WO1994027859A1

WO1994027859A1 - Cycle handlebar

Info

Publication number: WO1994027859A1
Application number: PCT/AU1994/000294
Authority: WO
Inventors: Anthony Julian Barnes
Original assignee: Anthony Julian Barnes
Priority date: 1993-06-02
Filing date: 1994-06-02
Publication date: 1994-12-08

Abstract

A biased pedal bicycle handlebar system comprising a handlebar (16) with a forward section (66) and a rear section (67) slidably mounted on a headpiece of a bicycle frame. Two rods (25) extending between the two sections (66, 67) and a bearing means (33) held by clamps (37) and clamp bolts (42, 43) to connection piece (32), which in turn is held by the headpiece of the bicycle, allow movement of the handlebars (16) relative to the headpiece and connection bar (32). Bands (44) provide biasing of the handlebars (16) around a point along the rods (25).

Description

TITLE: CYCLE HANDLEBAR

TECHNICAL FIELD

This invention relates to a cycle handlebar and relates particularly to a mounting therefor by which the handlebar is attached to cycle frame. The invention is particularly related to a pedal bicycle handlebar, although it will be appreciated that the invention may be used with any cycle or other vehicle employing handlebars.

BACKGROUND ART

The growth in interest in off-road cycling has required many modifications to bicycles to cope with the variable terrain. Not only is off-road cycling a major part of competitive racing but is also a leisure activity. Therefore there is a need to make the rough riding able to be endured longer by the bicycle and the rider.

Motorbike technology, for making the ride smoother and less destructive of the vehicle, is generally not applicable to pedal bicycles. The major reason is the weight difference between the vehicle and the rider. The motorbike can weigh about 200 kilograms while a pedal bicycle can be as light as 10 kilograms. For a rider who weighs about 70 kilograms, then the motorbike is nearly three times the weight of the rider whereas the rider is more than seven times the weight of the pedal bicycle. Although similar problems occur in riding motorbikes as pedal bicycles including the force of the front wheel encountering rough terrain being transferred to the rider's arms the weight differential results in pedal bicycles requiring different technology to motorbike technology to overcome the problem. It is therefore necessary to have a means for pedal bicycles which reduces fatigue and strain in hands and arms of a rider when riding off-road caused by the jackhammer effect of the front wheel encountering bumps and hollows in its forward rolling motion. One known apparatus for minimizing the effects of rough or bumpy terrain on a bicycle rider, is a bicycle front wheel fork which includes a shock absorbing system. Such a system may consist of springs or a complex dampening system. A problem with a spring in a fork shock absorbing system, however, is that when the front wheel engages a bump or hole the handlebar rebounds upwards after the weight of the rider has compressed the springs downwards. This compression and rebound effect results in an unwanted relatively large movement of the handlebars. Another problem with this type of apparatus is that when encountering the bump or hole the weight of the rider is on the front forks and the seat can be easily bounced upwards upon the back wheel encountering a further bump. A complex dampening system may limit the movement of the handlebars but is generally very heavy and expensive.

Another known apparatus uses a sprung handlebar system in which the handlebars are pivotally mounted on the body of the cycle and a spring biases the handlebars to a particular pivotal position. This system has a problem of the handlebar falling away when the rider exerts pressure on them, due to the spring compressing, and then rebounding against the exerted pressure when the spring recoils. Considerable strain and movement results which must be absorbed by the arms of the rider. Also, the pivotal mounting tends to wear resulting in undesired lateral movement of the handlebar. Still further, the system does not permit easy adjustments of spring tension to account for different weight and strengths of different riders.

It is desirable to provide an improved cycle handlebar which overcomes or ameliorates one or more of the disadvantages of known systems.

It is also desirable to provide a cycle handlebar mounting which substantially maintains the handlebars in a constant position relative to the rider even when the front wheel is encountering rough, bumpy or undulating terrain. Further, it is desirable to provide a handlebar mounting which is relatively cheap and easy to manufacture, install and use.

DISCLOSURE OF THE INVENTION

According to one aspect of the invention there is provided a cycle handlebar comprising a handlebar portion, a connection means adapted to be connected to the frame of a cycle, a guide means mounted on the connection means and movably supporting said handlebar portion, and biasing means for biasing said handlebar portion to allow shock absorbing movement of said handlebar portion relative to said connection means.

