DE20003339U1 - Lighting unit for muscle-powered vehicles - Google Patents

Description

PATENT ATTORNEYS ···* · *··"»!·· '..**.♦'

DIPL.-ING. R. LEWICKE DR.-ING. H. J. BROMMER DIPL.-ING. F. PETERSEN DIPL.-ING. D. BLUMENROHR

BISMARCKSTRASSE 16 76133 KARLSRUHE TELEPHONE (07 21) 91 28 00 TELEPHONE (07 21) 2 11 05

February 23, 2000 17 973 (A/ko)

Mister

Franz Bombik
Heidehofweg 122 b 22850 Norderstedt

Lighting unit for human-powered vehicles PATENT ATTORNEYS DIPL.-ING. R. LEMCKE DR.-ING. H. J. BROMMER DIPL.-ING. F. PETERSEN DIPL.-ING. D. BLUMENROHR

BISMARCKSTRASSE 16 76133 KARLSRUHE

TELEPHONE (07 21) 91 28 00 TELEPHONE (07 21) 21103

February 23, 2000 17 973 (A/ko)

Description

The invention relates to a lighting unit for muscle-powered vehicles with at least one headlight, which has at least one illuminant arranged within a housing for roadway illumination and at least one reflector, a voltage source for supplying energy to the lighting unit and a control device for controlling the same.

Lighting units for human-powered vehicles, especially bicycles, generally have headlights with only one light source for illuminating the road when driving at night. The light source - in most cases a light bulb - draws the energy needed to light up from a dynamo attached to the bicycle, which converts the kinetic energy of the bicycle that occurs during a ride into electrical energy. The way such a dynamo works is assumed to be known here.

If the lighting unit is designed as a front lamp, it is usually attached to the front end of the bicycle frame in such a way that the optical axis of the reflector runs approximately parallel to the road surface. This ensures that the axis of symmetry of the light cone emerging from the reflector also runs approximately parallel to the road surface, so that it is illuminated over as great a distance as possible.

Now it is desirable that during fast journeys, such as cross-country journeys over long distances, lighting is provided, while at

On the other hand, during slow city rides, the light only illuminates short distances. This is due, among other things, to the fact that when riding fast, it is necessary to recognise obstacles that are relatively far ahead of the bike early on in order to be able to avoid them despite the high speed. On the other hand, when riding slowly, it is sufficient to only illuminate a close area directly adjacent to the front end of the bike.

In this context, it is known in the prior art to design the fastening of the lighting unit to the bicycle frame in such a way that the lighting unit can be pivoted about a horizontal axis. Accordingly, the user can adjust the orientation of the light cone emerging from the reflector by specifying the angle formed by the optical axis of the reflector and the road surface by pivoting the lighting unit. However, such an angle adjustment must generally be carried out before starting the journey, as this would involve considerable risks during the journey. The user would have to take at least one hand off the handlebars of the bicycle and bend forward with great effort in order to be able to grasp the lighting unit for pivoting, which can naturally lead to serious accidents.

In order to avoid this disadvantage, a lighting unit is known from DE 197 39 519 in which the angle mentioned between the optical axis of the reflector and the road surface is adjusted automatically and depending on the speed while driving. When driving fast, the optical axis is largely parallel to the road surface over long distances and when driving slowly, the optical axis is adjusted at an angle to the road surface over short distances.

For this purpose, a power measuring device first determines the speed-dependent electrical power generated by the dynamo during driving. If the power exceeds a certain upper limit, a control device sends a signal

for pivoting a combination of reflector and bulb from a position at an angle to the road surface to an approximately parallel position, so that illumination is then provided over large distances.

To pivot the above-mentioned combination of bulb and reflector, it is mounted so that it can pivot about a horizontal axis, whereby a solenoid can pivot the bulb, which is supported by a pivoting support part, back and forth between a normal position and a high-speed position. A coil spring serves as a return element to the normal position.

