Patent Description:
The present invention also relates to a saddle vehicle, especially a motorcycle with two or more wheels, equipped with this gear shift.

As it is well known, a gear shift of a saddle vehicle allows changing the gear ratio by engaging various gears.

A gear shift usually comprises a shift lever controlling a selecting element through a ratchet gear. The selecting element is star-shaped and defines number and sequence of the gears.

In a saddle vehicle, gears are usually arranged so that the first gear is engaged by pushing the shift lever downwards, i.e. towards the ground. The subsequent gears, i.e. from the second and above, are engaged by moving the shift lever reversely, i.e. upwards.

In motorbike racings, motor vehicles are usually equipped with the so-called "reverse shift", wherein gears work in the reverse order, i.e. the first gear is engaged upwards, and the subsequent gears are engaged downwards.

Both in road and race shifts, the neutral gear is between the first gear and the second gear.

Therefore, when changing up gears, switching from the first gear to the second gear, the neutral gear could be engaged by accident.

This is especially undesired in performance motorbikes, i.e. motorbikes used for races. In fact, in general, at high speeds the undesired engaging of the neutral gear while changing gears could result in motorbike unbalancing, especially when entering a turn or driving along it.

A device for preventing engagement of the neutral gear according to the preamble of claim <NUM> is disclosed in <CIT>. This known device is particularly complex.

A need therefore exists, to solve the drawbacks and the limits of the prior art described above.

The object of the invention is to provide a gear shift of a saddle vehicle, which allows to avoid accidental and undesired engagement of the neutral gear and which is simpler and more reliable than the prior art shifts.

A further object of the invention is to provide a saddle vehicle comprising this gear shift and achieving the same results.

This need is met through the gear shift of claim <NUM> and the saddle vehicle of claim <NUM>.

In particular, the gear shift comprises a shift lever, a selecting element actuated through the shift lever, and a selector drum connected to the selecting element and adapted to engage gears.

The gear shift further comprises a block device functionally connected to the selector drum and configured so as to be switched between:.

Control means of the block device are also provided, remotely actuated by a rider, for example a control on the handlebar; when actuated, the control means define a third configuration, wherein the block device is disabled in order to allow engaging the neutral gear from the first gear in the second change direction.

In a preferred embodiment, the selecting element is so configured as to provide for a changing up of gears starting from the neutral gear N to the gear N+<NUM> above by actuating the shift lever in a single first change direction Up, and for a changing down of gears starting from the gear N+<NUM> above to the neutral gear N in a single second change direction Dwn opposite to the first change direction.

According to the present invention, through the block device and the control means, the gear shift can block the neutral gear when the vehicle is moving, i.e. once the rider has engaged the first gear. In this way, during the subsequent changing down of the gears, the block device inhibits the engaging of the neutral gear creating an abutment contrasting the rotation of the selector drum, as described in detail below. In other words, it defines a stop for the drum rotation; therefore, even by acting on the shift lever, this latter is blocked.

Moreover, the block device allows engaging autonomously the first gear from the neutral gear. The rider, with the vehicle still and the neutral gear engaged, can therefore normally control the shift lever to engage the first gear. Once the gear has been engaged, the block device automatically stops, inhibiting the neutral gear from being engaged again.

In order to engage again the neutral gear from the condition described right above, the rider shall act on the control means disabling the block device. Then, the rider can act on the shift lever and engage the neutral gear again. Once the control means have been released, the initial position of the block device in the neutral gear is configured again.

In particular, the block device comprises a stop element mounted integral with the selector drum and a block element co-acting with the stop element. The block element is adapted to switch from the first configuration, wherein the block element is fastened to the stop element allowing the rotation in the first change direction to engage the first gear from the neutral gear. In the second configuration, the block element is enabled and contrasts the stop element in engaging again the neutral gear from the first gear in the second change direction. Moreover, in the third configuration the block element is spaced from the stop element by the control means, to engage again the neutral gear from the first gear.

According to what described above, the stop element is a bushing comprising a tooth-shaped portion. The bushing is inserted on the shaft of the selector drum and has a radially projecting protuberance defining the tooth-shaped portion.

In particular, the block element is mounted rotatable around a rotation axis and comprises a first elastic element so as to take:.

Therefore, the block element is kept in contact with the stop element through the elastic element, or return element.

In the third configuration, the block element is spaced from the tooth-shaped portion through control means contrasting the elastic return force, allowing the selector drum to rotate in the second change direction to engage again the neutral gear from the first gear and to return to the first configuration.

