US2780721A

US2780721A - Portable flash light

Info

Publication number: US2780721A
Application number: US421821A
Authority: US
Inventors: Lenning Alvar
Original assignee: SVENSKA LASMUTTER AB
Current assignee: SVENSKA LASMUTTER AB
Priority date: 1954-04-08
Filing date: 1954-04-08
Publication date: 1957-02-05
Anticipated expiration: 1974-02-05

Description

Feb. 5, 195'? A. LENNING PORTABLE FLASH LIGHT Filed April 8, 1954 mmvrox All/Err Lend/ 2y Q ,9

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United States Patent O 2,780,721 PORTABLE FLASH LIGHT Alvar Lenning, Stockholm, Sweden, assignor to Svenska Lasmutter Ab, Stockholm, Sweden Application April 8, 1954, Serial No. 421,821 1 Claim. (Cl. 240-10.65)

The invention relates to portable electric flash lights and particularly such as are to be operated by means of 3 dry battery cells in series. One object of the invention is to provide a device which may readily be carried on a belt (as military, sport, and night watchmen equipment), and in which the current may be conveniently switched between a built-in lamp and an auxiliary lamp, such as a head lamp, connected to the device by means of a contact plug and cord. Further objects, and advantages of, the invention will be apparent from the following specification and accompanying drawing in which Fig. 1 is a rear elevational view of the device with the cover removed, and Fig. 2 a sectional view taken along the plane of line A-A of Fig. 1.

In Fig. 1 reference character 1 represents a casing, preferably consisting of an insulating plastic moulding. Its lid (only shown in Fig. 2, where the same reference numbers are used) is designated by 1a. Three (3) battery cells in the casing are enumerated 2, 3, and 4. Each is kept in position by localizing members in the casing. It should be observed that the battery cells are so grouped in the casing that they form an inverted U, leaving an open space for contact mechanisms etc. between them. The battery cells are connected in series by means of contact members 5 and 6. Terminal lugs marked and are connected to the battery set by means of spring portions 7 and 8 respectively.

In the front wall of the casing a lens body 9 is retatably mounted as shown in Fig. 2. It is kept in place by means of a locking spring 10. In the lens body an electric bulb 11 is located; it is carried by a threaded metal washer 12 having a contact lug 13. This assembly is kept in its power place inside the lens body by means of a pivoted contact spring 14 which is most clearly shown in Fig. 1.

The lens body 9 is provided on its exterior with a lug 15 for turning it about its axis. On the outside face of its inner portion it carries several axially directed grooves (16, 17, 18) which serves in conjunction with a contact lever 19, 20 to make and break the electrical circuit. Grooves 16 and 18 are the same distance from the center of rotation, and approximately the same central distance as the contact lug 13. Groove 17 is a somewhat greater distance from the center of rotation. These grooves thus serve as cams to move the lever 19, 20 into and out of circuit making position.

The contact lever 19, 20 is provided with a helical spring 21 to produce permanent mechanical contact with the lens body. Its extreme end 22 plays between two inwardly projecting prongs 23 and 24 which also serve as female contact members for a cord plug (not shown) for supplying an auxiliary lamp with current. The upper prong 23 is bare metal; the lower prong carries an insulating sleeve 25 to obviate electric contact with the lever portion 22. The device is wired as indicated by the dash-and-dot line in Fig. l i. e. the negative terminal is connected to members 14 and 24. In addition there is a wire connection (not shown) between the positive terminal and the contact lever 19, 20 for supplementing the electric connection provided by the spring 21.

For carrying purposes the device is provided with wire clasps 26 and 27 of which 26 is held by hinge rivets 29 and 30, which also pivotally mount the lid 1a on the casing 1. In addition a third wire clasp 28 is provided for locking the lid to the casing.

It will be apparent from the foregoing description that turning the lens body about its axis will provide contact between the contact lever 19 and prong 23 for the auxiliary lamp only in one specific position, i. e. when groove 17 is in, or nearly in, engagement with portion 20 of the contact lever 19. In said position the auxiliary lamp will burn. Turning the lens body in either direction from said contact position, i. e. by engaging portion 20 with groove 16 or 18, will break any electric connection .to either the auxiliary lamp or the built-in lamp. Rotation through a further 90 provides contact between the contact lever portion 20 and contact lug 13, causing the built-in lamp to burn.

It should be appreciated that disposing the battery cells in U-form and utilizing the space inside the U for a combined lens body and a double throw switch, for contact prongs to a head lamp, and also for a spare bulb (31) in the manner shown and described constitutes a heretofore unattained economy of space, material and manufacturing costs, considering the usefulness and versatility of the device. At the same time the general shape of the device is one which should be considered as very practical for the uses mentioned in the first paragraph.

I claim:

A portable battery operated flash light of the type having a built-in lamp and an auxiliary lamp comprising, in combination, a housing of generally rectangular crosssectional shape, a battery cell at each end of the housing extending parallel to the shorter dimension thereof, a third battery extending in the direction parallel to the longer dimension of .the rectangular housing along one wall thereof, said third cell extending between said first mentioned cells thereby arranging said cells in a U-shape, a lamp, a lamp housing, said lamp housing being rotatably mounted in a wall of said housing and comprising a sleeve-like inner extension extending into the space between the end battery cells, said sleeve-like extension housing said lamp, cam means on said sleeve-like extension, a lever mounted to engage said cam means, said lever being electrically connected to one pole of one of said end cells, said cells being connected in series arrangement, a stationary contact located adjacent an end of said lever, a second stationary contact located ad jacent said first stationary contact, said two contacts forming a receptacle for a plug connection for the auxiliary lamp, said second contact being permanently connected to the other pole of said series arranged cells, a metallic member mounting said lamp in said sleeve-like exten sion, a spring contact member holding said lamp and metallic member axially in position in said sleeve-like extension, said spring contact being connected to the second pole of said series arranged battery cells, and an extension on said metallic member, said extension cooperating with said contact lever whereby by rotation of said lamp housing either the built-in lamp or the auxiliary lamp may be energized at will or both may be deenergized.

References Cited in the file of this patent UNITED STATES PATENTS 777,510 Hubert Dec. 13, 1904 1,289,113 Campbell Dec. 31, 1918 1,393,675 Doe Oct. 11, 1921 2,276,370 Conrad Mar. 17, 1942 FOREIGN PATENTS 11,610 Great Britain of 1908 960,320 France Oct. 24, 1949 632,478 Great Britain Dec. 28, 1949