BICYCLE DYNAMO

Abstract: By forming the stator part of the hub dynamo in such a manner that it can be firmly secured against the outside of the rear cone (7), for reasons of recesses for the axle (1) and the two cone projections on both sides of the brake arm recess (4), the stator part can be fastened to existing bicycle hubs without any changes other than the removal of the existing brake arm. The rotor part can be fastened to a disc (16), the central opening of which passes over the hub (2), and which can be secured either permanently or releasably to the spokes (22) of the wheel. This releasable securing arrangement can consist of a pivotably mounted stud (21) which can move into engagement between the spokes (22) of the wheel.

Description: BICYCLE DYNAMO " ^ This invention relates to a dynamo for mounting on a bicycle, a moped or the like, consisting of a circu- 5 lar stator part with coils which is secured to the hub axle, and a rotor part with magnets which extends around the stator and is secured to the wheel. Hitherto known dynamos of this kind are designed for 10 building into a specially constructed hub, which also means that the dynamo has to be mounted with spokes adapted for the purpose, because on the side where the rotor part of the dynamo is placed, these have to be fastened to a spoke ring secured to the exterior 15 of the rotor. Moreover, since the dynamo is built in¬ to a hub with a built-in brake, a brake arm has to be mounted on the stator. This hub dynamo is thus inten¬ ded for use only in specially constructed wheels and, moreover, is expensive and difficult to produce. Fur- 20 ther to this, the dynamo is troublesome to repair, the reason being that it cannot be taken apart with¬ out the risk of damage to the dynamo's electrical components. - . 25 The object of the invention is to overcome the disad¬ vantages of the known hub dynamos while retaining their existing practical advantages, and this is ach¬ ieved when the stator coil is secured to a plate hav- ing a hole for the axle and which can lie up against •• j 30 the outside of the hub cone. This makes it possible to construct a hub dynamo which can be mounted on ex¬ isting wheels, in that the stator part is placed out¬ side the existing hub cone on the rear wheel hub op¬ posite the chain, and is locked firmly to the hub by OMPI tightening the hook nuts together. The wheel with hub and dynamo can then be mounted in the existing wheel fork without other changes. Iτι this simple manner a dynamo can be placed in an existing wheel, which involves great advantages for the user, who hereafter needs only to invest in the dynamo. After having been mounted, the dynamo has the advantageous characteristics of a hub dynamo, such as reliability, good efficiency and security against re¬ moval. By forming the plate as presented in claim 2, the dy¬ namo can be mounted on a rear hub with brake, in that the plate replaces the brake arm. By forming the rotor as presented in claim 3, this can be positioned outside the hub and secured to the wheel in a simple and reliable manner. By forming the rotor with a releasable coupling, as presented in claim 4, one can decouple the dynamo drive when there is no need for current, which in¬ creases the efficiency. By forming the coupling as presented in claim 5, the pivotable driving stud can be used as a coupling as well as a spring pin in the event of a blockage of the rotor. Finally, it is expedient to mount a sliding seal be¬ tween disc and hub, as presented in claim 6, in that one hereby achieves a watertight and dustproof assem¬ bly and the possibility of adapting the dynamo to suit hubs of different diameters. The invention will now be described in closer detail with reference to the drawing, where fig. 1 shows a side view of the dynamo mounted on a rear wheel, and fig. 2 shows a part-section of the dynamo seen in the direction II-I in fig. 1. The drawing shows a preferred embodiment of the dy¬ namo secured to and built into a rear hub. The hub itself is a normal hub (see fig. 2) which can have a built-in brake and possibly gears. The dynamo sits on the left side of the hub opposite the sprockets The hub is rotatably mounted on an axle 1, and in fig. 2 can be seen the left cone 7 with the longitud- inal recess 4 for the brake arm. The dynamo itself consists of a stator part and a .rotor part. The stator part is secured to a plate 8 which has a hole for the axle 1 and also recesses for the cone 7, so that the plate engages with the brake arm recess 4 as seen in the sectional drawing fig. 2. At a dis¬ tance above the hub, a ring is formed for the plate 8 which extends in over the hub. In order to be able to fasten the plate 8 to a cycle frame, the plate is provided with a brake arm (not shown) which, by means of generally known locking means 27, see fig. 1, can be fastened to a part of the frame, in the example shown to the fork part 26. On the ring is the actual stator coil 14, which ' is . surrounded by the stator irons 15 and inserted rest- ing against an end stop formed by the plate 8. The coil housing can be placed in the stator plate core 15 in a commonly known manner. On the outside of the plate 8 is fastened a cover- plate 9 which, as can be seen in the drawing, has its edge bent in over the coil, thus closing the dynamo off towards the outer side. This plate 8 with cover 9 is fastened firmly to the hub by means of the existing hook nuts 3, and secured to the fork 11 by means of the wheel nut 6 with wash¬ er 5. Moreover, as mentioned earlier, it"is fastened to the fork leg 26. Over the hub 2 is also placed a disc 16 having a cir¬ cular opening at its centre which is slightly larger than the hub. At the inner edge there is mounted a seating ring 13 which is flexible and ensures a tight seating against the hub. In order for the dynamo to be used with hubs of different sizes, intermediate rings (not shown) with sliding seals can be inserted in the recess instead of the shown sealing ring 12. The outer part of the disc 16 is bent over, and in the ring thus formed there is mounted a magnet ring 18 which, extends the whole way around. To the inside surface of this ring there are mounted or moulded-in magnets 17 of the desired number and size as well as power. The outer side of the ring 16 and the inner side of the cover 9 , together with ribs displaced from each other, form a labyrinth seal, so that protection is provided against the ingress of dust and water into the dynamo. This assembly of stator and rotor ensures that these are precisely centred and that the desired efficiency is thus achieved. The rotor disc 16 can be secured to the spokes with the help of retaining means such as fasteners or the like (not shown) , so that the rotor always follows the wheel's rotation under all circumstances. In order to be able to decouple the rotor when cur¬ rent is not needed, and thereby avoid having to over¬ come the influence of. the magnets on the stator, the rotor disc 16 is provided with releasable driving means. These comprise a bracket 19, the outer part of which forms a bearing pin 20 carrying a stud.21 which can be swung in between the spokes 22 of the wheel. In the position shown, the rotor turns with the wheel, and in the event of a blockage in _the .dynamo, the stud 21 will break off and protect the cyclist against injury and the dynamo against damage. The stud 21 can be swung away from engagement with the spokes into the position shown in the drawing by the stippled 'line, whereby the wheel can turn freely without driving the rotor around with it. In this way the efficiency of the bicycle is considerably in¬ creased when there is no need to produce current. OMPI The leads 23,24 necessary for taking off the current (see fig. 1} can, as shown in the drawing, be led through the frame parts 25,26, and thus lie protect¬ ed. The risk of the leads being damaged and/or ruin— ed is thus reduced, and this can further be safeguard¬ ed against by armouring the leads in a commonly known manner. Should ,it be desired to mount a rear light, this can be secured to the coverplate 9. Similarly, the cover¬ plate 9 can be provided with reflecting coatings or ' means (not shown) . The shape of the dynamo can, within the scope of the invention, be adapted to suit requirements. It can thus be made "dish-shaped" , in that the coverplate 9 can extend essentially parallel with the spokes 22.