In operation a large portion of the weight of the rider is on the handlebar. When the front wheel of the bicycle hits a bump the weight of the rider and the handlebar portion continues in the forward direction moving the handlebar portion away from the connection means which is connected to the frame, including the front forks, of the bicycle. The biasing means then rebounds the bicycle back towards the handlebar portion. Therefore not only does the rider feel less of the bump but the rebound by the bicycle minimizes the loss of speed of the bicycle.

Preferably said guide means includes a rod means and a bearing means for providing said movable support of said handlebar portion wherein said rod slidably engages with said bearing means and said handlebar portion is either connected to said rod means or said bearing means and the other is connected to the connection means.

Said handlebar portion can also include a forward handlebar section and a rearward handlebar section wherein said rod means extends between said forward and rearward sections.

Preferably said biasing means biases said bar portion around a preselected position on the rod means. In one convenient form the biasing means has one or more resilient bands extending between the bar portion and the connection means. Conveniently the guide means or the biasing means includes dampening means.

BRIEF DESCRIPTION OF THE DRAWINGS In order that the invention is more readily understood a particular embodiment thereof will now be described by way of example only with reference to the accompanying drawings:

Figure 1 is an underneath schematic view of a bicycle handlebar system in accordance with one embodiment of the invention.

Figure 2 is a side schematic elevation of the bicycle handlebar system of Figure 1 without the biasing means.

Figure 3 is an underneath side view of the bicycle handlebar system of Figure 2.

Figure 4 is a schematic part view of the bicycle handlebar system of Figure 1 without the biasing means.

Figure 5 is a schematic part underneath view of a bicycle handlebar system in accordance with a second embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

A bicycle typically has a frame, front forks, front wheel, headpiece and handlebar. The front wheel is connected to the frame by the forks and the handlebar is connected to the forks by the headpiece attached to a stem mounted in a bearing on the frame. There are many variations of headpieces and handlebars available which attach to the standard frame fitting thereby providing a multitude of possible handlebar configurations. Referring to the drawings, in the cycle handlebar mounting system 21 of the illustrated embodiment of the present invention the forwardly extending headpiece 15 is mounted to the frame 12 and a connection bar 32 carried by the headpiece 15 extends at right angles thereto. The connection bar 32 is mountable to a top part of a standard T- shaped headpiece 15 to which the handlebar is normally mounted. The mounting being such that the connection bar 32 can be rotated about its axis to any desired angle relative to the headpiece.

The handlebar 16 comprises a shaped bar which is symmetrical along a longitudinal central axis. Two pairs of handlebar mounting rings 23, 24 are attached to the handlebar 16 and slide rods 25 are fixed between the respective pairs of mounting rings 23, 24 such that the slide rods 25 are fixed at their ends, are parallel to each other, and extend between a forward 66 and rearward part 67 of the handlebar 16 on opposite sides of the longitudinal central axis of the handlebar 16. The slide rods 25 each pass through and are supported by linear bearings 33, which include an outer bearing casing 34 and an internal bearing race carrier 35 defining a guide for the slide rod 25. The bearing casings 34 of each linear bearing 33 are mounted to the connection bar 32, on opposite sides of the headpiece 15 such that the central axis of the handlebar 16 is aligned with the direction of forward extension of the headpiece 15. The mounting comprising U-shaped clamps 37 around the outer bearing casing 34 and closed by clamp bolts 42 and 43 which also engage with the connection bar 32.

The mounting system 21 provides a movable connection of the handlebar 16 relative to the headpiece 15 in that the handlebar 16 is able to slide in the direction of the axis of the slide rods 25. The magnitude of the movement is limited by the length of the bearing 33 and the slide rods 25. Generally in normal operation the mounting system 21 is set up so that the sliding movement of the handlebar 16 is in an approximately horizontal plane or at least within 30° of that plane.

