AU2005200639A1 - A device for propelling a bicycle or tricycle by levers - Google Patents

Description

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION STANDARD PATENT A DEVICE FOR PROPELLING A BICYCLE OR TRICYCLE BY

LEVERS

The following statement is a full description of this invention, including the best method of performing it known to me.

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c A DEVICE FOR PROPELLING A BICYCLE OR TRICYCLE BY LEVERS oSpecifications for Patent Application Robert Duff2005 1) The said device provides a means for converting physical human effort into vehicular propulsion for bicycles or tricycles by means of levers.

O 2) Bicycles or tricycles are generally classified into 2 main types; either 'recumbent' or M 'upright'. Almost all of these vehicles impel a chain-wheel, in the case of bicycleo chain driven vehicles, or something similar, in the case of shaft driven vehicles, o through the rotary motion of human feet activating pedals, attached to cranks, fixed to an axle set within a bicycle or tricycle frame. The primary problem with this o arrangement is that the human body is not adapted to producing a rotary motion of O this type.

3) The said device is designed to utilize the biomechanics of the human body in a more natural way thereby making the conversion of human physical effort into propulsive power more efficient, more comfortable and more effective. It is intended particularly to alleviate the common problems of knee strain, back fatigue, neck aggravation and general discomfort often associated with riding the common 'upright' conventional bicycles and tricycles and avoid the problems of poor visibility both as subject and as object associated with recumbent cycles.

4) The said device for facilitating human-powered bicycle or tricycle propulsion consists of a pair of second-class levers*, disposed opposite each other on a bicycle or tricycle frame, said levers connecting to a pair of attachments on a bicycle or tricycle frame at one pair of ends forming the fulcrums, the opposite ends of the levers supporting footpads or foot-pedals which provide the sites for the application of the effort by way of human feet and, at mid-points, connecting rods attach the levers to the ends of a pair of cranks disposed opposite each other upon a common axle positioned above the levers and remote from the road-wheel axles, said axle in turn driving a chain-wheel or similar which invested with a positive rotational bias then transfers the torque that is exploited to propel the bicycle or tricycle, ie the work produced.

*Note for people unfamiliar with the classification of levers: occurring along a lever's length are 3 relevant elements for classification; the fulcrum, the effort or power applied and, the load or work produced. These 3 elements can occur in any sequence and levers are classified according to that sequence. The sequence is characterised by which element occupies the middle place in first-class levers the fulcrum is in the middle (eg's, see-saw and crowbar), in second-class levers the load is in the middle (eg's, this device and the human ankle when raising up to tip-toes) and in third-class levers the effort is in the middle (eg's, treadle looms and spinning wheels).

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In the Drawings: oFIG. 1. Embodiment 1: (Preferred Embodiment). Note: side view only supplied as there are no features relevant to this patent specification disclosed in 'top', crosssectional or 'end' views that are not disclosed and are not better disclosed in the side view.

1) Attachment to bicycle or tricycle frame relatively stationary element a facility N built into the bicycle or tricycle frame allowing the lever to be attached to it it may be as simple as a drill-hole.

o 2) Fulcrum (bearing required) not an actual structure but a function facilitated by a c bearing between the frame and the lever allowing the lever to move in relation to the frame with minimal friction.

3) Lever a rod, bar or tube extending from the fulcrum to the end of the footpad/pedal.

4) Footpad/pedal a pad or pedal at the opposite end of the lever to the fulcrum facilitating actuation by human feet.

Mid-Lever Pivot Connecting rod/Lever attachment (bearing required) a pivot allowing the free movement of the connecting rod through its range at the point where it is attached to the lever.

6) Connecting rod a rod, bar or tube connecting the lever to the crank.

7) Connecting rod/Crank Attachment (bearing required) pivot allowing 360 degree rotation of crank attachment relative to connecting rod attachment.

8) Crank a rod, bar or tube connecting the end of the connecting rod to the axle.

9) Axle conventional axle remote from the road-wheel axles allowing a 360 degree rotation of cranks relative to frame.

Chain-wheel or Similar a wheel attached to axle providing the motion exploited (by conventional bicycle-chain or other means) to propel the bicycle or tricycle.

11) Axle Housing attachment to bicycle or tricycle frame (bearing required) conventional axle housing fixed to bicycle or tricycle frame, sitting above the levers and stationary relative to the device in motion.

The axle housing( 1) is raised allowing the cranks(8) to be driven by connecting rods(6) attached to levers(3) rather than by the feet directly. This facilitates the efficiency of allowing the rider to operate the vehicle from a truly upright and natural standing-type position. It also allows the frame design to be greatly simplified as in this embodiment where it is reduced to a single down-tube merging with the rear forks. ('Front' and 'forward' refer to the front of the bicycle 'Rear' and 'backward' refer to the rear of the bicycle.) The attachment to the frame(l) is at the extreme rear end of the lever(3), below the rear forks and in front of the rear axle.

