GB2297826A

GB2297826A - A lamp for a bicycle

Info

Publication number: GB2297826A
Application number: GB9502570A
Authority: GB
Inventors: Stephen William John Dear
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-02-10
Filing date: 1995-02-10
Publication date: 1996-08-14
Anticipated expiration: 2015-02-10
Also published as: GB9502570D0; GB2297826B

Abstract

A lamp 1 for a bicycle comprises a housing 2. The housing contains a bulb 4 and a generator 5. A bracket 11 is provided on the housing for securing the lamp to a bicycle to enable the generator 5 to generate power for the bulb for when a wheel of the bicycle is rotated.

Description

A LAMP FOR A BICYCLE The invention relates to a lamp for a bicycle.

More specifically the invention relates to a lamp comprising a generator and a bracket for securing the lamp to a bicycle.

The law concerning cyclists and visibility requires front and rear lights to be fitted to a bicycle and to be used from dusk to dawn. Cycle lamps are not inexpensive, and are easily stolen.

Furthermore, lamps are generally powered by a battery fitted within the lamp and in many of the models of lamps presently available charging the batteries is a difficult operation. Batteries too are expensive and of course only have a limited life. The dry cell batteries usually used in cycle lamps are unable to supply sufficient power to generate light by which the cyclist can see where he is going at night. Halogen bulbs produce a brighter light than ordinary coil bulbs but reduce the life of the batteries by about one third.

An alternative to wiring small individual batteries in each lamp is to provide a large heavy duty battery which is secured in a bracket on the bicycle. This alternative provides sufficient power for good illumination at night but is extremely cumbersome. The arrangement also requires wiring to connect the lamps to the battery. This means that the lamps will not be easily removable from the bicycle and will be susceptible to damage or theft.

Lamps powered by a generator, usually in the form of a dynamo, are also available for use on bicycles.

The dynamo may be provided in the hub of one of the wheels of the bicycle or may be supplied with a bracket which enables the dynamo to be secured to the bicycle. The bracket comprises a biassing member for biassing the dynamo towards the wheel so that rotation of the wheel causes rotation of the dynamo and thus the generation of electricity to power the lamp. An advantage of a dynamo powered lamp is that there are no batteries to replace. A disadvantage is that it is necessary to install wiring between the dynamo and each lamp and to fix the lamps in position on the bicycle. This renders the lamps susceptible to damage or theft.

A consequence of the problems and disadvantages of the above described known lamps is that many cyclists have only poor front and rear lights and a substantial proportion have no lights at all. The invention aims to overcome or at least reduce some of the above discussed problems and disadvantages of known lamps.

According to the invention there is provided a lamp for a bicycle, the lamp comprising a housing; a bulb in said housing; a generator in said housing; and a bracket on said housing for securing the lamp to a bicycle to enable the generator to generate power for the bulb when a wheel of the bicycle is rotated.

The above and further features of the invention are set forth with particularity in the appended claims and together with advantages thereof will become clearer from consideration of the following detailed description of an exemplary embodiment of the invention given with reference to the accompanying drawings.

In the drawings: Figure 1 is a schematic front view of a lamp embodying the invention secured to a bicycle; Figure 2 is a schematic rear view of the lamp in Figure 1; Figure 3 is a functional diagram illustrating principles of operation of a fixing bracket for the lamp; Figure 4 is a schematic circuit diagram of the lamp; Figure 5 is a schematic part view of an alternative lamp design; and Figure 6 is a schematic front view of another alternative lamp design; and Figure 7 is a schematic view of a further alternative lamp design.

Turning now to Figure 1 of the accompanying drawings there is shown a lamp 1 comprising a housing 2 with a reflector and lens unit 3 containing a bulb 4. A generator (e.g. a dynamo or alternator) 5 is mounted in said housing to extend outwardly therefrom.

The shaft (not shown) of the generator has an end knob 6 thereon which knob has a gripping surface for contacting in use part of a bicycle wheel 7. The gripping surface of the knob 6 may be formed from rubber in which case, as shown in Figure 1, the knob may contact the rim 8 of the wheel 7. Alternatively the gripping surface of the knob 6 may be formed from a harder material in which case the lamp may be positioned so that the knob contacts a portion of the tyre 9 on the wheel 7.

The lamp may be mounted at any convenient position on the bicycle, for example fork 10, by way of a bracket 11 as shown in Figure 2 of the accompanying drawings. The bracket 11 comprises a part 12 fixed to the body 2 and a part 13 mountable to the fork 10. The parts 12 and 13 of the bracket are arranged to enable the lamp 2 to be rotated in the direction of arrows 14 to or from the wheel 7 to enable the knob 6 to be brought into or out of contact with the wheel 7. The bracket may be biassed towards the wheel and lockable in position away from the wheel by suitable means not shown in the drawings.

Figure 3 of the accompanying drawings shows in schematic form the principle of operation of the bracket. In addition to the rotation movement in the direction of arrows 14, the two parts 12, 13 of the bracket are arranged to enable the lamp to be removed quickly from the bicycle. The part 12 fixed to the body 2 is mountable to and demountable from the part 13 in the direction of arrows 15. A suitable detente (not shown) between the parts 12 and 13 prevents accidental separation of the two parts.