The mounting system 21 further includes two or more resilient bands 44, such as nitrile rubber bands or springs, extending around the forward part 66 of the handlebar 16 near the mounting rings 24 to extended clamp bolts 42 protruding from clamp 37 holding the outer bearing casing 34. The resilient bands 44 bias the handlebar 16 rearwardly to a normal riding position. The handlebar 16 is able to move forward relative to the headpiece and away from the normal riding position with the slide rods 25 sliding through the linear bearing 33 against the resilient or elastic force resulting from extension of the resilient bands 44. A resilient cushion 46 such as a rubber 0- ring is positioned on the slide rods 25 so that when the handlebar 16 returns to the normal riding position under the action of the resilient bands 44, the impact of the mounting rings 24 against the bearing means 33 is cushioned or dampened.

The number of resilient bands 44 required will depend on the angle at which the handlebar 16 is mounted relative to the headpiece 15, the weight of the rider, and the type of terrain over which the bicycle is to be used. Thus, on normal, bitumen roads, a lesser number of bands may be required than if the handlebar mounting is to be used on a cross-country ride over rough ground.

One particular set-up of the cycle handlebar mounting system 21 comprises 6061 heat treated aluminium mounting rings 23, 24 mounted on a similar material handlebar 16. A hardened steel shaft 25 extends between the mounting rings 23, 24. Alternatively, a DU bushes incorporating TPFE (polytetrafluorethylene) and lead lining forms the bearing 33. A STAR compact linear bearing 33 is mounted on the steel shaft 25 and enclosed by an aluminum sleeve forming the outerbearing case 34 that is clamped to the connection bar 32 by clamp 37. The clamp 37 also comprises 6061 heat treated aluminium, the connection bar 32 is formed from 2011 aluminium and the biasing means can be EPDM O-rings.

With this particular set-up, on a set of 10cm rollers having a 2.5cm angle iron attached to the roller, and the cycle being pedalled to make the rollers rotate at about 1000 rpm, which is approximately fifty kilometres per hour, the system can cope with approximately 90% of the bumps. It will be appreciated that although the handlebar 16 of the illustrated embodiment is a single piece bar, the invention is applicable to two piece handlebars and to handlebars of other shapes and configurations.

Referring to Figure 5, a cycle handlebar mounting system 71 for a straight handlebar 76 is shown which corresponds closely to the cycle handlebar mounting system 21 of the first embodiment. In this system the straight handlebar 76 does not include a forward and rearward section similar to sections 66 and 67 of the first embodiment. However the essential operation is still the movement of the handlebar 76 relative to the connection means 32. The handlebar mounting rings 24 are attached to the handlebar 76 with the other handlebar mounting rings 23 connected to a joining bar 77 to ensure alignment of the slide rods 25. The length of the shaft therefore is not limited by the distance between parts of the handlebar but is of adequate length to allow suitable slide of the straight handlebar 76 away from the connection means 32 which is connected to the cycle frame.

The guides which guide the forward and rearward movement of the handlebar may be of any appropriate construction, the use of linear bearings as in the described embodiments being a preferred construction which minimizes wear and reduces any undesirable lateral movement of the handlebar relative to the headpiece.

It will also be appreciated that other biasing means may be used in place of resilient bands. Thus, springs, resilient blocks, hydraulic or pneumatic shock absorbing systems or the like may be incorporated in a handlebar mounting in accordance with the present invention. All such modifications which come within the scope of the invention shall be deemed to be within the scope of the above description.

Claims

CLAIMS:

1. A cycle handlebar comprising a handlebar portion, a connection means adapted to be connected to the frame of a cycle, a guide means mounted on the connection means and movably supporting said handlebar portion, and biasing means for biasing said handlebar portion to allow shock absorbing movement of said handlebar portion relative to said connection means.

2. A cycle handlebar according to claim 1, said guide means including a rod means and a bearing means for providing said movable support of said handlebar portion wherein said rod slidably engages with said bearing means and said handlebar portion is either connected to said rod means or to said bearing means and the other is connected to the connection means.

3. A cycle handlebar as defined in claim 2 wherein said handlebar portion includes a forward handlebar section and a rearward handlebar section , said rod means extending between said forward and rearward sections.

4. A cycle handlebar as defined in any one of the preceding claims wherein said biasing means biases said handlebar portion towards a preselected position on the rod means.

5. A cycle handlebar as defined in claim 4 wherein the biasing means has one or more resilient bands, extending between the bar portion and the connection means or said guide means.

6. A cycle handlebar as defined in any one of claims 1 to 3 wherein the guide means or biasing means includes dampening means.