US2742619A - Lighting fixture and tube - Google Patents

Description

A ril 17, 1956 A. P. BUQUOR LIGHTING FIXTURE AND TUBE Filed Sept. 17 1953 Jfy 1.

2 Sheet sSheet 1 INVENTOR ATTORNEYS an old one from the fixture.

, electrical contacts on the fixture.

United States Patent 2,742,619 LIGHTING FIXTURE AND TUiiE Adolph P. Buquor, Washington, D. C. Application September 17, 1953, Serial No. 380,742

21 Claims. (Cl. 339-12 .This invention relates to lighting fixtures and tubes therefor, and particularly to fixtures employing elongated fluorescent or the like tubes, although the invention is readilyadaptable to elongated tubes having incandescent filaments therein.

The invention particularly relates to means for holding suchielogated tubes in a supportingfixture for ready and .tube to move the prongs into the slot, and then rotation of the tube to place the prongs in contact with electrical contacts in the supporting fixture. It is time-consuming, and under many circumstances a difficult operation, to

properly orient the tube for installation in the present fixtures and there is danger of breaking the elongated tubes, which are usually quite fragile, during the twisting operation either in installing a new tube or in removing Furthermore, the present construction presents manufacturing difiiculties since the pair of prongs at each end of the tube must necessarily be 'quite accurately aligned to permit simultaneous insertion of the opposite ends thereof in the slot commonly provided in supporting fixtures.

The present invention contemplates the provision of 'a supporting fixture wherein careful orientation of the tube prior to insertionis not necessary and wherein the tube is firmly held in the fixture by magnetic means. In general, the fixture is provided with a permanent magnet and the tube is provided with an armature of paramagnetic material engageable with the magnet of the fixture. However, the armature 'could be on the fixture and the magnet on the tube with equal facility. When the: armature is engaged and held by the magnet the end contacts of the tube are held in engagement with Movement of the end contacts of the tube into engagement with the contacts of the fixture need not result from a rotary movement of the tube but may direct from the exterior of the fixture.

It is therefore an object of this invention to provide a fluorescent or other lighting fixture and wherein the tube may be easily replaced or removed by simply pullingthe "tube directly from the fixture without the necessity of rotary movements. 7

Another object of this invention is to provide a fixture for elongated tubes of conventional construction and provide a novel fixture and lighting tube wherein no predeice 2 termined orientation of the tube is necessary before its insertion into the fixture.

A further object of this invention is to provide a novel elongated lighting tube of the type described.

A still further object of this invention is to provide a lighting fixture and tube therefor employing a premanent magnet for holding the tube in the fixture and wherein the magnet constitutes the sole means for holding the tube in a predetermined position in the fixture.

Yet another object is to provide an attachment for a present-day conventional fluorescent tube whereby the tube may be inserted in and held by a novel fixture employing a magnetic holding means.

Further objects and advantages of the invention will become apparent to those skilled in the art as the description proceeds in connection with the accompanying drawings, wherein:

Fig. l is a side elevational view, with parts broken away, of a lighting fixture embodying the present invention;

Fig. 2 is a fragmentary sectional view' taken generally along the line 2-2 of Fig. 1;

Fig. 3 is a fragmentary sectional view taken generally along the line 33 of Fig. 1;

Fig. 4 is a side view of an attachment constituting a modification of the attachment shown in Fig. 3;

.Fig. 5 is a fragmentary side elevational view,with portions broken away, of a different embodiment .of the fixture and tube of the present invention;

Fig. 6 is a fragmentary sectional view taken generally along the line 6-6 of Fig. 5;

,Fig. 7 is a schematic view of a modification of the invention;

Fig. 8 is a partial sectional view showing an adaptor applied to a conventional fluorescent tube to adapt the tube for use with the holder of Fig. 5;

Fig. 9 is a fragmentary sectional view through the end of a modified form of fluorescent tube for use with a holder of'the general type as that shown in Fig. 5;

Fig. 10 is a sectional view through a portion of a holder for a fluorescent tube and showing, in fragmentary end section, a tube held therein;

Fig. 11 is .a front elevational view of the holder of Fig. 10 as viewed from the right side thereof;'

Fig. 12 is a view similar to Fig. 10 of a further modified form of tube and holder; and

Fig. 13 is a front elevational view of the holder of Fig. 12 as seen from the right side thereof.

