US2367888A - Flashlight - Google Patents

Description

Jan. 23, 1945. G. F. PRIDEAUX FLASHLI GHT Filed June 10, 1942 Fig. 3.

Inven+or: Gwnlgm E. Prideaux,

His At*torneg.

Patented Jan. 23, 1945 Gwilym F. Prideux, Cleveiand Heighta, h10, assignor to General Electric Company, a corporation 01 New York Application June 10, 1942, Serial No. 448,513

1 Claim. (Cl. 240 m.68)

My invention relates to electric lamp of the portable, self-contained, battery operated type commonly lmown as flashlights. The principal object of my invention is to provide a flashlight comprising an incandescent lamp and automatic means for interrupting the circuit including said lamp in predeterinined positions of said flashlight. Another object of my invention is to pro- V vide a. fiashlight comprising an incandescent lamp and an automatic swfltch constructed and arranged to so control the circuit including said lamp that the fla:;hlight is capable of emitting light in a selected angular path upwara or downward 90 from the horizontal and is incapable of emitting light in the angular path opposite to that selected. A further object of my.invention is to provide a fiashlight adapted to project light in a. horizontal direction or below the horizontal only.

Further objects and advantages of my invention will appea'rfrom the following detailed description of species thereof and from the accompanying drawing, in which Fig. 1 is a side elevational, schematic, partly sectional view of a species of flashlight embodying my invention; Fig. 2 is a sectional view taken along the longitudinal axis of a species of switch useful for the purposes of the invention in the fiashlight shown in Fig. 1 and showing the-switch in a contact making position; and Fig. 3 is a similar view of the switch in a contact breaking position.

Referring to Fig. 1 cf the drawing, the flashlight Il) comprises a tubular, electrically insulating, plastic casing Il closed at one end and having a screw cap fiuid flo-w switch battery M are switch I3, lent material, is provided with an electrical conductor in the form of a metal strip i5; the end of which is disposed between the switch 13 and the closed end of said casing il. Said strip l5 extends to the open end of said casing I l where it is bent outward. Said screw cap I2 encloses a metal 'washer l6 adapted to screw onto the screw base l! or the incandescent 1amp 18. A spring l9 is compressed between said washer l6 and the battery I4 and is spaced from thecentral termina] 20 of the battery l4. The force exerted by said spring [9 is sufiicient to hold the rim of the washer l6 firmly against the cap 12 and to press the battery il, the switch [3, and the end 01. Strip I5 together. The circuit including the battery I and the lamp l8, which is shown as broken in Fig. 1, is made by turning the screw 13 and a conventional flashlight disposed in said casing II. The

l2 at the open end thereof. A

which contains mercury or an equivalight comprises cap I! in the proper direction to Iurther compress the spring i9. The washer i6 is thus brought into contact with the end of strip l5 and the center contact of the lamp base Il into engagement with the center terminal 20 of the battery M. The washer i8 may be flexible to facilitate this operation and to avoid the necessity for close tolerances 01 the engasing parts. The lamp circuit is broken by tuzning the cap [2 in the opposite direction to permit expansion of the spring l9 which forces the washer i 6 and the center contact 0! the lamp base Il away from the terminal 20 and the end'of strip i 5, respectively.

The cap 12 is provided with a window 2! which transmits the light emitted by the lamp [8. The window 21 may consist of material capable of transmitting all of the light emitted by the lamp l8 or of screening ont au but a selected part of the light. Thus, bine, orange, or red screens or filters may be used. The rim portion or fiange 22 cf cap i2 is of larger diameter than that of the tubular casing il so that the longitudinal axis of said flashlight is directed or tilted upward from the horizontal with the lamp end higher than the opposite end thereof when the flashlight is Diaced upon a substantially horizontal surface, such as a floor, or a. table.

