WO1996025624A1

WO1996025624A1 - Light system

Info

Publication number: WO1996025624A1
Application number: PCT/SE1996/000197
Authority: WO
Inventors: Rolf Berg
Original assignee: Rolf Berg
Priority date: 1995-02-15
Filing date: 1996-02-14
Publication date: 1996-08-22
Also published as: SE504864C2; SE9500555L; DE69630599D1; AU4736796A; EP0826129B1; SE9500555D0; EP0826129A1; ATE253711T1

Abstract

A battery-light system and a lamp unit therefor. A battery light has a light body (1) in which batteries (7) are provided. A lamp unit (21) equipped with a pendulum balancing weight (45) is freely introduced through the open end (2) of the light body and placed on diametrically-opposed, recessed lamp current-supply plates (11, 12). The connecting wires (51, 52) of the incandescent lamp (41) belonging to the lamp unit (21) extend downwards on the frame element of the lamp unit to laterally-projecting, rigid suspension arms (58, 59), the contact elements of the lamp unit cooperating with the plates (11, 12). As a rigid coherent unit, the lamp unit (21) may pivot about a mounting axis defined by the contact points on the plates (11, 12). When the batteries are to be charged, the lamp unit (21) is removed, and the light body (1) is placed upside-down in a charger, the plates (11, 12) being in contact with charging electrodes.

Description

LIGHT SYSTEM

Field of the Invention

The present invention generally relates to lighting systems, and especially concerns a light system, in par¬ ticular a battery-light system, as well as a lamp unit which is eminently suitable for a light system according to the invention.

Description of the Prior Art

Light systems that comprise electric lights imitat- ing candles are previously known, for instance from SE-B- 451,400. Such electric lights have a pivotally suspended incandescent lamp, and the suspension is fairly compli¬ cated and does not enable expedient exchange of the in¬ candescent lamp proper. Also, the pivotal function has been found to be less than satisfactory.

Objects of the Invention

One object of this invention is to provide an im¬ proved light system with a pivotable incandescent lamp. Another object of the invention is to provide a battery-light system, especially a system which effi¬ ciently utilises the capacity of the batteries and which enables expedient and effective charging of the batte¬ ries. Another object of the invention is to provide a light system whose incandescent lamp is easy to replace.

Yet another object of the invention is to provide a lamp unit which is especially suited for use in light systems and which is easy to handle and apply and in- volves an improved pivotal function.

A further object of the invention is to provide a lamp unit which makes it possible to expediently vary the amplitude of the pivotal movement of the lamp unit. Finally, an additional object of the invention is to provide a pivotable lamp-unit suspension ensuring reliable current supply by means of contact elements also in difficult surroundings.

Summary of the invention

The above objects, as well as other objects which will appear from the following description, are achieved by a light system and a lamp unit exhibiting the inven- tive features stated in the appended claims.

Thus, the invention is based on the insight that it is highly advantageous to utilise a lamp unit which, in accordance with the invention, comprises a frame element having rigid mounting arms which project transversely in opposite directions, a contact means being arranged on the end underside of the respective arms, an incandescent lamp being fixed to the upper side of the frame element and equipped with connecting wires connected to, and pre¬ ferably constituting, said contact means, and a balancing means being fixed to the underside of said frame element, said contact means defining a transverse mounting axis about which the lamp unit may pivot or swing as a cohe¬ rent unit when, in use, it has been, from above, freely and directly placed in a lamp holder provided with cur- rent-supply contact means corresponding to the contact means of the lamp unit.