Referring first to Fig. 1, numeral 2 indicates generally a lighting fixture of a more or less conventional type including a top wall 4, end walls 6 and 8, side walls 10 and '12, and an internal horizontal partition 14. j The space between top wall 4. andv partition 14 defines "a compartment customarily housing electrical circuit components (not shown) which may include starting switches for fluorescent lighting tubes and may house other control devices not constituting a part of the present invention. The end walls 6 and 8 support contact housings 16 and 18 comprising blocks of insulating material with electrical contacts therein. Since the housings16 and 18 are of identical construction,- only one will i be described hereafter.

The housing 16, for instance, may compriseja block of insulating material having a pair of openings20 therethrough (see Fig. 2) through which electrical conductors 22 extend. The conductors 22 may be held in fixed pos ition in the openings 20 by filler pieces 24 ,or' the like. The upper terminal ends of conductors 22- extend outwardly of the housing 16 in the compartment abovepar- .tition14 for connection to the electrical circuit components referred to. At its lower end, the housing 16. is

provided with a pair of adjacent upwardly extending slots '26 separated by a central projection 28 whichmay taper downwardly as clearly shown in Fig. 2. The openings communicate with the upper ends of the slots 26 and the lowermost ends of conductors 22 extend into the -slots 26, the free-ends thereof being resilient and tending to move toward each other but beingdirected generally in adownwardly diverging direction. The slots 26 and the projection 28 are so proportioned that the endcontact prongs or pins 30 of a conventional fluorescent lighting tube may be respectively positioned in the slots 26 and respectively in engagement with the lower terminal .ends of conductors 22, as clearly shown in Fig. 20f the drawings.

It will be readily apparent that such a convention fluorescent lighting tube, as shown at 32 in Fig. 1, may be moved laterally into the supporting fixture to'position. its pins 30 against the terminal ends of conductors22 by a simple lateral movement of translation without having-first carefully aligned the pins with reference to any particular structure and without subsequent rotation of the tube 32. The downwardly tapering .fixture adjacent the housing 18.

projection 28 will effectively guide the. pins 30 into proper position, it only being necessary to insert the tube in the fixture to start the pins 30 in their respective slots 36, which does not require a high degree of accuracy in orienting those pins.

A permanent magnet 34 is fixed to the partition 14 adjacent the housing 16 at one end of the fixture and a similar magnet is positioned at the other end of the Themagnet 34 may be a bipolar magnet secured to the partition 14 by any suitable fastening means 36. If desired, a protective or "decorative sheath 38 may be positioned about the magnet The illuminating tube 32 is provided, adjacent each of its ends, with a surrounding band of any suitable -material to which is attachedan armature 42 of, paramagnetic material.

The band 40 may be frictionally held on the tube 32 whereby it may be readily removed along 'with its armature 42. The magnet 34, band 40 and armature42 are so proportioned and dimensioned that when the armature 42 engages and 'is held by'the magnet 34, contact pins 30 will be held in the position indicated in Fig. 2.

Magnets of small size but high attractive strength are readily available and it has been found'that a relatively small magnet has sufiicient strength to firmly hold the usualfiuorescent tube in a fixture of the type described.

Fig. 3 suggests that the band 40 may circumscribe the tube32 and have its ends attached in any suitable manner to the armature 42. If desired, the band 40 may be of -metal whereby it may be readily soldered or-welded to the armature 42.

Fig. 3 also schematically shows a filament 44 in the tube 32, the ends of the filament 44 beingelectrically connected to-the innermost ends of the pins 30 of the tube. "The filament 44 is conventionally used in a fiuorescent tube -merely for starting the same and is thereafter not heated .tiveforother reasons, the armature"thereon"may"be "readilyremoved and easily applied to a new tube'of *the 'same' construction which may then berapidly and easily "positioned inthe fixture and firr'nly heldtherein'in' operating position by themagnets 34.

