Land vehicles – Wheeled – Occupant propelled type
Reexamination Certificate
2000-06-07
2002-06-11
Lerner, Avraham H. (Department: 3618)
Land vehicles
Wheeled
Occupant propelled type
C180S219000
Reexamination Certificate
active
06402175
ABSTRACT:
TECHNICAL FIELD
The present invention relates to a front wheel suspension for a vehicle having only one front wheel, by which is primarily meant a motor cycle. In the front wheel suspension, the wheel is mounted in at least one preferably rearward-sloping supporting member which, with the aid of or via bearing units comprising link elements and possibly a springing function, is/are in turn mounted on the chassis of the vehicle. The bearing units allow springing motions in a springing direction for the supporting member, produced by means of connection to a shock absorber or spring function. The bearing units also effect torsional rigidity against the cross-directional action of the supporting member relative to the chassis, viewed in the longitudinal section of the vehicle. Moreover, the bearing units forcibly steer the supporting member in its motions in the said longitudinal section during the said springing motions.
PRIOR ART
A resilient front wheel suspension on, for example, motor cycles is currently realized principally as a telescopic springing or telescopic fork in which inner tubes and outer tubes are mutually longitudinally displaceable and supported one upon the other by means of bushes. The wheel is in this case mounted in the one tube or tubes, whilst the other tube or tubes is/are secured in the chassis. The securement in the chassis is usually realized in connection with a so-called fork crown (triple clamp) to which also the handlebar of the motor cycle is secured. The known arrangement operates with a steering joint and a sliding joint. The telescopic arrangement is rearward-sloping and a steering line for the motor cycle is likewise sloping (essentially parallel with the sloping of the telescopic arrangement) and extends down through the centre of turn of the handlebar, somewhat to the side of the centre of turn of the wheel and further down to a position on the ground plane or the support surface somewhat in front of the point of contact of the wheel with the ground plane or support surface (compare the concept “trail”). The term “steering line” constitutes a recognized concept and purely general reference is made to this. The bearing of the telescopic arrangement is realized at a relatively high level above the ground plane. Upon braking of the wheel, the securement is acted upon by torque. Moreover, the braking gives rise to a weight displacement force which endeavours to compress or boost the compression of the telescopic arrangement in a dive motion. Additional forces generated in the braking of the motor cycle can hereupon produce up to double jounce motions. The telescopic arrangement can be realized with different or desired springing or motion geometries. This term too is a recognized concept, to which purely general reference is made. Thus, for example, the motor cycle/telescopic arrangement can be provided with special so-called “anti-dive” arrangements, which oppose or produce desirably low dive effects in the event of braking actions with or on the front wheel. The telescopic arrangement has a relatively low rigidity and can be subjected to torsional oscillations of a self-oscillation nature (wobbling), which have to be compensated with component(s) in one way or another. High clamping loads can arise in the said fork crowns (upper and lower fork crowns). The inner and outer tubes in the telescopic arrangement are often long and the lateral forces upon the tubes mean that these can be locked to one another in certain travel situations in which the locking can occur by way of the bushes.
With a view to overcoming the weaknesses of the telescopic arrangement, in vehicles/motor cycles of this kind, attempts have been made to replace the telescopic fork with various types of link systems. Reference is made, inter alia, to the magazine “Motorcyclist/January 1987”, pages 47-53, which shows a variety of resilient front wheel suspensions with link systems which are intended to replace the springing function produced with the telescopic fork, which link systems are disposed between wheel supporting member(s) and the chassis. Reference is also made to the so-called “Webb” fork, which was used on motor cycles during the period 1920-1940.
It is also conceivable to try to transfer wheel suspension principles from four-wheeled vehicles (cars) to the present context. There are however no acceptable working proposals in existence for such transfers.
DESCRIPTION OF THE INVENTION
TECHNICAL PROBLEM
There is a general need to be able to eliminate all the drawbacks attached to the use of various telescopic fork constructions. Thus, for example, a greater freedom of choice is sought with regard to the procurement of a desired spring geometry, which will be able to be realized, moreover, without the use of complex and expensive additional components. The risk of self-oscillations (wobbling) at certain vehicle speeds has to be able to be effectively eliminated by simple means. There is also a need to be able to reduce the clamping forces in the securements of the wheel-supporting member in the chassis, inter alia by means of the facility to arrange separate securement functions at a relatively low height above the ground surface and thereby avoid tightly spaced bearing points high up in connection with the handlebar. There is also a requirement to be able to eliminate the need to mutually separate springing elements and steering linkage, in which the steering linkage hitherto often had to be relatively weakly dimensioned on structural engineering grounds, inter alia with a risk of the said self-oscillation tendencies within certain of the speed ranges of the vehicle. The invention sets out to solve these problems, inter alia, by proposing bearing or link units which produce distinct positions and motion diagrams for the supporting member by exhibiting high rigidity in certain directions and by exhibiting compliance for torsion or twisting motions which arise in the bearing unit arrangement in the event of torsional steering motions of the supporting member.
In connection with the introduction of the said link unit functions, it is important to overcome the deficiencies which hitherto attach to known link unit arrangements. A major drawback with these is a substantially reduced contact sensation for the driver between the handlebar and the ground surface or roadway. The invention sets out to solve this problem also and proposes a front wheel suspension offering contact sensation characteristics between the handlebar and the roadway equivalent to those which obtain with telescopic arrangements.
The known link unit systems additionally have relatively complex structures for the springing and steering functions per se and/or for components proposed to form part of these functions. The invention sets out to solve this problem also.
In certain types of motor cycles, for example special-purpose motor cycles, cross-country motor cycles, etc., it is important to be able to propose symmetrical wheel suspensions which can allow large wheel deflections or wheel turns. The use of swivelled-out links which extend by the side of the wheel is therefore inadmissible, but rather the link arrangement must be able to be applied above the front wheel so that it is as low as possible above the ground plane. The invention solves this problem also.
According to the present invention, the spring geometry (or the motion geometry) shall be adjustable by the choice of lengths of the bearing units and/or of the link elements and/or of their reciprocal angles and/or angles in relation to a horizontal line, everything viewed in the longitudinal section of the motor cycle (or vehicle) in question in, for example, upright or standing position. The invention solves this problem also.
According to the present invention, bearing unit(s) forming part of the subject of the invention shall be able to be arranged with certain compliance for certain torsion or twisting motions. The invention solves this problem also and proposes measures for the structure and choice of material in the unit(s) concerned, which
Connolly Bove & Lodge & Hutz LLP
Lerner Avraham H.
Öhlins Racing AB
LandOfFree
Front wheel suspension for preferably a motorcycle does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Front wheel suspension for preferably a motorcycle, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Front wheel suspension for preferably a motorcycle will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2905079