US 2423884 A
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July 15, 1947. w. GLASS 2,423,884
REFLECTOR SHIELD UNIT FOR GERMICIDAL LAMPS Filed July 31, 1944 2 Sheets-Sheet 1 v vwvv mm mm July 15, 1947. I w, GLASS 2,423,884
REFLECTOR SHIELD UNIT FOR GERMICIDAL LAMPS Filed July 31, 1944 2 Sheets- Shet 2 fi 56 Y 4 57 L P jnverzfofi W W m 1 .Wa ger Glass Patented July 15, 1941 anrmc'ron snmm Um FOR Ganmcnm. rams Walter Glass, Northbroohlll. Application July 31, 1944, Serial No. 547,503
l The present invention relates to reflector shield units or fixtures for germicidal lamps, its general aim being the provision of such a device for accomplishing not only the safe but efllcient concentration of the lethal rays from such a lamp in a zone adjacent the latter for the destruction of air-borne bacteria.
More particularly, it is an object of the invention to provide such a germicidal lamp reflector.
shield unit for reflectively directing the rays of the lamp in a beam and embodying an arrangement bordering the main or central portion of the reflector shield for minimizing fringing and enhancing the-concentration of rays by reflecting those falling on it back toward the main portion of the reflector and generally transversely of the beam axis.
Another object of the invention is to utilize th otherwise wasted heat generated in the ballast or the like used in the-supply circuit for the lamp in inducing a flow of air through a zone of maxi-- mum concentration of lethal rays emanating I from the lamp.
Further objects and advantages of the invention will become apparent as the following description proceeds, taken in connection with the accompanying drawings in which:
Figure 1 is a perspective view of a reflector shield unit for a germicidal lamp and which embodies a preferred form of the present invention. Fig. 2 is a fragmentary front view of the structure shown in Fig- 1 with parts cut away to show certain features of the internal construction.
Fig. 3 is a transverse sectional view taken substantially along th line 3-4 in Fig. 2.
Fig. 4 is a fragmentary detail view,'on an enlarged scale, of a portion of the reflector shield incorporated in the unit of Fig. 1.
Fig. 5 is a detail sectional view taken substantially along line 5-5 in Fi 4.-
Fig. 6 is a fragmentary view similar to that of Fig. 4 but showing a modified form of multiple surface reflector contour suitable for use on'the border portions of the reflector shield.
While the invention is susceptible of various modifications and alternative constructions, I have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.
The unit or flxture herein disclosed is intended primarily for the reception of germicidal lamps which have been developed to. emit ultraviolet energy or radiations .of sufllclent intensity to kill air-bornebacteriasubjected to such radiations for a reasonably short period of time. Such lamps have a variety of fields of application in hospitals, schools, theatres, factories, oflices, homes, etc., where communicable diseases may be spread by air-borne bacteria. Since ultraviolet energy is not itself useful for illuminating purposes and is, in fact, harmful in some respects to human beings, careful shielding of the lamps is necessary in order to expose the air in only unoccupied por-' tions of a room or other space to the rays emanating from the lamp. The present invention is primarily concerned with the problem of not only effecting such shielding for safety purposes, but also the emcient concentration of the rays as well as thecirculation of air through the zone of ray concentration in order that any air-borne bacteria present may be quickly killed.
Referring to the preferred embodiment of the invention shown in the accompanying drawings, the unit or fixture there illustrated is adapted to receive a germicidal lamp ID of conventional tubular form and construction (Fig. 1). unit includes a pair of sockets ii, I! into which the usual end terminals (not shown) are inserted. These sockets are carried by flanged end plates i3, i4 fixed to the opposite ends of a sheet metal housing I5 of generally O-shaped crosssection (Fig. 3) having an open side 19. Inset within the housing 15 and fixed to the latter in position to face toward the open side IQ of the housing is a reflector shield it of novel form and construction. a
The reflector shield It extends longitudinally of the lamp Ill and is of trough-shape, being curved transversely to partially surround or embrace the lamp on the side thereof opposite the housing opening 19. To secure the reflector shield It in place its upper edge 20 is welded or otherwise fixed to the adjacent inwardly curled edge 22 of. the housing ii. A sheet metal partition 24 extending longitudinally throughout the length of the housing i5 and secured to the latter by attachment of an edge flange'li to the lionsing underlies and supports the reflector shield IS. The material of which the reflector shield I6 is made should be impervious to, and highly reflective of, the ultraviolet'rays, sheet aluminum being suitable for the purpose.
