US3898450A

US3898450A - Reliable flashlight

Info

Publication number: US3898450A
Application number: US412007A
Authority: US
Inventors: Jack S Kilby
Original assignee: Texas Instruments Inc
Current assignee: Texas Instruments Inc
Priority date: 1973-11-01
Filing date: 1973-11-01
Publication date: 1975-08-05
Anticipated expiration: 1992-08-05

Abstract

A flashlight including a reusable reflector unit and a replaceable battery unit, where all of the electrical connections between lamp, batteries and switch are permanent, and are encased within the battery unit.

Description

United States Patent 1 1 1 3,898,450 Kilby 14 1 Aug. 5, 1975 [54] RELIABLE FLASHLIGHT 2,852,662 9/1958 Garland 240/ 10.66

3,097,799 7/1963 Mosman 240/1066 [75] Inventor: Jack Dallas 3,162,376 12/1964 Furuya 1 240/1066 73 Assigneez Texas Instruments Incorporated, 3,201,542 8/1965 Hutchlson... 240/1066 X Dallas Tex. 3,219,811 11/1965 Young 240/26 X 3,327,107 6/1967 Gey 240/1065 [22] Filed: Nov. 1, 1973 3,790,912 2 1974 Murphy 240/1066 3,794,825 2/1974 Krupansky 240/1066 [21] Appl. No.: 412,007

Primary Examiner.loseph F. Peters, Jr. 52 us. c1. 240/1066; 200/60; 240/26; Arwmey, Agent, or FirmRihardS, Harris & 335/219; 335/229 Medlock [51] Int. Cl. F211 7/00 [58] Field of Search 240/106, 10.65, 10.66, ABSTRACT 240/64 R, 26; 200/60; 335/219, 229 A flashlight including a reusable reflector unit and a replaceable battery unit, where all of the electrical [56] References Cited connections between lamp, batteries and switch are UNITED STATES PATENTS permanent, and are encased within the battery unit.

2,818,498 12/1957 Foch 240/106 R X 4 Claims, 3 Drawing Figures 1 RELIABLE FLASHLIGI-IT BACKGROUND OF INVENTION 1. Field of the Invention I The invention relates to a flashlight comprising a reflector unit, and a replaceable battery unit which encases and protects the entire electrical circuit. More particularly, the invention relates to a flashlight which attains increased reliability through permanent and sealed electrical connections.

2. History of the Prior Art In the past, flashlights of the household or general use variety have consisted of a reflector housing, and a battery housing in which the electrical components are connected serially through use of as many as a dozen pressure contacts. Leakage from the dry cell batteries or from the atmosphere creates corrosive conditions that tarnish these pressure contacts. Because of the low voltage involved, even small increases in the contact resistance are serious, and the flashlight becomes inoperative after even short periods of storage.

Flashlights are known which have a detachable housing that accommodates a storage battery to energize the light source. These also use many pressure contacts throughout the electrical circuit, and have an even more corrosive atmosphere near the battery. Reliability is thus lost because of the corroded contacts.

SUMMARY OF THE INVENTION The invention relates to a flashlight combination which completely eliminates the pressure contact problem. In the preferred embodiment, the combination consists of a reflector unit and a battery unit which may be detached and replaced. The reflector unit includes a housing which accommodates a reflector, a lens, and a permanent magnet. The battery unit includes an enclosed housing which encases a fixed electrical circuit consisting of the dry cell batteries, a lamp and a sealed switch. Permanent electrical connections are used throughout the circuit. In the preferred embodiment, the switch is an encapsulated reed switch which is activated magnetically. A portion of the lamp and the reed switch are exposed for interconnection with the reflector unit. The reflector unit is movable rotatably in relation to the battery unit. The permanent magnet, embedded in the molding of the reflector unit housing, may be moved in and out of the proximity of the reed switch to turn the lamp on and off. A related aspect of the invention is the increased reliability of the flashlight combination resulting from the permanent connections in and complete encasement of the series electrical circuit consisting of the dry cells, the lamp leads and the switch leads.

BRIEF DESCRIPTION OF THE DRAWINGS For a more complete understanding of the present invention and for further objects and advantages thereof, reference may now be had to the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 illustrates the flashlight unit showing the reflector unit and the battery unit.

FIG. 2 is a sectional view showing the interconnected reflector unit and battery unit, and the serial arrangement of the dry cell battery, a lamp and switch to form an enclosed, permanently connected circuit.

DETAILED DESCRIPTION Referring to FIG. 1, there is shown the battery unit 10 with lamp 15 and switch 16 held in position by a cylindrical, molded plastic part 12, shown in FIG. 2. Plastic part 12 has a cylindrical neck 14 within which the lamp is seated. In the preferred embodiment, the switch is an encapsulated reed switch and the entire battery unit assembly, including plastic part 12, is molded in a low cost plastic housing 11. It is understood that the battery unit housing 11 may be a paper tube or other desired encasement, with plastic part 12 forming a closure for the open tube end.

The reflector unit 20, in the preferred embodiment, consists of a molded plastic outer shell, reflector unit housing'2l, within which lens 22 is seated in a suitable groove. The reflector housing is molded in a form to allow the reflector to be seated directly beneath the lens 22. A cylindrical opening 23 allows the passage of cylindrical neck 14 and lamp 15 into the reflector housing when the reflector unit and battery unit are interconnected. The reflector unit housing 21, is shown with a vertical portion broken away to expose the embedded permanent magnet 26. Interconnection of the reflector unit and the battery unit is accomplished by the fastening of circular rib 25 of hollow neck 24 into groove 13 of plastic part 12. The reflector unit is thereby movable rotatably in relation to the battery unit. When the permanent magnet 26 is moved in the proximity of the reed switch 16, the lamp is turned on. The lamp is turned off by rotating the permanent magnet away from the reed switch.

