US2027298A - Portable electric lamp - Google Patents

Description

Jan. 7, 1936. WHEAT PORTABLE ELECTRIC LAMP' 2 Sheets-Sheet 1 Filed June 5, 1932 INVENTOR;

4 35 tureslof this naturewithalview s investedre tt stt:pprema i t aws apparatusoi the general type shown in mynprior 5 developed originally for use b yminers theythave gone into rather general use mother: lines, either in; approximately the forms illustratedin the paitentsorin modifications temlopzitiyi rig essentially I t the same'ideas.

Q-The most eommolr coninierciel forx nlof this 215- para,tus qonsists ot a headpiece or l tmp pasing adapted to be worn ongthe cap'ox carried. on the 11 person, one or more ir lc andesceut electric lamps mounted in saidgheadpieqe, a storage, {hgttery 'a l a t w ai fl e dple -a iri vol t ed, has come to, be an importentt clommereiel structures aredesighed pilrnalrilytor usetn mines wh j m s he, xp ed bvo r n x- T losive atmospheres, it is extremely; i m qj 'tflnt that precautions betakento preventany possi hility of a sparkoccurring ungier such-teondi tio s that 1 it could ignite a. eombustibIe gaseous mixture. Such sparksmay beproduoedoc casionally as an incident to. the normal operation .01 the t appar tus, orl acc'idehtafly, due to thebreakege t 30 of'some part,or eyen bythemisehieyous tar per- I ,quently indulged i bylthe miners themselyes f It is ,theg eneral obiecttofgthepresentr iuvenst am t t -l t to ,t tm mvinsth f eflmency; increasing their seryiceability teeth:

f titan-further; to improve'apd g f t tattifig thejcharging lof thebetterlesJudreducin is; Qe ew iu yt n e ffl u l a ew emperingmr corrosiop otthe parts. V The nature of theJnventidnyflillE u i i ir the"t ll nm s i t 451,1 tn qr winss;

w 36 ee a u w tin Etst 50 F g-t 318 .a rom V w i hqhea n ee Fig. 4 is a'view partlyxi t-vertieal -sectlo pertlyin sideelevation oflthetheadmeeezw.

side ws are 1 Patents Nos. 1,751,387, =-1,7 57,8 88 fand'f 1},75733895 While lamp structures of this general: type were Referring first to Fig. ,1,

"e 'eJi e e X-H t t t t it In' thes general 'res'peots."this h'nip orgartiz ettqri' 16 and eleetriefconductors ope rgtive'ly qonneetipg V t v l en m also, in whichessentiallytthe sam Ieaturestare th WP? h cht Fig. 1 2 4s; a. diagram or the pcireui't connectior'is there shown comprises a. headpiece orlamp easing 2 equippedwit h a. spring actuated clamping device i 3 for gripping the edges 'of; ,a meta1 plate 4 which is secured to the hunter a m nefs can! So: as 10 e to hold the headpiece esecurely on ;the;cap,'f A cable 6, 'ihqludiiig'suitable" electric conductors, f

of this typephdving referefice particularly tqthe.

illmni'na ition obtainable from a lamp 919; given 20 wattage; "Preferably a single main lamp or work'- jgs. 3 and 4, mounted in thie headin? l wn! gmr enc l 1 2 a9 much dle power t tarlth ma ril m o eieut illuh'xir ratiouftojiget out or the mine in the event thathis mam lamp bulb breaks. E01 ex g arhpleLthe m in lampjzhayk have q b'eamtoa ndle {Power of 20,,or ev en more, while the emergency i lamp ay be of perhafis Ztoj4 beam eapdle power. 7

whereby a tlargerproportioh oi the" surtgee of the refleotorhs u sed than i n prior flconstructlons 0t oth a ,m'ainlamp and an emer ThepresentYihvehtion prov idesjelnj arrangement r genayugm ere*emp d emwnne at thesemetime a5. permitting theu eof e1ther a. standard oraspecial lhmp bulb;asdesired.

