WO2016038530A1

WO2016038530A1 - Device for mounting a top box to a motorcycle

Info

Publication number: WO2016038530A1
Application number: PCT/IB2015/056856
Authority: WO
Inventors: Nicola PERRI
Original assignee: Perri Nicola
Priority date: 2014-09-09
Filing date: 2015-09-08
Publication date: 2016-03-17
Also published as: EP3191359A1

Abstract

Device (1) for mounting a top box (2) to a supporting frame (30), which supporting frame (30) is firmly fastened on a motorcycle (3) at the back of the rider seat with respect to the travel direction, comprising a first rigid element integrally fastenable to the upper part of the supporting frame (30), which first rigid element is provided with one or more sliding guides, and a second rigid element provided with means for fastening to the top box, which second rigid element is provided with one or more slides intended to be engaged in the sliding guides, such that the top box (2) is movable between an extreme forward position in the direction of the rider seat and an extreme backward position in a direction opposite to the rider seat.

Description

Device for mounting a top box to a motorcycle.

The present invention relates to a device for mounting a top box to a supporting frame, which supporting frame is firmly fastened on a motorcycle at the back of the rider seat with respect to the travel direction .

It is known that on motorcycles and the like it is often necessary to take helmets, small objects, notebooks, bags for several uses or also traditional shopping bags. Due to lack of available space under the motorcycle saddle, or in order to increase the carrying capacity, there is the need of using rear hard luggage, preferable over side luggage. Side luggage partially cancels one of the typical advantages offered by two- wheeled vehicles, namely the reduced width in the direction perpendicular to the front-to-back travel axis of the motorcycle, which is a necessary characteristic for making it more easy to pass in restricted spaces of cities congested with "heavy" and chaotic traffic.

Moreover side luggage provides considerable air drag and as a whole is heavier, even if having a center of gravity lower than a central top box. The backpack could be a good way to load items that are not much heavy but bulky, however it risks being very dangerous in case of accidental falls, particularly if transporting rigid items, and it can cause the motorcyclist to go off-balance when riding. Moreover it is very dangerous to carry plastic bags on the handlebar, since they could affect the steering angle, they may get caught on the cables forcing the acceleration or on the levers preventing them to break, moreover the asymmetrical or hanging load would cause the handlebar to oscillate, with very clear effects on safety. Finally the fact of carrying backpacks, bags and any other items on the rear part of the saddle is very dangerous due to possible movements of these items, particularly when riding fast.

Rear luggage is attached to the motorcycle by means of a special supporting frame, called also as "rack", in turn firmly fastened to the motorcycle frame. In the specific case of a top box, a term used for meaning the central rear bag, the fastening does not take place directly on the supporting frame but it requires a special plate to be interposed, this in order to enlarge the supporting surface for increasing stability and safety, above all when riding. Now, it is commonly known that the installation of a top box, even if placed at the center with respect to the motorcycle frame, in turn has several important drawbacks, above all as regards encumbrance spaces, and as regards active safety of the motorcycle when travelling, these are problems occurring even when the top box is empty. These drawbacks often are the base for the motorcyclist to choose not to acquire a rear top box, or to acquire it with a size smaller than necessary, and they can be summarized as follows:

· greater rear and side-rear encumbrance • loss in the optimal balance

• worsening of attitude

• less stability

• less agility

· less handling

• reduction in road holding

• worsening of aerodynamics

• motorcycle appearance is affected.

In order to try to reduce at least partially such drawbacks, attempts were made such to offer lighter materials, that however in most of the cases are much more expensive, such to dissuade from oversizing the top box too much, and such to limit its capacity to few kilograms. These solutions do not completely overcome said drawbacks, and on the contrary they introduce further disadvantages.

From documents US2012205411 , US2010/213695 and US2011/139843 frames for fastening top boxes to the motorcycle are known that allow the top box to be translated towards the rear end of the motorcycle, in order to set the dimensions of the rear saddle such to give the passenger more comfort.

Therefore such displacements start from an extreme forward position of the top box which however still provides the top box to protrude outside by an amount corresponding to a minimum space dimension for housing the passenger and therefore also such top box mounting systems do not allow drawbacks of known systems to be overcome especially in case the passenger is not present .

