Lighting Device for a Bicycle

The present invention pertains to a lighting device adapted for use with a wheel bicycle and, more particularly, to a bicycle lighting device which does not require frictional contact with the wheel or use storage batteries.

It is known that safety signalling on bicycles is usually accomplished by an electric generator having a part frictionally engaging the side of a wheel whereby the rotational energy thus obtained is converted into electric energy to light a lamp or other lighting device. In other cases, the lamp may be lit by means of an electronic device using batteries (see, for example, U.S. Pat. No. 5,121,305 issued Jun. 9, 1992 to Deed et al.). Such device provides the periodical lighting of an optical radiation element, such as an electroluminescent diode, a filament bulb or a xenon tube. The efficient operation of such safety devices depends on a constant verification of the state of the batteries. Since children are most frequent utilizers of bicycles, it is noted that, often, they neglect to signal the necessity of replacing the batteries, thus resulting in a real danger for their safety. Also to be considered is the expense caused by the repeat acquisition of batteries, which results in a number of users to abandon the use of such devices. Also, some of the substances used in these batteries contain materials dangerous to the environment.

Lighting devices which do not require the use of batteries exist wherein magnets are used for supplying electricity to bulbs (see, for example, U.S. Pat. No. 5,128,840 issued Jun. 7, 1992 to Seki et al. and French patent publication No. 2,413,731 published Jul. 27, 1979 to Kumakura).

Japanese specification 63-107446 (Norio Akamatsu) of May 12, 1988 describes a lamp unit for bicycle wherein a magnet is directly rotated by a wheel and wherein a magneto coil, not in contact with the magnet, induces an electromotive force when the magnet is rotated and passes close to the coil. However, with this device, the lamp unit is only lit when the bicycle wheel rotates (or when the bicycle is used). Hence, when the bicycle is not moving for any reasons, no warning is effected and this may result in serious consequences, especially at night.

It is an object of the present invention to overcome the above problems by providing a device which produces its own energy using the kinetic energy of the bicycle.

It is also an object of the present invention to provide a device which allows the lamp to be lit while the bicycle is in use as well as after it has come to a stop.

The present invention is achieved by using two components, one being fixed while the other is movable. The movement of the latter produces, when in proximity with the fixed element, an electromagnetic field generating an alternating current which is used to illuminate an electroluminescent element.

The present invention also includes means which will allow the storage of electrical energy so that, when the bicycle operator comes to a stationary condition (by reason of traffic lights or of other reasons), the electroluminescent element still flashes until the stored electrical energy is used.

Therefore, the present invention pertains to a lighting device which is adapted for use with a bicycle having a frame and wheels and which comprises:

magnetic field producing means adapted to be mounted on at least one of the wheels;

a housing adapted to be mounted on the frame;

solenoid means mounted in the housing and including a solenoid winding and a solenoid core; one extremity of the core being located closely adjacent to the wheel;

optical radiation means electrically connected to the solenoid winding allowing light to be emitted as a result of the magnetic field producing means passing by the extremity of the core; and

storage means for accumulating an excess of electrical energy during rotation of said one of said wheels whereby light may be emitted by the optical radiation means after the wheel has stopped rotating, until the excess has been used up.

In one form of the invention, the optical radiation means consist of one or more light emitting diodes and the magnetic field is produced by one or more magnets mounted on one or more of wheel spokes.

Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that this detailed description, while indicating preferred embodiments of the invention, is given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art.

FIG. 1 is an elevational view of the rear end of a bicycle, shown in dotted lines, illustrating the location of the lighting device used with the present invention;

FIG. 2 is a top view, partly cross-sectional, of the lighting device;

FIG. 3 is an elevational, partly cross-sectional, view thereof;

FIG. 4 is an elevational, partly cross-sectional, view of one embodiment of the lighting device made in accordance with the present invention;

FIG. 5 is a cross-sectional view taken along lines 5--5 of FIG. 4;

FIG. 6 is a block diagram of the electrical function; and

FIG. 7 is an electronic circuit of the lighting device.

FIG. 1 illustrates, in dotted lines, a bicycle 10 with a rear wheel 12 conventionally carried by a frame 14.

The lighting device of the present invention includes two elements 16 and 18, the former being mounted to the wheel, the latter being mounted to the frame of the bicycle.

Referring more particularly to FIGS. 2 and 3, element 16 comprises a magnet 20 mounted to a support 22 fixedly secured to two spokes 24 and 26 of the rear wheel 12 by means of attachments 25 and 27.

Element 18 comprises a housing 28 defining a chamber 30, preferably sealed, into which is mounted a solenoid consisting of a winding 32 and of a ferromagnetic core 34. Also mounted to the housing 28 is a diode 36 which is electrically connected to the solenoid winding 32.

