Electrically assisted bicycle provided with suspensions

Abstract

The invention relates to an electrically assisted bicycle comprising a frame provided with a front suspension and a rear suspension, and a motor rigidly connected to the frame, arranged on the bottom bracket axle, the frame comprising a front triangle (2) articulated on a fork (1) bearing the front wheel (10), and a rear arm (3) bearing the rear wheel (30), characterised in that the rear arm (3) is mounted in a mono-pivot configuration on an anterior portion of the front triangle (2) and the rear suspension (32) is arranged between the rear arm (3) and a posterior portion of the front triangle (2), and in that the motor (4) is arranged in a cavity (40) of the rear arm (3), so that the distance (d) between the axis of the rear wheel and the bottom bracket axle is constant.

Description

[0001] ELECTRICALLY ASSISTED BICYCLE WITH SUSPENSIONS

[0002] TECHNICAL FIELD

[0003] The invention relates to an electrically assisted bicycle provided with suspensions.

[0004] STATE OF THE ART

[0005] The market for electrically assisted bicycles is growing significantly, allowing users to travel longer distances and / or on routes with significant gradients.

[0006] To increase user comfort, especially when riding on paths or roads in poor condition or paved areas, suspensions can be provided at the front and rear of the frame.

[0007] On existing bicycles, integrating suspension into the rear of the frame involves a complex structure, including links to connect the different parts of the frame.

[0008] Furthermore, it is necessary to integrate a system for adjusting the tension of the transmission element between the crankset and the rear wheel.

[0009] This structure is complex to maintain.

[0010] SUMMARY OF THE INVENTION

[0011] An aim of the invention is to design an electrically assisted bicycle in which the integration of a suspension is achieved by means of a simpler structure.

[0012] To this end, the invention proposes an electrically assisted bicycle comprising a frame provided with a front suspension and a rear suspension, and a motor secured to the frame, arranged on the axis of the crankset, the frame comprising a front triangle articulated on a fork carrying the front wheel, and a rear arm carrying the rear wheel, the front triangle comprising an oblique tube, a seat tube and a base connecting the oblique tube and the seat tube in the lower part of the front triangle so that the frame is open, characterized in that the rear arm is mounted in a single-pivot pivoting manner on a front part of the base and the rear suspension is arranged vertically between the rear arm and the seat tube, and in that the motor is arranged in a cavity of the rear arm, so that the distance between the axis of the rear wheel and the axis of the crankset is constant.

[0013] Thanks to this design, it is possible to eliminate the need for a tensioning system for the transmission element, which simplifies bicycle maintenance.

[0014] According to other advantageous but optional characteristics, considered alone or in combination:

[0015] - the bicycle comprises at least one rear wheel support mounted on the rear arm, said support being adjustable between a mounting position of a transmission element between the crankset and the rear wheel and a tension position of said transmission element, located at the rear of the front arm relative to the mounting position;

[0016] - the rear arm comprises a guide means, such as an oblong hole, and each support of the rear wheel is mounted on the rear arm by means of a screw engaging in said guide means,

[0017] - the bicycle is therefore devoid of a mechanical tensioning system for the transmission element;

[0018] - the transmission element between the crankset and the rear wheel is a belt;

[0019] - the rear arm is made by molding;

[0020] - the rear arm cavity is provided with at least one engine ventilation hole;

[0021] - the bicycle further comprises a luggage rack fixed exclusively to the front triangle, so that said luggage rack is suspended;

[0022] - the front triangle is made by molding;

[0023] - the front triangle includes a hollow oblique tube receiving a battery supplying the motor.

[0024] BRIEF DESCRIPTION OF THE FIGURES

[0025] Other characteristics and advantages will emerge from the detailed description which follows, with reference to the attached drawings, in which:

[0026] - figure 1 is a right view of a bicycle according to one embodiment;

[0027] - figure 2 is a left view of the bicycle of figure 1;

[0028] - figure 3 is a right-hand view of a bicycle according to an alternative embodiment;

[0029] - figure 4 is an exploded view of the connection between the front triangle and the rear arm;

[0030] - figure 5 is an exploded view of the connection between the rear suspension and the frame;

[0031] - Figure 6 is a sectional view of the connection between the rear suspension and the frame;

[0032] - Figure 7 is an exploded view of the motor housing in the rear arm;

[0033] - figure 8 is a right-hand view of the connection between the front triangle and the rear arm in the assembled position;

[0034] - Figure 9 is a left-hand view of the connection between the front triangle and the rear arm in the assembled position.