The fulcrum(2) is at the extreme rear end of the lever.

The lever(3) extends forward almost as far as the back of the front wheel.

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The footpad/pedal(4) attaches to the front end of the lever.

The connecting rod(5) attaches to the point on the lever at the lever/connecting rod attachment point(6).

The lever/connecting rod attachment point is determined by a line extending downwards and backwards at an angle from the vertical through the centre of the axle to the lever when the lever is in the up position (it is this angular offset which produces a position O past top-dead-centre when the lever is at the uppermost limit of its range that sets up the M rotational bias).

o The connecting rod(6) is attached to the end of the crank(8) away from the axle(9) with a bearing allowing a 360 degree rotation at the connecting rod/crank attachment(7).

oThe crank(8) connects the end of the connecting rod(6)to the axle(9) which drives a o chain-wheel(10) which impels a conventional bicycle chain to a conventional hub to drive the rear road-wheel.

Because the two cranks are set opposite each other on the axle as one lever goes down the other comes up. The rider transfers their weight onto the lever in the up position and depresses the lever on that side meanwhile the lever on the opposite side is raised the rider then transfers their weight to the opposite foot depressing that lever and so, with an alternating depression of the footpads, the connecting rods and cranks produce rotary motion at the axle.

FIG.2. Embodiment 2. Saddleless [Scooter] Variant 1. Front-to-Back Reversal (Centerlines drawing provided for illustrative purposes only).

This type of variant could have a marked tendency to 'tip-up' and may be popular for trick-riding.

FIG. 3. Embodiment 3. Modified Conventional Bicycle Frame (Centerlines drawing provided for illustrative puposes only).

This embodiment represents the traditional 'diamond' frame (double triangle) format which can still be employed although the axle housing must sit much higher in the frame than in a conventional bicycle to accommodate the said device. Otherwise details and functioning substantially similar as for Embodiment 1.

FIG. 4. Embodiment 4. Saddleless [Scooter] Variant 2. (Centerlines drawing supplied for illustration purposes only).

This embodiment simply involves a frame design substantially similar to embodiment 1 except that it does not include a facility to accommodate a saddle. It derives logically from the fact that as the truly upright position facilitated by the said device is a comfortable natural position it significantly reduces the need for the rider to sit. The facility for the rider to sit may in some, if not all, cases be dispensed with entirely, that is, it may be used like a scooter with the rider remaining upright the whole time.

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C General Discussion of Modifications: This said device can be applied to bicycles or tricycles. It can be reversed front-to-back _so that the fulcrum is toward the front of the bike and the feet at the rear. It can be used to drive a differential rather than a chain-wheel or similar this may facilitate a greater difference in drive ratios and so facilitate the use of smaller wheels for compact or N collapsible versions. The single down-tube design is particularly suited to being made so it can 'pull-apart' or 'hinge' for storage or transport. It can be made into a saddleless O 'bicycle' ie a type of scooter.

0 C, General Discussion of Advantages: O The particular embodiments shown allow the rider to maintain an almost entirely upright O position.

The action of the human body in providing the propulsion through the said device closely matches the types of movements required to walk up hills and so is more natural to the human body than the rotary motion required by conventional bicycles. This changes the character of the basic bio-mechanical effort required to propel the bicycle or tricycle.

Once the rider has stepped up onto the footpad in 'the up position' the rider can simply allow their weight to depress the lever rather than rely on the active muscular extension of the knee to depress the pedal/footpad.

The said device requires the rider to apply pressure through their knees when their knees are flexed at a much reduced angle compared to that of conventional bicycles and so avoids the problem commonly associated with bicycle riding, particularly in the early stages, of knee strain.

The more truly upright position facilitates the rider maintaining the natural lower back curve while riding and so avoids a posture that causes a great deal of back fatigue.

The upright position also allows the neck to maintain a more natural position than the predominantly hyper-flexed position required in normal cycling this avoids the unnatural usage that triggers many types of neck problems.

The more upright position also facilitates the function of turning the head that makes it much easier to fulfil common requirements like checking the traffic behind the rider.

The more upright position also raises the rider's height and therefore eye-line that in turn aids visibility both as subject and as object.

The removal of the front to back displacement of the feet allows the rider to be positioned such that the angle between' the push of the feet' and 'the pull of the arms' can be greatly reduced and so greatly increase the effectiveness of upper-body effort in aiding the production of torque.

The embodiments 1 3 shown herein have an advantage over many other proposed bicycle and tricycle propulsion systems in that despite the differences of the said device from conventional cycles they still otherwise function substantially as conventional cycles do, even to the point of accommodating conventional derailleur gearing systems.