US2896067A - Flashlight - Google Patents

Description

July 21, 1959 u. LocKwooD- 2,896,067

FLASHLIGHT Filed April 3, 1953 I 2, Sheets-Sheet 1 INVENTOR leeJLoc/tu ood Y ATTORNEYS July- 2 1959 JJLOCKWOOD 2,896,067

FLASHLIGHT Filed April :5, 195s 2 Sheets-Sheet 2 /0/ INVENTOR Lee J-loc'kwood ATTORNEYS Unite FLASHLIGHT Lee J. Lockwood, Wonewoc, Wis., vassignor, by mesne assignments, to The Electric Storage Battery Company, Philadelphia, Pa., a corporation of New Jersey Application April 3, 1953,*Serial No. 346,577 '5 Claims. (Cl. 240-106) long periods of storage prior to use and where the maximum cell capacity must be available regardless of when the flashlight is placed in operation, Leclanche cell flashlights have not been entirely satisfactory. This is particularly true of those applications in which a flashlight is provided for use in case of emergency only and where the flashlight may not be placed in operation for several years. For such uses the flashlight must provide a completely reliable source of light when the need arises.

One such emergency use for flashlights is involved in the life jacket and life raft lights which are provided for sailors and air men. For many years there has been a need for a portable flashlight which will be completely reliable under the most severe conditions of use and which will deliver the full capacity of the cell even after long periods of standby storage.

It is therefore an object of the present invention to overcome the disadvantages of the Leclanche cell flashlight mentioned above and to provide a flashlight incorporating a dry cell which is not subject to deterioration during long periods of storage.

It is a further object of this invention to provide a flashlight employing a reserve type primary dry cell.

A still further object of this invention is to furnish a flashlight which is in an inactive condition prior to use and which can be activated by readily available activating fluids.

Another object of the invention is a'flas'hlight which remains hermetically sealed until placed in use.

Another object of the invention is to provide a flashlight with switching means which are simple in construction and which are protected from corrosion and other sources of malfunctioning during long periods of storage under adverse conditions.

Yet another object of the present invention is the furnishing of a flashlight in which the presence of a discharged cell can be readily detected byinspection and which can easily be checked to-determine if the flashlight has been put to unauthorized use at any time during the period of stand-by storage.

These and other objects of the invention will be apparent from the following description of the invention. It should be understood, however, that the detailed'description is given by way of illustration and is not to be taken as a limitation of the scope of the invention.

Broadly, the flashlight of the present invention comprises a reserve type primary dry cell enclosed within a rates Patent Patented July 21, 1959 vapor-impervious container, a flashlight lamp, and electrical connection between the terminals of the "cell and the flashlight lamp. In one embodiment of the invention, the reserve type cell is sealed within a molded plastic casing having a closed bottom end and a moldedplast'ic' light tray inserted in and hermetically sealing the open end thereof. The light tray is adapted to receive a suitable lamp socket for the flashlight lamp which is protected by a transparent light dome.

Flashlights constructed in accordance with the present invention maintain the cell in an inactive state and hermetically sealed within thevapor-impervious container until immediately prior to being placed in service and, as a result, they may be held in readiness for emergency usefor an indefinite period without deterioration of'the cell or loss of capacity. When the flashlight'is to be used, the vapor-impervious cell container is ruptured and activating fluid admitted to the cell whereupon the full electrochemical activity of the cell becomes available for supplying current to the flashlight lamp.

Since the primary cell of flashlights constructed in accordance with the present invention is maintained in an inactive state prior to-use, the lamp may be permanently connected to the cell terminals and no provision made for placing the cell on open circuit. With this construction the flashlight will furnish continuous light until the cell is exhausted. Flashlights embodying the present invention may, on the other hand, include suitable switching means if the use for which the flashlight is intended makes it desirable to prolong the active life of the flashlight by placing the cell on open circuit after the cell has been activated.

The present invention is more completely illustrated in the accompanying drawings in which:

Fig. 1 is a top plan view of a preferred, but illustrative, form of flashlight in accordance with the invention.

Fig. 2 is a side view, partly in section, taken along line 2-2 of Fig. 1.

Fig. 3 is an end view in cross section taken along line 33 of Fig. 2 showing details of one means for rupturing thevapor-impervious container.

Fig. 4 is a fragmentary viewin cross section taken along line 4--4 of Fig. 3.

Fig. 5 illustrates the operation of the rupturing means of Fig. 3.

Fig. 5a illustrates a suitable reserve cell in the structure shown in Fig. 5.

Fig. 6 is a fragmentary view in cross section of a side elevation showing the light tray assembly, light dome and a preferred switching means.

Fig. 7 is a fragmentary view in cross sectionof a side elevation showing the weakened knock-out disc.

Fig. 8 is a fragmentary view showing a modified form of knock-out disc.