Refe ring more especially to Figs. 1 wilLbe observed that themain lamp I 0 is 'mountediifimediatelyl in front of a concave refieetor I3, 40

the detailed coristructioh rime-n is bettersfllusr y necessgr li-tne lamp 10,15 or a special type hauins -a eward. b s w i -.brovid d w i u tmf h e t b b i w ma woendp A t terminals" l8 and 19., respecttyely, thesq t jpgflg 5Q beingconnectedto the respetlveleadipg in wires t 2B bind .2] While the; middle lead wire]! 15 elgqr Y;

the/lamp strueture 1 a trated-fih Figs. '5 and. 6. t tPrefrebly, although hot V rojecti'i ig from dtametrleally oppostte L5 poir1ts the1fgQn, oneof these being "shown in t t :Fig; 4 atjlj'. It ispretereble;ulsogtoquse a mam en emme w has its forward end forked and curved, as shown Fig. 7, which is secured in the headpiece 2, the

arms of thisspring straddling thelamp base i4 and having sockets or depressio ns,=- as clearly shown inFigsi' i and mo receivethe pins l5. In

order to support the lamp bulb against the pressure of the springs 24, 25, 26, a strong spring arm 2'! is secured firmly at one end to the casing and in Figs. 3, 4 and 7, to partly-embrace thelower end of the bulb I and to support this bulb, while at the same time holding it back againstthe re- 'fiector l3.

. 'I In the event that the bulb it should be broken,

I the spring 26, which is constantly held under tena relatively limited range of movement while the tance.

tirely behind the reflector, also 40' sion, will iorce the lamp base l4 downwardly, thus breaking the engagement of the'termin'als l8 and i'S with the contacts 24 and 25 sc"that any how of current through the lampwill be instantly .cut off. 'The contacts and 25 have spring 26 can move througha considerable dis- It will be observed that when this apparatus is in operation the spring arm 21 will cast a shadow on a part of the'lowe'r surface of therefiector i3. Advantagelis'taken of this iactto mount the emergency bulb i2 in this shadow. Also, in order to. reduce the unused area of the reflector so far as: possible, the bulb is is located chiefly behindfthe reflector and a hole 28,-Fig; 5, is cutthrough itto admit light'irom the bulb I2.

Thisfbulb' is of a standard constructiomas shown in Fig. 8, and the hole 28 is smaller in diameter than the bulb so that the filament is located enthe useful area of the reflector is made larger.

inits socket by a forked or cupped spring arm .30, "the socket comprising spring contact pieces .i'l an'd32, and the former having a hole therec through so that it engages only the metal base of the bulb, while the latterengages" simply the end terminal of the bulb. Consequently, if this'lamp bulb 'shouldbr'eak, the spring terminal 3i would throw the baseaway from theterminal 32 and thus 'stop any flow of current through the circuit of the emergency lamp. j Y

The mounting of the emergency lamp in'the manner above described increases the useful area of the reflector while still making the small-lamp I 2 available fore'mergency use. Ereferably the hole 28 includes a slot extending from the upper side thereof through which'the arm 21 can pro- 'Anelec'tricswitch is'mounted a .theheadplece to enable the operatorto use either filament i6 or ll'of the main lamp, or to turn on the emergenc'ylamp [2, as hemay desire; Referring to,

Fig. 7 it will be seen that this-switchicomprise s a' movable switch arm 3 3 arranged toengage with the ends'of eitherof the contacts 2 ,01 25, or

with another contact 34 which is connected to the spring contact 3! for the'emergency lamp. Q'Ihis switch arm 33, is secured on a short shaft on the outen'end of whicha sw'itchbutton fixedjor "with which it 'isr'nade integral.

I 'It should be noted that the s mammals jan'd H of the mainlamp lhulb l0 are arranged approximately in a single straightline'. 'While both filaments are coiled, the radius of the turns is've'ry small so .that for most practical purposes the filaments maybe regarded as straight line The bulb is held able material.

*lustrated in Fig. 4. The lamp is held against ro- 10 tation out of this position by the engagement of the pins -15 on the lamp base with the sockets in the arms of the spring 26. When the lamp vis so positioned and either filament is lighted lt casts only one shadow on the reflector due to 15 the fact that all of the leading-in wires are arranged in approximately the same vertical plane,

,this plane passing through the axis .of the refiector. In addition to producing this advantage, suchan arrangement also positions the filament in the best geometrical relationship to the re-' fiector when considered from an illuminating standpoint.