The present invention aims at overcoming said drawbacks of currently known devices by a device such as described hereinbefore, which further comprises a first rigid element integrally fastenable to the upper part of the supporting frame, which first element is provided with one or more sliding guides, and a second rigid element provided with means for fastening to the top box, which second element is provided with one or more slides intended to be engaged in the sliding guides, said guide and slide combination being placed relative to the longitudinal extension of the motorcycle and having such a length to determine two extreme positions of the top box one of which is an extreme forward position in the direction of the rider seat where the top box is moved as close as possible to the center of gravity of the motorcycle or to a position substantially vertically coinciding with the rear wheel, with reference to the position along the longitudinal axis and an extreme backward position in a direction opposite to the rider seat, where the top box is placed at such a distance from the rider seat to allow a passenger to sit.

By moving the top box in the extreme forward position, the rear and side rear encumbrance is clearly reduced and the big appendage generated at the rear part of the motorcycle is removed.

In a preferred embodiment, in the extreme forward position the top box does not protrude beyond the rear edge of the supporting frame. Preferably in said position the top box is placed substantially vertically aligned with at least the rear wheel .

On the contrary the extreme backward position can substantially coincide with the position the top box would take if directly mounted on the supporting frame.

Therefore the top box, once placed forwards on the rear part of the saddle, is aligned with the limit defined by the plate supporting frame, which, as it can be seen in most of the motorcycles, slightly protrudes beyond the number plate of the motorcycle. The advantage is very clear in several situations of use, firstly during manouvres for parking the motorcycle, where the restricted spaces offered by parking lots in metropolitan cities do not allow for sure easy manouvres .

When preparing to park, it is almost always preferred to make the manouvre in reverse, by inserting the tail of the motorcycle in the available space, therefore having the parking space behind, even if this involves a very poor visibility of external sharp corners , both whether they are part of other vehicles or of walls or so on, and of the protruding points of one's motorcycle. In such position, the start manoeuvre is made more easy but above all more safe, since the rider can have a much more wide view of the road whereon he/she is going to get. Now it is known that for a motorcyclist, in addition to being already clearly uncomfortable in making such reverse manouvre by using only his/her legs, both whether he/she remains on the motorcycle and whether he/she has to get off due to the height or weight thereof, the provision of a rear top box is a considerable complication, mostly due to the real increase in the rear and side rear encumbrance, and for many motorcyclists due also to the psychological effect in the visual control on a bigger motorcycle. The logical consequence is to correct many times the manouvre and to considerably increase attention, due to the risk of hitting with the top box the adjacent vehicles. In urban roads, congested with fast and chaotic traffic, the fact of taking much more time to position the motorcycle in the parking space, causes traffic to be possibly even if shortly hindered and it causes a greater danger for the motorcyclist and for the vehicles in transit. Once the parking action is ended, the increased dimension of the motorcycle often causes the front wheel to protrude (or the top box, in case of the opposite manouvre) beyond the space allowed by parking space dimensions; in this case the risk is to occupy the front or rear parking space or to be exposed to possible collisions with vehicles in transit in case the parking space is placed in front of a road.

The device of the present invention overcomes this problem by taking the motorcycle to the original dimensions.

This advantage of use is possible even when the path has been made with a passenger on board, he/she can get off before the manouvre and the top box can be placed in the forward position in few seconds.

A further advantage is created as regards passive safety of the rider, in case the top box protrudes on the road instead within the parking space. If the rider, before leaving the motorcycle or when starting riding again, needs to open or close the rear top box, he/she is exposed to the risk of being hit by the vehicles in transit, especially if the road is narrow or is one-way only and the speed of the vehicles is high .

By means of the device of the present invention the operations for loading and unloading the top box are completely safe and can be carried out calmly, positioning himself/herself at the sides of the motorcycle and thus being protected against possible accidental contacts with other vehicles.

Another aspect that can be improved by the device is motorcycle balancing.

Any motorcycle is designed with careful studies as regards its structure in order to guarantee the highest safety when riding and the driving pleasure which is more and more required to a modern motorcycle.