Thus, a light system according the invention com¬ prises electric lights, which each include a sleeve- shaped light body, current-supply means arranged in said light body, and a lamp unit of the above type which is arranged at the upper, upwardly open end of said light body, contact means connected to the current-supply means being so arranged in the light body as to be freely exposed at said end, thus forming a lamp holder having current-supply contact means corresponding to the contact means of the lamp unit. In a preferred embodiment of the invention, the lights are battery lights, said current-supply means com¬ prising one or more chargeable batteries arranged in said light body, a charging device for charging battery lights being provided and comprising a light stand adapted to separately accommodate, for charging purposes, one or more battery lights from which the associated lamp unit has been removed. Said light stand has, at each light- accommodating site, charging contact means adapted to come into contact with the contact means in the light body of a battery light when said light body is placed on the light-accommodating site at issue, said charging contact means being connected to a charging unit for emitting charging current to said charging contact means and, hence, to the batteries of an associated light body. Advantageously, the light stand of the charging device is adapted to receive the respective light bodies (thus without the associated lamp unit) turned upside- down, especially vertically, in a hole adapted to the light-body configuration, such that the light body is made to occupy a predetermined position adapted to the charging contact means arranged in said hole. The charg¬ ing contact means preferably comprises upwardly-converg¬ ing, spaced-apart contact elements with which the con- tact means of the light body are brought into engagement during charging. As is quite easily understood, such an engagement implies sliding between cooperating contact- element surfaces, which ensures good electrical contact. Advantageously, the holes of the light stand are throughgoing and so overdimensioned as to enable air to flow up through them and coolingly flow round the batte¬ ry lights placed in the respective holes in order to be charged. Should further cooling be desirable in connec¬ tion with the charging operation, for instance if the batteries are of nickel-metal-hydride type, the charging device may advantageously be placed in a cooling compart¬ ment, where the low temperature required, for instance of about 14-16°C, can easily be maintained during the charg¬ ing operation.

In connection with the charging operation, a battery light may thus simply be removed from its holder, where- upon the lamp unit is removed and the remainder of the battery light is placed in the charging device.

Advantageously, a lamp unit according to the inven¬ tion has a balancing means, preferably of pendulum type, which is connected to the frame element and which posi- tions the centre of gravity of the lamp unit below the mounting or pivot axis of the unit.

The frame element of the lamp unit may be equipped with arms which project transversely in opposite direc¬ tions and on which the contact means of the lamp unit are arranged. It has been found advantageous that the frame element of the lamp unit should have a generally cruci¬ form shape, the contact means of the lamp unit being ar¬ ranged on the underside of the respective frame-element arms projecting in the transverse direction. The balanc- ing means mentioned above may then be connected to a downwardly-directed frame-element projection, the incan¬ descent lamp of the lamp unit being connected to an upwardly-directed frame-element projection.

As is quite easily understood, a lamp unit according to the invention may very easily swing or pivot about its suspension axis. This will ensure relative motion between the contact means of the lamp unit and the corresponding contact means of the associated lamp holder or light body, thus ensuring excellent electrical contact also in difficult surroundings, where e.g. oxidation of the con¬ tact means would normally occur. It has been found that a lamp unit that is designed and suspended in accordance with the invention is highly liable to move as a result of jolts, air currents and the like, i.e. without any active creation of a pivoting or swinging movement.

According to the invention, however, one may advan¬ tageously make arrangements for an active, controlled pivoting or swinging movement of the lamp unit. In view hereof, the lamp unit may comprise an element which can be acted upon magnetically, preferably a permanent magnet element, means being arranged in the lamp holder of the lamp unit or its associated light body below the lamp unit to periodically generate a magnetic field, thereby to magnetically act upon said element, and hence the lamp unit, such that the latter is caused to pivot or swing periodically about its axis. Advantageously, the position of the element that can be acted upon magnetically can be adjusted in relation to the remainder of the lamp unit, such that the degree of magnetic action, and hence the amplitude of the pivotal movement of the lamp unit, is adjustable. Preferably, this can be achieved by arranging the element that can be acted upon magnetically on said balancing means, prefer¬ ably at the bottom thereof, said balancing means being arranged on the frame element of the lamp unit in such a manner as to be rotatable about a vertical axis. In a preferred embodiment of the invention, the lamp unit comprises an incandescent lamp having a bulb con¬ taining a filament and an associated filament base, whence project the connecting wires of the incandescent lamp, as well as a downwardly-directed mounting pin by means of which the incandescent lamp is fixed to the frame element of the lamp unit, preferably at an upward¬ ly-directed frame-element projection, which preferably is tubular at least at the top so as to receive said mount¬ ing pin. The connecting wires of the incandescent lamp are advantageously so arranged as to constitute the con¬ tact means of the lamp unit as well as arranged in such a manner that the incandescent lamp with the associated connecting wires may be expediently replaced. Advanta¬ geously, the connecting wires may be arranged along or inside the upwardly-directed frame-element projection down to the respective undersides of frame-element arms projecting in the transverse direction, and then outwards along the respective undersides, the connecting wires being then in locking fashion folded upwards at the outer ends of the frame-element arms projecting in the trans¬ verse direction. As is easily understood, one may expe- diently, once the lamp unit has been lifted out of the associated lamp holder or light body, unfasten the con¬ necting wires from the frame element and remove a broken incandescent lamp and subsequently mount a new incandes¬ cent lamp. As a result, exchanging an incandescent lamp is very inexpensive.

