FR2670174A1 - SOLIDARITY INTERMEDIATE TRAYS FOR BICYCLES. - Google Patents

Abstract

Two integral chain wheels (1) are fixed to a support (2) having a ball bearing (3) tightly mounted therein. A stationary spindle (4) is inserted into the inner bore of the ball bearing to allow the support/chain wheel assembly to rotate freely thereabout, and is held in a closed stirrup (6). The assembly thereby obtained is fixed to the bicycle frame by the stirrup yoke (10), and to the pivot bolts (9) between the crankset and the rear driving wheel. The smaller of the integral chain wheels (1) is linked by a chain to the chain ring of the crankset, the larger one being linked to the gear cluster of the rear wheel. This device is designed particularly for bicycles.

Description

DESCRIPTION
The present invention relates to the use of an intermediate chainring device provided with toothed wheels, located between the bottom bracket and the rear drive wheel of a bicycle.

A traditional bicycle is propelled by the rear wheel equipped with one or more pinions of a different number of teeth, driven by chain by one, two or three trays of toothed rodes (Number of different teeth) integral with the pedals.

A traditional bicycle thanks to its different rear wheel gears and the device of one or more chainwheels, allows a number of different developments (called speeds), generally from 1 to 10 and even up to 21.

The device according to the invention allows less effort to be exerted on the crankset, with equal development (ratio between number of turns of pedals of the crankset and number of turns of the rear wheel), whatever the development chosen.

The device according to the invention comprises two integral toothed plates rotating freely around a fixed axis by means of a needle bearing housed by force in the two plates. This axis is itself fixed to the frame of the bicycle.

A reinforcement making guide and bearing for the other end of the fixed axis and connected to the upper part of the frame, ensures the good rigidity of the whole.

The accompanying drawings illustrate the invention.

 Figure t shows the block diagram.

FIG. 2 represents a view of a bicycle equipped with the device
lon invention.

 FIG. 3 represents a front view of the device according to the invention.

FIG. 4 represents a top view of the device according to the invention.

FIG. 5 represents a front view of the device according to the invention on a larger scale.

FIG. 6 represents a top view in section of the device according to the invention.

 FIG. 7 represents a front view of the device according to the invention.

(Variant for several chainrings with pedals.)
FIG. 8 represents a top view in section of the device according to
invention. (Variant for several chainrings with pedals.)
With reference to these drawings, the device comprises: Two trays of integral toothed wheels (t) a needle bearing (2), a fixed axle (3), a bracket for fixing to the frame (4), a locking washer (5), a frame reinforcement bearing guide (6), fixing screw (7),
The device according to the invention allows various solutions concerning the choice of the number of teeth of each of the two intermediate integral plates. CSci according to the type of bicycle and the destination of this bicycle: Classic, walk, road, semi competition, competition, mountain bike etc ...

As a nonlimiting example, the two integral intermediate plates will respectively have 18 and 36 teeth or 18 and 38 - 18 and 40 teeth or 20 and 72 or 20 and 40 teeth - 16 and 36 teeth - t6 and 38 teeth or t6 and 40 teeth.

The assembly of this device according to the invention is carried out according to figure (1): The smallest chainring connected by chain to one of the chainrings of the crankset, the largest chainring connected by chain to one of the sprockets of the driving rear wheel.

A classic device (Derailleur 'allows the gear ratio change on the rear wheel as on all bicycles.

 Optionally, another derailleur fixed on the frame allows the change of chainring on 11 set of chainrings. In this case, for better use, the stirrup (4) slides in a housing provided and secured to the frame in order to move all of the intermediate plates opposite the chosen plate of the pedal unit.

The device according to the invention allows, as on a conventional bicycle, a choice of developments (speeds) stepped according to the intended destination for this bicycle.

The device according to the invention allows a lesser effort to be exerted on the pedals of the order of 25% at start-up and this with equal development compared to the conventional system for driving the chainwheel pedals / rear wheel sprockets.

The device according to the invention makes it possible, owing to the significant gain in the force exerted on the pedals, to envisage much greater developments than those generally practiced in this field.

The device according to the invention allows the use of a development (ratio of number of rear wheel turns - number of pedal pedals turns) of up to 6 or even more.

The device according to the invention therefore allows an increase in speed which can be achieved very significantly.

The device according to the invention makes it possible with only 4 different pinions on the rear wheel (nonlimiting example) and a double chainring with the pedals (~ temple without limitation), ie 8 positions of different speeds, to actually obtain a display of 8 different development reports. .

Or more simply, with 6 or 7 pinions on the rear wheel and a single bottom bracket to really get a display of -6 or 7 different and available development reports.

A classic bicycle offering (Example title):
- 5 rear wheel sprockets and two bottom brackets, i.e. 10 speeds,
actually offers about 7 different usable speeds.

- 7 rear wheel sprockets and two bottom brackets, i.e. 14 speeds,
actually offers about 9 different usable speeds.

- 7 rear wheel sprockets and three bottom brackets, i.e. 21 speeds,
actually offers about 10 different usable speeds.

The device according to the invention, because of its simplicity, can be adapted and included on all new bicycles during its manufacture and also adapted on all conventional second-hand bicycles whatever they are, by adaptation of a transformation assembly comprising the assembly of the device according to the invention, adaptable by requiring a slight transformation of the rear frame on the right side.

The device according to the invention is intended for the bicycle.

it can find other fields of application with a view to increasing development (Report) or decreasing the effort with equal development in all industrial sectors using mechanisms for transmitting circular movements.

Claims (3)

 crankset and rear wheel drive.  around a fixed axis (3), axis fixed on the frame of a bicycle between the block  by the fact that it includes two integral toothed wheels rotating freely t) Intermediate chainring device (t) for bicycles, characterized 2) Device according to claim 1 characterized by two integral plates  number of toothed wheels (t) of a number of teeth on each wheel, depending on  the destination and intended use of the bicycle.  from the whole. (Fig.  the upper part of the frame thus serving as reinforcement and ensuring good rigidity  serves as a bearing guide for the other end of the fixed axis (3) and is fixed to  sation, the fixed axis is kept tight in a stirrup. This slides in a housing provided on the frame in order to bring the intermediate plates opposite the selected bottom bracket. (Fig. 7 and Figo 8) 6) Device according to the preceding claims, characterized in that a part (6)  In the case of more than one chainring chainring and for better use  rear wheel, so on the right side rear frame  is fixed on the bicycle frame between the bottom bracket and the axle of the  the inside diameter of the needle bearing (2) 5) Device according to the preceding claims, characterized in that the fixed axis! 3)  on which the intermediate plates (t) freely rotate is introduced into  needles (2) is fitted tightly in the center of the intermediate plates (t) 4) Device according to the preceding claims, characterized in that the fixed axis (3)  28 and 38 - 32 and 40 - 16 and 36 - t6 and 40 3) Device according to claims t and 2 characterized in that a bearing with  By way of non-limiting example: 18 and 36 - 18 and 38 - 20 and 32 - 20 and 40  3) 7) Device according to the preceding claims characterized in that the  smallest toothed wheel of the intermediate plate (t) is connected by chain 9 one  chainrings of the bottom bracket and the largest to one of the pinions of the  rear wheel.  of the pedal unit.  rear wheel, and possibly another derailleur used to change the chainring  fixed on the frame of the bicycle allows the change of pinion on the  8) Device according to previous claims characterized in that a derail