The disadvantage of the device in this publication is that it is structurally complex, expensive and prone to errors. Furthermore, it is not possible to illuminate both large and small distances at the same time, since only one discrete position of the device is possible at a time.

The object of the present invention is therefore to provide a lighting unit for human-powered vehicles, in particular bicycles, which avoids the disadvantages of the prior art and, in particular, is structurally simple so that it can be produced inexpensively and is permanently functional.

This object is achieved according to the invention in that the lighting unit has an additional illuminant for illuminating the roadway, wherein the control device is designed such that at least part of the electrical power produced by the voltage source can be divided between the first illuminant and the at least one additional illuminant, wherein this division takes place in accordance with an input signal dependent on the vehicle speed.

The provision of an additional light source for roadway lighting has the advantage that it is no longer necessary to pivot one or more components of the lighting unit when switching between

the different lighting positions should be switched back and forth. For example, the first light source can be located in a first headlight whose orientation to the road surface is optimized for slower driving and the additional light source can be arranged in another headlight whose position to the road surface corresponds to a high-speed position.

The control device can divide the available electrical power between the two lamps depending on the speed.

Such a device is structurally simple, since no pivoting mechanisms are necessary, but rather commercially available headlights can be used.

Advantageously, the additional light source is located within the same headlight housing as the first light source. This means that only one headlight needs to be manufactured, which enables a more compact and cost-effective lighting unit than would be the case if separate headlights were used.

In this context, it is expedient for the first light source to be located approximately at the focal point of the reflector, whereas the additional light source is arranged outside the focal point in such a way that its light rays run essentially obliquely from top to bottom compared to a horizontal alignment of the optical axis of the reflector. The first light source in combination with the reflector then illuminates over large distances, since its light rays emerge from the reflector approximately parallel to the optical axis of the reflector. The light rays emitted by the additional light source serve to illuminate over smaller distances.

Especially for paraboloidal or ellipsoidal reflectors, a cover cap should be provided to limit the light propagation of the

additional light source in the reflector downwards. Otherwise, light rays would hit the lower half of the reflector and be emitted upwards, which would dazzle oncoming traffic.

However, it is also within the scope of the invention that the additional light source is arranged within a separate reflector. The headlight then has two reflectors that enable light distributions to be made in accordance with the respective driving speed. One reflector is therefore provided for the normal range and one reflector for the high-speed range. As already mentioned above, this separate reflector can also be arranged within an additional headlight.

The voltage source is advantageously designed as a dynamo attached to the vehicle, with the speed-dependent input signal depending on the electrical voltage of the dynamo. Such a dynamo is generally already present on commercially available bicycles, so that no additional voltage source is necessary. Since the voltage of such a dynamo is known to depend on the driving speed, the voltage can then be used directly - or indirectly after a signal conversion - for the control device as a speed-dependent input signal. In this case, no additional speed sensor would be necessary to measure the vehicle speed and provide a signal corresponding to this speed.

In particular, if the voltage source is not a dynamo but an accumulator, it is expedient for the input signal to be an electrical signal generated by a speed sensor attached to the vehicle, since the voltage of the accumulator naturally does not depend on the speed of the vehicle. A variety of designs are possible for the speed sensors. One possibility would be, for example, an inductive speed sensor that

delivers a specific frequency of voltage pulses depending on the speed of the front or rear wheel of the vehicle.

As far as the distribution of the available electrical power between the two lamps is concerned, it is advantageous if the electrical power can be divided in such a way that the light output of the first lamp is almost zero at lower speeds, whereas the light output of the additional lamp is almost zero at higher speeds. If the first lamp is intended for lighting over longer distances and the additional lamp is intended for lighting over shorter distances, this distribution of the electrical power means that during slow journeys - such as city trips - the full electrical power is initially available to the additional lamp. The close area directly adjacent to the front end of the bike is therefore optimally illuminated.