Fig. 4 illustrates'a modified form'of armature holding "means. Thearmature42 may be welded'or otherwise rial 46' constituting a split ring adapted to"be"slipped"over a tube 32. The split construction of the band 46 permits its ready mounting on tubes of varying diameters without danger of breaking the tubes while the resiliency of the material insures a snug grip to effect a firm hold when the tube is magnetically held in such a fixture as shown in Fig. l.

The modification'shownin Fig. 5 comprises an outer housing of the same construction as that shown in Fig. l and wherein similar parts are identified 'by the same reference numerals. In this modification the. housing 16 of Fig. 1 is replaced by a contact housing comprising a block of insulating material'48 havingra single conductor 50 extending therethrough with its lowermost end projecting into a vertical slot 52 extending upwardly from the bottom of the block 48 to a position above the lowermost end as shown. The magnet 34 in this modification, while being supported from the partition 14, is electrically insulated therefrom by suitable insulating means54,55,

56, and 57, as shown and is electrically connectedby a 'width of the slot'52 in block 48. Whenthetube 62. is

in'operating position in the fixture shown the end contact 64 engages the resilient lowermost end of conductor50. The end portion of tube 62 is surrounded by a ferrule orring 68 (see Fig. 6) of'paramagneticmaterial; which ring is electrically connected to the other end of the filament intube 62. The ring or ferrule 68may beprovided with an enlargement providing a' fiat surface'70 iengageable with the flat pole faces of magnet 34 andito establish electrical contacttherethrough'tolthe filament 44. It will be clearly evident that the single end contact 64 and the ferrule 68 constitute the electrical contactsfor the tube 62, and the ferrule 68 further constitutes an armature engageable with the magnet34 to hold the tube in'the fixture for operation. "Sineelthe ferrule 68 is in the electrical circuit to the tube 62,v it is -desirable that an outer covering of insulating material 72 be provided on all exposed surfaces thereof except the surface 70. By providing such insulation on the ferrule "68there is no danger of a person being subjected toelect'rical shock inadvertently while replacing or changing tubes in'the fixture.

'Fig. 7 shows an alternative arrangementthat may be employed either with the form of holder shown in'Fig' l or that shown in Fig. 5. In Fig. 7 the illuminating tube '74 is provided with a paramagnetic ring or ferrule76 "that has a cylindrical outer surface and'themagnet78, whether it be a non-current-conducting magnet asem- -'-=ployed in Fig. 1 ma current conducting contact as in Fig. 5, isformed with its pole faces 80' defining a cylindrical surface complementary to the outer surfaceofthe ring or ferrule 76. Thus it will be seen that the employment of:a magnet shaped as'shown inFig. 7wi1l result in an automatic centering of the tube 74 in the fixture or holder without relying on any other centering: means.

The ring orferrule 76 may be a-separable -ring to be frictionally applied to the tube, 'much like the ring 40 of Figs.. 1 and 3, or may even be the metal ferrulelconventionally applied to fluorescent tubes forthe purpose of holding the end contact structure in assembled relation to the glass tube envelope. If desired, thepresently used metal ferrule may be made of suificientthickness and of paramagnetic material to serve as the armature76 of Fig. 7.

Fig; 8 shows an adaptor for application to the end of a conventional fluorescent tube 32, 'as employed with 'a...centr.al contact for the tube.

theholderwofFigs. 1 and;.2, to adapt: such atuhe forruse viding an. upper flat surface. such as the surface 70. of

Eig.. 6 or it may be a. cylindrical armature ofthe type show-n: in-Fig 7 if the holder is provided with. a. magnet of. the. type. shown in Fig. 7. The; armature or ring 82. is. of such. dimension that it. may be frictionall-y applied to the; usual ferrule 86 found on conventional fluorescent tubesand, itsouter. end isclosed by a body 8801? suitable insulating material. The. body- 8.8.; of. in.- sulating material has fixed therein a pair of metalicups or. contacts 9.0and 92. adapted to snugly receive. the pins 30..Of. the tube 32: and to. make. electrical. contact there with. One. of the cups 92 may be electrically connected to. the ringer armature 82 by: a suitable conductor 9.4 andathe cup Emma-y be electrically connected,.by means of a conductor 96 to an exposed end contact 98f Qnrthe outermost end. of the insulating body 88. It. will; be readily apparent that aconventional fluorescent tube pro vided. with such. an adaptor may be readily inserted. in

and used. with such a holder. or fixture, asshown in. Fig.5..

