WO1995018740A1

WO1995018740A1 - Accelerator device for single ratio motorcycles

Info

Publication number: WO1995018740A1
Application number: PCT/IT1995/000002
Authority: WO
Inventors: Silvio Mercuri
Original assignee: Colica, Paolo; Patelli, Mauro
Priority date: 1994-01-04
Filing date: 1995-01-04
Publication date: 1995-07-13
Also published as: ITRM940001A0; EP0738221A1; AU1465395A; IT1271824B; ITRM940001A1

Abstract

Accelerator device for single ratio motorcycles comprising an accelerator knob (1), an axis (2) upon which said knob (1) is rotatably mounted, and a braking lever (3) connected to the brake wire, and mounted in the usual way, connecting and disconnecting means of said knob (1) with respect to the acceleration system (accelerator wheel (4)/wire), means (7) integral with said brake lever (3), suitable to act during the braking on said connecting and disconnecting means to release said knob (1) from said accelerator wheel (4)/wire, returning action means (5) suitable to maintain said connecting and disconnecting means in an engagement position of said knob (1) with the accelerator wheel (4)/wire, and bearing means (8, 6) between said means (7) integral with said brake lever (3) and said connecting and disconnecting means and between said connecting and disconnecting means and said returning action means (5).

Description

ACCELERATOR DEVICE FOR SINGLE RATIO MOTORCYCLES

The present invention refers to an accelerator device for single ratio motorcycles, suitable to automatically release the accelerator mechanism from the knob during the braking.

As it is known, in single ratio motorcycles, the main controls provided on the handlebar are the accelerator control (knob) and the brake actuating levers, respectively the front and back brake, unlike the plural ratio motorcycles and motorbicycles having on the handlebar the clutch actuating lever, usually provided on the left side, instead of the brake actuating lever. The presence of the clutch lever in the single ratio motorcycles is not necessary since they are provided with a centrifugal coupling automatic engagting and disengaging mechanism for the clutch, thus automatically realizing the engagement of the clutch only on the basis of the number of revolutions of the engine, in order to permit the "idle" mode with the minimum number of revolutions, i.e. during the stop with the engine on, and the "inserted ratio" mode when the number of revolutions increases. Although this kind of transmission is convenient and functional, it has the feature that when the engine number of revolutions is maintained higher than a determined value, the clutch still remains engaged, transmitting the motion to the wheels. This fact means that in order to obtain an optimum braking effect during the braking, it is contemporaneously necessary to release the accelerator knob, in order to allow to the engine accelerator mechanism to reduce the engine number of revolutions until the disconnection of the clutch centrifugal coupling is obtained.

Unfortunately, it often does not occur, particularly when the driver is performing a sudden braking or is in an anxiety status, since he aims to promptly actuate the brakes without releasing the accelerator knob, maintaining thus the clutch engaged and continuing to transmit the motive action to the wheel, this action remarkably reducing the braking effect with the following drawbacks: • extension of the stop distance;

• uncontrolled acceleration when releasing the brake, involving remarkable difficulties and dangers during the driving thus to compromise the safety of the driver. It is the object of the present invention that of providing an automatic release device of the accelerator mechanism from the accelerator knob during the braking, for single ratio motorcycles, said device being able to act contemporaneously with the braking (so as to allow to the driver to maintain the control of the driving in the best possible way), and being also reliable and sturdy, simple and cheap.

According to the present invention, in an accelerator device for single ratio motorcycles comprising an accelerator knob, an axis upon which said knob is rotatably mounted, and a braking lever connected to the brake wire, and mounted in the usual way, there are provided connecting and disconnecting means of said knob with respect to the acceleration system (accelerator wheel/wire), means integral with said brake lever, suitable to act during the braking on said connecting and disconnecting means to release said knob from said accelerator wheel/wire, returning action means suitable to maintain said connecting and disconnecting means in an engagement position of said knob with the accelerator wheel/wire, and bearing means between said means integral with said brake lever and said connecting and disconnecting means and between said connecting and disconnecting means and said returning action means.