From a certain speed, the control device then makes the electrical power available entirely to the first light source. As a result, the far area in front of the vehicle, which adjoins the near area, is now optimally illuminated, so that the user is able to see obstacles that are relatively far ahead of him and that are approaching him relatively quickly due to the high speed of the vehicle.

Of course, many other ways of dividing the electrical power are also conceivable; some of them will be described later in specific embodiments of a lighting unit according to the invention.

Advantageously, the control of the lighting unit is designed in such a way that if one of the lamps fails, the one that is still intact takes up the entire electrical power. If, in the manner described above for dividing the electrical power between the lamps - for example when driving at high speed - the first lamp fails, the additional lamp can be switched on and the

absorb electrical power so that the journey can continue without danger. In this case, only the immediate area is illuminated, but this is sufficient to be able to complete the journey safely.

The control device can advantageously be designed as an electronic circuit. There are many different designs for such circuits; what almost all of them have in common is that they can be manufactured very inexpensively and allow for a very compact design.

However, it is also useful if the control device has a microprocessor. For example, it can then be provided that a user selects a distribution program for the distribution of the electrical power that is tailored to his needs. Furthermore, with a microprocessor it is possible to implement a large number of different - even relatively complicated - distribution variants that were very difficult to implement with conventional electronic circuits.

As far as the two lighting means are concerned, both the first lighting means and the additional lighting means can advantageously be designed as incandescent lamps. Such incandescent lamps are easy to manufacture as mass-produced items and are inexpensive. However, it is also within the scope of the invention for the additional lighting means to be a second filament of the first lighting means designed as an incandescent lamp. This second filament can then be arranged within the glass bulb of the first lighting means at a distance from the first filament.

Advantageously, at least the additional light source is also designed as an LED component with at least one LED. Such LEDs are now also mass-produced items that have a long service life, are inexpensive to manufacture and have low energy consumption.

In a further development of the present lighting unit, it may be advantageous to provide an adjustable focusing device by means of which the light distribution caused by the lighting unit can be spatially changed, whereby the control device is designed in such a way that the focusing device can be adjusted depending on the speed. This makes it possible to adapt the light distribution to the respective driving speed. Here, too, focusing does not have to be carried out by a user before starting the journey, but is carried out automatically by the control device during the journey.

In this context, it is also advantageous if the light distribution is wider at low speeds than at higher speeds. As mentioned above, it is particularly important at higher speeds to be able to detect obstacles that are relatively far ahead of the vehicle early on so that a user has enough time to react. Due to high speeds, this time is naturally very limited, so detecting obstacles early on is of crucial importance.

There are various options for the structural design of such a focusing device. For example, the headlight housing of the lighting unit can have a lens at the front for the light output. Focusing effects can be achieved by changing the distance of the light source to this lens, for example. This mechanical change in distance can then be controlled by the control device.

Further advantages and features of the invention will become apparent from the following description of an embodiment.

Figure 1 shows a bicycle with a lighting unit according to the invention in a schematic side view;

Figure 2 two circuit diagrams of the control device of the lighting unit;

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Figure 3 shows four different variants of the distribution of electrical energy between the two light sources of the lighting unit using diagrams.

Figure 1 shows a human-powered vehicle - in this case a bicycle 1 - which has a lighting unit 2. This comprises a voltage source 4 arranged on the front wheel 3 of the bicycle 1, which is designed as a dynamo, a headlight 5 for a long-range area 10 with a first light source 6, another headlight 5' for a close-range area 9 with an additional light source 6' and a control device 8 which divides the electrical power generated by the dynamo 4 between the two light elements 6, 6' depending on the driving speed.

