US 1678351 A
Description (OCR text may contain errors)
Jul 24, 1928. 1,678,351
P'. D. PAYNE ELECTRIC SAFETY LANTERN Filed May 17, 1923 INVENTOR 'TTQRNEY persons for repair,
Patented July 24,
UNITED STATES PATENT oFF,Ic1E.;-Iff
Paar. 1). return, or mvme'ron, NEW JERSEY, ASSIGNOR 'ro 'Emsoms'roEneE EAT- .TERY COMPANY, or wEsr ORANGE, NEW JERSEY, a conronarron or- NEW 1 JERSEY.
. j Application filed May 17,
My invention relates to electric safety lanterns which while adapted for other uses, are especially designed for use in mines, tunnels, powder magazines and for places where gases or other materials of a highly combustible or explosive nature are likely to be present. In some aspects the present invention "is an improvement. on that disclosed in Patent No. 1,345,212 granted June 29, 1920, to J. F. Monahan, and entitled Electric safety lantern.
One of the objects of my invention is to providean improved constructionand arrangement in lanterns of this character for automatically effecting theopcningof the lamp circuit in order to insure against ignition of gases or other combustible materials, andwherein the opening of the lamp circuit is preferably controlled or effected by the breakage of the lamp bulb only, as distinguished from lanterns of this character in which the opening of the lamp circuit is dependent upon the breakage of some frangible membenother than the lamp bulb,
such for example as the lens or window of v the lamp casing.
Another object of my invention is to rovide a construction for lanterns of this c ar-- acter which renders it substantially impossible for workmen or other unauthorized persons to gain access to the parts within the lamp casing or to tamper with the lantern in such a manner as would be likely to produce a spark which might cause an explosion, without the same being detected.
My invention also contemplates the provision of a simple and improved arrangement and construction whereby the lantern may be easily and quickly assembled and disassembled and whereby the incandescent lamp and parts rendered readily accessible to authorized repla"ement, adjustment, etc., the arrangement preferably being such that this accessibility may be attained and the lamp and parts associated therewith repaired, replaced, adjusted, etc;, without involving any appreciable likelihood of the reflector usually employed in. lanterns of this character being handled and thereby soiled, defaced or otherwise impaired or damaged.
A further object of my invention is to provide an improved construction for atassociated therewith are ELECTRIC SAFETY LANTERN".
1923. Serial No. 639,496.
taching the conductors leading from a lamp or other casing to the latter, whereby such conductors will be relieved of practically all strain] by reason of suchJattaehment and 'WlllCh W111 effectively prevent the conductors from being pulled from the casing.
Otl1(3l' 0l)] CtS and features of my invent1on reslde 1n the details of construction and combinations of elements hereinafter more fully described and claimed.
In order "that my invention may be more clearly understood, attention is directed to with the parts shown in normaloperative positlon;
. Fig. 2 is a view similar to Fig. 1 showing the parts in the position they assume upon fracture of the lamp bulb;
Fig. 3 1s a detailed sectional view, partly i in elevation, of the mounting for the lamp; Fig 4 is a plan View of the mounting shown in Fig. 3; y y
Fig. 5 is a fragmental view in front elevation, partly in section, of a detail of construction illustrating the arrangement for securing the lens or window of the lamp casing in-place; and
Fig. 6 is an enlarged view in perspective ofadetail of the improved locking and sealing means which 1 preferably employ. The electric safety lantern illustrated in the drawing comprises a two-part separable lamp casing A consisting of a substantially semi-spherical member ,1 having an open circular front and a short cylindrical rear- -Ward extension 2, and a substantially cylindrical member 3 having at its forward end an annular spherical flange 4. When the lamp casing is assembled the cylindrical rearward extending portion 2 of member 1 fits closely within the cylindrical member 3, and the flared spherical flange 4 overlies and fits closely against the spherical portion of member 1 at the rear thereof. The member 1 is provided on the exterior-of its'spherical portion adjacent the rear end thereof with "an annular series of spaced struck-up prongs or projections 5, and the fiangey of member 3 is provided with a corresponding series of notches 6 of such shape and size that they are adapted to receive the proupon this being done the projection 5 will closely overlie solid portions of the flange 4 between the notches 6 and the forward edge of said flange will abut the shoulders formed where the projections join the member 1. The members 1 and 3 are then secured firmly together, as shown in Fig. 2, but ohviously may be readily separated upon turning the same relatively to each other until projections 5 register with the notches 6.