For projecting the rays from the lamp ill in a dense bundle or beam through the housingopen- The 3 ing [9, the mid portion 26 of the reflector shield I6 is concave and preferably smooth. This smooth mid portion 26 of the reflector shield extends from end to end of the latter and lies behind the lamp I0, facing directly toward the housing opening I9. The curvature of the mid,
portion 26 and its spacing from the lamp are such that a beam of desired span is produced.
In order to create a zone of concentration of the rays at a point in the path of the beam closely adjacent the lamp l0, and to minimize fringing or dispersion at the edges of the beam, the upper and lower marginal edge portions of the reflector shield l6 are shaped to provide a multiplicity of reflecting surfaces facing inwardly generally toward the lamp. In the present instance (Figs. 1 to 4) such supplemental reflecting surfaces are provided by longitudinal corrugations or flutes 29 and 30 in the respective upper and lower edge portions of the reflector shield. To further enhance the concentration of rays, transverse corrugations or flutes 32 and 33 are provided in the reflector shield at opposite ends of the longitudinally. corrugated portions. The beam-directing central reflecting surface 26 is thus bordered topand bottom by a multiplicity of reflecting surfaces angled to turn the rays falling thereon more or less transversely of the beam back into the central portion of the reflector to produce a maximum concentration of rays close in front of the lamp I0. Such an arrangement is substantially the opposite of that usually required in a reflector for an illuminating lamp.
In Fig. 6 is shown a modified form of multiple angled reflecting surfaces which may be fashioned in the border portions of the reflector shield l6 of Fig. 1 in lieu of the corrugations 29, 30 and 32, 33. In this modified arrangement a multiplicity of reflecting surfaces is provided by the side faces of a plurality of rows of, truncated pyramid protuberances 31 fashioned in the sheet metal reflector shield and defined by a plurality of rows of double or transverse corrugations, such as 35 and 36, intersecting each other at right angles.
Since the pyramidal shapes provide transversely disposed reflecting surfaces on each pyramid, the pattern may be continuous throughout the margins of the smooth central reflector portion 26.
To augment the normal circulation of air through the zone of maximum ray concentration, the otherwise wasted heat incident to the operation of a ballast I! for the lamp I is utilized. For that purpose the ballast I1 is mounted on bracket legs 40 secured to the rear wall of the housing I so that the ballast is located beneath the partition 24 and above an air supply louver or opening 38 in the housing? Air entering the louver 38 is warmed by heat from the ballast and thus caused to rise, emerging from an opening 39 defined between the lower edge of the reflector shield l6 and the adjacent edge 23 of the housing l5. As the stream of air emerges from the opening 39 the overhanging lip or edge 23 of the housing directs it inwardly of the reflector shield so that it passes upward and inward adjacent the lamp land into the zone of maximum ray concentration for thedestruction of bacteria carried by the air.
As a further precaution against entry of the lethal rays from the lamp Ill into the occupancy zone of a room or the like where the fixture is mounted, a supplementary shield 43 may be provided. This shield comprises a rectangular portion of sheet metal pivoted at its lower corners at 44' on the housin end plates l3, I4 for vertical swinging adjustment. The friction of the pivots is sufliciently great to maintain the auxiliary shield 43 in a desired position of adjustment. When it is swung upward into position to partially block the beam emerging from the unit the rays which it intercepts are reflected back to the main reflector shield IS.
The unit or fixture shown may be installed in a room or other place of use by mounting the same at a suitable height, as for example on a wall of the room. The supplemental shield 43 is adjusted to a position suited to cutting off any rays that might otherwise pass to an adjacent occupancy zone in the room. Of course if the fixture is high enough, the auxiliary shield 43 may be swung down to completely clear the housing opening 19 or removed entirely. The lamp I0 is connected to a suitable source of alternating current through the use of conventional supply connections which are well-known, and consequently need not be detailed here. Normally the same include a so-called ballast or iron core choke coil which remains in series with the lamp throughout the latters period of operation which has been indicated herein at H. As heretofore explained, the otherwise wasted heat given off by this ballast is utilized in the present unit for augmenting the circulation of air into the zone of lethal rays emanating from the lamp. When the unit is installed as described, and the lamp I0 is in operation, the ultraviolet radiations or rays from the latter are directed outward through the housing opening l9 in a dense bundle or beam with a maximum concentration of such rays close in front of the lamp or, in other words, approximately at the opening or mouth of the unit. The air circulating in the room or other spac passes through the beam of ultraviolet radiations so that the bacteria borne by this air are exposed to the radiations and quickly killed. In any ,room there is usually some convection circulation manner heretofore described.