There are a number of options for the way in which the electrical power is distributed between the lighting elements 6, 6'. In order to make the function of the lighting device clear, one variant will be selected and presented below:

As soon as a user sets the bicycle 1 in motion with the dynamo 4 switched on, the resulting kinetic energy is partially converted by the dynamo 4 into electrical energy or initially into electrical voltage. The magnitude of the voltage generated by the dynamo depends on the current driving speed. The voltage then serves as an input signal for the control device 8, which, for example, when starting to drive slowly, directs the power generated by the dynamo entirely to the additional light source 6'. The light source 6' consequently emits light, so that the close area 9 is illuminated. At the same time, the first light source 6 remains dark, so that the far area 10 remains unlit.

When the bicycle then travels at higher speeds, the full electrical power continues to be supplied to the lamp 6', which naturally shines more brightly due to the now higher power.

a certain, defined speed - for example 15 kilometers per hour (hereinafter: km/h) - the control device 8 switches the full electrical power from the lamp 6' to the lamp 6 based on the magnitude of the voltage generated by the dynamo corresponding to this speed. The close area 9 is then no longer illuminated because the lamp 6' no longer emits light. The lamp 6, on the other hand, emits light and thereby illuminates the long-distance area 10. As a result, it is then possible to recognize obstacles far ahead of the bicycle at an early stage when riding fast.

The control device 8 can therefore determine the speed of the bicycle from the magnitude of the voltage generated by the dynamo or, when the voltage reaches a certain magnitude, carry out the switching operations described above.

As far as the headlights 5 and 5' are concerned, their attachments to the front end of the bicycle 1 are not shown. However, the reflectors 7, T of the two headlights, which bundle the light from the lamps 6 and 6' and radiate it forwards, are clearly visible. It is important that the optical axes 16, 16' of the reflectors 7 and 7', shown in dash-dot lines, form such an angle with the road surface that they can illuminate the long-distance area 10 and the close-up area 9. Contrary to the illustration, the headlight 5, for example, can also be positioned so that its optical axis 16 runs approximately parallel to the road surface.

Figure 2 now shows two variants of electronic circuits, such as the control device 8 can have. Circuit I in Figure 2 shows how the dynamo 4, the lamps 6 and 6' and a combination of voltage divider 11 and solenoid 12 are arranged in the circuit. Depending on the voltage generated by the dynamo, the solenoid 12 adjusts the voltage divider 11 so that the electrical power generated by the dynamo 4 is divided between the lamps 6 and 6'.

In Figure 2, another circuit variant II is shown, which consists of the dynamo 4, the lighting means 6, 6', two resistors 13, 13', two transistors 14, 14' and a tens diode 15, the components being connected to one another in the manner shown.

Here too, the electrical power generated by the dynamo 4 is divided between the lamps 6 and 6'. However, up to a certain driving speed - i.e. up to a certain level of the voltage generated by the dynamo 4 - only the lamp 6' lights up. If a higher driving speed also generates a higher voltage, the tens diode 15 switches on so that the electrical power is evenly distributed between the two lamps 6, 6' so that they light up with the same intensity.

Figure 3 shows four diagrams in which different variants for the distribution of the electrical power between the lighting means 6 and 6' are shown. For this purpose, the dependence of the electrical power P on the driving speed v of the bicycle was entered in an X-Y coordinate system. The electrical power P is given in percent, the driving speed in kilometers per hour (km/h).

In diagram I, the dotted line 17 represents the percentage share of the light source 6' for the close range and the solid line 18 represents the percentage share of the light source b for the long range. As can be clearly seen, at a driving speed of zero the electrical power is divided between the light sources in such a way that eighty percent of the available power is taken up by the light source for the close range 6', while only twenty percent is taken up by the light source for the long range 6. At a speed of 15 km/h the control device 8 reverses the situation so that from this speed onwards the light source 6 for the long range takes up eighty percent of the power (and thus strongly illuminates the long range 10), whereas the light source 6' for the close range only takes up twenty percent.

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percent of the power. This means that even at a speed higher than 15 km/h, both the long-distance and close-up areas are illuminated, but the long-distance area is much brighter.