asing member 1, is provided at its front end with an outstanding annular flange 7 constituting a seat for a window or transparent front closure member 8 for the cas-. ing A. Forapurpose which will hereinafter appear, I would, if this were practicable, form the closure member 8 of absolutely non-shatterable transparent material. However, as this is not practicable, I preferably employ a closure member formed of the substantiallynon-shatterable material known as laminated non-shatterable glass, consisting of two outer layers 8' of glass and an intermediate layer 8"-of pyroxylin or celluloid. Reference character 9 represents a resilient split bezel which is sprung over the window 8 and the flange 7 of the casin member 1 and embraces the edge portion thereof, said bezel 9 having a front flanfge 10 overlying window 8 and a rear incline flange 11 overlyin flange 7 and bearing against the rearwardly directed rim 12 of the latter. An annular soft rubber gasket or washer 13,
I U-shaped in cross-section, is applied to and embraces the edge portion of the lens 8.
With the window 8, bezel 9 and gasket 13 positioned "as described,
of the casing A, by squeezing or contracting the bezel so as to move the ends the'reoftowards each other and then fastening the same in contracted'position. Upon thus contracting the bezel, the inclined flange 11 thereof coacts with the rim 12 of flange7, to effect bodily movement of the bezeltowards the lamp casing, whereupon the window 8 is drawn or forced tightly against the front of the casing, the gasket 13 serving as a cushion between the window and the flanges 7 and 10. Reference character 14 represents a fastening device for holding the bezel 9 contracted and the window 8 tightly against the front of the lamp casing, this device preferably being in the form of a spanner member fitting closely over the bezel and having a depending front flange 15 taking over the flange 10 of the bezel and a pair actions 5 respectively. In assembling memprojections 24. A shoulder the window may be forced and held tightly against the front.
of spaced lugs or projections 16 and 17 respectively engaging an aperture 18 adjacent one end of the bezel and one of a plurality of apertures 19 adjacent the other end thereof. In applying the fastening device 14, the bezel is contracted, and the device 14 is then positioned as shown in Figs. 1, 2 and 5 with the lug 1 6 in the aperture 18 and with the lug 17 in one or other of the apertures 19, dependent on the contraction of the bezel. It is apparent that because ,of the provision of a plurality of the apertures 19, the bezel may be held by member 14 under various degrees of contraction and accordingly the window 8 may be readily secured against the front of the casing with" the proper tightness. Member 14 has an arm comprising a rearwardly inclined portion 20 which, when said member is in operative position, lies closely adjacent the inclined flange 11 of bezel 9, an intermediate portion 21 and an upstanding end portion 22 pro-' vided with an aperture 23. The said intermediate portion 21 is provided at its opposite side edges with upstanding projections 24 having outwardly extending end portions, and slidably mounted on the portion 21, is a locking member 25, the latter being provided at its opposite side edges with projections 26, extending downwardl and then inwardly, embracing the en portions of the 27 formed be tween the inclined portion 20 of the rearwardly extending'arm of member 14 and the intermediate portion 21 thereof, is adapted to be engaged by the front edge 28 of the locking member to limit the forward movement of the latter. The locking member 25 is provided with a pair of spaced forwardly extending projections 29 adapted to straddle the portion 20 of the spanner memlea end portion 22 of the spanner member 14, I
and the arrangement of the parts is such' that with the members land 3 of the casing A assembled, the same-may be relatively r0- tated to a position in which the projections 5 overlie solid portions of flange 4 and in which said upstandingportions 31 and 22 are opposed The portions 31 and 22 will then be slightly spaced and if it is desired to.
