US3097798A

US3097798A - Flashlights

Info

Publication number: US3097798A
Application number: US56577A
Authority: US
Inventors: Schmidt Gerhard; Feindt Heinrich
Original assignee: Licentia Patent Verwaltungs GmbH
Current assignee: Licentia Patent Verwaltungs GmbH
Priority date: 1959-10-14
Filing date: 1960-09-16
Publication date: 1963-07-16
Anticipated expiration: 1980-07-16

Description

July 16, 1963 G. SCHMIDT ETA;

FLASHLIGHTS Filed sept. 1e, 1960 Inventors Kum/wl M 27" WMM United States Patent O 3,097,798 FLASHLIGHTS Gerhard Schmidt, Berlin-Frohnau, and Heinrich Feindt, Berlin-Grunewald, Germany, assignors to Licentia Patent-Verwaltungs-G.m.b.H., Frankfurt am Main, Germany Filed Sept. 16, 1960, Ser. No. 56,577 Claims priority, application Germany Oct. 14, 1959 2 Claims. (Cl. 240--10.65)

The present invention relates to flashlights.

There exist llashlights equipped with connector prongs that enable the llashlight to be connected to a source of electrical energy for the purpose of recharging the flashlight batteries.K In flashlights of this type, ditiiculties have arisen insofar as the problem of heat insulation is conce1-ned. Tha-t is to say, some of the component parts are not only better able to withstand heat than others but are, in fact, heat generators, so that those part-s which are less well able to withstand heat must be insulated ffrom the heat generators. Such heat generators, in a portable flashlight, are the bulb or lamp as well as the current limiting resistors which are interposed between the connector Iprongs and the recharging unit which is connected to the batteries Vand which converts the standard A C. or D.C. house voltage of 110 to P20 v. to a direct voltage of an amplitude suitable for charging the batteries.

Furthermore, in flashlights having prongs that enable the device to be connected to an outside source of electrical energy, these prongs are usually covered by a cover which is removably mounted on the ilashlight casing, the arrangement bein-g lsuch that the lamp is carried by this cover so that the 4lamp is physically as Well as electrically disconnected from the flashlight casing whenever the cover is removed in order to expose Ithe prongs. It is, therefore, essential that the electrical contacts whichy place the lamp in circuit 'with the other components of the flashlight circuit be especially designed to withstand the repeated connecting and disconnecting that takes place whenever the batteries are -to` be recharged. `Contacts 'which will fulll this need are not only complicated and expensive, but must be manufactured with a high degree of accuracy in order t-o insure the making of a good electrical contact every time the cover carrying the lamp is replaced on the flashlight casing.

It is, there-fore, an object of the present invention to provide a portable flashlight which overcomes the above disadvantage.

It is :another object of the present invention to provide a ashlight in which those components of the flashlight circuit which are best able to withstand heat are all located in the same general area within the llashlight casing.

It is still another object of the present invention to provide a flashlight in which the lamp is permanently connected to the flashlight .at the same end of the casing `from which the prongs project, and in which the cover :adapted to cover these prongs does not cause the lamp to be removed whenever the tlashlight batteries :are .to be recharged.

The objects of the present invention also include the provision of a as'hlight which is of compact construction and which may readily be manufactured at low cost,

With the above objects in view, the present invention resides mainly in a flashlight which comprises a casing having a longitudinal axis anda partition transverse to lthe axis and dividing the interior of the casing into two sections, a rechargeable battery arranged in said casing, a recharging unit :also arranged in the casing and electrically connected to the battery, a pair of prongs electrically connected to the recharging unit and enabling the lflashlight to be electrically and mechanically connected .to a source of electrical energy, a cover removably mounted on the ICC easing for covering the pron-gs when the same are disconnected from the source of electrical energy, a lamp arranged generally between the prongs and occupying along the longitudinal axis of the casing a position spaced inwardly from the free outer ends of the prongs, and resistor means electrically interposed between the prongs and the recharging unit and occupying in the casing approximately the same position along the longitudinal axis .as does the lamp. The lamp and the resistor means are located on one of the two sections of the casing while the rechargeable battery and the recharging unit are located in the -other section of the casing, so that the heat Igenerating components of the flashlight are grouped .together in one place and the heat-sensitive components of the flashlight are grouped together in another place.