In particular, the control means comprise an actuating element, controlled by a rider, and connecting means between the actuating element and the block element.

In an embodiment, the actuating element is a lever controlling the pull of a cable, directly or indirectly connected to the block element. In particular, the lever is provided on the handlebar of the saddle vehicle.

Alternatively, a button can be provided transmitting an actuation signal to an actuator controlling the block element.

In a preferred embodiment, a control element is provided, actuated through the connecting means and connected to the block element. In this way, the block element is indirectly controlled through the control element. The control element is so configured as to move the block element between the second configuration, where it is enabled on the stop element, and the third configuration, where it is spaced from the stop element to return to the first configuration.

In a preferred embodiment, the control element is rotatably connected to the block element coaxially with the rotation axis of the block element. The first elastic element connects the control element and the block element, and is so arranged as to generate an elastic force pushing the block element against the stop element, keeping it in position.

In particular, the control element comprises an abutment portion, to which the block element is fastened through the first elastic element. The abutment portion is adapted to draw the block element to the third configuration when the control means are actuated.

The control element comprises a second elastic element, in particular a torsional spring adapted to bring again the control element into position. The block element is brought again into position through the first elastic element.

Further characteristics and advantages of the invention will be more apparent from the description below of some preferred non-limiting embodiments, wherein:.

In the various embodiments described below, the same elements, or parts of elements, are indicated with the same reference numbers.

With reference to <FIG> and <FIG>, a gear shift <NUM> is shown of a saddle vehicle, here below referred to as motorbike, M. The gear shift <NUM> comprises a shift lever <NUM> controlling the rotation of a selecting element <NUM>.

In particular, a ratchet gear <NUM> is provided, controlled through the shift lever <NUM>. The selecting element <NUM> is controlled through the ratchet gear <NUM> and allows rotation by angular sectors in order to engage gears.

As shown in <FIG>, the shift lever <NUM> controls the ratchet gear <NUM> through a shaft <NUM>.

The selecting element <NUM> is keyed onto a selector drum, or desmodromic drum, <NUM>. As well known, the rotation of the selecting element <NUM> corresponds to a rotation of the desmodromic drum <NUM>, that, in turn, causes the shifting of forks (not shown) that are controlled by the tracks <NUM> provided on the desmodromic drum <NUM> and that combine the gearset differently so as to engage the corresponding gear.

The selecting element <NUM> is star-shaped with a plurality of hollows <NUM> interrupted by a plurality of crests <NUM> corresponding to a respective gear, i.e. first gear I, second gear II, third gear III, fourth gear IV, fifth gear V and sixth gear VI, as well as a neutral gear N as better shown in <FIG>. Obviously, the number of gears changes based on the type of motorbike.

The angular sector of each gear is defined by a respective hollow <NUM> in the selecting element <NUM>. Changing a gear consists therefore in overcoming a crest <NUM> up to the following hollow.

The gear shift <NUM> provides for sequentially engaging gears, through the shift lever <NUM>, with only one change direction Up starting from a neutral gear N. In particular, it provides for changing up gears from the neutral gear N by moving the shift lever <NUM> always upwards, i.e. with a movement Up. Vice versa, it provides for changing down gears by moving the shift lever <NUM> always downwards, i.e. with a movement Dwn. The neutral gear N is provided in the first angular sector of the selecting element <NUM> and defines, therefore, a starting position.

The gear shift further comprises a block device <NUM> functionally connected to the selector drum <NUM> (<FIG>). The block device <NUM> is configured so as to be switched between a first configuration, wherein it allows engaging a first gear I from a neutral gear N in a first change direction Up (<FIG>), and a second configuration, wherein it inhibits the subsequent engagement of the neutral gear N from the first gear I in a second change direction Dwn (<FIG> or <FIG>).

In other words, the block device <NUM> allows engaging the first gear I from a neutral gear N and, once the first gear has been engaged, i.e. once the motorbike is moving it inhibits engaging the neutral gear N during the vehicle motion.

Control means <NUM> of block device <NUM> are also provided, remotely actuated by the rider G for instance through a control <NUM> on the handlebar <NUM>, in particular at the side of the clutch lever <NUM> (<FIG>). When the control means are actuated, the block device <NUM> takes a third configuration (<FIG> and <FIG>), wherein the block device <NUM> is disabled in order to allow engaging again the neutral gear N from the first gear I in the second change direction Dwn.