In order to facilitate correct positioning of the lamp unit in a lamp holder or light body, the contact means found in the lamp holder or light body are prefer¬ ably formed with concavely-recessed upper contact edges. As a result, the lamp unit will automatically come to occupy the correct position after being applied, at the same time as contact-resistance-reducing relative motion at the correct place is ensured.

When being a battery light, an electric light in accordance with the invention advantageously comprises an electronic circuit adapted to convert, by pulse modu¬ lation, an incoming battery supply voltage from a number of batteries connected in series to an outgoing lamp sup¬ ply voltage which is lower than the nominal supply vol- tage from a smallest number of utilised batteries con¬ nected in series. This has been found to prolong the bat¬ tery life and to improve the utilisation of the batte¬ ries, while enabling the use of one and the same lamp unit for different battery lights, regardless of whether the battery lights have, say, two, three or four batte¬ ries connected in series, depending on the size of the lights.

When use is made of electric lights other than bat¬ tery lights, the light body may, of course, be provided with a base of conventional type for current-supplying engagement with a holder of suitable design. If so, cur- rent may be supplied to the holder from a suitable exter¬ nal source of current.

If external current supply is carried out at such a high voltage that it is deemed unsuitable that this vol- tage should be freely exposed on the contact means on which the lamp unit is intended to rest, one may, for instance in a light body, arrange a transformer means or the like instead of batteries, thereby reducing the vol¬ tage to a suitable level. An embodiment of the invention will now be described in more detail with reference to the accompanying draw¬ ings.

Brief Description of the Drawings In the drawings,

Fig. 1 is a schematic, partially sectional view of an embodiment of a battery light according to the inven¬ tion,

Fig. 2 is a schematic perspective view of an embodi- ment of a lamp unit according to the invention,

Fig. 3 is a schematic perspective view of the lamp unit in Fig. 2 as seen obliquely from below,

Fig. 4 is a schematic perspective view of an incan¬ descent lamp with associated connecting wires for a lamp unit of the type shown in Figs 2 and 3,

Fig. 5 is an enlarged schematic top view of the bat¬ tery light shown in Fig. 1, the lamp unit having been removed, the Figure being intended to illustrate the pro¬ vision of contact plates for the lamp unit, Fig. 6 is a schematic side view of one of the con¬ tact plates of the battery light for the lamp unit,

Fig. 7 is a schematic side view of a charging device with a number of battery lights (without lamp units) placed therein in order to be charged, Fig. 8 is a schematic top view of the charger shown in Fig. 7, Fig. 9 is an enlarged partially sectional view of the lower part of a charging hole in the charger of Figs 7 and 8, the position of a light body introduced into the hole in order to be charged being indicated by dashed lines, and

Fig. 10 is a flow chart which schematically illu¬ strates the design of the electric circuit in the battery light of Fig. 1.