prevent unauthorized persons'from gaining access to the interior of the lamp casing, the
locking member 25 is moved to its foremost position and a hollow seal 33 of soft metal,
I such as lead, is placed over said portions 22 and 31 and compressed by a suitable tool so as to force the material thereof into the apertures 23 and 32; care being taken that the seal is pushed downwardly onto the portions 22 and 31 a distance sufficient to engage in the space between portion 22 and the rear edge of locking member It-is apparent that it will then be impossible either to slide member 7 25 rearwardly from its operative locking position so as to permit the removal of fastening device 14, or to turn the casing members 1 and 3 relatively to each other so as to permit the same to be separated, without removing the seal. Any such removal of the seal by an unauthorized person may be readily detected from the condition of the seal. It is also apparent that the seal 33 constitutes unitary means for sealing the casing members 1 and 3 in connected position and for sealing the means for securing the window 8 against the front of the lamp casing. v
' Disposed within the casing A 'is a parabolic reflector R having at its front end a narrow flange 35 adapted to bear against the window 8 and at its rear end a centrally located opening 36 ofsufiicient size to accommodate the bulb L of the incandescent lamp the opening 36 by means of a stiff metal ring.
employed in my improved lantern. The reflector R is reinforced at its rear end about 37, the material of the reflector being turned flector and will hold the latter so that it en- 'over and substantially enclosing said ring.- The arrangement and constructionare such that when the window 8 is removed from the front of the casing A, the reflector'R may rest loosely in the casing, but when the window is secured in position tightly against the front of the casing, it will bear firmly against the flange 35 at the front of the regages the inner surface of the casing member 1 adjacent the front end thereof with substantially a line bearing. The reflector will thus be firmly. held in proper fixed position in the casing A. Suitably secured to the inside of the casing member 1 adjacent the rearend thereof, is an annular reinforcing member 38 which serves to strengthen such member and acts as an additional protection against injury to the lamp and its socket such, for example, as might result in the event that the casing A were. struck by a thick point, a piece of coal or other hard objeet or substance.
Disposed within the rear casing member 3 is the base M of the mounting I prefer to use for the incandescent lamp. This base M is preferably formed of insulating ma terial, and the bottom thereof is shaped through an opening 40' in the base and is I threaded into the bottom 41 of said casing member 3. The center contact for the incandescent lamp is mounted on the base M substantially centrally thereof and comprises anopen-ended cylinder 42 rigidly secured within an opening provided therefor in the base M, an inverted cup-shaped member or plunger 43 slidably mounted within the cylinder 42 and a coil spring 44 disposed within the members 42 and 43 and by means of which the member 43 is biased to its uppermost position, shown in Fig. 3. The cylinder 44 is provided at its upper open end with an inturned flange 45 and the plunger 43 is provided at its lower end with a flange 46 which coacts with the flange 45 to limit the upward-movement of the plunger with respect to the cylinder. The top 43' of the plunger 43 is adapted to engage the terminal located at the center of the base of the incandescent lamp. A strip 47 of conducting material is disposed within'a recess provided in the bottom of the base M, the ends of this strip being suitably secured to the bottom of,
the cylinder 42 and to the lower end of a nut 48 embedded in the base,whereby said cylinder is electrically connected to a terminal connecting screw 49 which extends through an opening in the base and is threaded into the nut 48. A flat ring 50 formed of conducting material, is seated in a recess in the top of'base M andis firmly secured to the latter as by means of ascrew 51, said ring 50 preferably being arranged concentrically with respect to the cylinder 42 and in spaced rela- The ring 50 has an extension tion thereto. 50 and a secondv terminal connecting screw 52 extends through such' extension and is threaded into another nut 53 embedded in base M. A plurality of parallel equi-spaced rods 54 are secured at their lower ends to to limit the upward movement of the socket 56 with respect tothe base M. Coil springs 58 are respectively disposed about the rods.