'Ilheouter portion of the. armature. or ferrule. 82. is-preferably provided. with a suitable insulating coating .100 covering the entire outer surface thereof except. thetupper flatsurface; in. the event the armature. is of the; shape shown in.Fig. 6, or covering all of the outer, surface except: those portions engageable with pole. faces. 80. if a.magnet.-of.-the type. shown in Fig. 7 is. employed.

Fig.9 shows; a form of fluorescenttube. specially con.- structed. for. use witha. holder. of .the. type. shown in; Fig. .5 but wherein. a magnet of the shape ofmagnet78- of Fig. 7. isemployed. InFig. 9 the glass envelope 1010f.- the illuminatingtube is. provided with the. usualzfil'ament. 104 and. electrical conductors 106 and. 108 extending through an end wall thereof. The conductor 108 extends .through aninsulatingdisc. 1:10.. and central hoss112. thereon and is electrically connected. to an end. contact. 114... The conductor 106- also extends through. the. insulating; disc 110. and.is suitably electrically connected. totametalLfer- 1111c 116. having anend flange. 118. overlying theperiphery of. the insulating. disc. 110'and a cylindrical body portion extending. into. circumscribing. relation to an. endpottion of the. envelope. 102. The. ferrule. 116 maybe cemented or. otherwise, fixed to the envelope 102 in..any conyen: tional. manner and serves. to. hold the. insulating disc 110 and its associated parts in assembled. relation to. the envelope. 102. The ring or ferrule 116-is,.of' paramagnetic material and serves as, an electricallcontactfor.the starting, filament 104 and also-serves asan. armature. to hold the tube in operating position. in a holder or. fixture. It. is contemplated that the holder. or. fixture for the tube of Fig. 9be of the type shown in Fig. 5. but wherein the permanent magnet is ofthe type shownin Fig. 7i The modificationshown in Figs. 10 and 11 employs a tubehaving the usual glass envelope I02 and" an insulating disc 120 held in assembled relation to thez end of-aenvelope 102 by the usual ring or ferrule.- 86. The insulating disc 120 is provided'at its center: with a. con- .ducting tubular structure 122 through which. conductor 108-extends. The conductor 108 may be soldered: tothe tube..122..at its. outer end. and the assembly constitutes Also fixed to. the insulating disc 1-20 is an annular contact of conducting .material 124; The annular contact 124 may be fixed to the disc 120 by means of inturned ears or lugs 1'26- extending through the disc 120 and to one of'which conductor 106' is-soldered or'otherwise electrically-connected. The annular contact 124 is concentric to but spaced'fi'om both thecentral contact 122 and the ferrule 86 whereb'y it is 'electrically insulated from each; The ferrule8'6 isof ai s uitable paramagnetic. material whereby it'may beaheld by;a;pem1anent.magnetal28rfixednto a-blocleof insulating material; 130.. The magnet; 128E provided: with" pole faces defining; a cylindrical; surface complementary to; the omen-surface of. the; ferrule 36;. inztheimannerr. shown in Fig. 7; The blockof. insulatingmaterialn'lflods provided witln arrupwardly extending groove or slot.- 132' on: its innecface; WhiChiSlOtilS somewhatwider than the diameter of the tubular: central: contact The. block 1330 is funtherrprovidedwith suitable. conductorsw134 and 136 terminating. at their: lowerrends; in. resilient. contacts 138 and 140;.respectinely- The conductors-134 and: l=36 rnay terminate at their upper ends in connector lugs 14-2. and ltltlarespectively and .whenathe. block 1305is mounted in a suitable. housing of the: type: shown in: Figs 1. and. 5, the: lugs .142: and; 144l-wi1libe\inzztheacompartment above .pantitionz wall: 14 for connection to suitable switches,

starting mechanisms, or: the like;