Description of an Embodiment

The illustrated embodiment of a battery light ac¬ cording to the invention comprises the following main components a cylindrical, tubular light body 1, which at the top is completely open (the opening 2) and which at the bottom is equipped with a closed, tapering foot element 3 and at the top is formed with an outward, longitudinal bead or ridge 5 imitating trickled, solidified candle grease and serving as guiding means in connection with the charging operation, as will be described in more detail below, a battery stack 7 consisting of a number of batte¬ ries which are connected in series and stacked upon one another inside the light body 1 and which are surrounded by a paper sleeve 8, a sleeve-shaped holder element 9 which is arranged on top of the battery stack 7 and whose upper end is open and is located slightly below the opening 2 and supports lamp current-supply contact plates 11, 12 that are freely exposed in the upward direction, and whose lower part comprises a bottom 13 formed with a central hole 14 for receiving the central plus pole 15 of the uppermost bat¬ tery in the battery stack 7, an electronic circuit 17 which is arranged at the bottom 13 in the holder element 9 and on which is arrang¬ ed an associated magnetic-field-generating coil 18, the electronic circuit having a connector (not illustrated in detail) which is in electrical contact with the plus pole 15 of the battery stack 7, and a lamp unit 21 which is arranged at the open end of the light body 1 in such a manner as to rest on the con- tact plates 11, 12.

As appears more clearly from Figs 5 and 6, the con¬ tact plates 11, 12 have a curved configuration which is adapted to the curvature of the holder element 9, and the contact plates are further arranged in corresponding, diametrically-opposed recesses 23, 24 in the upper circu¬ lar edge 25 of the holder element 9. The contact plates 11, 12 have a concavely-recessed upper edge 27, on which the lamp unit is intended to rest while being supplied with current. From the contact plate 11, a conductor 29 extends downwards along the outside of the holder element 9 and is connected to the electronic circuit 17. From the con¬ tact plate 12, a conductor 30 extends in similar fashion downwards along the outside of the holder element 9 and the outside of the paper sleeve 8 of the battery stack 7 to the underside of the battery stack, where it contacts the negative bottom electrode 31 of the lowermost batte¬ ry. The conductor 30 is also connected to the electronic circuit 17 at 32. In the illustrated embodiment, the contact plates 11, 12 have a restricted circumferential extension, but it will be appreciated that they might have an extension up to slightly below half the circumference, i.e. such that the contact plates basically cover the whole circum- ference but do not come into contact with one another. Such a design would facilitate the introduction of the lamp unit 21, since the concavity will result in the lamp unit automatically striving to occupy a centred position. The lamp unit 21, which is illustrated in more detail in Figs 2-4, consists of an incandescent lamp

41, a frame element 43 and a diameter-reduced pendulum balancing body 45. The incandescent lamp 41 comprises a bulb 47, which essentially has the shape of a candle flame and has an inner base 48 supporting a filament 49. From the base extend two connecting wires 51, 52 through the lower part of the bulb, as well as a downwardly- directed pin 50 intended for centred, guided mounting of the incandescent lamp in the frame element 43.

The frame element 43 comprises a central portion 55, whence projects an upwardly-directed cylindrical projec¬ tion 56 having an axial, dimensionally-adapted bore which is arranged at least at the top so as to receive the mounting pin 50 of the incandescent lamp. From the cen¬ tral portion 55 projects a downwardly-directed, opposite cylindrical projection 57, on which the circular-cylin¬ drical pendulum body 45 is centrally mounted. The projec- tion 57 is with good fit introduced into a bore formed in the pendulum body 45, such that the latter will be retained but nevertheless be rotatable about the projec¬ tion 57, for reasons which will be accounted for in the following. Two diametrically-opposed and rather narrow arms 58, 59 project in the lateral direction from the central por¬ tion. With the aid of these arms, the lamp unit 21 rests freely in the light body 1, i.e. on the contact plates 11, 12. The connecting wires 51, 52 of the incandescent lamp 41 extend downwards along the projection 56, through the central portion 55 in through-holes provided therefor, further outwards on the flat undersides of the respective arms 58, 59, and then back onto the upper sides of said arms via the oblique free end surfaces of the arms, suit¬ ably in grooves provided therefor.

In an alternative embodiment, the connecting wires may be arranged inside the projection, extending either through special holes or channels provided therefor or through an adapted, completely throughgoing axial bore, connection being of course provided with the above-men¬ tioned holes in the central portion. If the connecting wires are to be arranged through a throughgoing axial channel in the upward projection of the frame element, this channel may advantageously have an oval cross-section (at least at the top where the downwardly-directed pin of the incandescent lamp is received) , such that the connecting wires can be receiv¬ ed on both sides of the guided, centrally-received pin of the incandescent lamp.