All the elements of this structure, besides their constructional quality, have to show precise requirements in order to interface with each other at best; a necessary relation for the motorcyclist to reach an optimal balance.

A particular importance is given to the relation between the frame, suspensions and the motor components, above all as regards their positioning in the space and the distribution of masses deriving therefrom. This is particularly important if reference is made to a two-wheeled vehicle, where the search for an immediate dynamic balance is essential for safety and drivability purposes, and this is still more valid if less experienced drivers have to drive the vehicle.

The result of such search leads to essential components, such as motorcycle balancing, attitude, stability, road holding and handling. A wrong weight distribution for example will change the reaction of the vehicle to external stimuli or rider's stimuli, making the motorcycle less safe, above all when facing emergency situations.

If a mass is placed at a point outside the motorcycle structure, such mass will act in a more evident manner on the vehicle stability depending on how much it is off-center, increasing the transfer of load and its influence.

Now a top box placed at the rear part of a motorcycle, protruding much beyond the physical length of the vehicle, is a rear protrusion part not provided in the designing phase, a virtual increase in dimensions not falling within the wheelbase of the motorcycle but falling outside it.

The first evidence of the above will be observed during direction changes, above all if made at higher speeds, where a wrong balancing can cause the vehicle to be lose stability, which is more evident as the load in question is heavier, affecting also the possibility of overtaking under complete safety.

Therefore one has to remind that by overloading the rear axle the front carriage tends to lift, decreasing its grip on the road surface. In order to well convey the idea to the motorcyclist, it is possible to show him/her, with exaggeration, how even the riding position affects stability and side road holding, by moving the weight to the front part the vehicle is made as more "stuck" on the road.

All the above, in addition, leads to a greater driving comfort, as well as to a easiness in riding the motorcycle even for less experienced drivers.

Another unpleasant effect of the positioning of a rear top box, is the one occurring when riding fast, above all in presence of side wind. The top box for motorcycles is an item designed to be vaguely aerodynamic, but only in presence of a passenger, since he/she "closes" the void created between the driver and the top box placed in the extreme rear part of the motorcycle. By operating the device of the present invention, the top box is placed directly close to the driver, forming a "cone" that allows basic aerodynamics to be improved. The new position of the rear top box, can be immediately noticed upon disappearing of the typical trembling of the handlebar, a not so much comfortable effect and a quite dangerous one if it is not immediately corrected by applying the weight of the driver's body.

The loading capacity limit allowed by current regulations for top boxes of motorcycles and scooters, is measured in kilograms, and the weight can vary from 3 to 7 Kg as the maximum depending on the model or on the type of rack. The reason for such limited capacity is due to the possibility of breaking the supporting frame due to stresses exerted on the top box when the motorcycle is travelling. The sudden changes of direction, the pitching of the motorcycle, the continuous shocks when driving on uneven roads or not well-finished roads, and the air pressure at high speeds, are all possible conditions straining the resistance of the supporting frame to the limit. It is clear that by placing the top box towards the center of the motorcycle the structure is subjected to a lower air drag but above all to a lower load lever, reducing the risk of collapsing, a collapse that, should it take place, would be mitigated and "received" by the saddle immediately below.

In one embodiment said sliding guides are composed of tubular elements arranged parallel to the front-to- back travel axis of the motorcycle and said slides are composed of elongated elements intended to be fitted in a slidable manner in said sliding guides, which elongated elements have a section along a plane perpendicular to the front-to-back travel axis of the motorcycle corresponding to the section of the inner cavity of said tubular elements along such plane.

In a further example there are provided means for removably locking the second element with respect to the first element.

Preferably the top box is lockable by such means only in the extreme forward position or in the extreme backward position. However it is possible to provide one or more intermediate locking positions, or at the very least means locking the top box in any intermediate positions between the two extreme positions .

In a preferred embodiment the locking means comprise openings provided in the second element and one or more movable pins provided in the first element and intended to selectively engage one or more of the openings .

In one embodiment there are provided means for automatically moving the top box between the extreme forward position and the extreme backward position.

