NL2022479B1 - Bicycle - Google Patents

Abstract

Bicycle comprising a frame that holds a back wheel and a front wheel, wherein the frame comprises pedals connect— ed to a first sprocket wheel and wherein a second sprocket wheel is mounted on an axle of the back wheel, and a chain is 5 guided over the first and second sprocket wheels, wherein said bicycle is provided with auxiliary drive means, wherein said auxiliary drive means comprise a windable spring which is re— leasably connectable to the chain for selectively storing and regaining of drive energy.

Description

Bicycle The invention relates to a bicycle comprising a frame that holds a back wheel and a front wheel, wherein the frame comprises pedals connected to a first sprocket wheel and wherein a second sprocket wheel is mounted on an axle of the back wheel, and a chain is guided over the first and second sprocket wheels, wherein said bicycle is provided with auxil- iary drive means.

Such a bicycle is commonly known. For decades bicy- cles with auxiliary drive means are applied in practice, wherein the auxiliary drive means are embodied as a combustion engine. People of older age will be able to remember the so- called Solex, a French design with a pitiful combustion engine driving the front wheel. More sturdy and stabler designs of later date comprised a combustion engine close to the pedals.

In Dutch they were called brommers, which name reflected the sound produced by the engines in operation and which were at a certain time particularly used by nozems (rebels without a cause), also in the sixties of the previous century called brozems as a contamination of brommers and nozems.

Nowadays such conventional designs with combustion engines are intended to be faded out because of their rela- tively large negative impact on the environment, in particular the production of COZ and minute particles that are harmful for anyone breathing. As an increasingly popular alternative bicycles have appeared on the market wherein the auxiliary drive means is embodied as an electric motor powered by an onboard battery. The battery of course requires regular re- charging, and then is able to provide power to the electric motor to assist a cyclist, particularly when he or she is ex- periencing a strong head wind or when he or she is simply too lazy or weak to drive the bicycle by human power only.

A disadvantage of all the bicycles provided by known auxiliary drive means is that such auxiliary drive means re- quire external energy, and therewith these known bicycles still impose a burden to the environment.

It is an object of the invention to solve this prob- lem.

Accordingly a bicycle is proposed having the features of one or more of the appended claims.

Essentially the bicycle of the invention is provided with the feature that the auxiliary drive means comprise a windable spring which is releasably connectable to the chain for selectively storing and regaining of drive energy.

In this way a truly autonomous bicycle is made avail- able wherein no external energy is required to assist the cy- clist during hard cycling times, for instance when strong headwinds are present or when the cyclist is ascending a steep cycle track. When the cyclist before that situation occurs has arranged for a wound up spring, the energy that thus has been stored in the spring can be released to drive the chain and assist the cyclist.

Winding up of the spring can occur for instance when the cyclist is descending a cycle track, or when the cyclist experiences a (strong) back wind. Accordingly the amount of effort requested from the cyclist to wind up the spring can remain very limited, whilst the stored energy may assist the cyclist at harder cycling times, at which time it can simply be made available at the volition of the cyclist.

To make storing of energy in the windable spring pos- sible it is preferable that the windable spring is connected to a main gear that is contactable with the chain. In particu- lar it is desirable then that the main gear is directly con- tactable with the chain so as to avoid parts that may intro- duce energy losses.

On the other hand for releasing the energy stored in the windable spring it is appropriate that the main gear is contactable with the chain through a secondary gear which is arranged to be selectively placeable between the main gear and the chain. The secondary gear makes possible that the windable spring can unwind and drive the main gear in a direction oppo- site to the direction of the main gear when winding the spring, whilst the chain that drives the back wheel can always maintain its same direction.

The invention will hereinafter be further elucidated with reference to the drawing of some schematically depictedparts of a bicycle according to the invention that is not lim- iting as to the appended claims.

The drawing of a single figure shows features of the drive train of a bicycle. The construction of a bicycle as such is considered to be so widely spread known, that it is considered superfluous to show such a bicycle and explain it with reference to the drawing. Accordingly the drawing does not show the complete construction of a bicycle, but only the parts of the drivetrain that form the essence of the inven- tion.

