have been removed, said wall means being defined by at
least one of said removed central disc portions, said socket opening extending through
said at least of said removed central disc portions.
23. The apparatus of Claim 22 wherein:
said series of annular cooling fins are axially press-fitted onto said tubular section,
and said wall means are defined by a plurality of said removed central disc portions
axially press-fitted into the interior of said tubular section.
24. The apparatus of Claim 23 wherein:
said body has an end wall defined by one of said removed central disc portions press-fitted
into an end of said tubular section.
25. The apparatus of Claim 24 wherein:
said tubular section has a duality of counterbores extending inwardly through opposite
ends thereof and defining axially oppositely facing annular internal ledges therein,
said plurality of removed central disc portions abut one of said ledges, and
said end wall abuts the other of said ledges.
26. The apparatus of Claim 25 wherein:
said electrical connector means are secured to said plurality of removed central disc
portions, and
said plurality of removed central disc portions and said end wall are intersecured
by a plurality of elongated connecting members extending therebetween within said
tubular section.
27. The apparatus of Claim 22 wherein:
said apparatus further comprises an annular lens-retaining cap portion which receives
a front end portion of said tubular section, and means for frictionally retaining
said cap portion on said front end portion of said tubular section.
28. The apparatus of Claim 27 wherein:
said means for frictionally retaining said cap portion include an O-ring seal element
carried in an annular groove formed around an exterior surface portion of said front
end portion of said tubular section, said O-ring seal element frictionally engaging
an interior surface portion of said cap portion.
29. Heat dissipating electrical connector apparatus comprising:
a hollow, thermally conductive cooling body having an internal cavity and an inwardly
extending socket opening communicating with said cavity and adapted to receive a
lamp element base portion having connector pins thereon;
heat conducting means carried by said cooling body and adapted to be compressed between
the interior surface of said socket opening and a lamp base portion received in said
socket opening; and
an electrical connector captively retained within said cavity and including:
a spaced duality of thermally and electrically conductive elements adapted to receive
electrical power from a source thereof, each of said elements having pin opening formed
therethrough for operatively receiving one of said connector pins, and
a thermally conductive, electrically resistive material encapsulating and separating
said duality of thermally and electrically conductive elements, and engaging the interior
surface of said cavity.
30. The electrical connector apparatus of Claim 29 wherein:
said duality of thermally and electrically conductive elements each comprise first
and second separate portions resiliently held in engagement along facing surfaces
thereof by said thermally conductive, electrically resistive material, and
said pin openings are cross-sectionally smaller than said connector pins and extend
along the facing surface junctures between said first and second separate portions,
whereby entry of said connector pins into said pin openings separates the engaged
first and second portions against the resilient force of said thermally conductive,
electrically resistive material to thereby create in said electrical connector apparatus
an automatic pin-wiping action.
31. The electrical connector apparatus of Claim 30 wherein:
each set of said first and second separate portions is defined by a stacked pair of
metal blocks.
32. The electrical connector apparatus of Claim 31 wherein:
said thermally conductive, electrically resistive material is a silicon insulating
material.
33. The electrical connector apparatus of Claim 29 wherein:
said cooling body includes two separate metal body sections, and
said electrical connector apparatus further comprises means for removably interconnecting
said separate metal body sections.
34. The electrical connector apparatus of Claim 33 wherein:
said separate metal body sections are metal extrusions, and
said means for removably interconnecting include a duality of plate members held against
opposite sides of said cooling body and defining opposite side wall portions of said
internal cavity and said socket opening.
35. The electrical connector apparatus of Claim 34 wherein:
said metal extrusions have crenelated opposite side surface portions which define
on opposite sides of said cooling body external heat dissipating cooling fins.
36. The electrical connector apparatus of Claim 29 wherein:
said heat conducting means include at least one graphite foil element.
37. The electrical connector apparatus of Claim 36 wherein:
said heat conducting means include a duality of graphite foil elements each having
a first portion retained within a groove formed in the interior surface of said socket
opening, and a second portion extending inwardly into said socket opening from said
first portion.
38. Heat dissipating electrical connector apparatus comprising:
a cooling body having first and second spaced sections formed from a thermally and
electrically conductive material adapted to receive electrical power from a source
thereof, said cooling body further having a socket opening extending inwardly through
a front end portion thereof and having an interior side surface and an inner end,
said socket opening being adapted to receive a lamp element base portion having connector
pins thereon, said first and second sections of said cooling body each having a pin
opening formed therein which extends rearwardly from said inner end of said socket
opening and is adapted to receive one of said connector pins;
a thermally conductive, electrically resistive material encapsulating and separating
said first and second spaced sections of said cooling body; and heat conducting material
disposed along said interior side surface of said socket opening and adapted to be
compressed between said interior side surface and a lamp base portion inserted into
said socket openings.
