US3004144A

US3004144A - Lighting fixture

Info

Publication number: US3004144A
Application number: US10238A
Authority: US
Inventors: William C Agrell
Original assignee: Thomas Industries Inc
Current assignee: Thomas Industries Inc
Priority date: 1960-02-23
Filing date: 1960-02-23
Publication date: 1961-10-10
Anticipated expiration: 1978-10-10

Description

Oct. 10, 1961 w. c. AGRELL LIGHTING FIXTURE Filed Feb. 23, 1960 IN V EN TOR. @re [1 w z/zmm 6.

BY 7 I M 3,004,144 LIGHTING FIXTURE William C. Agrell, Forest Park, Ill., assignor, by mesne assignments, to Ehomas Industries, Inc., Louisville, Ky., a corporation of Delaware Filed Feb. 23, 1960, Ser. No. 10,238 1 Claim. (Cl. 240-11.2)

The present invention relates to lighting fixtures particularly to those adapted for outdoor use.

Many buildings to which entrance at night is desired have one or more lights adjacent the doorway. This is a common provision on residences. Such lights are generally embodied in outdoor fixtures which are exposed to the weather, and hence subject to moisture and corrosive influences. Also, they are exposed to dirt, smoke, insects and so forth. Fixtures of this type generally comprise a mounting, including a base containing a socket for an incandescent lamp, which lamp screws into the socket, and a transparent or translucent globe of glass or the like secured to and sealed to the base and mounting. Notinfrequently the globe or cover is pro tected by a screen or guard member of open screen or grille construction protecting the globe and its contained lamp from mechanical injury.

In case the lamp burns out, it becomes necessary to open the fixture to renew the lamp. Also, at times it may be desired to renew or to clean the globe. Structures of the prior art wherein the globe and/or guard are held to the base by means of screws, either by a series of spaced machine screws or by a globe encircling screw thread between the guard and the base, are unsatisfactory. The screw threads become corroded, and the guard cannot be taken off without great difiiculty or destruction of the guard when it is desired to renew the lamp. When the lamp is to be replaced in the case where the connecting screw threads are disposed on the inside periphery of the guard and the external periphery of the base, or vice versa, it is diflicult to unscrew the parts to get the fixture open, because the threads are usually found to be corroded together so tightly that it is impossible to turn the parts on the screw threads. Then after the lamp is replaced and the fixture is to be reassembled, it is difiicult to get the threads to engage without becoming crossed. Also, since the matching of the threads can be made to occur at only one limited angular position throughout the entire periphery, it is dilficult for an unskilled person to avoid crossing these threads in trying to assemble the fixture. The operator cannot see whether he has the fixture accurately in axial alignment with the base, and he must support the parts in vertical position while trying to align them and thread them together. The finer the pitch of the threads and the larger their diameter and the longer the guard, the more diflicult does this operation become. This screw threaded type of fixture has been on the market and widely used for many years, but no one has provided any means to overcome the above difliculty.

It is the aim of the present invention to provide a lighting fixture of the outdoor bracket type which can easily be assembled and/ or disassembled and reassembled by an unskilled person, even though it has long been exposed to the weather.

According to the preferred form of the present invention, I utilize a lug and slot of the type known as a bayonet joint instead of a screw thread to make the connection between the guard and the base or body of the fixture. This permits the parts to be assembled, disassembled and reassembled by an unskilled operator without the difficulties above described.

The guard need not be a complete cup. It may be rates atent 3,004,144 Patented Oct. 10, 1961 ice Assembling the fixture of my invention does not require I matching of a fine screw thread which can match at only one precise point in 360, and which will become crossed if endwise pressure is exerted on the parts when the threads are not in register, and the one part is turned relative to the other. The present fixture cannot cross any threads and need no delicate manipulation. Rotation of the guard relative to the base for only a fraction of a complete turn brings the lugs or pins into register with the slots. This can be easily detected by the feel of the positive stop which occurs when any one of the lugs drops into its corresponding slot. The other pin or pins and slot or slots may then readily be engaged by wobbling the guard slightly, whereupon the other lug or lugs will enter the slot or slots, and a short angular turn of the guard will cause the cam portions of the slots to draw the lugs in an axial direction to close the parts together, and compressing the globe against a cooperating gasket to make the connection weather tight. This operation of assembly or reassembly is readily performed even though the parts are not exactly in axial alignment when first engaged, since by my invention the parts are more or less self-aligning and fool proof.