The; resilient: contacts 13.81am 140 are located in the slot. 132m.- suchapositionathatt when tube 102 is held in thezfixturerby magnet: 128;.-the1 resilient contact 138 will engage a. side of the cenn alfi contact 122" of the tube and resilientrcontact'. 140: will I engage the annular contact 124 on the disoz12'0: Byithi'sarrangement the -armature 865.13.}5 'which thetuberis heldin .the fixture isnot'an electnicak conductorand: the dangenofielectrical shock to the user is minimized; Since the armature or: ferrule 86' is nflttina theelectricali cirouits-tofthe fixture; no insulation needabe: provided: on. its" outer surfaceand therefore the tube: 102 may be:- inserted. in the. holderin any position of. orientation about its: axis. Regardless of the position of rotation? ofi thetube I02 a'bout itsaxis, thecontacts 1'38, and. 122 willa'lways be in engagement and the re-. silient contact: l40 will a'lways 'engage some-portionof the annular contact 1:24am completeethe circuits to the" tube:

Figs; 12 and 18 showa further modificationof tube and; holder'havihg'the same advantages asthat shown in Figs; lO and 1 1 In this modificationthe tube envelope 102i maybe the same" asthat showniii-Fig. 10 having conductors 106 and 108 extending therefrom. The ferrule 86: may be id'enti'calto that ofiFig. l'Oand functioning to hold an:insulatingdiscl fi tos-the tube -102i Theinsul'afingrdis'c 1463'is provid'edwith' a central cylindrical boss'or extension. l48 having anouterannularmetallicelectrically conducting'surface150 to which conductor-106 is soldered on otherwise 'el'ectrically connected The di'sc 1'46 and boss mscfurther' support'a centrally positioned" central contact 1523to which conductor 108 is electrically connected. The cent-rahcontactalSZ-iextends axially outwardly of the hossw148-i and; as" is apparent, is electrically insulated fromathe.condnctingsurface which', in turn, is electrically insulated from'the ferrule 86Z An insulatingblock of material lswsupports -a magnet 128; whichmay be the same. asathatshown in Fi'g. 10,- in-position to engage and hold the ferrule 86. The block 154 is further provided with a relatively wideshallow groove or slot 156' of a width. suflicient to loosely receive the boss 148 and its conductingrsur'face 150E Centrally of the groove 156, the-block 1545s: provided with a deeper slotorgroove' 158 of a width slightly greater than the diameter of'the central contact 152 whereby when the tube 102 is placed in the holder-to: be: held therein by -magnet 128; the end contact dfinediby surface-150 and the central" contact 152-extend into. grooves1'S6 and158; respectively.

The block. 15.4 is" further provided with electrical'conductors 160. zmd: 162: terminating at; their upper ends in lugs: 16.4.:fon connection to" the. starting and controlling devicesheretofore mentioned and attheir lower ends terminate in resilient: contact portions 1'66 and 168, respectively. The resilienttendcontact 166'- extends across the slot; or: groove. 158 at the upper end thereof and the resilient. end: contact 168 extends transversely across the uppenend: of-groove 156. The parts areso proportioned and". arranged that when the tube 102 is placed in the holder and-iheldtherein by magnet 12%, the contacts 150 and; 152.are held'- imposition-toslightly fiexancf electrically engage resilient end contacts 168 and 166, respectively, thus establishing suitable electrical circuits to the tube 102.

In this modification also the armature or ferrule 86 is not in the electrical circuits of the fixture and therefore need not be insulated since its exposed surface presents no danger of shock to the user. Likewise, this modification provides an arrangement wherein the end contact elements of the tube 102 need not be properly oriented before insertion in the holder and the tube 102 may assume any position of rotation about its axis and still be firmly held in the fixture and make proper contact with the resilient contacts 166 and 168.

While reference herein has been made to a fluorescent lighting tube, it is to be understood that the invention is not limited thereto but may be applied to certain types of incandescent tubes or other electrical illuminating tubes such as gas discharge tubes of the so-called neon" type.

In those forms of the device employing magnets and armatures having flat contacting surfaces, the magnet and/or armature may be mounted on its supporting structure for limited tilting movement to insure full surface contact between magnet and armature, even though one or more elements may be slightly misaligned.

