US3108753A

US3108753A - Lighting fixture

Info

Publication number: US3108753A
Application number: US18592A
Authority: US
Inventors: Coffey James Selwyn Kempthorne
Original assignee: Lightolier Inc
Current assignee: Lightolier Inc
Priority date: 1959-04-10
Filing date: 1960-03-30
Publication date: 1963-10-29
Anticipated expiration: 1980-10-29

Description

Oct. 29, 1963 J. s. K. COFFEY 3,108,753

LIGHTING FIXTURE Filed March 30, 1960 INVENTOR. .umss szzmw KEMP/MM; cams-r ties trite Claims This invention relates to the art of lighting fixtures, and more particularly to a releasable support for a translucent diffuser. 1

As conducive to an understanding of the invention, it is to be noted that where a diffuser, which may be in the form of a bowl preferably of rigid translucent glass or plastic, is held in position in a supporting ring or bezel by means of clamping screws which react against the periphery of the diffuser, excessive tightening of such screws may lead to breakage of the glass or plastic diffuser, and furthermore, such screws are unattractive in appearance. In addition, as normally a plurality of screws are used to hold the diffuser in place, insertion and removal of the diffuser is both awkward and laborious, especially when the person inserting or removing the diffuser is standing on a ladder.

It is accordingly among the objects of the invention to provide a lighting fixture of simple and inexpensive construction in which the diffuser thereof may be readily and rapidly inserted and removed to afford access for relamping, cleaning orother service, without awkward manipulations or the need for any tools, or the unloosening or tightening of screws or the like, and without the need for visible retaining means which detract from the desired uninterrupted external configuration of the fixture, and in which the diffuser will dependably remain in closed position without possibility of accidental dislodgement.

According to the invent-ion, these objects are accomplished by the arrangement and combination of elements hereinafter described and more particularly recited in the claim.

In the accompanying drawings in which is shownone of various possible embodiments of the several features of the invention,

FIG. 1 isa perspective view of the lighting fixture,

'FIG. 2 is a bottom plan view of the lighting fixture with the diffuser removed,

FIG. 3 is a sectional view on an enlarged scale taken along line '3-3 of FIG. 2, and

FIG. 4 is a perspective view of the spring retainer for the diffuser.

Referring now to the drawings, the lighting fixture comprises a cup-shaped supporting member 11, preferably formed from thin sheet metal, having a fiat floor 12 and a circular deformable side wall or' bezel '13, the rim 14 of which is inwardly bent as shown.

The surface 12 may have a central aperture 15 to permit mounting of the supporting member to a ceiling, for example, in any conventional manner and has conventional sockets 16 thereon to accommodate suitable electric lamps.

The light diffuser 17 is illustratively in the form of a translucent glass bowl, the side wall 18 of which tapers inwardly from the mouth or rim'19 of the-bowl, which is of larger diameter than the remaining portion of said side wall, the outer diameter of said mouth '19 being slightly greater than the inner diameter of the rim 14. I

Mounted on the undersurface of floor 12 of the supporting member 11 adjacent its periphery and equidistantly spaced therearound are a plurality of resilient members, illustratively three leaf springs 21, each having 3-,lfi 8,753 Patented Oct. 29, 1963 2 a mounting portion 22 secured to the surface 12 as by rivets 23-.

Each of the leaf springs has a leg 24 extending at an incline outwardly from saidmoun-ting portion 22 toward the rim 14,the end of each of the legs 24 being curved as at 25, and a finger 26 integral with said curved portion 25 at the inner edge thereof extends toward the rim 14 and is adjacent the side wall 13 of the supporting member 11.

To mount the diffuser 17 to the supporting member 11, the diffuser is tilted relative to the floor 12 of the latter, as shown in broken lines in FIG, 3, so that a portion of the mouth :19 of the diffuser may pass into the concavity of the supporting member beyond the rim 14, with adjacent portions of said mouth 19 being positioned inside said rim 1-4 as shown at 27, and upward pressure is applied to the diffuser 17 so that the portions of said mouth 19' positioned inside the rim 14 will react thereagainst to move the latter outwardly, deforming the rim slightly so that its diameter becomes greater than the maximum diameter 19" of the mouth 19 of the diffuser. This will permit ready movement of the entire month 19 into the bezel opening defined by rim 14- of the diffuser, at which time the rim 14 will resume its original shape.

As the side wall 18 of the diffuser is tapered, with the larger diameter or rim portion 19 thereof being inwardly of said rim 14, by reason of the leaf springs 21,

the curved ends 25 of which react against the rim 19. of the diffuser, the outer surface of such rim 19 will be firmly retained in even engagement with the inner surface of the inwardly bent rim 14, the fingers 26' of the springs which straddle the rim 19 of the diffuser preventing lateral displacement of the diffuser.

When it is desired to remove the diffuser 17 to relamp the lighting fixture or for cleaning purposes, it is necessary to exert a slight pressure against the diffuser 17 at any portion of its periphery to move it upwardly. This will cause the diffuser to tilt as it is subject to the downward action of the leaf springs at other points on its circumference.

Such rtilting of the diffuser will cause the portion of its rim 19 opposed to the portion to which pressure is applied to move away from the associated portion of rim 14 of the supporting member. As the suppo-rting--mem-- her is made of thin sheet metal, the rim 114 will readily deform as the diffuser is pulled downwardly and laterally permitting complete removal of the diffuser through the opening defined by rim 14.

Although the side wall 13 has been shown integral with the floor 12, it is of course to be understood that it could be formed as a separate component. It is also to be understood that a double-sided bezel could be made to embrace the rims of two diffuser bowls to join them together to form a completely closed chamber.

As many changes could be made in the above construction, and many apparently widely different embodihaving a floor and a side wall with an inwardly extending annular rim at the mouth thereof defining a continuous circular opening, a cup-shaped diffuser member having a tapering side wall of largest diameter at the thereby locally.

mouth thereof and defining a circular rim, the outside diameter of said rim being slightly greater than the inside diameter of said inwardly extending rim, the diameter of the portion of the difiuser member adjacent the rim thereof progressively decreasing, said rim of said supporting member being deformable to receive the mouth of said diifuser member and to encompass the latter, releasably to retain said difiuser member in place, and a plurality of resilient means mounted on said supporting member adjacent its periphery and circum ferentially spaced thereon and reacting against the rim of said diffuser member at spaced intervals around its circumference to urge the wall portion of the difiuser member adjacent its mouth against the inwardly extending rim in a direction at right angles to the floor, each of said resilient means comprising a leaf spring having a mounting portion secured to the undersurface of said floor and a leg extending at an incline from said mounting References Cited in the file of this patent UNITED STATES PATENTS 957,956 Hine May 17, 1910 1,193,520 Crownfield Aug. 8, 1916 1,746,339 Doane Feb. 11, 1930 2,208,155 Daehler July 16, 1940 15 2,209,008 Sutherland July 23, 1940 FOREIGN PATENTS Great Britain of 1 896