Disassembly of the fitting is equally simple and easy. The operator rotates the guard or wing, and unlocks the lugs or pins from the slots or grooves. Preferably, two pins or lugs and two corresponding slots or grooves are employed, since this provides a balanced connection with minimum metal surfaces subject to sticking due to corrosion. Three lugs and grooves provide a slightly more accurate and more evenly balanced connection. The area of engagement of lugs and slots should be limited to what is consistent with the necessary strength of the parts.

To reassemble after replacing a lamp, the guard with the globe inside it is slipped over the lamp and the rim of the guard is pressed against a corresponding annular part of the base. The lugs may be on the base, and the slots may be on the rim of the guard, or, alternatively, the lugs may be on the guard and the slots on the 'base of the fixture. Preferably, the base has a rim overhanging the rim or slip of the guard for directing moisture outwardly and downwardly, although this is not essential, the seal being made at other parts. To reassemble, the guard with the 'globe inside it is slipped up over the lamp and the rim of the guard is brought into register with the corresponding part of the base, whereby the lugs on one part engage the solid end wall of the other part. While so pressed upwardly, the guard is rotated until the lugs register with the vertical portions of the slots. There is no uncertainty about the registration, as in the case of screw threads. A slight tilting of the guard out of axial alignment does not jam the parts as does crossing of the threads in a threaded installation. A simple turning movement engages the lugs with the inclined cam portions of the slots, and provides the desired connection. A gasket or sealing ring is disposed between the globe and the base, and this provides a degree of resilience which makes tightening of the connection easier. Also, preferably there is a yielding gasket between the flange of the glass globe and an annular shoulder on the guard to avoid localized stresses upon the glass due to slight unevenness of the rigid parts.

Now in order to acquaint those skilled in the art with the manner of constructing and operating an embodiment of my invention, I shall describe in connection with the accompanying drawings an embodiment of the same.

In the drawings:

FIGURE 1 is a vertical longitudinal section taken on the

line

1, 1 of FIGURE 2; 9

FIGURE 2 is a side elevation showing parts in section;

FIGURE 3 is a horizontal cross sectional view taken on the

line

3, 3 of FIGURE 1;

FIGURE 4 is a fragmentaryv detail view of the registering pin and slot arrangement;

FIGURE 5 is a sectional view taken on the line 5,, i of FIGURE 2; and I 'I FIGURE 6 is a detail view taken on the

line

6, 6 of F GUR In the embodiment illustrated in the drawings, an electric outlet box 1 of known or preferred construe; tion is suitably mounted in or on a wall 2 shown in dotted lines, or is otherwise suitably supported to pei' mit the fixture 3 to be attached thereto for support and electric supply connection. Interiorly disposed conduit, not shown, communicates through the wall with the outlet box 1, and electric conductors extend into. the outlet box and have terminals, not shown, for making. connection with the fixture wires (not shown) bribe fixture 3. Such fixture and supply conductors are conventional. The cfixture 3 is in the form of a bracket fixture having a foot or base member 4 which is fastened by

machine screws

5, 5 to an adapter ring 6, which adapter ring is fastened by screws 7 to

lugs

8, 8 of the outlet box. The ring connects the base of; the, fixture to the box. The fixture 3 comprises a horizontal shelf-like portion 9 which is integral with the base 4, and it provides an internal tunnel '10 for the fixture wires which lead from the lamp socket terminals to the outlet box 1. A hollow circular pluglike depending base portion 12 has a horizontal bottom wall 13 with an opening at the center for receiving the upwardly projecting cylindrical body 14 of a lamp socket 1 5. The body 14 of the socket 15 includes an annular flange 16 between which and the horizontal wall 13 the gasket 17 is clamped by the screws 18. The depending cylindrical base portion 12 has integral radially outwardly projecting lugs 19, see FIGURES l, 3 and 4, which lugs 19, when the fixture is closed, are disposed'in the horizontally extending portions of L-shaped grooves 22 formed on the inside of the cylindrical ring 24 of the guard member 25. This guard member 25 comprises an upper cylindrical ring member 24 and generally cylindrical sidewalls consisting of circumferentially and 10agitudinally extending