It has been found that very small permanent magnets of a type readily available and commonly known as Alnico magnets have sufficient holding power to hold a conventional tube of this type firmly in a fixture against all danger of accidental removal. Such magnets are metallic and sufficiently good electrical conductors to be employed with the modifications shown in Figs. 5, 6, 8 and 9. They may also be employed in the modifications of Figs. 1, 10 and 12 wherein the magnet does not form part of the electrical circuits of the fixture. In those modifications Where the magnet is not employed to conduct electricity, other types of magnets may be used. For instance, there is available a permanent magnet comprising a fused or sintered body of BaFeizOis. Magnets of this material are readilyavailable and are substantially nonconducting.

In all of the modifications shown and described, the contacts on the fixture engage the contacts on the tube with sufficient pressure to establish good electrical contact but since no part of the contacts on the fixture engage the tube or tube contacts on outwardly facing surfaces, no part of the contact pressure resists removal of the tube from the fixture in any substantial degree. In other words, the spring contacts on the fixture are not of the hook type and are not relied on inany degree to hold the tube in the fixture and do not act to mechanically resist removal of the tube. While such contacts as shown at 50 in Fig. and 140 in Fig. press axially against the tube contacts, they offer some slight resistance to lateral movement of the tube but that resistance is not substantial and can be ignored.

While a limited number of modifications have been shown and described herein, it is to be understood that further modifications may be resorted to, within the scope of the appended claims, without departing from the invention herein.

I claim:

1. In a lighting fixture, an elongated illuminating tube having electrical contacts at the ends thereof, said fixture having spaced electrical contacts releasably engaging the contacts on the ends of said tube, said spaced electrical contacts being arranged to engage the contacts at the ends of said tube without substantially resisting removal of said tube from said fixture, said tube being readily removable from and insertable in said fixture by movement of said tube laterally of its length, a first means on a side of said tube inwardly of the ends thereof cooperating with a second means on said fixture for holding said tube therein, one of said means comprising a permanent magnet and the other means comprising an armature therefor, said magnet and armature having engaging faces extending generally transversely .of the axis of saidtube.

2. A device as defined in claim 1 wherein said first means comprises an armature carried by said tube and wherein said second means comprises a permanent magnet carried by said fixture.

3. A device as defined in claim 1 wherein said first means comprises an armature adjacent each end of said tube and wherein said second means comprises permanent magnets adjacent the spaced contacts on said fixture.

4. A device as defined in claim 1 wherein said tube and said fixture are each provided with a pair of cooperating electrical contacts at each end of said tube and wherein said first means is said armature, said first means comprising a member releasably mounted on said tube and having said armature afiixed thereto.

5. A device as defined in claim 1 wherein said tube and said fixture are each provided with a pair of cooperating electrical contacts at each end of said tube and wherein said first means is said armature, said first means comprising a ring of paramagnetic material surrounding said tube.

6. A device as defined in claim 1 wherein said tube and said fixture are each provided with a pair of cooperating electrical contacts at each end of said tube and wherein said first means is said armature, said first means comprising a ring of paramagnetic material surrounding said tube, said ring being electrically insulated from the electrical contacts on said tube.

7. A device as defined in claim 1 wherein said tube and said fixture are each provided with a pair of cooperating electrical contacts at each end of said tube and wherein said first means is said armature, said first means comprising a ring of paramagnetic material around each end of said tube, each of said rings constituting one of the electrical contacts on said tube, said second means comprising a pair of permanent magnets on said fixture in position thereon to respectively engage and hold said rings, said magnets each comprising one of the electrical contacts on said fixture.

8. A device as defined in claim 1 wherein said tube and said fixture are each provided with a pair of cooperating electrical contacts at each end of said tube and wherein said first means is said armature, said first means comprising a body of paramagnetic material at each end of said tube, each of said bodies constituting one of the electrical contacts on said tube, said second means comprising a pair of permanent magnets on said fixture in position thereon to respectively engage and hold said bodies, said magnets each comprising one of the electrical contacts on said fixture.