Additional objects and advantages of the pr-esent invention will become apparent upon consideration of the yfollowing description when taken in conjunction with the accompanying drawings, in which:

FIGURE 1 is a sectional view of one embodiment of la flashlight according to the present invention;

FIGURE 2 is a sectional view ltaken along line 2 2 of IFIGURE l;

FIGURE 3 is a sectional view taken along line 3-3 of FIGURE l;

FIGURE 4 is a sectional view similar to FIGURE l, except that the current limiting resistors are shown as being differently oriented; and

FIGURE 5 is a schematic circuit diagram of the electrical components.

Referring now to the drawings and to FIGURES 1 to 3 thereof in particular, there is shown a flashlight having a casing composed of two intert-ting cup-shaped parts l1 and 13, the part 1 containing one or more rechargeable batteries 2 land a recharging .unit 3 while the part 113 carries a pair of connector prongs 4 by means of which the llashlight can be plugged into a conventional outlet box.

The part 13 is formed in its center and between the prongs 4 with a depression 13a having an opening through which a lamp or .bulb 6 is inserted. The lamp is engaged by contact springs 18 and 19 mounted on a support plate 15 extending transversely across the interior of the casing and dividing this interior into two sections, there being Vabutment :blocks 14 which may press against the contact springs. The socket `actu-ally mounting the lamp 6 is of conventional construction Vand is, therefore, not shown in detail.

The contact spring 18 is connected to a line 17, whereas the contact spring 19 extends into a movable switch contact portion 11 which cooperates with a station-ary switch contact portion 12, the latter leading to a line 1-6. The switch is actuated by an actuating slide 1t) which has a serrated hand piece 9 projecting through a cutout 7a of a cover 7, this cover being removably mounted on the casing and covering the prongs 4 when the same lare not in use, Thus, the switch 11, 12 may be closed by moving the slide 9, 10 downwardly, and be opened by raising the slide upwardly. When the cover 7 is removed, the slide 9', 10 will be carried along and withdrawn from the casing so that the switch 11, 12 can not be inadvertently closed while the prongs 4 are received in Ian outlet box.

As show-n in the drawing, the cover is formed with an inwardly tapering portion `8 which is in alignment with the lamp 6V and protrudes somewhat into the depression 13a of the casing. In order to improve the lighting characteristics, the portion 8 is fashioned asa reilector. Alternatively or additionally, the portion 8 may contain a suitable optical focusing lens 5.

The il-ashlight casing further contains resistor means which are interposed between the prongs 4 and the recharging unit 3 in order to limit the charging current. The resistor means comprise two pairs of resistors 20,

21 and 22, 23 which are connected in a series-parallel circuit, i.e., the two resistors of each pair being connected to forni a parallel circuit which itself is serially connected to -a respective prong 4, as shown in FIGURE 5, which illustrates the electrical connections of the various component parts, these connections not being shown, for purposes of clarity, in FIGURES 1 to 3. It will be noted that the recharging unit 3 is depicted as a rectifier bridge circuit incorporating four rectifier elements 3a.

As stated above, the lamp and the resistors are the elements best capable of withstanding heat and, as is shown in FIGURES l to 3, these component parts are arranged in the same general area within the ashlight casing. Thus, the lamp 6 is arranged generally between the prongs 4 and occupies along the longitudinal axis of the casing, indicated by the dotted line x, a position spaced inwardly from the free outer ends 4a of the prongs 4, and the resistors 2t), 21, 22 and 23 occupy within the casing lapproximately the same position along this longitudinal axis x as does the lamp `6. As a result, the lamp 6 and

resistors

29, 211, 22 and 23 are all in close proximity to each other and are separated by the transverse support plate 15 from the space occupied by the recharging unit 3 and the batteries 2. In this way, the space is utilized with maximum eiciency; also, the recharging unit 3 and the batteries 2 are more easily heat-insulated than would be possible if these component parts were so arranged within the casing as to be close to the lamp 6 and the

resistors

20, 21, 22 and 23.

The resistors are so oriented that the axes y of the

resistors

20 and 21 lie in `a plane forming a right angle with the plane containing the longitudinal axis x land the two prongs 4, and that the axes y of the

resistors

22 and 23 lie in another plane which also forms a right angle with the plane containing the longitudinal axis x land the two prongs 4. In the embodiment of FIGURES y1 to 3, the axes y of the resistors are parallel to the longitudinal axis x, whereas in the embodiment of FIGURE 4, which is otherwise identical to that of FIGURES l to 3, the axes y form right angles with the aforo-mentioned plane containing axis x Iand the prongs 4.