Claims: C L A I M S 1. Dynamo for mounting on a bicycle, a moped or 'the like, and consisting of a circular stator part with coils which is secured to the hub axle, and a rotor part with magnets which extends around the stator and is secured to the wheel, c h a r a c t e r i z e d in that the stator coil (14) is fastened to a plate (8) having a hole for the axle (1) and which can lie up against the outside of the hub cone (7) . 2. Dynamo according to claim 1, c h a r a c t e r ¬ i z e d in that the plate (8) also extends into the brake arm recess (4) in the cone (7) , and in that the plate (8) is provided with means (27) for securing the plate to a frame part (26) . 3. Dynamo according to claims 1 and 2, c h a r a c ¬ t e r i z e d in that the rotor magnets (17) are mounted on a ring (18) , said ring being secured to a disc (16) which is provided with a central opening for introduction on the hub (2) and with means for securing to the wheel. 4. Dynamo according to. claim 3, c h a r a c t e r ¬ i z e d in that the disc (16) is provided with driv¬ ing means (19, 20, 21) which, in one position, can connect the rotor to the wheel (22) and, in a second position, release this connection. 5. Dynamo according to claim 5, c h a r a c t e r ¬ i z e d in that the driving means consists of a stud (21) which is pivotably mounted on a bracket (19) which is connected to the disc (16) , said stud (21) being capable of being swung in and out of movement -transferring engagement with the wheel. 6. Dynamo according to claim 3, c h a r a c t e r ¬ i z e d in that in the disc (16) there is mounted a sliding seal (12) between the disc (16) and the hub (2).

Inventors: NIELSEN AXEL GROENLUND, NIELSEN, AXEL, GROENLUND
Applicants: INCENTIVE TEKNIK AS, INCENTIVE TEKNIK A/S
Application year: 1983
Main classification: B62J5
IPC codes: B62J6