39. The electrical connector apparatus of Claim 38 wherein:
said first and second sections of said cooling body are metal extrusions.
40. The electrical connector apparatus of Claim 39 wherein:
said extrusions have crenelated opposite side surface portions which define on opposite
sides of said cooling body external heat dissipating cooling fins.
41. The electrical connector apparatus of Claim 38 wherein:
said heat conducting material comprises at least one graphite foil element.
42. The electrical connector apparatus of Claim 41 wherein:
said heat conducting material comprises a duality of graphite foil elements each having
a first portion retained within a groove formed in said interior side surface of said
socket opening, and a second portion extending inwardly into said socket opening from
said first portion.
43. The electrical connector apparatus of Claim 38 wherein:
said thermally conductive, electrically resistive material is silicon insulating material.
44. The electrical connector apparatus of Claim 38 wherein:
said cooling body and its encapsulating material are partially split along a joint
line which extends rearwardly through said front end portion of said cooling body
along central portions of said socket opening and said pin openings to a point positioned
forwardly of a rear end portion of said cooling body so that opposite side portions
of each of said first and second sections are retained in adjacency by a rear portion
of the section, and
said pin openings are cross-sectionally smaller than the cross-sections of connector
pins which they are adapted to receive,
whereby, upon insertion of such connector pins into said pin openings, the opposite
side portions of each of said first and second sections are separated by the connector
pins, against a resilient resisting force of said rear portions of said first and
second sections, to thereby create in said first and second sections an automatic
pin-wiping action.
45. Heat dissipating electrical connector apparatus comprising:
heat conducting body means adapted to receive electrical power from a source thereof
and transmit the received electrical power to a lamp element operatively connected
thereto, said heat conducting body means having:
a socket opening extending inwardly through an exterior surface thereof and adapted
to receive a lamp element base portion having connector pins thereon,
first and second interior portions each split into two sections facing along a juncture
area through which a connector pin-receiving opening extends, and
a heat conductive electrical insulating material separating and electrically isolating
said first and second interior portions from one another;
means, integrally defined by a portion of said body means, for resiliently holding
said two sections of each interior body means portion in close adjacency; and
heat conducting means carried within said socket opening and adapted to be compressed
between an interior surface portion of said socket opening and a lamp element base
portion received in said socket opening.
46. A method of fabricating a light fixture comprising the steps of:
providing a tubular, heat conductive first element adapted to form a portion of a
lamp housing;
providing a series of generally flat, heat conductive second elements;
removing a central portion from each of said second elements to form a series of third
elements;
press-fitting at least one of the removed central portions into the interior of said
tubular first element to form therein a transversely extending internal heat shield
wall;
forming through said at least one of the removed central portions a socket opening
adapted to receive a lamp element base portion having connector pins;
securing a pin-receiving electrical connector to one side of the heat shield wall
over said socket opening;
positioning in said socket opening a heat conductive material adapted to be compressed
between an interior surface portion of said socket opening and a lamp element base
portion received in said socket opening; and
press-fitting said series of third elements onto said tubular first element to form
thereon an longitudinally spaced series of cooling fins.
47. The method of Claim 46 wherein:
said method further comprises the step of press-fitting one of the removed central
portions into said tubular first element to form an end wall thereon.
48. The method of Claim 47 wherein:
said step of providing a tubular, heat conductive first element is performed by providing
a tubular, heat conductive first element having a circular cross-section,
said step of providing a series of generally flat, heat conductive second elements
is performed by providing a series of generally disc-shaped heat conductive second
elements,
said step of removing a central portion is performed by removing a circular central
portion from each of said second elements,
said method further comprises the step of counter-boring opposite end portions of
said tubular element to form therein oppositely facing, first and second annular interior
ledges,
said step of press-fitting at least one of the removed central portions is performed
by press-fitting said at least one of the removed central portions into engagement
with said first annular ledge,
said step of press-fitting one of the removed central portions into said tubular first
element to form an end wall thereon is performed by press-fitting one of the removed
central portions into engagement with said second annular ledge, and
interconnecting said end wall with said internal heat shield wall.
49. The method of Claim 46 wherein:
said step of positioning in said socket opening a heat conductive material is performed
utilizing at least one graphite foil element.
50. The method of Claim 49 wherein:
said step of positioning in said socket opening a heat conducting material includes
the steps of securing a graphite foil element to said internal heat shield wall and
positioning a portion of said graphite foil element to be bent inwardly into said
socket opening by a lamp element base portion inserted therein.