US2911637A

US2911637A - Electric flashlights or torches

Info

Publication number: US2911637A
Application number: US735194A
Authority: US
Inventors: Wortmann Herbert
Original assignee: CARL VON DER CRONE AND CO
Current assignee: CARL VON DER CRONE AND CO
Priority date: 1957-05-16
Filing date: 1958-05-14
Publication date: 1959-11-03
Anticipated expiration: 1976-11-03

Description

NOV. 3, H WQRTMANN ELECTRIC FLASHLIGHTS OR TORCl-IES Filed May 14, 1958 F/& 1?

FIG. I

MM WWW M W United States Patent F ELECTRIC FLASHLIGH'I'S OR TORCHES Herbert Wortmann, Luedenscheid, Germany, assignor to Carl von der Crone & C0., Lnedenscheid, Germany Application May 14, 1958, Serial No. 7 35,194 Claims priority, application Germany May 16, 1957 6 Claims. (Cl. 340-321) This invention relates to flashlights, and more particularly to flashlights provided with flasher means adapted to cyclically close and open an electric circuit including an incandescent lamp so as to produce intermittent light flashes in a predetermined rhythm.

It is one object of the invention to provide an attach- 1 ment for converting a standard flashlight having a cylindrical casing for receiving dry cells into an intermittently operating signalling light.

It is another object of this invention to provide an attachment of the aforementioned character which draws a minimum of current from the dry cells of the standard flashlight by which it is supplied with current.

Another object of this invention is to provide an attachment of the aforementioned character comprising a rugged mechanical flasher switch involving a bimetallic control strip rather than a highly sensitive flasher switch as, for instance, a mercury switch operated and controlled by an electromagnet, or solenoid.

The novel features that are characteristic of the invenition are set forth in particular in the appended claims.

The invention itself, however, both as to structure and operation together with additional objects and advantages thereof will best be understood from the following detailed description of a preferred embodiment thereof when read in connection with the accompanying drawing in which:

Fig. 1 illustrates a cylindrical flashlight, the lower portion of which is shown in section;

Fig. 2 is the wiring diagram of a flashlight attachment embodying the invention;

Figs. 3 to 9 are details of the end cap, viz,

Fig. 3 is a front view of the cap, the bottom thereof iaving been broken away to expose its inside to view;

Fig. 4 is a front view of an insulating partition housed I in the cap;

Figs. 5 and 6 show the end cap seen from the outside, nd from the inside, respectively; and

Figs. 7 to 9 show the constituent parts of a sliding switch on the base of the cap, Fig. 7 being a top plan view of the movable contact of the switch, Fig. 8 being a section taken along line 88 of Fig. 7, and Fig. 9 being a side elevation of the manual operator of the switch.

The cylindrical casing 1 comprises the usual type of main switch 2 adapted to remain either in the open position or closed position thereof. Casing 1 is screwthreaded at 1a. Cap 3 has a screw-threaded side portion 3a and a bottom portion 4 defining an external reces's 4a. Transverse insulating partition 5 is arranged inside of cap 3 between the base 4 of the cap and the open end thereof. The upper surface of partition 5 supports a metal cup 6. Cup 6 is secured to partition 5 by means of screws 7 or the like. Cup 6 detachably engages with its upturned edge the largest winding of tapering compression coil spring 8, which is a cell-supporting spring and makes contact with the bottom end of the cylindrical dry cell 9. The base of the cup 6 has a thread receiving ICC screw lflforming a fixed adjustable Contact of a bimetal flasher switch. The bimetal strip 11 is provided on the free end thereof with a movable contact 12. The heating wire 13 is wound around the bimetal strip 11 and adapted to heat the latter. Contact 12 is preferably made of silver and adapted to conductively connect one end of heating winding 13 to bimetal strip 11. The opposite end of winding 13 is conductively connected to fixed contact 10. As long as bimetal strip 11 is relatively

cool contacts

10, 12 are spaced and the current supplied by dry cell 9 flows through heating winding 13. When bimetal strip 11 is sufficiently warm and warped,

contacts

10, 12 are in engagement and then winding 13 is shunted out of the circuit of cell 9.

The diagram of Fig. 2 shows that the circuit of dry cell 9 includes incandescent lamp 15. The circuit of dry cell 9 is controlled by the main switch 2 arranged in series with two other switches connected in parallel, i.e. the

bimetal switch

10, 11, 12, 13 on the one hand, and the sliding switch 14, on the other hand. If the main switch 2 is closed and the switch 14 is open, the current flows through the heating wire 13 and heats the bimetal strip 11, thus causing the contact 12 thereof to abut against the fixed contact 10. As a result, the heating wire 13 is deenergized and cools oif. Consequently the bimetal strip 11 disengages its contact 12 from the contact 10. Therefore" a periodical intermittent light signal is emitted as long as switch 2 is closed. If a permanent light beam is desired or required, switch 14 is closed, and the

bimetal switch

10, 11, 12, 13 shunted out and rendered inoperative. It is thus apparent that any standard flashlight having a cylindrical screw-threaded casing may be converted into a flashlight adapted to emit at will either a steady light, or intermittent light signals.

.Partition 5 forms an integral part of a cap of insulating material to which the same reference character has been applied. Cap 5 is arranged inside of cap 3. The open end of cap 5 is juxtaposed to the closed or bottom end of cap 3. Thus

caps

3 and 5 define the entirely closed chamber A

accommodating switch

10, 11, 12, 13. Cap 3 forms an open chamber B accommodating parts 6 and 8.

