Heavy duty floodlight fixture

A wide beam floodlight fixture by which the light from a lamp bulb that radiates light in all directions away from its axis, directs that light in a wide well defined beam. The fixture comprises a housing with a transparent front wall, and opposite opaque top, bottom and side walls. A curved reflector in the rear of the fixture housing embraces the lamp bulb and directs its light out of the transparent front wall. The top and bottom walls of the fixture have aligned access ports through either of which the lamp bulb may be removed and replaced. A socket housing removably attached to the bottom wall of the fixture housing closes the bottom access port and has the socket for the lamp bulb base shock-resistantly mounted therein. The access port in the top wall of the fixture housing is closed by a removable cover, from the underside of which a flanged ring is resiliently supported to embrace the upper end portion of the lamp bulb.

This invention relates generally to industrial lighting fixtures and more 
particularly to a heavy duty floodlight by which the light from a high 
intensity axially symmetrical lamp bulb is projected onto any selected 
area. 
The type of lamp bulb for which the lighting fixture of this invention is 
intended radiates light in all directions away from its axis. For 
efficient utilization of its intense light, the lamp bulb is installed in 
a fixture that includes a reflector positioned to direct the light out of 
the front of the fixture in a well defined wide beam. By adjusting the 
orientation of the fixture on its supporting structure, the beam can be 
directed onto any selected area. 
Obviously, of course, the lamp bulb must be replaceable, but since these 
floodlights are often mounted in difficult to reach locations, as for 
instance the outer end of the boom of a crane, it is important that the 
fixture be adapted for quick and easy removal and replacement of the bulb. 
It is also important that the mounting of the lamp bulb in the fixture 
will always hold the bulb in a predetermined relationship to the 
reflector, but in a manner that fairly well insulates the lamp from the 
vibration and mechanical shocks to which the fixture is subjected by the 
rough environment of its typical installation. 
With these considerations in mind, it is a general object of this invention 
to provide a heavy duty floodlight fixture well adapted for use in 
locations that are subject to vibration and mechanical shocks, and in 
which a shock resistant mounting holds a high intensity axially 
symmetrical lamp bulb in substantially fixed relation to a reflector in 
the fixture, in a manner that allows the lamp to have limited yielding 
movement relative to the fixture. 
Another object of the invention is to provide a heavy duty floodlight 
fixture of the character described with coaxial lamp supports by which the 
lamp bulb is held at both its ends, in a manner allowing the lamp to have 
limited freedom for yielding shock resistant motion relative to the 
fixture. 
A further amd more specific object of the invention is to provide a heavy 
duty floodlight fixture which achieves the aforesaid objectives and which, 
in addition, is characterized by exceptionally convenient provision for 
removing and replacing the lamp bulb, either upwardly through the top or 
downwardly through the bottom of the fixture, so that the orientation of 
the fixture with respect to the structure on which it is mounted need not 
be disturbed when lamp replacement is needed. 
With these observations and objectives in mind, the manner in which the 
invention achieves its purpose will be appreciated from the following 
description and the accompanying drawings, which exemplify the invention, 
it being understood that changes may be made in the specific apparatus 
disclosed herein without departing from the essentials of the invention 
set forth in the appended claims.

Referring now to the accompanying drawings, the numeral 5 designates 
generally a heavy duty flood light fixture embodying the principles of the 
invention, and adapted to have an axially symmetrical lamp bulb 6 mounted 
therein. The lamp bulb, which is typicaly rated at 1,000 watts, may be of 
the mercury vapor, metal halide or high pressure sodium variety. Each of 
these lamps has a screw threaded base 7 by which the lamp is secured in a 
mating socket 8, and a glass envelope 9 which, in the case of the high 
pressure sodium lamp, has a uniform diameter for its entire length. The 
envelope of the other two types -- as shown in FIGS. 4 and 5 -- has a 
large diameter generally egg-shaped medial portion 10 and a smaller 
diameter cylindrical and coaxial protuberance 11 on its end remote from 
the base. 
The fixture 5 comprises housing structure having the general shape of a 
rectangular pan with a transparent front wall 12 across its open side. The 
transparent front wall is oriented with its shorter dimension extending 
more or less vertically and its longer dimension extending generally 
horizontally. Assuming such normal orientation, the housing further 
comprises structure defining rigid, opposite top and bottom walls 14 and 
15, respectively, both substantially perpendicular to the transparent 
front wall, a rear wall 16 and upright side walls 17 which diverge 
angularly from the rear wall to the side edges of the front wall and 
connect the top and bottom walls. The lamp bulb 6 is situated in the 
housing symmetrically between its side walls, with its axis upright and 
thus substantially parallel to the transparent front wall and in 
intersecting relation to the top and bottom walls. 
A curved reflector 19 is mounted in the rear of the housing with its medial 
portion close to the rear wall and its opposite ends near the junctions of 
the transparent front wall with the side walls. The reflector curves 
around the lamp bulb to reflect the light emanating therefrom outwardly 
through the transparent front wall in a well defined wide beam which may 
be directed onto any selected area by appropriately orienting the fixture 
on the structure to which it is secured. 