I claim as my invention:
1. In a fixture for elongated tubular germicidal lamps, the combination of an elongated sheet. metal housing closed at its ends and having a longitudinally extending opening in an upper side portion thereof, a trough-shaped reflector shield mounted in said housing to extend longitudinally of the latter in position to face toward said opening, the upper edge of said shield being in engagement with said housing and the lower edge being spaced from the edge of said housing defining the lower edge of said opening to provide an air exit passage therebetween, said shield having a central longitudinally extending portion presenting a smooth, highly reflective surface and the longitudinal marginal portions of said shield being configurated to present a multiplicity of reflective surfaces facing.
a generally inward toward the central portion of whereby air entering said louver is warmed by heat generated by said ballast as a normal incident to its operation and upon being warmed rises to emerge through-said exit passage into lamps,,the combination of an. elongated sheet metal housing closed at its ends and having a longitudinally extending opening in an upper side portion thereof, a trough-shaped reflector shield mounted in said housing to extend longitudinally of the latter in position to face toward'said opening, the upper edge of said shield being in engagement with said housing and the lower edge being spaced from the edge of said housing defining the lower edge of said opening to provide an air exit passage therebetween, means for supporting the lamp in front of said shield for beaming of its rays by the latter out of said opening, a-ballast for said lamp mounted in said housing beneath said shield, and said housing having a louver therein in the lower portion of its side wall opposite said opening for the admission of air, whereby air entering said louver is warmed by emanating from said lamp and beamed by the re-.
, supporting. a germicidal --lamp'.in front of said heat generated by said ballast as a normal in-..
cident to its operation and upon being warmed rises to emerge through said exit passage into the path of rays emanating from said lamp.
3. In a fixture for germicidal lamps, the combination of transversely elongated housing and reflector elements, said housing element having an open side therein extending along the upper portion thereof, said reflector element bein mounted in said housing elementand covering said open side for beaming-the rays from a lamp mounted in front of said reflector element, means in saidhousing element for mounting the lamp opening communicating between the interior of a said housing element and the front of the reflector element, and a ballast mounted in said housing element below said reflector element and above said elongated opening in-the rear portionof said housing element, said ballast constituting a source of heat during the normal operation thereof in connection with the lamp for produc: ing a thermally-induced flow of air through the housing element, whereby al entering the elongated opening in the rear portion of saidhouslng element is warmed by heat generated by said ballast as a normal incident to its operation,
said air, upon being warmed,emerging-tlirough the opening between the interior of saldrhousingj;
. v 6 element and the front of said reflector element forwardly of the lamp and into the path of rays fiector element.
4. In a fixture for elongated tubular germicidal lamps, the combination of an elongated sheetmetal housing closed at its ends and having a longitudinally extending opening in an upper side portion'thereof, a trough-shaped-reflector shield mounted in said housing to extend longitudinally of the latter in position'to face toward said opening, there being an air exit passage communicating between the interior of the housing and that side of said reflector shield which faces toward said opening, said reflector shield having a central longitudinally extending portion presenting a smooth, highly reflective surfaceand the longitudinal marginal portions of said shield being conflgurated to present a multiplicity of reflective surfaces facing generally inward toward the central portion of said reflector shield, means for shield for beaming of' its rays by the latter out of said opening, a ballast for said lamp mounted in said housing beneath said shield and beneath said air exit passage, and said housing having an air inlet opening therein beneath said ballast and beneath said air exit passage, whereby air entering said air inlet opening is warmed by heat generated vby said ballast as a normal incident to its operation and upon being warmed rises to emerge through said air-exit passage into the zone of rays concentrated by said multiplicity of REL anENcEs CITED The following references are of record in the I flle of this patent:
.UNI'I'ED STATES PATENTS Number Name 1 Date 2,016,474 Wood Oct. 8, 1985 2,348,617 Furedy 1 May'9,-1944 1,993,147 Cathrill .1. Mar. 5; 1935 2,335,951 Mansell Dec. 7, 1943 2,313,131 Elias Mar. 9, 1943 2,313,983 Yost et al. Mar.,16, 1943 2,339,010 Greenwald Jan. 11, 1944 1,900,551 Guth Mar. 7, 1933 1,621,312 Crandall 1 Mar; 15, 1927 2,381,450. Hrabak -1 Aug. 7-, 1945 1,823,535 Frutlow Feb. 15, 1931' 1,281,754 Beck Oct; 15, 1918 2,006,402 Maxson July 2, 1935 2,338,077 Scribner Dec. 28, 1943 Alexander June 6, 1944