The lower surface of insulating partition 5 supports by means of screws 7 a plate 15. Screws '7 provide a conductive connection between plate 15 and cup 6. A contact flap or tab 15b which may also be formed by a cut-out portion of this disc 15projeets through a slot 15a in plate 15 into chamber A. This flap 15b is a fixed contact. Fixed contact 15b is adapted to cooperate with a sliding contact of the sliding switch 14, which is disposed on the inner surface of the cap bottom 4. The above sliding contact comprises a contact end 1412 cooperating with the fixed tab 15b. Operating handle or slide 14g of switch 14 is arranged in recess 4a and has flaps 14a which project through slots in the cap bottom 4 and are bent over sliding contact 140 (see Fig. 6). The end 14d of the slide contact 14c is adapted to establish two stable end positions and to minimize contact resistance between

parts

14c and 4. The right end 11a of bimetal strip 11 is extended far enough to contact the live cap bottom 4.

The adjustable screw 10 may be substituted by a second or additional bimetal strip, to compensate for changes in ambient temperature, thus automatically maintaining a constant flash frequency. It will be understood that although but one embodiment of the invention has been illustrated and described in detail, the invention is not. limited thereto. It will also be understood that the struc-- ture illustrated may be modified without departing from. thespirit and scope of the invention as set forth in the;

accompanying claims.

Patented Nov. 3, 1959 j I claim as my invention:

1. An attachment for converting a standard flashlight having a cylindrical screw-threaded casing for receiving dry cells into an intermittently operating signal-ling light comprising a screw-threaded cap adapted to close a flashlight casing; a transverse insulating partition arranged inside of said cap subdividing said cap into an open chamher and a closed chamber; a cell-supporting spring sup ported by said partition and arranged in said open chamher; said closed chamber accommodating a pair of cooperating separable contacts, a bimetal strip supporting one of said pair of contacts, and a resistor adapted to heat said bimetal strip connected across said pair of contacts to be shunted out upon warping of said bimetal strip causing engagementof said pair of contacts; and means conductively connecting one of said pair of contacts to said spring and the other of said pair of contacts to said cap.

. 2. An attachment as specified in claim 1 wherein said closed chamber accommodates a manually operable switch adapted to shunt said pair of contacts at will.

3. An attachment as specified in claim 1 wherein the other of said pair of contacts is supported by an additional bimetal strip.

4. An attachment for converting a standard flashlight having a cylindrical screw-threaded casing for receiving dry cells into an intermittently operating signalling light comprising a cap adapted to close a flashlight casing and having a screw-threaded side portion and a bottom portion defining an external recess therein; a transverse insulating partition arranged inside of said cap subdividing said cap into an open chamber and a closed chamber; a cell-supporting spring supported by said partition and arranged in said open chamber; said closed chamber ac commodating a fixed contact supported by said partition, a cooperating movable contact, a bimetal strip supporting said movable contact adjacent one of the ends thereof and being supported by said partition, and a resistor wound around said bimetal strip and connected across said fixed contact and said movable contact to be shunted out upon warpingof said bimetal strip causing engagement of said fixed contact by said movable contact; means conductively connecting said fixed contact to said spring and said himetal strip to said cap; said closed chamber further accommodating a manually operable switch adapted to shunt at will said fixed contact and said movable con tact, and said switch comprising an operating member arranged in said external recess defined by said bottom portion of said cap and movable in the direction of a diameter of said cap.

5. An attachment for converting a standard flashlight having a screw-threaded cylindrical casing for receiving dry cells into an intermittently operating signalling light comprising a first cap adapted to close a flashlight casing and having a screw-threaded side portion and a bottom portion defining an external recess therein; a second cap of insulating material arranged inside said first cap, the I winding held in position by said upturned edge of said metal cup; said closed chamber accommodating a pair of cooperating separable contacts, a bimetal strip supporting one of said pair of contacts, and a resistor adapted to heat said bimetal strip connected across said pair of contacts to be shunted out upon warping of said bimetal strip causing engagement of said pair of contacts; means for conductively connecting one of said pair of contacts to said spring and the other of said pair of contacts to said first cap; said closed chamber further accommodating a manually operable switch adapted to shunt at will said fixed contact and said movable contact, and said switch comprising an operating member arranged in said external a recess defined by said bottom of said first cap;',

, able switch 6. An attachment for converting a standard flashlight having a cylindrical screw-threaded casing for receiving dry cells into an intermittently operating signalling light comprising a cap adapted to close a flashlight casing and having a screw-threaded side portion and a bottom portion defining an external recess therein; a transverse insulating partition arranged inside of said cap subdividing'said cap into an open chamber and a closed chamber; a cellsupporting spring supported by said partition and arranged in said open chamber; said closed chamber accommodating a fixed contact supported by said partition, a bimetal strip supported by said partition at a point intermediate both ends thereof and having one end conductively connected to said cap, a movable contact cooperating with said fixed contact supported by said bimetal strip adjacent the other end thereof, and a resistor wound around said bimetal strip and having one end connected to said fixed contact and the other end connected to said bimetal strip;-

means extending transversely across said partition conductively connecting said spring to said fixed contact; said closed chamber further accommodating a manually operadapted to shunt at will said fixed contact and said movable contact, and said switch comprising an operating member arranged within said external recess defined by said bottom portion of said cap.

References Cited in the file of this patent UNITED STATES PATENTS 2,090,293 Haines Aug. 17, 1937 2,557,859 Bernstein June 19, 1951 2,675,545 Wolfer Apr. 13, 1954 2,739,305 Harmon Mar. 20, 1956 2,804,611 Craddoek Aug. 27, 1957