'54 between the base M and the socket 56, the saidsocketbeing biased by these springs to its uppermost position, shown in Figs. 2 and 3. Socket 56 is provided with the usual opening 59 in which the threaded base 60 of the, incandescent lamp is mounted. Reference characters 65 and 66 represent the conductors for supplying electric current to the lamp" from a suitable source such as a storage battery which, in the case of a miners cap lantern 1 outfit, is usually supported by a belt on theback of the miner. The conductors 65 and 66 are respectively provided at their inner ends with terminals in the form of flat rings or eyes 67 and 68 through which thescrews 49 and 52 respectively extend to secure the conductors 65 and 66 to the base M. The rings 67 and 68 are respectively provided with laterally extending lugs 69 and (39 which, when the conductors 65 and 66 are connected to the base, respectively engage small recesses 70 and 71 provided in said base and coact with the walls of the latter to prevent turning of the conductors with respect to the base. With this construction there is little likelihood of the terminals working loose, being broken or .be-
rigidly secured within said opening by having one end peened over against casing member 3 about the opening and by a flange 91 formed on the tubular member adjacent said end. The tubular member 77 is provided on the inside at its inner end, with a flared conical surface portion 78 forming a seat for a clamping member which is applied to and embraces the inner end of the cable 7 6, said clampin member comprising a split annular collar prongs or projections 80 extending therefrom longitudinally of the cable. This clamping member is preferably made from a single flat piece of sheet metal, pressed and formed into shape on the cable and into firm gripping engagement therewith. The collar 7 9 is conical and conforms to the flared conical seat 78 in which it is disposed, and it will be apparent that by reason of the construction described, when a pull is exerted upon the cable 76 from a point without the lamp casing A, the resulting strains will be transmitted to the tubular member 77 and the lamp casing through the collar 79 and the conical. seat 78, and that the conductors 65 and 66 will thus be wholly relieved from such strains. Moreover, the harder the pull exerted upon the cable 76, the more'firmly will the clamping member be gripped onto the cable and the more firmly will the collar 79 be forcedagainst its seat 78.
-To prevent the cable 76 becoming worn and broken adjacent the lamp casing, a pro-' tective winding preferably in the form of a fairly hea' ,coil spring 82, is disposed about the cab e' where it emerges from the lamp casing. The protective wlndmg or 0011 9 having a plurality of '94: to the base of bracket 85.
-spring 82 is held in position by a beveled annular collar or flange 83 formed on the reduced outer end portion 84 of the tubular member 77 .and over which the inner end of the spring is forced.
i In order that the lantern may be readily mounted on a suitable support such as the leather bracket on the ordinary miners cap, I provide the same with a bracket 85 vided with legs 86 and 87, the latter bein in the form of a. hook. This bracket is pre erably in the form of an inverted U and is secured to the lamp casing b having the end of one of its legs 86 rivete at'its lower end to the casing member 3, as indicated at 88, and also by an arm 89 extending from the bracket'and provided at its lower end with a lateral extension 90 in the form of a flat ring through which the tubular member 77 extends and which is firmly secured between the casing member 3 and the flange 91 on said tubular member. To increase the rigidity with which the bracket 85 is secured to the lamp casing, the leg 86 thereof is formed so that the portion thereof just above the rivet 88 conforms to and lies closely adjacent the bottom 41 of easing member 3, and such portion is provided with an opening into which the end of the screw 40 is The screw 40 thus constitutes threaded. unitary means for securing the lamp mount-' ing within the casing member 3 and forv connecting the bracket 85 to the lamp casing.
- In order to maintain the cable 76, especially the portion thereof adjacent the lamp casing, in proper position relative to the lamp casing when the lantern is in use, I provide a spring clip or clamp 93 which is adapted to receive and yieldingly andfrictionally hold the protective winding or coil sprin 82 and the cable 76 at a point adjacent the lamp casing. The spring clip 93 is suitably secured in fixed relation to the lamp casing preferably by being riveted at The winding 82 may be forced between the spring jaws of clip 93 so that the said winding andcthe portion of the cable enclosed thereby will be quite firmly held in the position shown in Figs. 1 and 2, but may be readily released from the clamp by pulling upwardly on the cable.
Reference character R designates a small auxiliary reflector shaped to conform to the lamp bulb L and having a central opening through which the base (30 of the lamp loosely extends; A resilient washer or ring 95 of soft rubber or the like is disposed on v the lamp base GO'betwcen the auxiliary reflector R and the lamp socket 56, and upon bulb L, asshown in Fig. 1.