As shown in Figure 4 of the accompanying drawings the lamp 1 contains electrical circuitry 15 in the form of a battery 16 which together with the generator 5 is connected to a switching circuit 17. In use, power from the generator is supplied via the switching circuit 17 to the bulb 4. The switching circuit 17 is arranged to monitor the power from the generator 5 and to switch to the battery 16 in the event that the power from the generator 5 falls below a predetermined level. This circuitry arrangement ensures that the lamp remains powered even when the bicycle is stationary. The battery 16 may be a standard disposable battery or it may be a rechargeable battery. In the event that a rechargeable battery is used the circuitry 15 may be adapted to include a charging circuit 18 which serves to charge the battery with power from the generator 5.

Figures 5 and 6 of the accompanying drawings show alternative lamp designs. In Figure 5 the lamp 19 comprises two lens and reflector assemblies 20, 21 each having its own bulb powered by the generator 5.

The upper lens is directed for distance illumination and the lower lens 21 is directed for illumination of an area immediately in front of the bicycle. The lamp 22 in Figure 6 has a modified body which may be more suitable for use on some bicycles. A further alternative design (not shown) comprises one lamp such as the lamp 2 in Figure 1 and a second lamp without a generator connected to the first lamp by way of a connecting cable. This alternative would enable a lamp to be fitted on each side of the wheel of a bicycle thereby increasing the visibility of the bicycle. The lens may be of a wrap-around design which enables light to be emitted from the lamp over a wide angle. The lens may be removable for example to enable a clear lens for use with a lamp at the front of a bicycle to be replaced by a red lens for use at the rear of a bicycle.

A further alternative lamp design is shown in Figure 7 of the accompanying drawings. As shown in Figure 7 the lamp 25 contains a generator 26 oriented to be substantially parallel of the parallel axis 27 of the lamp. The lamp may be positioned on the bike such that in use a tapered wheel 28 is driven by the rim 29 of a bicycle wheel 30 thereby causing the generator 26 to generate electrical power. Other variations in the design are, of course, possible.

For example, the generator might be positioned in a substantially horizontal orientation to be driven by the inwardly directed face of the rim of the bicycle wheel. All such modifications are well within the ability of those skilled in the art.

The generator comprises moving parts which operate in the hostile environment in the proximity of the wheel of the bicycle. Therefore during use of the lamp, the greatest wear will be on the generator 5.

It is likely that with normal use the generator will wear out before other parts of the lamp. The generator may be provided as a replaceable unit which is removably insertable into the body 2 of the lamp.

Having thus described the present invention by reference to a preferred embodiment it is to be well understood that the embodiment in question is exemplary only and that modifications and variations such as will occur to those possessed of appropriate knowledge and skills may be made without departure from the spirit and scope of the invention as set forth in the appended claims and equivalents thereof.

Claims

CLAIMS:

1. A lamp for a bicycle, the lamp comprising: a housing; a bulb in said housing; a generator in said housing; and a bracket on said housing for securing the lamp to a bicycle to enable the generator to generate power for the bulb when a wheel of the bicycle is rotated.

2. A lamp as claimed in claim 1, wherein the generator is a dynamo.

3. A lamp as claimed in claim 1 or 2, wherein the generator is removable from the housing.

4. A lamp as claimed in claim 1 or 2 or 3, wherein the generator is arranged to generate power by rotation of a shaft arranged to contact in use the wheel of the bicycle.

5. A lamp as claimed in claim 4, wherein the shaft comprises an end knob with a gripping surface for contacting in use a portion of the wheel.

6. A lamp as claimed in any preceding claim wherein the bracket is arranged to facilitate mounting and demounting of the lamp to and from the bicycle.

7. A lamp as claimed in any preceding claim, wherein the bracket comprises a first part securable to the bicycle and a second part fixed to the housing and releasably mountable to the first part.

8. A lamp as claimed in any preceding claim, wherein the bracket comprises a biassing member for biassing the generator to a generating position.

9. A lamp as claimed in any preceding claim, further comprising a power source and a switch for switching the power source to supply power to the bulb when power is not being supplied by the generator.

10. A lamp as claimed in claim 9, wherein the switch comprises a circuit for monitoring power from the generator and controlling the switching in dependence thereon.

11. A lamp as claimed in claim 9 or 10, wherein the power source comprises a battery.

12. A lamp as claimed in claim 11 wherein the battery is rechargeable.

13. A lamp as claimed in claim 12, further comprising a charging circuit connected to receive power from the generator for charging the battery.

14. A lamp as claimed in any preceding claim, further comprising a lens for directing light from the bulb.

15. A lamp as claimed in claim 14, wherein the lens is a wrap-around lens arranged to distribute light from the bulb over a wide angle.

16. A lamp as claimed in claim 14 or 15, wherein the lens is removable to enable a lens to be replaced by a lens of a different colour and/or light distribution.

17. A lamp substantially as described herein with reference to the accompanying drawings.