At least the projection 56 of the frame element 43 may advantageously be coloured, for instance transparent¬ ly blue, in order to enhance the impression of a candle wick.

As will be appreciated, the above configurations en¬ tail that the incandescent lamp 41 can easily be mounted on as well as be dismounted from the frame element, i.e. the incandescent lamp may be expediently replaced, if need be. Owing to its simple design, the incandescent lamp is, in addition, very inexpensive.

The arranged connecting wires 51, 52 form lamp con- tact means farthest out on the undersides of the arms 58, 59, in that the connecting wires will here rest on the contact plates 11, 12 when the lamp unit 21 has been dropped into the light body 1.

It will be appreciated that the width of the arms 58, 59, the diameter of the connecting wires 51, 52 and the concavity of the contact plates 11, 12 should be so chosen as to ensure reliable electrical contact, also when the lamp unit 21 swings about the mounting axis resulting from the suspension structure described above. In view hereof, as well as in consideration of the requirements for simple handling of the connecting wires, it has been found suitable to have a wire diameter of typically about 0.3-0.5 mm, preferably in the lower part of this range, when using conventional material for the wires.

In order to actively produce a swinging or pivotal movement of the lamp unit, use is made of magnetic and periodic action on a permanent magnet means 61, which is arranged at the bottom of the pendulum body 45. The mag¬ netic action is brought about with the aid of the magne¬ tic coil 18 and the associated operating circuit in the electronic circuit 17, conveniently in accordance with the teachings of the above SE-B-451,400, which is hereby incorporated by way of reference.

In the illustrated embodiment, the permanent magnet means 61 is a round bar magnet having a north pole in the one end surface and a south pole in the other end sur¬ face. The bar magnet is inserted in a corresponding dia¬ metral groove perpendicular to the axis of said body 45 and in connection with the lower surface of said body. Maximum action is obtained when the extension of the bar magnet is perpendicular to the arms 58, 59. As will be appreciated, the magnetic action may easily be reduced by rotating the body 45 about the projection 57. Minimum action is obtained when the bar magnet is parallel to the arms 58, 59. Alternatively, the magnet means 61 may be unsymme- trical in order to give the lamp unit a more "flickering" swinging movement. The bar magnet may, for instance, have half the length shown in the Figures, i.e. be arranged radially out from the centre of the body 45 to the peri- phery thereof.

In order to charge a battery light 1, the latter is removed from its holder or candle stick, and the lamp unit 21 is removed. Then, the battery light is placed upside-down in a charging hole in a charging device 71, which is schematically illustrated in Figs 7-9.

The charging device comprises a light stand 73 in the form of a parallelepipedic frame, which is formed with four vertical, throughgoing charging holes 75. The respective holes have a diameter slightly exceeding that of a battery light, thereby to enable cooling air to flow upwards round the light in a hole. Furthermore, each hole 75 has in its wall a throughgoing groove 77 having a cross-section corresponding to that of the ridge 5 of the light body 1, such that a light can only be placed in a single, correct position in a charging hole 75. Also the groove 77 may be slightly overdimensioned to enable the passage of air.

Each hole 75 is associated with a separate, intel¬ ligent charging unit 79 (not illustrated in detail) of a suitable conventional type, as well as two signal lamps 80, 81 indicating, respectively, that a light is being charged and that a light has been fully charged.

At the bottom of each hole 75, there are provided two charging electrodes 83, 84 (see Fig. 9) which, via conductors 85, 86, are connected to an associated charging unit 79. The electrodes 83, 84 consist of flat or slightly outwardly-bulging plates, which are attached to a transverse beam 85 and which converge conically upwards. The upper ends of the plates are interconnected by an insulating spacer 89. The transverse beam 87 is fastened by snap-in action at the bottom of the groove 77 and an opposite recess 90 in the wall of the hole 75.

As is easily understood, positioning of a light body 1 in charging position in a hole 75, as indicated by dashed lines in Fig. 9, means that the contact plates 11, 12 of the light body are brought into reliable electrical engagement with the charging contact plates 83, 84.