To mount the fixture where desired, its housing is embraced between and 
connected to the legs 20 of a U-shaped mounting bracket 21, the base 22 of 
which is securable to the machine part or other structure upon which the 
fixture is to be mounted in a manner allowing for some adjustment of the 
mounting bracket about a vertical axis. To provide for tilting adjustment 
of the fixture housing about a horizontal axis parallel to its transparent 
front wall, coaxial lockable swivel connections 23 secure its side walls 
to the upper end of the legs 20 of the mounting bracket. 
As best seen in FIG. 3, the top and bottom walls of the housing have 
coaxial round holes 24 and 25, respectively. These holes provide access 
ports into the interior of the housing and enable the lamp bulb to be 
inserted and removed either upwardly through the hole or port 24 or 
downwardly through the port 25. 
A closure member in the form of socket housing 26 detachably connected to 
the bottom wall 15 of the housing closes the port 25 and the port 24 is 
closed by a cover or lid 27. In each instance the closure member is 
removably connected to its respective housing wall by the interengagement 
of circumferentially spaced keyhole slots 28 in the peripheral portion of 
the closure member with screws 29 threaded into the adjacent housing wall 
and also, in each case, a gasket 30 clamped between the closure member and 
the housing wall assures a weathertight joint. 
A socket housing 26 is shaped to provide an upwardly opening central main 
cavity 31 in which the lamp socket 8 is located and a laterally adjacent 
smaller cavity which is separated from the main cavity by a partition wall 
33. The cavity 32 serves as a junction or splice box for the electrical 
connections 34 between the supply line 35 and the leads 36 from the 
terminals of the socket. Access into the cavity 32 from the exterior of 
the fixture is through its open bottom which is closed by a removable 
cover 37. 
The upper portion of the socket housing 26 forms a flange 38 that encircles 
the open top of its central cavity 31 and has a planar top surface to 
clamp the adjacent gasket 30 against the flat bottom wall of the fixture 
housing when the screws 29 are tightened. Spaced downward a short distance 
from the flange 38 the side wall of the socket housing has a ledge 39, and 
seated on and secured to this ledge by circumferentially spaced screws in 
an annular diaphragm 40 of rubber or the like. The inner edge of this 
diaphragm is secured, as by means of rivets 41, to a flange 42 that 
encircles and projects radially from the mouth of a cylindrical metal cup 
42' to the bottom of which the lamp socket is secured. The cup 42' serves 
as a substantialy rigid carrier for the lamp socket, and by virture of the 
securement of its flange 42 to the inner edge of the rubber diaphragm 40, 
the latter provides a resilient shock absorbing mount for the lamp socket. 
Attention is directed to the fact that the manner in which the lamp socket 
is mounted not only resiliently isolates the socket -- and hence the lamp 
-- from the effects of shock and vibration to which the fixture is 
subjected, but also has the virture of enabling the height of the housing 
to be held to a dimension only slightly greater than the height of the 
envelope of the lamp. This desirable compactness results from the fact 
that the entire lamp socket assembly, which includes the carrier 42' , is 
located within the cavity 31, to which it is confined by the securement of 
the peripheral portion of the rubber diaphragm 40 to the ledge 39 at the 
mouth of the cavity. 
It will be apparent that if the lamp bulb were supported only by its base, 
the yieldability of the shock mounting of the socket 8, combined with the 
leverage of the rather large envelope 9 could result in relatively large 
excursions of the lamp bulb from its intended position in response to 
mechanical shocks and vibrations imparted to the fixture. To prevent that 
objectionable consequence, the lamp bulb is steadied at its upper end in a 
manner which allows it to have 
limited yielding movement relative to the housing without subjecting its 
relatively fragile glass envelope to the danger of breakage even though 
the envelope becomes highly heated when the lamp is burning and the 
steadying means engages it firmly. 
The means for thus steadying the lamp bulb comprises a flanged ring 43 
which has a resilient connection with the lid or cover 27 and embraces the 
upper end portion of the lamp when the lid or cover is in place closing 
the hole or port 24. In the case of the lamp illustrated, the upper end 
portion thereof is its cylindrical protuberance 11. 
The ring 43 can comprise a single piece of light sheet metal formed to 
define a cylindrical medial portion 44, a wide upper flange 45 and a 
frustoconical lower flange 46. The inner surface of the cylindrical medial 
portion and the bottom of the lower flange are preferably lined with heat 
insulating material 47. 
The cylindrical medial portion 44 of the ring has an axial length about 
equal to that of the cylindrical protuberance 11 on the bulb, and with its 
liner 47 it has an inside diameter to fit that protuberance or the upper 
end portion of a uniform diameter high pressure sodium lamp, rather 
loosely. If the lamp is of the type illustrated, the frustoconical lower 
flange 46 rests on the larger diameter portion of the lamp envelope that 
is downwardly adjacent to its cylindrical protuberance 11, and to 
facilitate that engagement, the flange 46 is downwardly and outwardly 
flared to mate with the outwardly radiating envelope surface on which it 
rests. 