In FIG. 2, the reflector unit and the battery unit are shown interconnected.

Batteries

30 and 31 are shown enclosed within battery unit 10. Lamp 15, reed switch 16 and the dry cell batteries are shown connected in a series electrical circuit which serves to energize the lamp. The dry cell batteries are connected by means of a cap 36 which is soldered or welded to the outer shell of battery 30 and press-fitted to the carbon electrode of battery 31. Cap 33 is likewise press-fitted to the carbon electrode 32 of battery 30, and welded or soldered to lead 37 of lamp 15. A second lamp lead 38 is soldered or welded to a lead of reed switch 16. A second lead of reed switch 16 is welded or soldered to a conductive lead 34, which may be made of a flat ribbon. One end of lead 34 is connected to the negative electrode of battery 31 by soldering or welding. Conductive lead 34 is insulated from the outer electrode of battery 30 by insulation layer 10a. The entire electrical circuit, composed only of permanent connections, is encased within the battery unit housing 11. The only components of these circuits that are exposed external to the battery unit housing 11 are lamp 15 and reed switch 16, which are shown seated in the molded plastic part 12. Lamp 15 may be correctly positioned within cylindrical neck 14 by means of a suitable adhesive. Permanent magnet 26, embedded within the reflector unit housing 21, is shown positioned directly above reed switch 16. In this position, the reed switch is on, and the lamp 15 is energized. By means of the connecting groove 13, the reflector unit is allowed to move rotatable in relation to the battery unit. The permanent magnet 26 may thus be moved away from the switch to turn lamp off.

FIG. 3 shows an exploded view of reflector unit housing 21, lens 22, permanent magnet 26, lamp l5. reed switch 16 and the battery unit 10 without its housing.

Having described the invention in connection with certain specific embodiments thereof, it is to be understood that further modifications may now suggest themselves to those skilled in the art. and it is intended to cover those modifications that fall within the scope of the appended claims.

What is claimed is:

1. In a flashlight with a separable reflector unit, the combination comprising:

a. a lamp, a battery and a magnetically operable switch having permanent connecting means to form a series circuit therefrom,

b. said circuit being mounted in a permanent housing with at least a portion of said lamp exposed, and

c. a cover mounted on said housing with a reflector and a magnet movable with respect to said housing to operate said switch.

2. The combination as set forth in claim 1, wherein:

a. said permanent connecting means includes interconnecting leads soldered to a cap, which cap is press-fitted to the carbon electrode of said battery; and

b. said permanent housing is a molded plastic.

3. In a flashlight wherein a reflector unit is to be connected to a battery unit including a serially connected 4 lamp, battery and switch, the combination comprises:

a. an encapsulated reed switch which is activated magnetically;

b. a magnet movable into and out of registration with said switch to turn said lamp on and off, said magnet being embedded in the molding of said reflector unit;

c. means for permanently connecting said lamp, battery and switch in a fixed electrical circuit; and

d. a battery unit housing, permanently encasing said circuit with a portion of said lamp exposed to emit light, said reflector unit being movable rotatably in relation with said permanent housing, thereby moving said magnet into and out of registration with said reed switch.

4. In a flashlight wherein a reflector unit is to be connected to a battery unit including a serially connected lamp, battery and switch, the combination comprises:

a. an encapsulated reed switch which is activated magnetically;

b. a magnet movable into and out of registration with said switch to turn said lamp on and off;

d. a battery unit housing, permanently encasing said circuit with a portion of said lamp exposed to emit light, said housing being a tube with open end closed by a molded plastic part upon which said lamp and said reed switch are seated.

Claims

1. In a flashlight with a separable reflector unit, the combination comprising: a. a lamp, a battery and a magnetically operable switch having permanent connecting means to form a series circuit therefrom, b. said circuit being mounted in a permanent housing with at least a portion of said lamp exposed, and c. a cover mounted on said housing with a reflector and a magnet movable with respect to said housing to operate said switch.

2. The combination as set forth in claim 1, wherein: a. said permanent connecting means includes interconnecting leads soldered to a cap, which cap is press-fitted to the carbon electrode of said battery; and b. said permanent housing is a molded plastic.

3. In a flashlight wherein a reflector unit is to be connected to a battery unit including a serially connected lamp, battery and switch, the combination comprises: a. an encapsulated reed switch which is activated magnetically; b. a magnet movable into and out of registration with said switch to turn said lamp on and off, said magnet being embedded in the molding of said reflector unit; c. means for permanently connecting said lamp, battery and switch in a fixed electrical circuit; and d. a battery unit housing, permanently encasing said circuit with a portion of said lamp exposed to emit light, said reflector unit being movable rotatably in relation with said permanent housing, thereby moving said magnet into and out of registration with said reed switch.

4. In a flashlight wherein a reflector unit is to be connected to a battery unit including a serially connected lamp, battery and switch, the combination comprises: a. an encapsulated reed switch which is activated magnetically; b. a magnet movable into and out of registration with said switch to turn said lamp on and off; c. means for permanently connecting said lamp, battery and switch in a fixed electrical circuit; and d. a battery unit housing, permanently encasing said circuit with a portion of said lamp exposed to emit light, said housing being a tube with open end closed by a molded plastic part upon which said lamp and said reed switch are seated.