bars

26, 27 joined to a bottom por-v tion 28. It thus constitutes a cup-shaped member which has openings therethrough for light, but provides a mechanical guard and connection means for the cup shaped translucent or transparent glass globe 29;, which it embraces. The glass globe 29 has an outwardly extending rim or head 32 which provides a shoulder which is adapted to be engaged by an annular shoulder on the guard member 25 through the interposition of a cushion ring 33. The purpose of the cushion ring is mainly to avoid putting high localized stresses uponthe rim of the glass globe 29'. There is some resiliency in the cushion ring 331. It makes the assembling and dis; as m of the P ts eas e and ntev asta e f the glass globe.

Th lamp o k h c c e m nal 4, 325. see FIGURES 1 and 3, to which the internal wiring (not shgown) is connected. The incandescent lamp 36 is threaded into the socket 15 and is removable therefrom for renewal in the usual manner.

To disassemble the device shown in the drawings, the guard member 25 is rotated angularly a small amount sufficient to bring the lugs 19 into register with the axially extending portions 23 of the L-shaped groove 22. The guard may then be dropped down and with it the globe 29. Thereupon the lamp 36 may be removed and: a fresh lamp substituted.

If there is, any adhesion of the parts due to corrosion, the parts may be jarred to break such cohesion. To reassemble the fixtures, the guard 25, with the enclosed globe 26, is moved up endwise to embrace the lamp 36 until the, wing 24 embraces the cylindrical body 12 below the lugs .19, 19. This endwise and lateral alignment is readily determined, since there is ample clearance between the

parts

12 and 24, as shown at FIG- URE 2. The guard 25. is then rotated until the lugs 19 drop: into the vertical parts 23 of the L-shaped slots 22. This is' very readily detected 'by the operator.

the guard 25 is given a turn or twist to bring the lugs .19 onto the cam surfaces 37 and to pull the

parts

12 and 24 towards each other sufliciently to clamp the globe against the gasket 17. This manipulation is readily per formed by. an unskilled person even in the dark.

In a vapor and weather tight lighting fixture, the combination of a bracket providing a downwardly fac ing flat annular base portion, a lamp socket having an exterior circumferential flange underlying and secured to said base portion, a sealing gasket confined under compression between said flange and said base portion and providing a vapor and weather tight seal about said socket, said gasket extending' radially outward beyond said flange, said socket facing downwardly and being. adapted to receive and support a lamp, a cup shaped light transmitting globe adapted to surround and enclose the and socket and to engage said base portion, said globe having at its upper end an outwardly extending annular shoulder seating on the portion of said gasket extending radially outward beyond said flange of said socket rnembe rr a cup-shaped foraminous guard loosely embracing said globe and having at its upper enda substantially continuous ring member extending upward about said base portion and provided at its lower end with an inw'ardly extending annular shoulder facing axially upward and underlying said shoulder of said globe, a cushion sealing ring disposed between said shoulder of said guard and said shoulder of said globe, said base portion and said ring member having annular coaxial connecting parts disposed in telescopic relation, one of said parts comprising a plurality of lugs and the other of said parts comprising a plurality of grooves, each of said grooves opening axially to admit the corresponding lug and extending angularly providing means for camming said base portion and guard together effective for compressing the radially outer portion of said gasket and said cushion sealing ring' thereby providing a vapor and'weather tight seal between said base portion and the upperend of said globe and a vapor and weather tight seal between said shoulder of said guard and the under face of said shoulder of said globe.

References Cited in the file of this patent UNiTED STATES PATENTS 2,050,839 Hastings Aug. 11, 1936 2,157,738 Kollath May 9, 1939 2,749,435 Appleton June 5, d 2,813,970 Lester Nov. 19., 1957