The skilled person knows from day-to-day experience that a bicycle comprises a frame that holds a back wheel and a front wheel, wherein the frame comprises pedals connected to a first sprocket wheel and wherein a second sprocket wheel is mounted on an axle of the back wheel, and a chain is guided over the first and second sprocket wheels. The skilled person is further knowledgeable with the fact that it is known to provide such a bicycle with auxiliary drive means. The drawing shows how these auxiliary drive means according to the inven- tion are embodied.

The drawing shows schematically the back wheel 1, which is for clarity removed from its mounting position at reference 2, at which location a sprocket wheel that drives the back wheel 1 is present. Further, very schematically, ped- als 3 are shown which connect to another sprocket wheel at reference 4, and between said two sprocket wheels a drive chain 5 is guided.

According to the invention the auxiliary drive means comprise a windable spring 6 which is releasably connectable to the chain 5 for selectively storing and regaining of drive energy. Storing of energy may occur by the operation of a main gear 7 on to which the windable spring 6 is mounted. The main gear 7 is preferably in direct contact with the chain 5, to harvest energy and store it in the windable spring 6 which is connected to the main gear 7. In the embodiment as shown in the drawing the main gear 7 is not in direct contact with the chain 5 but through an intermediate drive rod 9, however this construction is not essential.

The drawing further shows that the main gear 7 may also be contacted with the chain 5 through an intermediate secondary gear 8 which is selectively placeable between the main gear 7 and the chain 5, so as to enable reversing rota- tion of the main gear 7 so that after winding up the windable spring 6 that is connected to the main gear 7, said windable spring 6 may unwind and release its energy to drive the chain

5.

Although the invention has been discussed in the foregoing with reference to an exemplary embodiment of the bi- cycle of the invention, the invention is not restricted to this particular embodiment which can be varied in many ways without departing from the invention. The discussed exemplary embodiment shall therefore not be used to construe the append- ed claims strictly in accordance therewith. On the contrary the embodiment is merely intended to explain the wording of the appended claims without intent to limit the claims to this exemplary embodiment. The scope of protection of the invention shall therefore be construed in accordance with the appended claims only, wherein a possible ambiguity in the wording of the claims shall be resolved using this exemplary embodiment. Aspects of the inventions are itemized in the follow- ing section.

1. Bicycle comprising a frame that holds a back wheel (1) and a front wheel, wherein the frame comprises pedals (3) con- nected to a first sprocket wheel (4) and wherein a second sprocket wheel is mounted on an axle of the back wheel {1}, and a chain (5) is guided over the first and second sprocket wheels, wherein said bicycle is provided with auxiliary drive means, characterized in that said auxilia- ry drive means comprise a windable spring (6) which is re- leasably connectable to the chain (5) for selectively storing and regaining of drive energy.

2. Bicycle according to claim 1, characterized in that the windable spring (6) is connected to a main gear (7) that is contactable with the chain (5).

3. Bicycle according to claim 1 or 2, characterized in that the main gear (7) is directly contactable with the chain (5).

4. Bicycle according to any one of claims 1 - 3, character- ized in that the main gear (7) is contactable with the chain (5) through a secondary gear (8) which is arranged to be selectively placeable between the main gear (7) and 5 the chain (5).

Claims (4)

CONCLUSIONS A bicycle comprising a frame with a rear wheel (1) and a front wheel, the frame comprising pedals (3) connected to a first sprocket (4) and a second sprocket mounted on an axle of the rear wheel ( 1), and a chain {5) is guided over the first and second sprockets, said bicycle being provided with auxiliary driving means, characterized in that said auxiliary driving means comprise a wind-up spring (6) which is detachably connectable to the chain ( 5) for selectively storing and recovering propulsion energy. Bicycle according to claim 1, characterized in that the wind-up spring (6) is connected to a main drive wheel (7) which is connectable to the chain (5). Bicycle according to claim 1 or 2, characterized in that the main drive wheel (7) can be brought into direct contact with the chain (5). A bicycle according to any one of claims 1 to 3, characterized in that the main drive wheel (7) is connectable to the chain (5) via a secondary drive wheel (8) which is arranged to be selectively placed between the main drive wheel (8). drive wheel (7) and chain (5).