The present invention will be better illustrated in the following by the specification of a preferred embodiment, provided with illustrative and not limitative purpose, making reference to the sole figure of the enclosed drawing showing a top schematic view of the device according to the invention.

Making reference to the figure, an accelerator knob is indicated by the reference 1 , rotatably mounted on the handlebar by a supporting axis 2; a lever 3 connected to the brake wire (not shown) in order to act on said brake when necessary, is provided on said supporting axis 2, either directly or on a support integral with said supporting axis. According to the present invention, a wheel acceleration mechanism 4, coaxially mounted on said supporting axis 2 so as to rotate and to make the connection between the knob and the accelerator wire (not shown), is longitudinally movable along said axis 2 between a tooth connection position with said knob 1 , where it integrally rotates with the same knob (position shown in the figure), and a disconnection position, i.e. disconnected with respect to the knob 1 (position displaced leftward with respect to the position shown in the figure). A returning coil spring 5 is suitable to maintain said acceleration mechanism 4 connected with said knob 1 ; a thrust bearing 6 is inserted between the spring 5 and the mechanism 4; a cam lever arm 7 made up of an appendix of said brake lever 3, makes contact with the mechanism 4 by a bearing 8. The reference 9 refers to a normal rubber cover.

During the regular working of the motorcycle, the knob 1 is integral with the wheel mechanism 4 by coupling, and thus each revolution of the knob corresponds to a displacement of the accelerator wire, the knob 1 acting as the regular knob for motorcycles. Furthermore, acting on the brake lever 3, the regular displacement of the brake wire is obtained, and thus the stop of the motorcycle.

The above arrangement of the device according to the invention is such that while making a braking, in a motion condition, and thus with the accelerator knob rotated with respect to the minimum number of revolutions position of the engine, the cam lever arm 7 thrusts upon the bearing 8 and consequently upon the wheel mechanism 4 in a removal direction with respect to the knob 1 , pressing the spring 5, until said wheel mechanism 4 is disconnected from said knob 1 , the wheel mechanism 4 being still free of rotating under the action of the returning spring (not shown) of the accelerator wire, thus causing the engine to reach the minimum number of revolutions and thus automatically disconnecting in an usual way the clutch and the transmission to the wheel; this action clearly allows to make an optimum braking. As soon as the brake lever 3 is released, the wheel mechanism

4 is thrusted, by the action of the spring 5, toward the accelerator knob 1. Said knob 1, manually brought in the starting position (minimum of the accelerator), restores the coupling with the accelerator system and thus the connection between the accelerator wire and the knob. Said connection is maintained until the driver acts again on the brake lever 3, disconnecting again the acceleration mechanism of the accelerator knob.

The present invention is not limited by the described embodiment, but includes every modification.

Claims

1. Accelerator device for single ratio motorcycles comprising: an accelerator knob, rotatably mounted on a supporting axis of the handlebar; a braking lever mounted on said axis; and coupling means of said knob to the accelerator wheel/wire, rotatably mounted on said supporting axis, said device being characterized in that said coupling means comprises connecting and disconnecting means of said knob with respect to the accelerator wheel/wire, the device further comprising means integral with said brake lever, suitable to act during the braking on said connecting and disconnecting means to release said knob from said accelerator wheel/wire, returning action means suitable to maintain said connecting and disconnecting means in an engagement position of said knob with the accelerator wheel/wire, and bearing means between said means integral with said brake lever and said connecting and disconnecting means and between said connecting and disconnecting means and said returning action means.

2. Device according to claim 1 , wherein said connection and disconnection means are made up of a wheel acceleration mechanism longitudinally movable along said supporting axis between a position where it is rotatably integral with said knob and a disconnection position with respect to said knob.

3. Device according to claim 2, wherein said means integral with said brake lever comprises a cam lever arm made up of an appendix of said brake lever, suitable to thrust, while braking, said acceleration mechanism in a removal and release direction with respect to said knob, against the action of said returning action means.

4. Device according to claim 1, wherein said returning action means are made up of a coil spring coaxially mounted on said supporting axis.

5. Device substantially as before described with reference to the sole figure of the enclosed drawing.