Double filament lamps of "the character illustrated in Fig. 4 cost only slightly more than a single filament lamp having a rated life of two hundred hours. Theycan be obtained with two regular? filaments each having a lifeoi approximately't'wo hundred hours so that a single bulb will have a total life of approximately four hundred hours. Or, such'lamps may be purchasedin which the filaments will have a higher eiiiciency and will givemore light, but each filament will have a life of only approximately one hundred hours. Such a lamp is of advantage where a greater volume of light from a given battery is desired. In addition,- thes'e'lamps can also be obtained'in which one filament is of the regular two hundred hour variety, while the other has a shorter life, 'takesa higher amperage, and 4D gives a greater candle power. Any of these lamps can be usedsuccessiully in the apparatus shown and, in addition, a lamp of this type can be used which has one service filament and an emergency filament. The latter, however, usually is not desired because of the fact that the apparatus customarily is equipped with an emergency bulbl2.' j The headpiece or lampcasing 2 may be made of metal, v'ulcanite, bak'elitaor'any other suit- It'has an open end which normally is closed by a lens 31, the term lens being here used in'itscommon trade sense asdistinguished from a strict or scientific sense, since thisp'art3'! rarely is given the shape of a true lens. A bezel 65 38 screwed on to' the main body of the headpiece holds the lens in place, a rubber gasket!!! preferably being interposed between the lens and the end of the casing or head piece. Inorder to assist in positioning thisg asket I have bent-the margin of the reflector I 3 outwardly to form an .arinularfiange M, Fig. 5, and shaped the inner portion of this flange in the form of an annular head 42. r The gasket 40 encircles this bead so that thelatter assists in holding the gasket pr'operly centered. Lugs 43-43 are bent backwardly from the flange 4| and extend into depressions. 44'6d, Fig. 7, in the casing to prevent the reiiector from turning when the bezel is screwed into position or is unscrewed to remove it.

For convenience in charging the battery, charging terminals 5|5l, FigsQZQand 4, are located on the neck or shankof the headpiece'as-shown in one of my earlier-patents above designated. .It

will be evident that if these terminals were com 1 L 11y I ,tinuously connected with thebattery it weuidfbe either accidentally f r iritentiorrally. I ce se quently, these terminals are connected to the 1 battery through a'switch which is normally held open. In order to; reduce the duties of the a ttendant at the lamp house, and, in fact, to avoid the necessity for an attendant inthe lamp house j of. a small mine, itis of advantage to provide such an arrangement that the miner can place his lamp in I the charging rack as he leaves the mine and make the proper adjustments to put the battery on charge. These requirements aresatisfied in the construction shown by providing a control circuit for automatically closing the normally openswitch above mentioned when the lamp is properly placed in the charging rack and acharging potential is applied to. the two charging "terminals 5l-5l. V Referring more particularly to Figs. 2 and 7 it will be seen thatthe switch arm 3'3, previously mentioned, is arranged to engage an additional contact 52 which isconnected with one 01" the charging terminals 5|. The switch 33 is continuously connectedwlth one terminal of the battery. The other battery terminal is'connected through a thermostatic switch 53 to the other charging terminal 5!. This switch includes a bimetallic strip 54 around which is wound a coil 55 of resistance wire. The strip carries a con- 3 .i-act 56 adapted to engage a stationary contact 51 I i which is carried by, but is insulated from, the

switch base. Acasing encloses theswitch parts. Normally the bi-metalllc strip, It is warped or sprung to such anextent that it holds the contact a 56 out of engagement withxthe contact 51 and. consequently, maintains the charging circuit open.

1 [As soon, however, as the lamp is properly placed j perature of the thermostatic switch and causes its free end to swing toward the stationary con- "45 in the charging rack, a current flows from. one charging terminal 5| through the resistance coil 55 and. the thermostatic switch 54 back to the other charging terminal. This raises the tem tact5l, thus closing the switch. If the manually operated switch 33 has previously, or is now,

moved to bring its arm 33 into engagement with the contact 52, a charging current will then flow, through the battery 1. When the miner takes 'ing, it is. simply necessary for him to turn the. I the switch arm 33 far enough to light eneor the Y his lamp out of "the charging rack in the morn-.