The resilient connection between the ring 43 and the lid or cover 29 
comprises a plurality of circumferentially spaced studs 48 that project 
downwardly from the underside of the lid or cover 27 and extend through 
loosely fitting holes 49 in the upper flange 45 of the ring 43. The ring 
43 is thus capable of up and down motion relative to the lid or cover 27, 
and by virture of the loose fit of the studs 48 in the holes 49, also has 
some freedom to shift in radial directions. Enlarged heads 50 on the lower 
ends of the studs define the lower limit of downward motion of the ring 
relative to the lid or cover 27; and coiled expansion springs 51 that 
encircle the studs and react between the lid or cover 27 and the upper 
flange 45, yieldingly urge the ring downwardly. 
When the lid or cover 27 is secured in place on the top wall 14 of the 
housing, and the ring 43 is engaged with the upper end portion of the lamp 
bulb, the springs 51 hold the frustoconical lower flange 46 of the ring 
firmly seated on the outwardly bulging envelope surface beneath the 
protuberance 11. Obviously, of course, if the lamp is of the type having a 
uniform diameter envelope, the springs hold the ring in its lowermost 
position seated on the heads 50 of the studs. In each instance, though, 
the springs 51 cooperate with the studs 48 to yieldingly limit radial 
motion of the lamp bulb, and generally cooperate with the resilient 
shock-cushioning mount of the lamp socket to insulate the lamp bulb from 
the mechanical shocks and vibrations to which the fixture is subjected. 
It will be apparent that, in addition to cushioning the lamp bulb from 
mechanical shocks and vibrations imparted to the fixture, the springs 51 
also serve to accommodate axial thermal expansion and contraction of the 
bulb envelope, in the case of lamps of the type illustrated, which can be 
rather substantial inasmuch as high intensity lamp bulbs become highly 
heated when in use. The springs can perform this function by reason of the 
frustoconical configuration of the lower flange 46 and its cooperation 
with the correspondingly shaped portion of the lamp bulb envelope that it 
engages. Furthermore, because the lower flange 46 is maintained firmly 
seated on the underlying portion of the lamp bulb envelope under the 
biasing force of the springs, the cylindrical medial portion 44 of the 
ring 43 can fit rather loosely around the cylindrical protuberance 11 so 
that there is no danger of the envelope being cracked in consequence of 
its engagement by the ring. 
Inasmuch as the ring 43 lifts off of the lamp bulb when the lid or cover 27 
is removed from the housing. and more or less automatically fits itself 
properly onto the lamp when the cover is installed, no invonvenience is 
experienced in replacing a lamp bulb through the port 25 in the top wall 
of the hohsing, since this opening is large enough to permit insertion of 
the hand. 
Removal and replacement of the lamp bulb through the port 25 in the bottom 
wall of the fixture housing is equally easy, and in fact easier, since in 
this case it is not necessary to insert the hand into the fixture housing 
to unscrew the lamp from its socket and replace it with a new lamp. 
In either case, a screw driver or the like is all that is needed to loosen 
the screws holding the selected port closure, i.e. the lid or cover 27 or 
the socket housing 26 in place. Anyone who has ever had to crawl out onto 
the boom of a crane to change a lamp bulb in a floodlight will appreciate 
the ease with which this can be done in the floodlight of this invention; 
but even more will he appreciate the option of being able to effect the 
exchange through either the top or bottom of the fixture. Because of that 
option, re-lamping very seldom, if ever, requires disturbing the 
orientation of the fixture on the structure to which it is secured. This 
is a significant advantage, since special tools are needed to loosen and 
retighten the connections 23 by which the fixture housing is secured to 
the mounting bracket in the desired orientation; but -- even more 
important -- reorientation of the fixture is not easily effected. 
In this connection, attention is directed to the fact that the lid or cover 
27 has a handle 52 fixed thereon. This handle not only facilitates removal 
and replacement of the lid or cover, but also provides sighting means that 
is useful in orienting the fixture. To this end, the legs of the U-shaped 
handle 52 have aligned "peep" holes 53, the axis of which bears a defined 
relationship to the light beam projected from the fixture. 
Another advantageous feature of the fixture of this invention resides in 
the fact that while the cavity 32 that provides the junction or splice box 
is an integral part of the socket housing, the partition which separates 
this cavity from the cavity 31 in which the lamp socket is located 
protects the connections 34 of the socket leads with the supply line as 
well as the adjacent portions of the supply line from the high heat in the 
lamp socket cavity. 
With a view to minimizing the transfer of the high heat of the lamp bulb to 
the lamp socket and its leads, a shield 55 is mounted in the bottom of the 
fixture housing. This shield -- which is centrally apertured to 
accommodate the base of the lamp bulb -- extends across the mouth of the 
socket housing and is secured to the peripheral top surface thereof by 
screws 56. 
From the foregoing description taken with the accompanying drawings, it 
will be apparent that this invention provides a heavy duty floodlight 
fixture that is far superior to any heretofore available. 
Those skilled in the art will appreciate that the invention can be embodied 
in forms other than as herein disclosed for purposes of illustration.