[0035] DETAILED DESCRIPTION OF EMBODIMENTS

[0036] In this text, the terms "front" and "rear", "anterior" and "posterior" refer to the direction in which the bicycle is rolling. The terms "right", "left", "horizontal", "upper", "lower" refer to the position of the bicycle when rolling on horizontal ground.

[0037] Figures 1 to 3 are general views of an electrically assisted bicycle provided with suspensions. The bicycle comprises a fork 1 supporting a front wheel 10 and a handlebar 11. The fork comprises a front suspension which is of a known type and will not be described in detail in this text.

[0038] The fork is hinged on a frame comprising a front triangle 2 and a rear arm 3.

[0039] The front triangle comprises a down tube 20, a seat tube 21 and a substantially horizontal base 22 connecting the down tube and the seat tube in the lower part of the triangle. The front triangle also comprises a head tube 12 articulated to the fork. Advantageously, the frame is open, that is to say that the front triangle does not have a top tube connecting the down tube and the seat tube. This allows the user to sit more easily on the saddle, since he does not have to step over a top tube.

[0040] Alternatively, the front triangle 2 includes a top tube (not shown) connecting the seat tube 21 and the down tube 20 or the head tube 12 to increase the rigidity of the frame.

[0041] The front triangle is hollow, which allows the battery to be housed there and the brake cables and the cables connecting the battery to the motor to be routed through it.

[0042] More specifically, the oblique tube 20 comprises an interior housing for the battery (not shown). For this purpose, the oblique tube may have an upper opening allowing the insertion or removal of the battery. Said opening is closed by a cover making it possible to protect the battery and to prevent the introduction of water or solid particles inside the oblique tube.

[0043] Advantageously, the front triangle is made from a single piece by molding, in particular by casting or injection, which is made possible by its simple structure. Production by casting or injection allows for simplicity of production and a reduction in costs. In addition, such a production technique makes it possible to obtain a single-piece frame, which is mechanically simpler and more solid.

[0044] The rear arm 3 comprises a housing 40 for the motor 4 and the crankset, the motor being in the axis of the crankset. The rear arm can be single (single-arm), formed of two half-arms in one piece extending on either side of the rear wheel, or, as in the figures, made up of two half-arms 3a, 3b assembled on either side of the rear wheel.

[0045] The front triangle 2 is pivotally mounted on the rear arm 3 around a horizontal axis 31. Said pivot axis is located in the lower part of the front triangle, typically at the junction between the oblique tube 21 and the base 22. This type of articulation is called “single-pivot”.

[0046] As illustrated in Figure 4, the front triangle comprises in its lower part a fixing lug comprising a central opening 201 and a through hole 200 which extends on either side of the opening 201. The rear arm comprises in its front part a fixing lug 313 adapted to engage in the opening 201 and provided with a through hole 314. The holes 200 and 314 are coaxial when the rear arm is assembled on the front triangle and receive an axle 310 mounted on bearings 311. The assembly is held by screws 312.

[0047] A shock absorber 32 is arranged between the front triangle 2 and the rear arm 3, behind the seat tube, to form the rear suspension of the bicycle. Said shock absorber may be of the pneumatic, hydraulic or hydro-pneumatic type. Preferably, the shock absorber is adjustable in order to allow adjustment of the suspension.

[0048] The shock absorber 32 is arranged in a substantially vertical direction, substantially in the axis of the seat tube. Thus, the damping takes place in the axis of the seat tube, which is more comfortable for the user because this is the axis on which his weight is applied.

[0049] As illustrated in Figure 5, the shock absorber comprises an upper end 320 secured to the seat tube 21 and a lower end 321 secured to each rear half-arm 3a, 3b. Said lower end is therefore arranged substantially at the end of the base 22 of the front triangle opposite the pivot axis 31. As can be seen better in Figure 6, each end 320, 321 of the shock absorber may comprise a through-hole arranged opposite a respective through-hole of the seat tube and the arms allowing the passage of a respective screw 322, 323 for fixing the ends of the shock absorber by means of rings 324.