The housing 28 is mounted to a bolt 38, which may be an extension of the core 34. However, it has a threaded portion so that a nut 40 may secure the housing 28 to the bolt 38.

Also mounted to the bolt 38 is a bracket 42 which is displaceable thereon and may be secured by means of a pair of nuts 44 and 46. One end 50 of bracket 42 is U-shaped so as to be placed on a frame element 14a of the bicycle. A fastening element 48 insures the securement of the bracket end extremity 50 to the frame element 14a.

In operation, as the wheel 12 rotates, the magnet 20 of the element 16 passes by the extremity of the core 34 of the solenoid, thus producing a magnetic field generating a current in the solenoid winding 32 and producing a lighting pulse in the diode 36.

As illustrated in FIG. 1, more than one magnet carrying support may be provided on the spokes of the wheel; for example, a second element 16' may be used as illustrated in a diametrically opposite position to element 16 to provide proper balancing of the wheel. Hence, in this case, two lighting pulses will be made for each rotation of the wheel.

Referring to FIGS. 4 and 5, there is illustrated a second embodiment of the present invention consisting of a rotatable element 116 mounted to the spokes of the bicycle wheel and a fixed element 118 mounted to the frame element 114a of a bicycle (not shown).

The rotatable element comprises a magnet 120 mounted to an oval shaped support 122 adapted to be secured to the spokes of the wheel by appropriate fastening elements 123. As can be seen, these fastening elements 123 are mounted into slots 125 to adjust to the various distances separating spokes. In this embodiment, the magnet 120 is protected by a surface layer 121 which still enables the effect of the magnet to be produced.

The fixed element 118 comprises a housing 128 of cylindrical shape supporting a second housing 129 enclosing the solenoid winding 132 and its ferromagnetic core 134.

In this embodiment, there is illustrated a set of three diodes 136, 140 and 142 which are electrically connected to the solenoid winding 132.

In operation, the magnet 120 and its support 122 move in the direction as illustrated by arrow 150 so that as a result of the magnet passing near the core 134 of the solenoid, electronic pulses are generated in the three diodes 136, 140 and 142. Hence, the kinetic energy of the wheel is used to generate the electrical energy for lighting.

FIG. 6 shows the magnet 20 (which is fixed to the wheel) in the proximity of the coil or solenoid element 18. The alternating current produced by the magnet passage near the coil is fed to an electronic circuitry 200 that includes a diode bridge 201 which rectifies the signal which is then fed to an electronic signalling device 202 that produces electronic pulses to the electroluminescent diode 36. This signalling may be intermittent or continuous and can be displayed at the front or rear of the vehicle.

The electronic circuitry 200 also includes components which will allow the storage of any excess current produced during wheel rotation. A germanium zener diode 204 allows this excess of the energy produced by the magnet and coil arrangement, which is not utilized by the electronic device 202 and the diode 36 (or diodes 136, 140, 142), to be stored by an energy accumulator 206, for example, a capacitor. When the bicycle wheel stops rotating, the capacitor will discharge through the zener diode 204 (which then operates as an ordinary diode). The current storage is in direct proportion to the electricity produced during rotation of the wheel. The diode bridge 201 blocks the current in the reverse direction, as the capacitor discharges.

FIG. 7 gives a detailed circuitry of the lighting device of the present invention. The magnetic field created by the rotation of the magnet 20 generates an alternating current in the coil 32 which is transformed into a direct current as it passes through the diode bridge 201 formed of three electroluminescent diodes 201a, 201b, 201c and one regular diode 201d. The direct current is then stored in the electronic reservoir 206. Zener diode 204 serves to protect this capacitor from an overload. Optionally, a capacitor 208 may be also used to complement the capacitor 206, which has a high capacity value, in order to use the maximum electrical energy received from the diode bridge 201. In some cases, capacitor 206 may have a tendency to neglect load peaks.

The electronic device 202 includes diode 210 and chip 212. Diode 210 is used to provide a signal to neutralize the flashing operation of the electronic chip 212 during wheel rotation since the fluctuation of the moving magnet 20 creates its own flashing. The capacitor 214 serves to regulate the signal received from the diode 210 which emits a pulsating signal. As long as this signal is generated, capacitor 214 remains charged and prevents the electronic chip 212 from operating during wheel rotation. When the wheel is stopped from turning, there is no signal received in diode 210; hence, chip 212 allows the diodes 36, 36' to flash.

Although the invention has been described above with respect with one specific form, it will be evident to a person skilled in the art that it may be modified and refined in various ways. For example, some bicycle wheels do not have spokes, but a circular surface; therefore, the magnet of the present invention could be mounted to such surface. Also, it is evident that the present lighting device could be mounted to the front wheel of a bicycle. Furthermore, a halogen lamp could be used instead of a diode as well other low energy consumption lights. It is therefore wished to have it understood that the present invention should not be limited in scope, except by the terms of the following claims.