The mercury switch [3 is ccnstructed and arranged to automatically interrupt the lamp circuit when the lamp end of the flashlight i higher than the opposite end thereof. Thus the flashmanuaily controlled means for making and breaking the Iamp circuit in any position of the flashlight and automatically operating means for making the lamp circuit when the lamp supporting end of the flashlight is pointecl downward and for breaking the lamp circuit when said lamp supporting end is directed upward.

Thus, the light from the flashlight cannot be inadvertently directed upward. This is advantageous in many locations, such as in theaters, where an upwardly directed light source in the hands of an usher, for example, is not desirable.

A species of mercury switch useful in the flashlight illustratea in Fig. 1 is shown in Fig. 2 in a circuit making position and in Fig. 3 in a circuit breaking position. The switch I3 is tubular in shape and is mounted with its longitudinal axis coincident with or parallel to the longitudinal axis of the flashlight il). Said switch [3 comprises two motel contact members 23 and 24 joined in spaced relation by a tubular sleeve 25 of electrically insulating material to form an enclosure for a. drop of mercury 26, or equivaleni material. The contact member 23 is hollow tu provide space for the movcment or the mercury 20 and terminas in the sleeve 25 a. sllght distance from the siishtly rounded part of the solld contact 24 in said sleeve 25. The drop of mercury as is sufllcient in size i:o bridge tbe gap between the contacts 28 and Il when the longitudinal axis or the switch is vertical and the contact2l is in the lowest position. The mercury Il also bridges this gap as the axis of the switch Il la moved irom a vertical to a horizontal position When the switch axis ls tllted iurther to mise the contact 14 above the contact 23 the drop of mercury 25 moves toward the and or the contact 23 remote from the contact 24, as shown in Fig. 3, to break the elcctrically conducting path in the switch II.

As pointed out above, the switch I:I is monnted with its longitudinal axis parallel to or coincident with the longitdinal aida of the flashlight. In 50 mountinz said switch I: the contact 2 should be closer to the lump and of the fiash light than the contact 23 when automatic interruption of the lamp circuit by the switch i3 on pointing the lamp end of the fiashlight above the horizontal is desired. or course, the position 01 the contacts la reversed when the flashlight is desired for emitting light upwardly only.

While I have shown and desoribed a specifio lorm of flashlight and mercury switch, it Will be understood that I contemplate chat other types of flaslilights and swltchesmay be used wi'thot depafl;lng from my invention. For exarnplc, my invention may be used in flashlights comprising a manuaily Operated swi tch distinct rom the 6ap l2. It isoiso seful in connection witli commercial fiashlights incorpofating a. reflector to collect and pr'oject the light from the lamp I! in a beam, the axis oi whlch may be coincident With or normal to that of the battery enclosing casing. In. mounting the switch il in such flashlights, the longitudinal axis thereol is coincident with or parallel to the beam axis. The switch may be interposed between the central terminal of the battery and the center contact of the lamp base in flashlights similar to that shown in Fig. 1. This arrangement is preierred in flashllghts projecting a beam having its axis normal to that 01 the battery case.

What I claim as new and desire to secure by Letters Patent of the United States la:

A portable flashlight comprising a cylindrical casing having an open front and, a battcry in said casing, an opaque outwardly rounded cap mounted on the open end of said casing so as to be movable relative to the casing and having a small window at the center thereof, a lamp at the open and of the casing, connections for completing an electric circuit from the battery through the lamp. means to support the lump grom the cap, spring means arranged to hold the 1mnp in open circuit position, and gravitwoperated switch means in the electric circuit, soir! switch menus being tubular, of uniform bore and disposed with its longitudinual axis concident with that of the casing so as to open the circuit only When the flashllght is pointed above the horizontal, the said cap serving to move th lamp into closed circuit position when the cap is moved relative to the casing and also having a. p'oripln cry of larger diameter'than the casing whlch serves to point the fiasblight above the horizontal, when t is set on a horizontal surface; and thereby move the gravitycontroiled switch to open position.

GWILYM F. PRIDEAK.

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