[0050] Advantageously, the front arm (or the two half-arms) is made by molding, in particular by casting or injection. This manufacturing process makes it possible to form a housing precisely sized to receive the engine, which makes it possible to encapsulate any type of engine inside the frame.

[0051] Since the rear arm is hollow, heat generated by the engine can be evacuated through ventilation holes in the rear arm.

[0052] The motor 4 is fixed by screws in the housing 40 provided in the rear arm 3.

[0053] The rear arm also supports, in its rear part, a support 300 for the rear wheel. Said support 300 is in the form of a tab adapted to receive the hub of the rear wheel, and one or more tapped holes to receive a fixing screw 302.

[0054] Particularly advantageously, each fixing screw 302 passes through a respective oblong hole 301 of the rear arm. When the screw is not tightened, it is then possible to slide the support 300 along the oblong hole, between a front position allowing the mounting of a transmission element (chain or belt) between the crankset and the rear wheel, and a rear position allowing the mechanical tension in the transmission element to be adjusted. Once the required tension is reached, the screws 302 can be tightened in order to maintain the support 300 in the position of use of the bicycle. It is thus possible to dispense with a tensioner or any other additional system allowing the mechanical tension in the transmission element to be adjusted.

[0055] Naturally, any other guiding means than an oblong hole can be used, said guiding means making it possible to guide each screw 302 between the mounting position and the tension adjustment position, along a rectilinear, curvilinear or any other suitable shape path.

[0056] This design of the bicycle therefore allows in particular to use a belt without the use of a belt tensioner in the form of a spring-mounted tensioner or eccentric or any other system of this type which is a more reliable, silent and maintenance-free transmission element, and this, without requiring the addition of a tensioner.

[0057] The bicycle may include a luggage rack, preferably removable according to the user's needs. Particularly advantageously, as illustrated in Figure 3, said luggage rack is attached exclusively to the front triangle, more precisely to the seat tube. Thus, the luggage rack benefits from the suspension of the front triangle.

Claims

CLAIMS 1 . Electrically assisted bicycle comprising a frame provided with a front suspension and a rear suspension, and a motor integral with the frame, arranged on the crankset axis, the frame comprising a front triangle (2) articulated on a fork (1) carrying the front wheel (10), and a rear arm (3) carrying the rear wheel (30), the front triangle (2) comprising an oblique tube (20), a seat tube (21) and a base (22) connecting the oblique tube (20) and the seat tube (21) in the lower part of the front triangle (2) so that the frame is open, characterized in that the rear arm (3) is mounted in a single-pivot pivoting manner on a front part of the base (22) and the rear suspension (32) is arranged vertically between the rear arm (3) and the seat tube (21), and in that the motor (4) is arranged in a cavity (40) of the rear arm (3), so that the distance (d) between the rear wheel axle and the bottom bracket axle are constant.

2. Bicycle according to claim 1, comprising at least one rear wheel support (300) mounted on the rear arm (3), said support (300) being adjustable between a mounting position of a transmission element (33) between the crankset and the rear wheel and a tension position of said transmission element (33), located at the rear of the front arm relative to the mounting position.

3. Bicycle according to claim 2, wherein the rear arm (3) comprises a guide means, such as an oblong hole (301), and each support (300) of the rear wheel is mounted on the rear arm by means of a screw (302) engaging in said guide means.

4. Bicycle according to one of claims 2 to 3, without a system for mechanically tensioning the transmission element.

5. Bicycle according to one of claims 2 to 4, in which the transmission element (33) between the crankset and the rear wheel is a belt.

6. Bicycle according to one of claims 1 to 5, in which the rear arm (3) is produced by molding.

7. Bicycle according to one of claims 1 to 6, in which the cavity (40) of the rear arm (3) is provided with at least one motor ventilation orifice.

8. Bicycle according to one of claims 1 to 7, further comprising a luggage rack (5) fixed exclusively on the front triangle (2), so that said luggage rack is suspended.

9. Bicycle according to one of claims 1 to 8, in which the front triangle (2) is produced by molding.

10. A bicycle according to claim 9, wherein the hollow downtube (20) comprises a battery.

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