Referring to the drawings wherein like reference numerals refer to similar elements, a preferred form of flashlight embodying the invention is illustrated in Figs. 1 and 2 of the drawings. The flashlight comprises a vaporimpervious container 20, a reserve type primary dry cell 21 and light dome 22. Thecontainer 20 is preferably formed of a rigid, synthetic plastic composition molded in the form of a cylindrical tube having one closed end. Polystyrene and cellulose ester plastics have been found particularly suitable for forming a durable vapor-impervious container 'forcell-zl.

The closed end of container 20 is preferably formed with an anular recessed'shoulder 23 having a hollow cylindrical bore which encloses 3..W63k6l16d knock out disc 24 in the closed end of the container. 'In order to ensurerthat disc 24 will rupture along its-peripheral edges, the thickness of the disc is preferably reduced from that of the side walls of the cell container and a groove .opposite side therefrom, opening 27. A bail wire 28 is provided at one end with an inwardly extending section 29 which has a leg 30 bent at an angle from the horizontal, and at the opposite end'with a short inwardly bent portion 31. In attaching the bail wire, leg 30, is first inserted through opening 26 which is formed with an enlarged opening on the outside surface of shoulder 23, as shown in Fig. 3. The bail wire is then rotated downwardly and sprung open slightly in order to insert end 31 in opening 27. With the bail wire in position,

leg 30 abuts against knock-out disc 24 while the ring portion of the bail wire is seated in' the annular groove 32 formed between the bottom edge of the container and recessed shoulder 23. When it is desired to rupture the .cell container the ring portion of the bail wire is lifted out of groove 32 and pivoted about openings 26 and 27 so that leg 30 rotates inwardly against knock-out disc 24 as shown in Fig. 5. Preferably the bail wire is seated within tapered indentations 33, as best shown in Figs. 3 and 4, in order to resist being rotated and accidentally rupturing the cell container. The bail wire may be further restrained against movement by a strip of adhesive tape or other suitable means if desired.

While it is preferred to position the weakened knockout disc within the cylindrical recess as described above in order to protect the container from being ruptured by rough handling or other accidental cause, it will be understood that other means for rupturing the container may be provided. For example, openings may be formed in the side walls of the container and sealed with a vaporimpervious plastic tape 72 as shown in Fig. 8. Or if desired, a weakened section may be provided in the side wall of container 20 and the container ruptured by pressing against this section with the thumb or by fracturing it against a sharp object.

Electrical energy'for flashlights of the present invention may be furnished by any suitable reserve type primary dry cells. Primary dry cells of the reserve type are well known in the art and are characterized by re- .taining the electrolyte or activating fluid out of contact with the active cell elements until it is desired to place the cell in operation. A particularly suitable reserve cell for use in the present invention is the water activated system cuprous chloride-magnesium. Such a cell is shown in Fig. a wherein the parts of the container and rupture rneans therefor are designated by the primed form of the same numerals applied to corresponding parts in Fig. 5.

.The negative electrode of the cell is preferably formed of a length of magnesium tubing 101. Around the outside surface of the magnesium is wrapped an electrolyte ab- .sorbent material 102 such as Vinyon, rayon or Webril.

The positive electrode element is suitablya bronze screen ,103 coated witha cuprous chloride paste made up with 'a polystyrene paste solution. The positive screenis wound over the electrolyte absorbent to form a cell assembly of cylindrical shape having a hollow central bore. The cell assembly may then be inserted within the open end of container 20.

The inner surface of container 20 is notched back a .short distance from the open end to provide an annular recessed seat 34. Light tray 35 which is molded of polystyrene or other plastic to fit snugly against the side walls 'of the recess is placed against seat 34 to close the open end of the cell container.

Light tray 35 contains a centrally located perpendicularly off-set well having side walls '36 and end wall 37 which projects within the hollow bore of cell 21. An opening in the center of end wall 37 is provided for rivet 38, one head of which is fastened over one end of a flat spring contact 39 and the other head of which is connected to cell terminal 40. Also located in the off-set portion of the light tray is a coiled spring 41 which serves as the lamp support. The bottom coil of 4 spring 41 has a downwardly bend end 42 which extends through an opening in end wall 37 to make electrical contact with the other terminal 43 of the cell. The as sembly is completed by sealing the peripheral edges of the light tray and the openings in end wall 37 with plastic adhesive to form a vapor-impervious container for the cell.

As shown in the drawings, lamp 44 may be of the bayonet type, or if desired, a lamp having a threaded base may be used, in which case the coils of spring 41 receive the screw threads of the lamp.

The flashlight is completed by attaching a transparent plastic light dome 22 to the cell-light tray assembly by means of threads 45. On the outside surface of the container is a projecting shoulder 46 which, with shoulder 47 of the light dome, serves as a stop to prevent the light dome from being screwed on too far.

The inner surface of the light dome is preferably provided with a flat surface portion 48. With the light dome attached to the cell container, surface 48 abuts against the glass bulb of lamp 44 and, as the light dome is screwed down, the lamp is forced into the well in the light tray thereby compressing spring 41. As the light dome is screwed down further, the center terminal of the lamp makes contact with flat spring 39 to complete the electrical circuit. The compression of coil spring 41 and the resiliency of flat spring contact 39 together with the action of shoulder stops 46 and 47 prevent the lamp from being crushed against the end wall of the light tray which might occur if the light dome were screwed down too far.