From a constructive viewpoint, the block device <NUM> is mounted on a support plate <NUM> keyed on the desmodromic drum <NUM>. On the same support plate there is also provided the shift lever <NUM>, mounted in a seat <NUM>' and fastened through fastening screws <NUM> screwed in the holes <NUM>'. The shaft <NUM> extends from the seat <NUM> and is connected to the ratchet gear <NUM>.

In particular, the block device <NUM> comprises a stop element <NUM>,<NUM>', mounted integral with the selector drum <NUM>, and a block element <NUM>, co-acting with the stop element <NUM>,<NUM>'.

The stop element is a bushing <NUM> comprising a tooth-shaped portion <NUM>'. The bushing <NUM> is inserted on the shaft of the selector drum <NUM>.

The block element <NUM> is adapted to switch in the first configuration (<FIG>), in which the block element <NUM> is fastened to the stop element <NUM>,<NUM>' allowing rotation in the first change direction for engaging the first gear I from the neutral gear N. Conversely, in the second configuration the block element <NUM> is enabled and contrasts the stop element <NUM>,<NUM>' inhibiting the engagement of the neutral gear N from the first gear I in the second change direction Dwn (<FIG> and <FIG>). Furthermore, in the third configuration (<FIG>), by means of the control means <NUM> the block element <NUM> is spaced from the stop element <NUM>, <NUM>' allowing to engage again the neutral gear N from the first gear I.

In particular, the block element <NUM> is rotatably connected around a rotation axis X-X thereof, and is advantageously mounted on the support plate <NUM>. The block element <NUM> comprises a first elastic element <NUM>. The first elastic element <NUM> allows abutting the block element <NUM> against the stop element <NUM>,<NUM>'.

In this way, the block element <NUM> can take three different configurations.

In a first configuration, corresponding to the neutral gear N (<FIG>), the block element <NUM> is fastened to the tooth-shaped portion <NUM>' of the stop element <NUM>, i.e. there is a corner contact with the tooth-shaped portion <NUM>'. This configuration allows the selector drum to rotate in the first change direction Up when the first gear I is engaged.

In more detail, the contact is, in this case, a friction corner contact. In fact, in this position the rider G, moving the shift lever <NUM> upwards for engaging the first gear I, controls the rotation of the selecting element <NUM> by a given angular sector. The rotation of the desmodromic drum <NUM> causes the rotation of the tooth-shaped portion <NUM>', that slides for a given segment on the block element <NUM> and leaves the corner contact position to achieve the first gear I.

Once the first gear I has been engaged, the block element <NUM>, pushed by the first elastic element <NUM>, moves farther up to touch the surface of the bushing <NUM> (<FIG>). In fact, the elastic element acts on the block element <NUM> allowing it to touch permanently the stop element <NUM>,<NUM>'.

The engagement of the first gear I defines an enabled configuration A of the block element <NUM> on the stop element <NUM>,<NUM>'. In this way, the block device <NUM> is enabled whenever the first gear I is engaged from the neutral gear N through the first elastic element <NUM> that triggers the block element <NUM> and makes it rotate up to abut again against the surface of the bushing <NUM> of the stop element <NUM>'.

Therefore, in the enabled configuration A, when the first gear I is engaged, the block element <NUM> laterally touches the tooth-shaped portion <NUM>' and consequently prevents the neutral gear N from being engaged again and thus the desmodromic drum <NUM> from rotating starting from the first gear I in the second change direction Dwn.

In this position, the rider G can engage again the neutral gear N only by releasing the block element <NUM>, as explained below.

The enabled block element <NUM> allows the rider regularly to engage all gears, but it inhibits the engagement of the neutral gear when changing down.

In fact, starting from the first gear I in the first change direction Up the tooth-shaped portion <NUM>' relatively rotates (<FIG>) up to achieve the position of sixth gear, where it touches the block element <NUM> at the opposite side. In the opposite change direction Dwn, the tooth-shaped portion <NUM>' rotates again towards the block element up to be fastened thereto in the position of first gear I.

In order to engage the neutral gear N again, the rider shall thus disable the block element <NUM> through the control means <NUM>.

In particular, the control means comprise the above-mentioned actuating element <NUM>, in particular a lever controlled by the rider G and provided on the handlebar <NUM> of the saddle vehicle (<FIG>).

Alternatively, even if not shown in the figures, a button can be provided transmitting an actuation signal to an actuator controlling the block element <NUM>.

The lever <NUM> is connected to the block element <NUM> through a cable <NUM>. The traction T of the cable <NUM> causes the rotation of the block element <NUM> and the disabling D thereof in order to engage the neutral gear N again.

