US2428479A - Lamp construction - Google Patents

Description

Oct. 7, 1947, c. E. TsoURos l2,428,479

LAMP CONSTRUCTION Filed Sept. 22, 1944 I N V EN TOR. y fans afzaf'mma 24 Y wrom/5K5 Patented Oct. 7, 1947 LAIVIP CONSTRUCTION Constantine E. Tsouros, Brooklyn, N.'Y., assigner to E. A. Laboratories, Inc., Brooklyn, N. Y., a corporation of New York Application September 22, 1944, Serial No. 555,242

2y Claims. 1

This invention relates to improvements in electric lamp construction and particularly to an improved means for securing the lens and reflector of a lamp in proper relationship to-a casing.

The invention is particularly applicable to electric lamps of the sealed-beam type, in which the lamp and reflector are a single unit, although it will be apparent that it is useful with conventional lamp forms. Sealed-beam lamps, however, are becoming increasingly popular in exposed installations, such as automobile, marine, and aircraft service, and the invention will be described in association with such lamps.

Sealed-beam lamps comprise a reflector portion and a lamp portion bonded together and evacuated after the lamp filament is installed therein. The joint between the reflector and lens portions is a continuous circumferential bead, having a shoulder for cooperation with an abutment or rim portion on the lamp casing for securernent thereagainst. Lamp manufacturers have found it commercially impracticable to hold the width of the bead to an exact dimension and it is standard practice for such lamps to have a tolerance plus or minus .035 in the overall width of the bead.

It is common practice to retain such lamps within the housing or casing by means of a clamping ring, bezel or the like. Because of the total of .070 variation in the width of the bead, it has been diicult properly to secure the lamps within their casings by the presently used `types of holding rings.

The present invention contemplates an improved holding ring, made of material such as spring steel. In cross section, the wall of the ring is curved, the concave surface being innermost. The ring is adapted to grip the casing and to engage a forward shoulder or abutment of the bead of the lamp, thereby holding the lamp in position. The width of the ring is so proportioned that it will properly hold within the casing a lamp having the minimum width of bead. When lamps having greater than minimum thickness are encountered, the inherent resiliency of the holding ring permits increasing its width suitably to accommodate the increased width of the lamp joint. Hence, lamps of minimum and maximum dimensions are properly maintained in operative relationship with their casings.

It is an object of the invention, therefore to provide an improved means for securing a lamp within a casing.

It is another object of the invention to provide (Cl. 24E-41.5)

Z an improved retaining ring for lamps, which may be distended to accommodate lamp structures having greater than normal dimension.

It is another object of the invention to provide an improved lamp embodying a sealed-beam lamp, a casing therefor, and an improved retaining ring for holdingv said lamp within said casing.

In the accompanying drawings:

Fig. 1 is an elevation partly in section of one type of lamp embodying the present invention;

Fig. 2 is a side elevation in section of the retaining ring;

Fig` 3 is a front elevation of one form of retaining ring; and

Fig. 4 is a front elevation of a other form of retaining ringj,

Referring to the drawings, a lamp illustrated in Fig. 1 comprises a casing I0, a lamp II and a retaining ring l2. The casing may be of co-nventional configuration, usually substantially hemispherical and is provided. adjacent its equator with a shoulder I4 which may result from a rolled groove I5.

The lamp I I is illustratively of the sealed-beam type and includes a reflector portion I6 and a lens portion Il. As is well known, the sealedbearn lamps are characterized by a bead-like peripheral joint I8 at which the reflector and lens portions are secured together. The joint I8 is usually so conflgurated that a rear, wall 20 serves as the surface upon which the lamp is supported, and a forward wall 2| provides a shoulder or abutment which may be gripped by a suitable retainer for holding the lamp within the casing. Practical considerations of manufacture of the lamps render it impossible to maintain the width between Walls ZI! and 2| to precise dimension and the manufacturers of such lamps have standardized on a tolerance of plus or minus .O3-5 in width between the respective walls.

Lamps of the sealed-beam type generally afford no means of securement to a housing other than with a retaining ring or equivalent. By reason of the aforementioned variation in the thickness at the joint I8however, difficulty has been experienced in adequately securing the lamp within the casing by means of a standardized retaining ring. Such retaining rings will not adjust to the diierences in the thickness of the lamp at the location of its attachment to the housing. It has therefore previously been necessary individually to fit a ring to a particular lamp.