In Fig. 7, three light bodies 1 are placed in the charging device 73 in order to be charged, these light bodies having different lengths, since they contain dif¬ ferent numbers of batteries, for instance 4, 2 and 3, respectively, as seen from the left in the Figure.

As already mentioned, it is advantageous that the light bodies 1 are cooled during the charging operation by coming into contact with air passing in the upward direction. In order to further enhance this effect, cool- ing channels 91 are so arranged as to be throughgoing in the foot element 3 of the light bodies 1, thereby enabl¬ ing air to flow through also the interior of the light bodies. This may be especially suitable when the batte¬ ries are of nickel-metal-hydride type, the charging of which is highly sensitive to temperature. It should here be emphasised that the charging device 71 may easily in its entirety be placed in, say, a refrigerator, thus ensuring a controlled low temperature during the charging operation.

Fig. 10 schematically illustrates a possible con¬ struction of the electronic circuit 17 with the associat- ed magnetic coil 18. The magnetic coil 18 is periodically supplied with current pulses from a circuit 95, which in turn is supplied with current directly from the battery stack 7. The contact plates 11, 12 are supplied with cur¬ rent via a circuit 96 producing pulse-modulated supply to the incandescent lamp 41 corresponding to an incandes¬ cent-lamp supply voltage that is lower than the supply voltage of the battery stack 7. For exemplifying pur¬ poses, the following typical values may be indicated: a voltage of 2.4-6 V of the battery stack corresponding to 2-5 batteries connected in series; a nominal voltage of about 1.3 V of the incandescent lamp; and a pulse supply corresponding to a ordinary supply of about 1.8 V, i.e. a certain excess-voltage.

This type of supply has been found to involve a par- ticularly excellent utilisation of the capacity of the batteries, there being an even high flow of light from the incandescent lamp 41, regardless of the number of batteries in the stack 7. The circuit 96 may be con¬ structed in a manner well-known to those skilled in the art as regards pulsed or switched, voltage-reducing cur¬ rent supply.

A diode 97 is so connected across the circuit 96 as to bridge over this circuit 96 and permit a current flow in the opposite direction in connection with charging, i.e. when a charging voltage is applied to the contact plates 11, 12 in the charging device 71. The circuit illustrated in Fig. 10 does not comprise any switch, since such a device is not called for. As will be appreciated, the incandescent lamp may easily be switched off when need be by a change of its position in the light body, such that the current-supply contacts will no longer be in contact with each other. It goes without saying that a switch might, however, be arranged on the light body 1, for instance at the bottom thereof, in order to break the conductor 30 to the lower pole 31 of the battery stack 7. Such a switch might also be so designed as to imitate trickled, solidified candle grease.

Claims

1. A light system comprising electric lights, which each include a sleeve-shaped light body (1), current-sup¬ ply means (7) which is arranged in said light body, and a lamp unit (21) which is arranged at the upper, upwardly open end of said light body and which comprises an incan¬ descent lamp (41), first contact means (11, 12) connect- ed to the current-supply means being so arranged in the light body as to be freely exposed at said end, and second contact means (51, 52) being arranged on a frame element (43) of the lamp unit and connected to the fila¬ ment (49 ) of the incandescent lamp (41 ) belonging to the lamp unit (21), and said first and second contact means being so arranged, and said frame element being so de¬ signed, that the lamp unit may, from above, be freely and directly placed in the open end of the light body with said second contact means (51, 52) resting on and being in electrical contact with said first contact means (11, 12), such that the contact points define a pivot axis which is horizontal when the light is vertically arranged and about which the lamp unit may pivot as a coherent unit during relative motion between said first and second contact means.

2. A light system as set forth in claim 1, c h a r a c t e r i s e d in that the lamp unit ( 21 ) of the lights has a balancing means (45), preferably of pen¬ dulum type, which is connected to the frame element (43) and which positions the centre of gravity of the lamp unit below said pivot axis.

3. A light system as set forth in claim 1 or 2, c h a r a c t e r i s e d in that the frame element (43 ) of the lamp unit (21) comprises arms (58, 59) which pro- ject transversely in opposite directions and on which are arranged said second contact means (51, 52).