9. In a lighting fixture, a holder for holding an illuminating tube having end contacts and a body of paramagnetic material carried thereon, said fixture having a permanent magnet in position thereon to engage and attract said body of paramagnetic material and thereby hold said tube in said holder, said fixture having resilient electrical contacts in position thereon to engage the end contacts of said tube when said tube is held in said holder by said magnet, said magnet being between said resilient contacts and said resilient contacts being arranged to engage the end contacts of said tube without substantially resisting removal of said tube from said fixture.

10. In a lighting fixture, a fixture for holding an illuminating tube having end contacts and a body of paramagnetic material carried thereon, said fixture having spaced contacts thereon arranged to engage the end contacts on said tube when said tube is moved laterally of its length into said fixture, a permanent magnet on said fixture arranged to attract and hold said body of material and said tube in said fixture and to urge said tube in a tacts and said spaced contacts being arranged to engage the end contacts of said tube without substantially resisting removal of said tube from said fixture.

11. In a lighting fixture, a fixture for an elongated illuminating tube for use with a tube having end contacts and a body of paramagnetic material thereon having a substantially flat face directed laterally of said tube; said fixture having spaced contacts thereon arranged to engage the end contacts of said tube, a permanent magnet on said fixture between said spaced contacts and having a flat pole face to attract and hold the flat face of said body of material whereby to hold said tube in said fixture and to hold the end contacts of said tube against the spaced contacts of said fixture, said spaced contacts being arranged to engage the end contacts of said tube without substantially resisting removal of said tube from said fixture.

12. A fixture as defined in claim 9 wherein said magnet comprises one of the electrical contacts of said fixture.

13. In a lighting fixture, a fixture for holding an illuminating tube having a ring of paramagnetic material extending about its periphery and elecrtical contacts centrally positioned on its ends; said fixture having spaced contacts for engaging the-end contacts of said tube, a permanent magnet on said fixture and having pole faces defining a surface complementary to a portion of the outer .surface of the ring on said tube, said surface being substantially concentrically arranged about an axis joining said spaced contacts. I

14. A fixture as defined in claim 13 for use with an illuminating tube wherein said ring is an electrical contact for said tube; said magnet constituting a further electrical contact on said fixture for connecting a source of electric current to a tube held thereby.

15. A fixture as defined in claim 13 for use with an illuminating tube having a central contact at each end, an annular contact on each end concentric to said central contact and wherein said ring is electrically insulated from said contacts; said spaced contacts being arranged to engage the central contacts on the ends of said tubes, and a further contact adjacent each of said spaced contacts arranged to engage said annular contacts.

16. In combination, an elongated illuminating tube and a fixture therefor, said tube having a ring of paramagnetic material extending therearound in a plane normal to its longitudinal axis and electrical contacts at the ends thereof, said fixture having a permanent magnet thereon, the poles of said magnet engaging spaced areas of the periphcry of said ring whereby to hold said tube in said fixture in any position of rotation of said tube about its longitudinal axis, said fixture having electrical contacts thereon engaging the electrical contacts at the ends of said tube irrespective of the position of rotation of said tube about its axis when in said fixture.

17. An elongated illuminating tube having a centrally located contact at each of its ends and a ring about said tube adjacent each end, each of said rings being of paramagnetic material.

18. An illuminating tube as defined in claim 17 wherein said rings constitute further electrical contacts for said tube.

19. An illuminating tube as defined in claim 17 wherein said rings are provided with a fiat outer surface facing radially outwardly of said tube.

20. An illuminating tube as defined in claim 18 having an annular electrical contact at each end thereof concentric to but insulated from said central contact, said rings being electrically insulated from said contacts.

21. An attachment for an elongated illuminating tube, comprising; a member having arcuate portions releasably engageable with the outer surface of said tube to be held firmly thereon, and an armature of paramagnetic material fixed to said member whereby said armature, member and tube may be firmly magnetically held by and in fixed relation to a magnet.

References Cited in the file of this patent UNITED STATES PATENTS 2,170,287 Kinnebrew Aug. 22, 1939 2,234,982 Ross Mar. 18, 1941 2,248,598 Yoder July 8, 1941 2,254,706 Mueller et a1 Sept. 2, 1941 2,257,786 Chirelstein Oct. 7, 1941 2,414,653 Lookholder Jan. 21, 1947 2,447,801 Gaynor Aug. 24, 1948

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