1 filaments lfior I1, and he can then goto work.

The bi-metallic strip 54. cools of! rapidly and opens the thermostatic switch very shortly after the lamp has been removed from the charging rack, and switch arm is turned.

This construction, therefore, enables the miner to recharge his own lamp, and in many mines While I have hereinshown preferred embodimentjor my inventiomjit will be I understood that the invention may be embodied,

'inother forms without departing from the spirit I or scope thereof. I f 1,

The novel features of the construction designed and described 1. I U M i r w g cniaa eherei in or en at a r-s cutting ofjthe battery by the accidentabor in;

minals'are'j not claimed here but" are claimed in a divisionalapplication, Serial No. 712,739, flied 5 February24",1934@ Having thus described my invention, what I desire to claim as new is: a

1. Ina portable lamp structure, the combination of a headpiece,'a main electric lamp bulb 10 mounted in said headpiece, a reflector in said headpiece behind said bulb, a lens supported in said headpiece at the opposite side of said bulb from said reflector, said lens closing the normally open 'end 01' the headpiece, means for supportmg said bulb with its axis lying approximately parallelto said lens and with the filament. or the lamp approximately centered with reference to saidreflector, the base of said lamp projecting I through a hole in said reflector, a spring arm engaging the bulb of saidlamp to assist in holding said bulb in its operative position, and an emergency lamp of a smaller candle power than said main lamp located chiefly behind said reflector,

said spring arm being positioned between said 2 emergency lamp and said main lamp bulb.

2. In a portable lamp structurejthe combination of a headpiece, amain electric lamp mounted in said headpiece, a socket in which the base of said lamp is mounted, a reflector in said headpiece behind the bulb of said lamp, an arm projecting in front oisaid reflector fortengaging the] lamp bulb and cooperating withsaid socket to hold said. lamp. in; its operative position, an

emergency electric lamp of I a' smaller candle 5 power than said main lamp, and means for sup-. 7 porting said emergency lamp with its bulb in the I shadow of saidarm.

3, In a portable lamp structure,. the combinationot a headpiece, a main electric lamp mount- 40 ed in said headpiece, a socket in' which the base of saidlamp is mounted, a reflector in said headpiecebehlnd the bulb of said lamp, an arm projecting iniiront otsaidreflector {or engaging the .lamp bulb and cooperating with said socket to hold said lamp in its operative position, an

jem'ergency electric lamp oi a smaller candle power than said main lamp, and means for supporting saidemergency lamp in said headpiece, y and positioned chiefly behindsald reflector, said reflectorhaving an aperture for the passage oi! light from said emergency lamp, said aperture being located in the shadow of said arm.

J 4. In a portable lamp structure, the combina tion of a headpiece, a main electric lamp mounted in said headpiece, a'socket in which the base of said lamp is mounted, a reflector in said headpiece behind the bulb of said lamp, an arm projecting in front of saidreflector for engaging the lamp bulb and cooperating with'said socket to hold said lamp in its l operative position, an

emergency electric lamp of a; smaller candle power than said main lamp, and means for supporting said emergency lamp in said headpiece "and positioned chiefly behind said reflector, said I reflector having an aperture ion the passage of light from said emergencylamp, said arm being secured to said headpiece and projecting through a said aperture andv said aperture being located in?-o the shadowof said arm. 5.1In a miner's lamp, the combination of a headpiece, an elect-riclamp bulb mounted in said headpiece, a concave reflector in said-headpiece, said lamp having two fllamentsboth arranged substantially in a single straight. line extending To lamp bulb, means for supporting said lamp bulb with the line of said filaments lying approximately in and' coincident with the axis of said reflector, said' lamp supporting means comprising resilient means engaging the globe ofthe b'ulB, and resilient. electrical connections engag-.

' at approximately right angles to the axis of said ing the terminals on the base of said lamp bulb, a. switch mounted in said headpiece, and supply conductors associated with said terminals and said switch toenahle the miner to turn the current on or off either of said filaments at will.

GRANT WHEAT.

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