4. A light system as set forth in claims 2 and 3, c h a r a c t e r i s e d in that the frame element (43) of the lamp unit is generally cruciform, said second con¬ tact means (51, 52) being arranged on the underside of the respective frame-element arms (59, 58) projecting in the transverse direction, said balancing means (45) being connected to a downwardly-directed frame-element projec¬ tion (57), and the incandescent lamp (41) itself being connected to an upwardly-directed frame-element pro ec- tion (56).

5. A light system as set forth in claim 4, c h a r a c t e r i s e d in that the incandescent lamp (41) comprises a bulb (47) containing a filament (49) and an associated filament base (48), whence project the con- necting wires (51, 52) of the incandescent lamp, as well as a downwardly-directed mounting pin (50) by means of which the incandescent lamp is fixed to the upwardly- directed frame-element projection (56), which preferably is tubular at least at the top so as to receive said mounting pin.

6. A light system as set forth in any one of the preceding claims, c h a r a c t e r i s e d in that said second contact means consist of the provided connecting wires (51, 52) of the incandescent lamp (41).

7. A light system as set forth in claim 6, c h a r a c t e r i s e d in that the connecting wires (51, 52) are detachably arranged, thus enabling expedient exchange of the incandescent lamp (41 ) with associated connecting wires.

8. A light system as set forth in any one of claims 3-5 in combination with claim 6 or 7, c h a r a c t e r ¬ i s e d in that the connecting wires (51, 52) extend down to the respective undersides of the transversely-project¬ ing frame-element arms (58, 59) and then outwards along the respective undersides, said connecting wires being then folded upwards in locking fashion at the outer ends of the frame-element arms projecting in the transverse direction.

9. A light system as set forth in claim 1, 2 or 3, c h a r a c t e r i s e d in that the incandescent lamp (41) is, preferably in detachable fashion, so arranged as to be spaced apart from the frame element (43) and be supported by its connecting wires and/or spacers ( 50, 56), said connecting wires (51, 52) being arranged on the transversely-projecting arms (58, 59) of the frame ele- ment, thereby to form said second connecting means.

10. A light system as set forth in any one of the preceding claims, c h a r a c t e r i s e d in that said first contact means (11, 12) consist of opposite and up¬ right contact plates having concavely-recessed upper con- tact edges (27).

11. A light system as set forth in any one of the preceding claims, c h a r a c t e r i s e d in that the lamp unit (21) comprises an element (61) which can be acted upon magnetically, preferably a permanent magnet element, and that means (17, 18) are arranged in the light body ( 1 ) below the lamp unit to periodically gene¬ rate a magnetic field, thereby to magnetically act upon said element, and hence the lamp unit, such that the latter is caused to pivot periodically about its pivot axis.

12. A light system as set forth in claim 11, c h a r a c t e r i s e d in that the position of the ele¬ ment (61) that can be acted upon magnetically is adjust¬ able in relation to the remainder of the lamp unit (21), such that the degree of magnetic action, and hence the amplitude of the pivotal movement of the lamp unit, is adjustable.

13. A light system as set forth in claim 12 and claim 2, c h a r a c t e r i s e d in that the element (61) that can be acted upon magnetically is arranged on said balancing means (45), preferably at the bottom thereof, and that said balancing means is so arranged on the frame element (43) of the lamp unit as to be rotat- able about a vertical axis.

14. A light system as set forth in any one of the preceding claims, c h a r a c t e r i s e d in that the lights are battery lights, said current-supply means com¬ prising one or more chargeable batteries (7) arranged in said light body, a charging device (71) for charging the battery lights being provided and comprising a light stand (73) adapted to accommodate, for charging purposes, one or more battery lights from which the associated lamp unit has been removed, said light stand having, at each light-accommodating site, charging contact means (83, 84) adapted to come into contact with said first contact means (11, 12) in the light body (1) of a battery light when said light body is placed on the light-accommodating site at issue, said charging contact means (83, 84) being connected to a charging unit (79 ) for emitting charging current to said charging contact means and, hence, to the batteries of an associated light body.

