claim is: 1. An explosion resisting lighting unit comprising a body member having an annular depending portion, a 15 globe supporting ring detachably secured to said annular portion and a globe mounted in flame tight relation with said ring, said annular por-tion being formed with an opening, a venting member formed of porous sintered material closing said opening and being attached in flame 20 tight relation to said annular portion, said body member being provided with a radiahy extending flange encircling said depending portion, a lamp receptacle mounted in the body member and forming, in conjunction with said annular depending portion and the globe, a flame tight 25 compartment. 2. An explosion resisting lighting unit comprising a rigid body member having an annular depending portion, a globe unit detachably secured to said annular portion, said annular portion being formed with an opening, a 30 venting member formed of porous sintered material closing said opening and being attached to said portion in flame tight relation, a conical shield carried by the body and extending circumferentially of said annular portion and being spaced outwardly therefrom, a lamp receptacle 35 mounted in the body and forniing, in conjunction with said globe unit and annular portion, a flame proof compartment. 3. An explosion proof Jighting unit comprising a body member having concentricafly arranged intemafly 40 threaded depending flanges, a second body member having an internauy threaded flange, an externary threaded annular connecting member threaded into the flange of said second body member and the outer flange of said first body member and encircling the inner flange there45 of, said connecting member comprising a band of porous sintered metal having reinforcing rings bonded to the opposite ends thereof, said rings having axially extending reinforcing connecting members, a cap member threaded into said inner flange, a lamp receptacle threaded into 50 said cap member, and a globe carried by said second body member. 4. An explosion proof lighting unit comprising a body member formed with a pair of inner and outer depending annular flanges arranged in spaced concentric rela55 tion and being threaded on their inner stirfaces, an extemahy threaded annular member threaded into said outer flange and encircling said inner flange in spaced relation thereto, a -lobe detachably connected to said annular member in flame tight relation thereto, said an60 nular member being formed with an opening, an arcuate shaped venting member formed of porous sintered metal closing said opening and being bonded to said annular member, a cap member tbreaded into said inner flange, a lamp receptacle threaded into said cap member and 65 forming, in conjunction with said globe and annular member, a flame proof compartment. 5. An explosion resisting lighting unit comprising a body member formed with depending inner and outer 70 flanges arranged concentricauy and being threaded on their inner surfaces, an annular supporting member threaded into said outer flange and depending therefrom, said supporting member encircling said inner flange in spaced relation thereto, a globe unit threaded on the 75 depending portion of said supporting member, said body being formed with an external conical flange encircling

2,702,849 3 4 said supporting member, and said member being formed References Cited in the Me of this patent with an opening, a venting member formed of porous -said opening and sintered metal form'm-g a closure for UNITED STATES PATENTS being bonded to said supporting member, a cap member 489,150 Keil ------------- ------ Jan. 3, 1893 threaded into said inner flange, and a 1.@MP receptacle 5 2,050,839 Hastings -------------- Aug. 11, 1936 threaded into said cap member and forming, in conjunc2,530,135 Tornblom ------------ Nov. 14, 1950 tion with said supporting member and globe unit, a flame proof compartinent. FOREIGN PATENTS 640,249 France --------------- Mar. 24, 1928 10 444,877 Great Britain ---------- Mar. 31, 1936 365,648 Italy ------------------ Dec. 9, 1938

United States Patent Office 21702,849 2,702,849 EXPLOSION RESISTING LIGHTING UNff Carl H. BisseB, Syracuse, N. Y., assignor to Crouselends Company, Syracuse, N. Y., a corporation of New York Application August 23, 1949, Serial No. 111,797 5 Claims. (Cl. 240-11.2) This invention relates to explosion resisting lightin.units, and more particularly of the type provided with a flame proof venting structure to reneve intemal pressure in the event an explosive mixture within the unit is ignited. The invention has as an object a lighting unit of the type referred to embodying a structure economical to manufacture and assemble and in which there is incorporated a relatively large venting area, the arrangement permitting access to the interior of the unit for relamping without distarbing the venting structure. The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed. In describing this invention, reference is had to the accompanying drawings in which.like characters designate corresponding parts in all the views. In the drawingsFigure 1 is a side elevational view of a lighting unit embodying my invention. Figure 2 is a horizontal sectional view taken on line 2-21 Figure 1. Figure 3 is a vertical sectional view taken on a line corresponding to line 3-3, Figure 2. 'Ihe lighting unit consists of a body 10 fon-ned of cast metal and of substantially annular forination and having a depending annular flange 11, the lower portion of which is threaded externary to receive a second annular body portion 12 in the form of a globe supporting ring. The member 12 is threaded internally to permit it to be detachably secured to the flange 11 and, as shown in Figure 3, is formed with a Range 13 extending radially inwardly and against which a glass globe 14 abuts and which is held in flame tight relation to the ring 12 by a ring nut 15 threaded into the member 12. In the structure shoivn, the flange 11 is also detachably secured to the body 10 as by being threaded into a flange 17 spaced outwardly from and concentrically with a flange 18. With this arrangement, the flange 11 serves as an annular connecting member for the body portions 10, 12, and may be conveniently removed from the unit for cleaning, or replacement. The upper end of the body 10 and the flange portion 18 are threaded int6rnally to receive a cap portion 19 and a lamp receptacle 20 respectively. The receptacle 20, being threaded into the body, forms a flame tight barrier between the upper and lower portions of the unit, the lower portion being encircled by the flange 11 and the globe 14. The cap member 19 is threaded intemally, as at 21, for attachment to a conduit line. The flange 11 is formed with one or more openings which are closed by arcuate shaped venting members 23 formed of porous sintered metal. As shown in Figure 2, the venting member is in the form of a ring about which the flange 11 is cast or otherwise formed, whereby the ring, or the arcuate portions thereof, are permane,ntly bonded in the flange. Preferably, the flange 11 is formed with a plurality of openings of susbtantial dimension, whereby a relatively large area of porous sintered material is made available and which functions to quickly vent the interior of the unit and thereby prevent the building up of any pressure within the unit. Patented Feb. 22, 1955 2 The unit is relamped by loosening the set screw 28 and unscrewing the globe unit, including the annular member 12, from the flange 11, this without disturbing the flame tight joint between the glass globe 14 and the ring 12, and without disturbing the bond between the sintered material 23 and the flange 11. 'fhe body 10 is formed with a conical flange 30 encircling the flange 11 and forming a protective canopy over the vents 23 to minimize the accumulation of dust, or 10 other foreign material, that niight have a tendency to plug up, or close, the interstices in the material. What I