The present invention relates to a hub-steering bearing assembly for journalling the steering wheel of a vehicle relative to the frame of a vehicle, said assembly com¬ prising a bearing axle mounted on the frame of a vehicle, which axle carries the journallingmeans for said wheel and around which axle said wheel rotates with an axis of rotation defined by the journallingmeans serving as a centre axis, and a steering shaft rotatably journalled relative to the bearing axle and extending perpendicular¬ ly to the axis of rotation, as well as means for turn¬ ing the wheel relative to the steering shaft.

An object of the invention is to provide a possibility of designing particularly a bicycle or some other two- wheel vehicle, whereby the centre of mass common to a vehicle and to a load can be positioned on a level sub¬ stantially lower than that in the available bi- and motorcycles, yet without losing any of their handling characteristics. However, the invention is not limited to two-wheel vehicles but can also be applied in multi- wheel vehicles.

A lower position of the centre of gravity makes it possible to design e.g. a streamlined pedalled vehicle, wherein a driver is nearly in a horizontal, backwardr- leaning position, the effect of air resistance being reduced even down to 1:10 of what it is at present and the power required for driving down to 27 % of what is normally required.

Particularly in motorcycles there has recently been a strong tendency towards this type of designs in efforts of creating a so-called "forkless" motorcycle. Merely the complexity and costly construction of thus far de-

scribed designs is enough to indicate that all possible means are employed to achieve this aim.

Thus far, the means for lowering the centre of gravity of a vehicle have mainly been restricted to reducing the size of a front wheel, resulting in an increased resistance to rotation and a possible hazard of abrupt stoppage and fallheadlongcaused by the bursting of a front tyre.

DE Patent publication 584 566 discloses a bicycle steering bearing, which is fitted inside the hub of a steering wheel. In this prior known bicycle, the com¬ mon centre of mass of a vehicle and a cyclist has been successfully lowered to a level substantially lower than in a conventional bicycle. However, a drawback of this prior art cycle is poor handling characteristics.

In order to provide a steering bearing, which would fulfil the same handling criteria that are known from current high-quality bicycles, such bearing should function identically even when the cyclist releases his or her gripfrom the handlebar, the same way as in the latter. In other words, the steering bearing must have all qualities of a front axle, a steering axle and a front fork included in the concept of handling and, in addition, it must be located below the common centre of mass of a driver and a vehicle, so that the driver could control the balance by shifting his or her own centre of gravity.

In order to fulfil these above-described criteria, a hub-steering bearing assembly of the invention is ar¬ ranged in a manner and a hub-steering bearing assembly of the invention is characterized in that the steering shaft and the rotating axis of a wheel are spaced from

each other, and that the steerinσ shaft is at an oblique angle α relative to the driving surface of a vehicle as the vehicle is laid upon its wheels on a flat driving surface.

The invention will now be described in more detail with reference made to the accompanying drawings, in which:

fig. 1 shows a schematic side view of a bicycle provided with a steering bearing assembly of the inven¬ tion for pivoting or journalling the steering wheel relative to the frame of a bicycle.

Fig. 2 shows a plan view of the bicycle shown in fig. 1.

Fig. 3 shows a section along a line III-III in fig. 1 with the wheel turned to one of its extreme po¬ sitions.

Fig. 4 shows a section along a line IV-IV in fig. 3.

A hub-steering bearing assembly of the invention is intended for pivoting or journalling a steering wheel 1 relative to a. vehicle frame 2, said wheel being in¬ cluded in various vehicles, but especially in a bicycle or some other two-wheeler, such as a motorcycle or a moped. For the sake of clarity, the following specifica¬ tion only describes the invention as applied to a bi¬ cycle but, as pointed out above, the invention can of course be applied to other vehicles as well.

A hub-steering bearing assembly of the invention re¬ places a front fork in a bicycle and makes it possible to construct a pedal-powered vehicle, wherein the driver is in a position substantially lower than in the avail¬ able bicycles and, yet, the vehicle loses none of its

handling characteristics as compared to the available bicycles.

The hub-steering bearing assembly comprises a bearing axle 3 secured to a vehicle frame 2. The axle 3 sup¬ ports journalling members 4 included in a steering wheel 1. The wheel 1 rotates around said axle 3 with a rota¬ ting axis 5 defined by journalling members 4 serving as the centre axis.

Said bearing axle 3, which is fixed relative to a bi¬ cycle frame 2, is provided with a steering shaft 6 ro- tatably journalled relative to axle 3, said wheel being turned relative to said shaft-for steering a bicycle. The steering shaft 6 is perpendicular to the rotating axis 5 of wheel 1.

In an embodiment shown in figs. 3 and 4, a hub-steering bearing of the invention is designed as follows. In¬ side the hub 10 of wheel 1 is in a per se known manner and by means of bearing members 4 journalled a cylin¬ drical tube 11. Inside said tube 11 are cylinder seg¬ ments 12, 13, which are ground smooth on their flat faces and between which is a flat-shaped bearing axle 3 which is of equal thickness and ground smooth on both sides. Said segments 12, 13 inside tube 11 and said bearing axle 3 are linked to each other by means of a steering shaft 6, the latter being perpendicular to said flat surfaces.

Cylinder segments 12, 13 are locked in said tube 11 by means of clamping elements, not shown.

Bearing axle 3 is dimensioned in a manner that said tube 11 is capable of pivoting together with cylinder seg¬ ments 12, 13 upon said steering shaft 6 relative to

bearing axle 3 mounted on frame 2. In order to reduce friction, it is possible to employ e.g. bearing balls 15.

In order to provide preferred steering characteristics, said steering shaft 6 is located close to the trailing edge of bearing axle 3 (to have a sufficient distance between axis 5 and shaft 6) and said axle 3 is mounted on frame 2 in a manner that said steering shaft 6 is at an oblique angle α , e.g. 70 , relative to a driving surface 8, the vehicle resting upon its wheels 1 , 9 on a flat driving surface (travelling direction of a bicycle indicated by an arrow 16 in fig. 4) .

The angle of inclination α of steering shaft 6 can be selected as desired by locking said bearing axle 3 in a desired position relative to frame 2. In view of motorcycles, the adjustment of said angle of inclination a can even be made automatically variable according to driving speed.

The steering of a bicycle is effected through the inter¬ mediary of a bar 7 mounted on tube 11 , said bar being manipulated by the cyclist with one hand by means of a lever 14 but, by virtue of the low position of the centre of gravity, the steering is also considerably achieved by leaning the bicycle in the turning direc¬ tion, just like in a normal bicycle. Therefore, there is no need to provide the wheel with a major turning angle, which on its part simplifies the design.

The structural drawings illustrate a practical embodi¬ ment of the idea by using an existing, wheel hub with minor modifications, by adding just the necessary accessories. The design can be simplified even further

by using totally new parts.