15. A light system as set forth in claim 14, c h a r a c t e r i s e d in that the light stand (73 ) of the charging device (71 ) is adapted to receive the respective light bodies turned upside-down, preferably at least essentially vertically, in a hole (75) adapted to the light-body configuration, such that the light body is made to occupy a predetermined position adapted to the charging contact means (83, 84) arranged in said hole, said charging contact means preferably comprising upward¬ ly-converging, spaced-apart contact elements with which the first contact means of the light body are brought into engagement during charging.

16. A light system as set forth in claim 15, c h a r a c t e r i s e d in that the holes (75) of the light stand (73) are throughgoing and so dimensioned that air can flow up through them and coolingly flow round a battery light placed in a hole in order to be charged.

17. A light system as set forth in claim 14, 15 or 16, c h a r a c t e r i s e d in that the light body (1) of a battery light on the outside has one or more eleva¬ tions (5), ridges or the like, which are unsymmetrically arranged and extend in the longitudinal direction and which preferably imitate candle grease that has trickled down and solidified, and that the light-stand holes (75) have corresponding guiding grooves (77) in their walls.

18. A light system as set forth in any one of claims 14-17, c h a r a c t e r i s e d in that a battery light comprises an electronic circuit (17) adapted to convert, preferably with the aid of pulse modulation, an incoming supply voltage from a number of batteries (7) connected in series to an outgoing lamp supply voltage which is lower than the nominal supply voltage from a smallest number of utilised batteries connected in series.

19. A lamp unit intended especially for a light system as set forth in any one of the preceding claims, c h a r a c t e r i s e d in that it comprises a frame element (43) having rigid mounting arms (58, 59) which project transversely in opposite directions, a contact means (51, 52) being arranged on the end underside of the respective arms, an incandescent lamp (41) being fixed to the upper side of the frame element and equipped with connecting wires (51, 52) connected to, and preferably constituting, said contact means, and a balancing means (45) being fixed to the underside of said frame element, said contact means defining a transverse mounting axis about which the lamp unit may pivot as a coherent unit when, in use, it is, from above, freely and directly placed in a lamp holder provided with current-supply con¬ tact means corresponding to the contact means of the lamp unit.

20. A lamp unit as set forth in claim 19, c h a r - a c t e r i s e d in that the incandescent lamp (41) is arranged, preferably in detachable fashion, so as to be spaced apart from the frame element (43 ) and be supported by its connecting wires (51, 52) and/or spacers (56, 50), said connecting wires being arranged on the transversely- projecting arms (58, 59) of the frame element, thereby to form said contact means,

21. A lamp unit as set forth in claim 19 or 20, c h a r a c t e r i s e d in that the incandescent lamp (41 ) comprises a bulb (47) containing a filament (49) and an associated filament base (48), whence project the con¬ necting wires (51, 52) of the incandescent lamp, as well as a downwardly-directed mounting pin ( 50) by means of which the incandescent lamp is fixed to an upwardly- directed frame-element projection (56) which is tubular, preferably at least at the top, in order to receive said mounting pin.

22. A lamp unit as set forth in any one of claims

19-21, c h a r a c t e r i s e d in that it comprises an element (61) which can be acted upon magnetically, pre¬ ferably a permanent magnet element, and which is adapted to be acted upon by a magnetic field periodically gene- rated in the lamp holder in order to magnetically act upon said element, and hence the lamp unit, such that the latter is caused to pivot periodically about its mounting axis.

23. A lamp unit as set forth in claim 22, c h a r - a c t e r i s e d in that the position of the element

(61) that can be acted upon magnetically is adjustable in relation to the remainder of the lamp unit (21 ), such that the degree of magnetic action, and hence the ampli¬ tude of the pivotal movement of the lamp unit, is adjust- able.

24. A lamp unit as set forth in claim 22 or 23, c h a r a c t e r i s e d in that the element (61) that can be acted upon magnetically is arranged on said balancing means (45), preferably at the bottom thereof, and that said balancing means is so arranged on the frame element (43) of the lamp unit (21) as to be rotatable about a vertical axis.