Purely for the purpose of simplifying the exposition of the present invention, in the course of the description reference will be made to a manual control lever which is associated with the handlebars of a motorcycle and which is to operate the pump of the braking system, and which is referred to hereinafter as the brake lever.

As is known, in motorcycles the brake lever is positioned at the right-hand end of the handlebars in the vicinity of the hand and steering grip with which the accelerator control is associated.

It is also known that the position of the brake lever, and more precisely the distance between the brake lever and the grip of the handlebars, is determined at the design stage on the basis of general anthropometric standards and that, therefore, it is very often not suitable for the actual needs of individual users, owing to the anthropometric differences between each of them and the standard. Therefore, a great need is felt for a

device which enables the distance between the brake lever and the hand grip of the handlebars to be adjusted precisely and reliably.

In order to satisfy the above-mentioned requirement, a proposal has been made for the use of adjustment devices which permit adjustment of the angular position of the brake lever relative to the hydraulic actuator and therefore adjustment of the distance with respect to the hand grip of the motorcycle handlebars.

Those known adjustment devices are interposed between a main lever, on which the user acts manually in order to brake, and a regulation lever, which transmits the command from the main lever to the hydraulic actuator.

During the approach movement of the main lever to the hand grip of the handlebars it is in fact the regulation lever associated operatively therewith which operates the braking system pump piston. The regulation lever remains '. ' constantly bearing on the thrust members of the hydraulic actuator while the main lever is connected thereto in an adjustable manner.

In some known types of device, the adjustable connection between the main lever and the regulation lever is obtained by means of a threaded pin. In order to be able to rotate the threaded pin easily, there is a knurled ring nut which projects between the main lever and the

regulation lever in such a manner that the user can rotate it and therefore adjust the relative distance.

Within the scope of those solutions, in order to permit precise and reliable adjustment, it is also known to use means for the stepped rotation of the threaded pin.

However, in other known types of device, the adjustable connection between the main lever and the regulation lever is obtained by means of a cam, the surface of which is not continuous but has some discrete positions of stable equilibrium. In this case too, in order to be able to rotate the cam, there is a knurled ring nut which projects between the main lever and the regulation lever in such a manner that the user can rotate it and therefore adjust the relative distance.

It should be pointed out that the above-mentioned adjustment devices have the disadvantage of necessarily having to be produced by assembling various mechanical components. In order to obtain those mechanical components it is necessary to carry out machining operations which may be long and complex and which may in their turn require the use of skilled labour. The production of those known adjustment devices is therefore relatively expensive.

It should then be noted that those known devices require that portions of the components remain exposed in order

that they can, be easily reached and activated. In addition'to the evident disadvantages of an aesthetic nature, there is also the disadvantage that dirt may very easily come into contact with the components of those devices during the normal operative life of the motorcycle.

The problem underlying the present invention is to provide and produce a position adjustment device for an operation lever of a hydraulic actuator, such as, for example, a brake lever of a motorcycle, which device has structural and functional features such as to satisfy the above-mentioned requirements. and, at the same time, to overcome the disadvantages mentioned with reference to the prior art.

The problem is solved by a position adjustment device for an operation lever of a hydraulic actuator in accordance with claim 1.

Further features and advantages of the adjustment device according to the invention will emerge from the following description of some of its preferred embodiments'which are given by way of non-limiting example with reference to the appended drawings in which: Figure 1 is an overall perspective view of a first embodiment of the adjustment device according to the si invention, applied to a brake lever of a motorcycle;

Figure 2 is a perspective view of the device of Figure 1 in which some parts have been sectioned for greater clarity; Figure 3 is a partly sectioned plan view of the device of Figure 1; Figure 3a is a view similar to that of Figure 3 with a different adjustment of the device; Figure 4 is an exploded view of the device of Figure 1; Figure 5 is an overall perspective view of a second embodiment of the adjustment device according to the invention; Figure 6 is an exploded view of the device of Figure 5; Figure 7 is a partly sectioned perspective view of a third embodiment of the adjustment device according to the invention.

With reference to the appended drawings, 1 indicates a support which, constrained on the handlebars (not shown) of the motorcycle in the vicinity of the hand grip (not shown), carries the entire unit comprising a brake lever 2 and a hydraulic actuator 3. The support 1 may be produced integrally with part of the hydraulic actuator, for example with a cylinder 33 and with an operating fluid reservoir 34. There may also be space on the support for a hole 10 for mounting a rear-view mirror.

For the sake of greater clarity it should be remembered

here that the brake'lever represented in the drawings is mounted on the right-hand end of the handlebars of a motorcycle. 30 indicates a brake pump and AA indicates a longitudinal axis of the cylinder 33 which, for the sake of simplicity, is illustrated only in the embodiment of Figure 3 but may similarly be found in the illustrated embodiments.

The axis AA of the cylinder 33 of the brake pump 30 is in this case almost parallel with the axis of the hand grip.

It will, however, be clear to the person skilled in the art that the invention may equally be applied to %, r hydraulic actuators having other configurations, in which, for example, the cylinder of the pump has an axis which is inclined or perpendicular relative to the axis of the hand grip.

The brake lever 2 comprises a main lever 20 which is in turn constituted by a grip portion 203 and by a bulge 204. Inside the bulge 204 is a cavity 206 which partially contains a regulation lever 21. In the preferred embodiments represented in the drawings, a first pin 201 of the main lever 20 and a second pin 211 of the regulation lever 21 coincide, constraining both of the levers on the support 1 at a single point.. Another possible choice is to pivot the two levers at different points, thus separating the two pins 201 and 211. It will

be clear to the person skilled in the art that it is also possible to pivot directly on the support 1 only one of the two levers, for example the regulation lever 21, and then to pivot the other lever, for example the main lever 20, on the regulation lever 21.