The retaining ring I2 of the present invention is spun or otherwise formed of spring material such as relatively thin cold rolled steel. The

portion of ancentral wall is deeply concave. The rear or right hand wall 22 of the ring, as Viewed in Fig 2, is preferably slightly re-entrant; said Wall ts within and tightly grips the wall of the groove l provided in the housing I0. The opposite wall 23 is substantially flat and engages the forward shoulder 2| of the lamp. Y

' The "normal "rclaxed-uwidth `of thez ring r r2i-is such that'withfthe minimum thickness of the joint I8, the lamp is tightly, but resiliently, held against shoulder lll. When a lamp having/la maximum thickness of joint is encounteredsaid thickness being usually a matter of .070 greater than the minimum thickness, zthejresi'liency; of ring l2 permits it to expand' to embracersuch maximum thickness. A standard retaining ring, therefore, serves for all lampsnvithin the usual commercial tolerance of bead width.

In some lamp constructions, it is practicable t0 have the ring I2 devoid of joint, there being cenoughfresilienyinfthe ringe and in the `lamp scasingfl `to;permit,theeedge 22 of ;.thei'ring,to cam over. the-outer edge -of.- Vthe casingaand snap .11i-nto thegfgroovef t5. The; reentrant edge 22V-of the ffringapermits this. Fori-larger; lamps, iin which the material. of theecasing- I O-and/or; the ring l 2 :may f fbe -of heavieri-gafuge, the ring :may fbegsplit,Y i at its bottom and providedswithftabs44,24 through @which .a'screwfZ- -or'fequiva-lentgmay; pass, for, se- '.curement bya' nut orlikedevice.

:InzsuchA form, the relaxeddiameterofithe ring I2 will be sufcient to pass over the ibeadorjoint ofzthe lamp,;and:over ltheifrontfedgetof: the lamp casing. After positioning, the Screw: 25a-maybe made up: to; tighten the' ring.

Whereas it is obviciusthatffamongfthe; several Aeobjects ,of the :inventionaas specifically' aforenoted care iachieved, ,z it :is fa'pparent that nnumerous fchangesin:construction :and rearrangements of -i therpartsamightrbe 4resortedftorwithoui;v departing fromth'e.l spiritfof? thelinvention vas defined' by fthe'claims.

I claim:

1.' In j combinationfgwithfa lamp of i the sealed ebeam type" having; a'pe'ripheral bead' delineating i rbetween] the? lensiandf-rfiectorsections of said Vflarrrn3 a-flampi easing ofcircularcrosssection subastanti alrlyequal'jinl 'diameter to the. diameterv of rfsaid lamp'- immediately'behind i said bead, said scasing' bei-ng -'formed :adjacent its `forward -edge awith 2a fde'epf circumference: groove4V providing "a :substantiallyi fiat"-inner-=casing wallT terminating -inaan iinwardly extending radial shoulder, said vwallifand= sai'dshoulderfdningffapocket' toY receivef and "engage :with fsad lamp; and -a` lamp 35 i'nto. the casing.

retaining ring of thin springablenaterial having a concave inner wall terminating in a radially extending inwardly curved rear Wall engageable with said casing groove and a radially extending substantially flat front wall engageablel With the forward wall of said lamp bead; the normal width of said ring measured from edge to edge of the 'frespective walls being'slessithanthe minimumv -standard Width; of the bead of `a"sealed beam lamp, and said ring being expansible to accom- .modate the maximum standardV bead width of `v`saidelamp While retaining the curvature of the rear wall of said ring. f

'2.IIn.combination' With a lamp of the sealed` 1.5ebeamftype'having an external peripheral bead d'elineating between the lens and reflector sec- .,tions thereof and a substantially cylindrical, relatively short, Wall structure rearwardly of said bead; a=casing having a front wall portion to relatively snugly receive said cylindrical wall and hav` f a retaining ring of thin, springable materialhaving,- a stili? rradial-lya:I extending Wall: seating 4vwithin ssaid'fgroovelanda substantially radially extending K .-'frontfawallengageablef with thef forward surface -Q'said cylindricaltbead; therelaxedwidth ofsa-id 30 *'ringrmeasured' frornsedgecto;V edgeof'its respective @Walls :being less-than fthe r-rrrinimum standard @width-ofthe saidzbea'dsof arsea'ledebeamlamp; the

forward =wallifof=:saidrretainin'g: ring 'being elastic, so as to resilientlylurgefthesaidlamp rearwardly eoNsTAN'rINEfn TsoURos.

REFERENGES? CITED Tlief following references are or" record; in the 'ilaoft this Y"patent:

PUNITED. sfr-ATESf-PATENTs v 1VNumber 1 Name Y 7Date l 13313,'716 Mazzeo `Aug; 19,`v 1919 111681,1042, r`#Kuen Aug.` 14, 1928 i 1,884,076 lMi'chel' 'Oct. 25,'1932 2,138,077 Taylor et al Nov. 29,- 1938 '22,267,707 Bosten fDec. 30,1941 V2,363,147 j-Roper Nov, 21, 1944 '172253328 "'-Krapp 'Aug` 26,'1941 '22715425 4I-Iarris Jan. 27, l1942 FOREIGN .PATENTS Number Country Date j :A733025 Germany i'1929

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