We claim:

1. In a ashlight incorporating a casing having a longitudinal axis and a partition transverse to said axis and dividing the interior of said casing into two sections, a rechargeable battery arranged in said casing, a recharging unit also arranged in said casing `and electrical-1y connected to said battery, ya pair of prongs electrically connected to said recharging unit and enabling the flashlight to be electrically and mechanically connected to a source of electrical energy, and la cover removably mounted on said casing for covering said prongs when the same are disconnected from the source of electrical energy, the improvement which comprises: a lamp arranged generally between said prongs and occupying along said longitudinal axis of said casing a position spaced inwardly from the free outer ends of said prongs, and resistor means electrically interposed between said prongs and said recharging unit and occupying in said casing approximately the same position along said longitudinal axis as does said lamp, said lamp and said resistor means being located in one of said sections of said casing, said rechargeable battery and said recharging unit being located in the other of said sections of said casing, whereby the heat genenating components of the flashlight are grouped together in one place and the heat-sensitive components of the flashlight are grouped together in vanother place.

2. A flashlight comprising, in combination: a casing having a longitudinal axis and a partition transverse to said axis and dividing the interior of said casing into two sections; a rechargeable battery arranged=in said casing; a recharging unit also arranged in said casing and electrically connected to said battery; a pair of prongs electrically connected to said recharging unit and enabling the ilashlight to be electrically and mechanically connected to a source of electrical energy; a cover removably mounted on said casing for covering said prongs when the same are disconnected from the source of electrical energy; a larnp arnanged generally between said prongs and occupying along said longitudinal axis of said casing a position spaced inwardly from the free outer ends of said prongs; and resistor means electrically interposed between .said prongs and said recharging unit and occupying in said casing 'approximately the same position along -said longitudinal laxis `as does said lamp; Said lamp and said resistor means being located in one of said sections of said casing and said rechargeable battery and said recharging unit being located in the other of said sections of said casing, whereby the heat generating components of the flashlight are grouped together in one place and the heat-sensitive components of the flashlight are grouped together in another place, thereby utilizing the space within said casing with maximum eiciency and facilitating heatinsulation of said heat-sensitive components.

References Cited in the tile of this patent UNITED STATES PATENTS 2,873,358 Dunker Feb. 10, 1959 2,880,306 Witte Mar. 31, 1959 FOREIGN PATENTS 813,863 Germany Sept. 17, 1951 566,286 Canada Nov. 18, 1958 1,211,940 France Oct. 12, 1959

Claims

1. IN A FLASHLIGHT INCORPORATING A CASING HAVING A LONGITUDINAL AXIS AND A PARTITION TRANSVERSE TO SAID AXIS AND DIVIDING THE INTERIOR OF SAID CASING INTO TWO SECTIONS, A RECHARGEABLE BATTERY ARRANGED IN SAID CASING, A RECHARGING UNIT ALSO ARRANGED IN SAID CASING AND ELECTRICALLY CONNECTED TO SAID BATTERY, A PAIR OF PRONGS ELECTRICALLY CONNECTED TO SAID RECHARGING UNIT AND ENABLING THE FLASHLIGHT TO BE ELECTRICALLY AND MECHANICALLY CONNECTED TO A SOURCE OF ELECTRICAL ENERGY, AND A COVER REMOVABLY MOUNTED ON SAID CASING FOR COVERING SAID PRONGS WHEN THE SAME ARE DISCONNECTED FROM THE SOURCE OF ELECTRICAL ENERGY, THE IMPROVEMENT WHICH COMPRISES: A LAMP ARRANGED GENERALLY BETWEEN SAID PRONGS AND OCCUPYING ALONG SAID LONGITUDINAL AXIS OF SAID CASING A POSITION SPACED INWARDLY FROM THE FREE OUTER ENDS OF SAID PRONGS, AND RESISTOR MEANS ELECTRICALLY INTERPOSED BETWEEN SAID PRONGS AND SAID RECHARGING UNIT AND OCCUPYING IN SAID CASING APPROXIMATELY THE SAME POSITION ALONG SAID LONGITUDINAL AXIS AS DOES SAID LAMP, SAID LAMP AND SAID RESISTOR MEANS BEING LOCATED IN ONE OF SAID SECTIONS OF SAID CASING, SAID RECHARGEABLE BATTERY AND SAID RECHARGING UNIT BEING LOCATED IN THE OTHER OF SAID SECTIONS OF SAID CASING, WHEREBY THE HEAT GENERATING COMPONENTS OF THE FLASHLIGHT ARE GROUPED TOGETHER IN ONE PLACE AND THE HEAT-SENSITIVE COMPONENTS OF THE FLASHLIGHT ARE GROUPED TOGETHER IN ANOTHER PLACE.