In a preferred embodiment, the block element <NUM> is associated with a control element <NUM>, as better shown in <FIG>.

The control element <NUM> is rotatably connected to the block element <NUM> coaxially with the rotation axis X-X on the support plate <NUM> (<FIG>).

Both the block element <NUM> and the control element <NUM> are mounted on a shaft <NUM> defining the axis X-X (<FIG>). The control element <NUM> is mounted overlapping the block element <NUM>. A second elastic element <NUM>, in particular a torsional spring <NUM>, is provided on the shaft <NUM>. The spring is rotatably blocked around a portion <NUM>' fastened to the support plate <NUM> through a pin <NUM>'.

The block element <NUM> comprises, at a side, a first hook-shaped portion <NUM>'. The control element <NUM> comprises, at the opposite side, a second hook-shaped portion <NUM>'. The spring <NUM>, constituting the first elastic member, is provided between the two hook- shaped portions <NUM>' and <NUM>'.

The first elastic element <NUM> therefore connects the control element <NUM> and the block element <NUM>, so as to generate an elastic force pushing the block element <NUM> against the stop element <NUM>, keeping it in position.

The control element <NUM> comprises a seat <NUM>" where a stop <NUM>' is provided for the connection with the traction cable <NUM> (<FIG>).

In particular, the control element <NUM> comprises an abutment portion <NUM>', to which the block element <NUM> is fastened. The abutment portion <NUM>' is adapted to draw the block element <NUM> when the traction cable <NUM> is actuated through the lever <NUM>. The traction of the cable overcomes the elastic force of the spring <NUM> and relatively rotates the control element <NUM> that draws, through the abutment <NUM>', the block element <NUM>.

In this phase, the third configuration is provided, wherein the block element <NUM> is spaced from the tooth-shaped portion <NUM>', allowing the selector drum <NUM> to rotate to engage again the neutral gear (N) from the first gear (I) in the second change direction (Dwn) and to return to the first configuration.

Once the neutral gear has been engaged again, the torsional spring <NUM> brings the control element <NUM> and the block element <NUM> again in position.

Claim 1:
Gear shift (<NUM>) of a saddle vehicle (M) comprising:
a shift lever (<NUM>);
a selecting element (<NUM>) actuated through the shift lever (<NUM>);
a selector drum (<NUM>) connected to the selecting element (<NUM>) and adapted to engage gears;
a block device (<NUM>) functionally connected to the selector drum (<NUM>) and configured so as to be switched between:
∘ a first configuration, wherein the block device (<NUM>) allows engaging a first gear (I) from a neutral gear (N) in a first change direction of rotation (Up), and
∘ a second configuration, wherein the block device (<NUM>) inhibits the subsequent engagement of the neutral gear (N) from the first gear (I) in a second change direction of rotation (Dwn);
control means (<NUM>) of the block device (<NUM>) configured to be actuated by a rider (G) so as to define a third configuration, wherein the block device (<NUM>) is disabled in order to allow engaging the neutral gear (N) from the first gear (I) in the second change direction (Dwn);
wherein the block device (<NUM>) comprises:
- a stop element (<NUM>,<NUM>') constituted by a bushing (<NUM>) comprising a tooth-shaped portion (<NUM>'), mounted integral with the selector drum (<NUM>); and
- a block element (<NUM>) co-acting with the stop element (<NUM>,<NUM>') and adapted to switch between the first configuration, the second configuration and the third configuration;
characterized in that the block element (<NUM>) is mounted rotatable around a rotation axis (X-X) and comprises a first elastic element (<NUM>) so as to take:
the first configuration, wherein the block element (<NUM>) is fastened to the tooth-shaped portion (<NUM>'), corresponding to the neutral gear (N), allowing the selector drum (<NUM>) to rotate in the first change direction (Up) to engage the first gear (I) and the subsequent gears;
the second configuration, wherein the block element (<NUM>) is adjacent to, and touching, the tooth-shaped portion (<NUM>'), corresponding to the first gear (I), preventing the selector drum (<NUM>) from rotating in the second change direction (Dwn) to engage again the neutral gear (N) from the first gear (I);
the third configuration, wherein the block element (<NUM>) is spaced from the tooth-shaped portion (<NUM>') through the control means (<NUM>), allowing the selector drum (<NUM>) to rotate in the second change direction (Dwn) to engage again the neutral gear (N) from the first gear (I) and to return to the first configuration.