When the light dome is backed-01f from stop 46, the

force of coil spring 41 urges the lamp against the flat surface of the light dome and thus breaks the electrical circuit.

If the use for which the light is intended makes it desirable to attach the light to the person or to an article of clothing or equipment such as a life-jacket or a life raft, suitable fastening means may be incorporated on the flashlight. In the flashlight in Figs. 1 and 2 a clasp 49 is shown attached to lugs 50 and 51 by means of rivets 52 and 53.

Flashlights embodying the present invention are prepared for operation by rupturing the plastic container and admitting activating fluid to the cell. The entire flashlight may be submerged in sea-water, for example, or the activating fluid may be poured or otherwise introduced into the cell container. Excess activating fiuid may be drained out of the container and the light is then ready for operation. 'It is an advantageof the present invention that the light may be successfully operated under extremely adverse conditions of use and may be subjected to continual salt-water spray or even complete emersion in saltwater during operation without ill-elfect.

charge is not harmful since, at the comparatively low voltages necessary to operate the lamp, any current loss due to the shorting of the cell through moisture does not .causesuflicient variation in the voltage output of the cell to interfere with the operation of the lamp.

A small quantity of silica gel or other desiccant may be added to the plastic container in order' to remove any moisture in the air which is entrapped within the sealed container or which may subsequently be admitted thereto due to defects in the seal or imperfections in the plastic. Although it is not essential to do so, the container may be evacuated after inserting the reserve cell and before sealing so as'to e limina'te all moisture from within the sealed container. If desired, a suitable agent for indicating the presenceof moisture may be placed within the container as an aid'to the ready visual detection of fiashlightsin which the reserve cell has been activated prematurely by leakage of the container or other means. Suitably a small amount of an anhydrous cobalt halide, anhydrous cupric sulphate, an indicating silica gel or other agent which changes color in the presence of moisture may be placed within a transparent plastic container together with the reserve cell. If the container is constructed of colored or opaque plastic, a transparent window may conveniently be provided in the container wall. Periodic inspections of the flashlights may then be made :during periods of storage and any defective flashlights can readily be detected by the change in color of the moisture indicating agent.

Since it is obvious that further changes can be made in the construction and in the materials used without departing from the invention, it is intended that all matter shown in the accompanying drawings or described hereinbefore shall be interpreted as illustrative and not in a limiting sense.

I claim:

1. A flashlight comprising a substantially rigid, hollow plastic tube having both ends closed to form a vaporimpervious container, the dry components only of a reserve type primary dry cell hermetically sealed within said container, and a flashlight lamp electrically connected to the terminals of said cell, said tube having at one end thereof a recessed shoulder encircling a hollow bore in said shoulder, said tube being closed across the said hollow bore by a thin-walled, weakened section, said shoulder being provided with two oppositely-disposed openings each extending through said shoulder to the hollow bore thereof, and a wire half-ring member positioned on the outer surface of said shoulder and having inturned end members inserted within said openings, one of said ends having an upwardly extending leg resting against said thin-walled section and adapted to be rotated against said wall section to rupture said tube and admit a liquid therein from the exterior thereof for the activation of said dry cell.

2. The flashlight defined in claim 1 wherein the reserve cell comprises a hollow inner core of magnesium tubing, a layer of absorbent, and an outer layer of supported cuprous chloride paste.

3. A hermetically-sealed flashlight comprising a molded substantially rigid plastic tube having one closed end, the dry components only of a hollow bore cylindrical reserve cell disposed within said tube, a flashlight lamp, a molded plastic light tray positioned in the open end of said tube and hermetically sealed to the side walls thereof, said light tray having a perpendicularly off-set, annular, center well extending within the hollow bore of said reserve cell, a coiled spring in said well adapted to receive said lamp and electrically connected to one terminal of said cell, a flat spring contact positioned inside the coils of said coil spring and connected to the other terminal of said cell, and a transparent dome removably attached to said tube and enclosing said lamp, said tube having means therein adapted to admit a liquid into the tube from the exterior thereof for the activation of said dry cell.

4. The flashlight defined in claim 3 wherein the lamp is disposed, under compression, between the dome and the that spring contact.

5. The flashlight defined in claim 3 wherein an annular shoulder stop for said dome is positioned on the outside surface of said tube.

References Cited in the file of this patent UNITED STATES PATENTS 1,843,234 Karnes et al. Feb. 2, 1932 1,964,466 Helmholtz June 26, 1934 2,147,116 Winckler Feb. 14, 1939 2,355,247 Slocum Aug. 8, 1944 2,427,017 Miller Sept. 9, 1947 2,446,361 Clibbon Aug. 3, 1948 2,543,106 Harriss Feb. 27, 1951 2,553,307 Falge May 15, 1951 2,639,306 Fischbach May 19, 1953 FOREIGN PATENTS 479,417 Great Britain Feb. 4, 1938 679,186 Great Britain Sept. 17, 1952

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