The main lever 20 defines a first bearing track, indicated 200, and the regulation lever 21 defines a second bearing track indicated 210. A spacing slider 22 is disposed on the first and second bearing tracks 200 and 210, which are not parallel with one another, and bears slidably on both of them. In the embodiment represented in Figures 1 to 4, the bearing track 210 is arranged substantially in a direction similar to that in which the grip portion 203 of the main lever 20 extends.

This arrangement has been found to be particularly convenient and; efficient but it is possible, if necessary, to arrange the bearing tracks 200 and 210 in different directions. For example, it is possible to arrange them in such a manner that one of them is almost parallel with the axis of the handlebars and it is likewise possible to arrange them in such a manner that one of them is perpendicular to that axis or is disposed at any other angle-which may be suitable for the particular circumstances.

In the embodiment represented in Figures 1 to 4, the

first bearing track 200 has a slight medium concavity facing the spacing'slider 22. A notched portion 205 is then arranged on the concavity for the purpose of defining positions of stable equilibrium for the spacing slider 22 which, in the region in which it bears on the track 200, is in turn shaped with a notched portion 225 which has at least one tooth and which complements the notched portion 205.

A push-button 220 is connected to the spacing slider 22.

In the represented in ~Figures 1 to 4, a stepped portion 216 on the regulation lever 21 and the resilient behaviour of the structure of the push-button 220 permit the definition, also in relation to the second bearing track 210, of positions of stable equilibrium for the spacing slider 22, which positions correspond to those defined by the notched portion 205.

It will be clear to the expert that the choice of forming one of the two bearing tracks with some, more or less marked, concavity, or with some convexity, like the choice of producing both of them flat or with any other profile, nevertheless comes within the scope of the inventive idea and depends only on the particular structural choices and/or requirements of gradualness in the adjustment of the position of the main lever 20.

It is also clear that the notched portion 205 of the

first bearing track 200 and the notched portion 225 of the spacing slider 22, like the stepped portion 216 and the resilient behaviour of the push-button 220, are only some of the possible means of defining positions of stable equilibrium for the spacing slider 22. If the particular circumstances suggest it, knurled portions, other types of interference or friction detents, with or without resilient return, or any other technical equivalent could be used instead of those means.

In the embodiments represented, 202 and 212 indicate seats which are formed in the body of the main lever 20 and of the regulation lever 21, respectively, and which are to accommodate a preloaded helical compression spring 221. The spring 221 abuts the levers in order to ensure contact between the first bearing track 200 and the slider 22 and between the latter and the second bearing track 210 in any state, including the resting state. If the expert considers it expedient, the helical spring 221 could be replaced by other resilient means capable of maintaining contact between the bearing tracks and the 'spacing slider; it would be possible to adopt, for example, a torsion spring placed around the first pin 201 of the main lever, or a preloaded traction spring placed between the bearing tracks 200 and 210, or any other technical equivalent.

The regulation lever 21 has a thrust portion 217 which acts in a manner known per se on a push rod 31 provided with hemispherical ends. The push rod 31 acts on a piston 32 of the pump of the hydraulic system. Arranged inside the pump is a spring which ensures the return of the piston 32 and, in the resting position, contact between the piston 32 and the push rod 31 and between the latter and the thrust portion 217 of the regulation lever 21.

However, it is possible for the return of the piston 32 and the contact between the components, which are clearly necessary for the correct functioning of the hydraulic actuator, to be obtained by other known solutions.

From an operative point of view, if the user wishes to adjust the position of the brake lever relative to the hand grip, he first pushes the main lever 20, moving it away from the hand grip (arrow B in Figure 3a) and then acts on the push-button 220,'pushing it in the direction in which the bearing track 210 extends (arrow C in Figure 3a). The spacing slider 22, which is connected to the push-button 220, thus passes through the various positions of stable equilibrium, forcing the main lever 20 to assume gradually different angular positions. When the position assumed by the lever relative to the hand grip is considered satisfactory, the adjusting operation is complete. In fact the synergy between the means for

defining the positions of stable equilibrium for the spacing slider 22 and the means for the resilient return of the main lever 20 enables the adjustment device to maintain indefinitely the position laid down by the user.

The various embodiments represented and described are combined in the same inventive idea and differ from one another only on the basis of secondary structural details, such as the form of the notched portion 205, the form of the spacing slider 22 or the connection of the push-button 220 to the spacing slider. For example, the embodiment represented in Figures 5 and 6 differs from the others because the push-button 22 therein is not in the plane defined by the first bearing track 200 and by the second bearing track 210.

As may be ; appreciated from the above description, the adjustment device according to the invention satisfies the above-mentioned requirements and at the same time avoids the disadvantages referred to in the introductory part of the description. The simplicity of the device in its preferred form illustrated in the drawings will be particularly appreciated. The reduction in the number of mechanical components translates directly into a reduction in the cost of producing the entire brake lever. Similarly, the simplicity of those mechanical components does not require that they undergo further

machining operations after being produced, for example, by pressing.

It will also be appreciated that the device forming the subject-matter of the invention is contained entirely within the cavity 206 formed-inside the main lever 20, so that nothing is exposed outside except the push-button 220 for operating the slider 22. Therefore, this solution on the one hand permits greater protection of the device from dirt and on the other hand permits substantial elegance and cleanness of form with extremely remarkable advantages in aesthetic terms.

For the purpose of satisfying contingent and specific requirements, a person skilled in the art could introduce numerous modifications, adaptations and substitutions of elements by other functionally equivalent elements to the above-described preferred embodiments of the adjustment device without departing from the scope of the following claims.