screwing the lamp base 60 tightly into the When the lantern is assembled as shown in Fig. 1, the incandescent lamp and its socket 56 are held by the window 8, preferably by direct engagement of the latter with the lamp bulb L in circuit-closing position against the action of spnngs 58 with the terminal-of the lampfilament located at the center of the lamp base 60 engaging the spring-pressed plunger 43 of the center contactfor the lamp which is mounted'in base M. Current will then be supplied to the lamp as follows: from "one pole of the battery comprising the source of current, through conductor 65,. terminal 67, connecting screw 49, nut/l8, conducting strip 47, cylinder 42 and plunger 43 to one terminal of the lamp filament, and then through said filament, lamp base 60, socket 56, rods 54, member 50, terminal 68 and conductor 66 back to the other pole of said. battery. It is practically impossible because of manufacturing difficulties, to obtain small incan descent lamps of the type used in my lantern which are of uniform size. However, by reason of the construction of the center con.-
tact carried by the base M, wherein the plunger member 43 is slidably mounted in the cylfnder 42 under spring pressure, proper engagement of the lamp terminal located at the center of the lamp ba e with said center contact is assured in the case of different lamps regardless of variations in the size of the latter due to manufacturing conditions. The springs 58 exert sufficient pressure so that in case the bulb L is cracked, the incandescent lamp and its socket-56 will be forced forwardly to circuit-opening position,
in which movement the lamp bulb L is fra c tured against the window 8 under the pressure of said springs. Accordingly, when the lantern is subjected to a shock or blow which causes the bulb L to crack, or said bulb is otherwise cracked or fractured as by a pick point piercing the window 8 or the lamp cas' ing and striking the bulb, the lamp will be immediately moved by springs 58 to circuitopening position, shown in Fig. 2 and the lamp thus extinguished. The laminated glass window 8 offers remarkable resistance to blows or shocks to which the lantern is subjected in service. For example, when this window is given a heavy direct blow, it
is not shattered into pieces but merely cracked along lines radiating from the point where it is struck. Also, when the window is hit withla pick point, this merely results in a hole being made in the window-of the shape of the pick point and in cracking the glass along lines radiating from said 'hole.
The substantially non-shatterable window8 may, as a matter of fact, be pierced with a pick at points between the center of the win-.
dow and the edge thereof without resulting in the fracture of the lamp bulb L, in which event the filament of .the'lamp, of course,
continues to glow. It is thus apparent that the opening, of the lamp circuit is dependent only upon the cracking or fracture of the lamp bulb L and not upon the-shattering of the window or lens of the lamp casing as is frequently the'case in lanterns of this charactor.- The circuit of the incandescent lamp will therefore be interrupted only when this is necessary, namely, upon exposure of the lamp filament.
In my improved lantern, it is never necessary'to remove the bezel 9 and window 8 in -order to gain access to the lamp, lamp mounting, terminals and cable' connection, for purposes of repair, replacement, etc. such a case, it is merely necessary to remove the lead seal 33, to turn the casing member 3 relatively to casing member 1 until the pro jections 5 register with notches 6, and to then separate said casing members. After the repair, replacement or the like has been touched. This is a decided advantage, as
the intensity of-illumination and distribution of light in most lanterns of this character are seriously affected by reflectors which have i been soiled or otherwise impaired in the operatlon of replaclng lamps, making repairs to.
the lamp'mounting, etc; In case it is desired to replace the window 8 or to remove i the same for any reason, this may readily be effected upon removing the lead seal 33,
by sliding the locking member 25 rear-v wardly, then slightly contracting the split bezel 9 and disengaging the fastening device 14 therefrom, and then expanding the bezel and disengaging the same from flange 7 of the casing member 1 and the window 8.
While I have shown and specifically described a preferred embodiment of my invention, it is to be understood that the same is subject to numerous changes and modifications without departure from the spirit of the invention or the scope of the appended claims. 4
Having now described my invention, what I claim as new and desire to protect by Letters Patent, is as follows:
1. In an electric safety lantern, a two-part separable casing, a window for said casing, means for securing said window'to the easing, and unitary means for maintaining'said securing means in operative position and for holding the parts of said casing in connected position, substantially as described.
2. In adevice of the character described, a two-part separable casing having an open circular front, a circular closure member applied tosaid front, means for securing sald closure member 1n position comprising a split bezel embracing the edge portion of unent of the latter towards the casing is effected to thereby force the closure member towards the front end of the casing, means for holding said bezel contracted, and unitary means for sealing said holding means in operative position and for sealing the parts of said casing in connected substantially as described. a
This specification signed this 15th'day of May, 1923.
PAUL D. PAYNE.