Knockdown shade assembly for lighting fixture

Abstract

The shade assembly for use in a lighting fixture is characterized by a knockdown construction so that it may be easily disassembled for purpose of storage or transport. The shade assembly is in the general form of a regular polyhedron and includes a set of at least three flat trapezoidal windows arranged in a closed figure with their short sides on top and their long sides on the bottom. A base member is centrally disposed in the region above the windows. There are also a set of at least three ribs, each rib extending along the juncture of two of the windows and having its upper end removably secured to the base member. Each window is removably secured to the two adjacent ribs.

What is claimed is: 
     
       1. In a lighting fixture, an easily disassembled shade assembly comprising, in combination: a flat horizontally disposed base member having a central opening for receiving electrical circuit means extending vertically downward therethrough, and also having a plurality of slots 4  circumferentially spaced about its outer edge and extending radially inward therefrom;   a plurality of elongated ribs, one for each of said slots 4  each rib having an inner end extending into the associated slot 5  and releasably secured therein, the rib extending radially outward from said base member, bending downward through an angle of about 50°, and having a straight outer end portion;   a polygonal brace member having a number of straight sections equal to the number of said ribs, said brace member being horizontally disposed, positioned beneath said base member, and located inside the straight portions of said ribs with each apex of said brace member being releasably secured to the interior and underside of an associated one of said ribs; and   a plurality of flat trapezoidal windows, each of said windows being disposed between two adjacent ribs and each end of each window being aligned with the associated rib on the exterior side thereof;   said plurality of windows collectively forming a regular polyhedron surrounding the lower ends of said ribs;   the vertical height of said windows being less than the vertical height of said ribs, thereby leaving a vertical open space above said windows and below said base member.   
     
     
       2. In a shade assembly for a lighting fixture, an elongated rib structure integrally formed of resilient plastic material, comprising: an elongated flat substantially linear beam having inner and outer sides, an elongated central ridge on its outer side, and an outwardly turned hook forming a lower end thereof;   a short finger protruding from the outer side of the upper end of said beam, said finger extending towards said hook at an angle of about 45° to said beam;   a ball secured to the outer end of said finger, said ball and the outer part of said hook being substantially equidistant from said beam;   said beam having an elongated central ridge on its inner side, said inner ridge having transverse latch openings 6  opposite both said hook and said ball, each of said latch openings 6  being arcuately curved through more than 180; and   an elongated extension of the upper end of said beam, said beam extension being curved through an angle of about 50° in a direction away from said finger.   
     
     
       3. In a snap-together shade assembly for a lighting fixture, the combination comprising: an elongated resilient plastic rib member having two longitudinal spaced protrusions thereon, one of said protrusions being a hook and the other of said protrusions being finger extending toward said hook at an angle of about 45° to the member;   a ball secured to the outer end of said finger; and   a flat trapezoidal window 7  adapted to be removably supported upon said elongated member between said protrusions;   whereby one edge of said trapezoidal window 7  may first be brought into engagement with said hook, and then the other edge of said trapezoidal window 7  may be forced against said ball so as to snap between said ball and said member when said finger flexes in response to the force applied to said ball.   
     
     
       4. The apparatus of claim 3 wherein said elongated resilient plastic member has an elongated central ridge on the side thereof opposite said hook and said finger, said central ridge having at least one transverse latch opening with an arcuate wall curved through more than 180°. 
     
     
       5. The apparatus of claim 3 wherein said elongated resilient plastic member has an elongated central ridge extending between said short finger and said hook. 
     
     
       6. Apparatus as claimed in claim 5 wherein said hook has an interior V-shaped protrusion disposed opposite said central ridge. 
     
     
       7. In a snap-together shade assembly for a lighting fixture, apparatus comprising, in combination: an elongated resilient plastic rib member having a lower end upon which an outwardly turned hook is formed, and also having a finger spaced longitudinally above said hook and extending toward said hook at an angle of about 45° to said rib member;   a ball secured to the outer end of the finger, said ball and said hook being substantially equidistant from said rib member; and   a pair of flat trapezoidal windows 8  having mating ends adapted to be removably supported upon said rib member intermediate to said hook and said finger;   said hook being of sufficient width in a direction perpendicular to the plane of said finger to receive a corner portion of each of said trapezoidal windows 8  ; and   the other corners of the mating ends of said trapezoidal windows 8  being adapted to snap underneath said ball in engagement with said rib member, being retained there by resilient outward deflection of said finger.   
     
     
       8. The apparatus of claim 7 wherein said elongated resilient plastic member has an elongated central ridge on the side thereof opposite said hook and said finger, said central ridge having at least one transverse latch opening with an arcuate wall curved through more than 180°. 
     
     
       9. The apparatus of claim 7 wherein said elongated resilient plastic member has an elongated central ridge extending between said short finger and said hook. 
     
     
       10. Apparatus as claimed in claim 7 wherein said hook has an interior V-shaped protrusion disposed opposite said central ridge. .Iadd. 
     
     
       11.  A snap-together frame for supporting the shade of a lighting fixture comprising in combination: a plastic base member formed by cementing identical upper and lower plates together, each having a stub shaft and a recess for receiving said stub shaft so as to effect proper orientation of one plate with respect to the other;   a central opening in said plastic base member;   a plurality of radially extending slots in said plastic base member, each slot having an internal recess therein;   a plurality of elongated ribs made of resilient plastic material, each of said ribs having an upper attachment portion adapted to be slideably inserted into one of said plurality of radially extending slots, and a lower portion, said upper attachment portion having a protrusion adapted for snap locking engagement with the internal recess in said slot and also having an internal angular disposition of greater than 90° with respect to the lower portion thereof so that when said ribs are thus inserted their lower portions depend downwardly relative to the plane of said plastic base member;   each of said ribs also having first and second notches on its underside, each of said notches having an arcuate surface extending through an arc of greater than 180 degrees;   a first metal brace adapted for snap fit insertion into a first latch opening of each said ribs; and   a second metal brace adapted for snap fit insertion into a second latch opening of each of said ribs..Iaddend. .Iadd.   
     
     
       12.  A snap-together frame for supporting the shade of a lighting fixture comprising in combination: a plastic base member formed by cementing upper and lower plates together;   a central opening in said plastic base member;   at least one radially extending slot in said plastic base member, said slot having an internal recess therein;   at least one elongated rib made of resilient plastic material, said rib having an upper attachment portion adapted to be slideably inserted into said radially extending slot, and having a protrusion adapted for snap locking engagement with the internal recess in said slot;   said rib also having a lower portion, said upper attachment portion having an angular disposition of greater than 90° with respect to said lower portion;   said rib also having first and second latch openings on its underside, each of said latch openings having an arcuate surface extending through an arc of greater than 180 degrees; and   at least one metal brace adapted for snap fit insertion into said first latch opening of said rib..Iaddend.