In diagram II the conditions are more extreme in that when driving slowly up to about 15 km/h the close area is completely illuminated, while the far area is practically unlit. From about 15 km/h the control device 8 then switches over, so that with this variant of power distribution the conditions are completely reversed. Then only the far area is illuminated with about one hundred percent of the power, while the close area remains practically dark.

Diagram III shows another variant of the distribution of electrical power. At a driving speed of zero, the conditions are as in diagram II, i.e. the near area is completely illuminated. As the speed increases, the light output of the lamp for the near area drops in a straight line until it consumes almost no power (zero percent). The power curve of the lamp for the long-range area is exactly the opposite: at the beginning, the long-range area is not illuminated at all (zero percent), and as the speed increases, the power consumption of the lamp 6' also increases in a straight line until it reaches one hundred percent.

With this variant, there is no defined driving speed at which one lamp is switched on and the other is switched off.

Finally, diagram IV shows a variant in which the increase or decrease in the power of the lamp for the long-range or close-range does not run in a straight line as in diagram III, but in a stepped manner. From a speed of 20 km/h, the lamp for the long-range 6 takes up full power, while the lamp for the close-range 6' goes dark.

Claims (14)

1. Lighting unit for muscle-powered vehicles with at least one headlight which has at least one lamp for roadway illumination arranged within a housing and at least one reflector, with a voltage source for supplying energy to the lighting unit and a control device for controlling the same, characterized in that an additional lamp for roadway illumination is provided and that the control device is designed such that at least part of the electrical power produced by the voltage source can be divided between the first lamp for roadway illumination and the at least one additional lamp for roadway illumination, this division taking place in accordance with an input signal which is dependent on the vehicle speed. 2. Lighting unit for muscle-powered vehicles according to claim 1, characterized in that the additional lighting means is arranged within the headlight housing. 3. Lighting unit for muscle-powered vehicles according to claim 2, characterized in that the first lighting means is located approximately at the focal point of the reflector, whereas the additional lighting means is arranged outside the focal point in such a way that its light rays run essentially obliquely from top to bottom with respect to a horizontal alignment of the optical axis of the reflector. 4. Lighting unit for muscle-powered vehicles according to claim 1, characterized in that the additional lighting means is arranged within a separate reflector. 5. Lighting unit for muscle-powered vehicles according to claim 1, characterized in that the voltage source is designed as a dynamo attached to the vehicle, the speed-dependent input signal depending on the voltage of the dynamo. 6. Lighting unit for human-powered vehicles according to claim 1, characterized in that the input signal is an electrical signal generated by a speed sensor attached to the vehicle. 7. Lighting unit for human-powered vehicles according to claim 1, characterized in that the electrical power can be divided in such a way that the light output of the first lighting means is approximately zero at lower speeds, whereas the light output of the additional lighting means is approximately zero at higher speeds. 8. Lighting unit for muscle-powered vehicles according to claim 1, characterized in that in the event of failure of one of the lighting means, the lighting means which is still intact absorbs the entire electrical power. 9. Lighting unit for muscle-powered vehicles according to claim 1, characterized in that the control device is designed as an electronic circuit. 10. Lighting unit for muscle-powered vehicles according to claim 1, characterized in that the control comprises a microprocessor. 11. Lighting unit for muscle-powered vehicles according to claim 1, characterized in that both the first lighting means and the additional lighting means are designed as incandescent lamps. 12. Lighting unit for muscle-powered vehicles according to claim 1, characterized in that at least the additional lighting means is designed as an LED unit with at least one LED. 13. Lighting unit for muscle-powered vehicles according to claim 1, characterized in that an adjustable focusing device is provided by which the light distribution caused by the lighting unit can be spatially varied, and that the control device is designed such that the focusing device can be adjusted as a function of speed. 14. Lighting unit for human-powered vehicles according to claim 13, characterized in that the light distribution is wider at lower speeds compared to higher speeds.