Such means can comprise double-acting linear actuators, such as for example an hydraulic piston, an electric motor with a mechanical transmission for example recirculating balls or male and female screw or rack and pinion or the like. In this case there are provided control means for the user, that allow the movement of the top box to be operated. Such means can provide a switch placed near the top box, or near the handlebar.

Control means can provide the automatic movement of the top box in the extreme backward or forward position upon turning on or off the electric panel or the motor respectively.

According to an improvement when the top box is in the extreme forward position, the second element is in such a position to prevent the compartment under the saddle from being opened.

This is a considerable aspect for people that have been subjected to thefts in the compartment under the saddle: the device, once operated in the forward position locks the opening of the saddle, making very difficult to open it and discouraging a possible prowler .

In one embodiment the two extreme positions are defined by abutment elements between the first and second element.

According to one embodiment the abutment element defining the extreme backward position is composed of an end wall provided in each tubular element, against which the respective elongated element is intended to abut in the maximum insertion condition.

This allows the extreme backward position to be defined as corresponding to the maximum insertion condition of the second element into the first one.

According to a further embodiment the abutment element defining the extreme forward condition is composed of a rod-like element fastened at one fastening end to the second element and placed parallel to the front-to-back travel axis of the motorcycle, which rod-like element passes through a hole provided in the first element and provided at the free end with an enlarged head.

This allows the extreme forward position to be defined as corresponding to the maximum removal condition of the second element from the first one, such condition being defined by the abutment of the enlarged head of the rod-like element on the edges of the hole provided in the first element.

Still according to one embodiment, the slides and guides are provided with means for locking in place of the removable and release type which can be manually controlled by the user.

A particular embodiment provides a release locking mechanism, wherein the slide is tubular and it bears a cam controlling a rounded locking element. Said cam is mounted so as to slide within the tubular slide by means of control members between two positions where it laterally pushes in or out the rounded locking element, while the guide in a position longitudinally coinciding with the rounded locking element in the path of the slide into the guide, has a series of fitting apertures for the rounded locking element. An elastic element firmly urges the cam in the position where it pushes outwardly, towards the fitting apertures, the locking member, while said cam is moved in the position where it allows the locking member to return with reference to the fitting apertures by a manual member moving the cam itself.

Advantageously the manual member is a button on the side of the slide facing the motorcyclist, the movement of such button is transmitted to the cam by means of a control rod.

These and other characteristics and advantages of the present invention will be more clear from the following description of some embodiments shown in the annexed drawings wherein:

Fig.l is a schematic view of the device mounted on a motorcycle;

Fig.2 is a perspective view of the device; Figs.3 to 5 are different views of the components of the first element;

Figs. 6 to 8 are different views of the components of the second element;

Figures 9 to 11 are a variant embodiment where there are provided hand-operated means removably locking the slide in the guides.

Figure 1 shows the device of the present invention, for mounting a top box 2 to a supporting frame 30 in a translatable manner, which supporting frame 30 is firmly fastened on a motorcycle 3 at the back of the rider seat and therefore of the saddle 31 with respect to the travel direction.

Therefore the device is interposed between the top box 2 and the supporting frame 30 and it is firmly fastened to both of them, and it allows the top box 2 to translate relative to the supporting frame 30 and therefore to the motorcycle 3, such that the top box 2 is movable between an extreme forward position, where the top box 2 is shown by a continuous line in the figure, and an extreme backward position, where the top box 2 is shown by a broken line.

Such as shown in the figure, in the extreme forward position denoted by 2 or 2' the top box does not protrude beyond the rear edge of the supporting frame 30.

Particularly the extreme forward position may be selected as denoted by 2 such that in said position the top box is substantially in a position vertically overlapping the rear wheel . It is also possible to select an extreme position denoted by 2' where the top box is placed as close as possible to the center of gravity of the motorcycle with reference to the position thereof along the longitudinal axis of the motorcycle.

Said extreme forward position 2 or 2' may be selected also such that when the top box is in said extreme forward position 2 or 2' , the top box and/or the device 1 are placed in a position overlapped to the rear part of the saddle such to prevent the saddle 31 from being lifted and therefore to prevent it from being swung upwardly for opening the compartment under the saddle.

Figure 2 shows a perspective view of a first embodiment of the device, in the condition removed from the motorcycle and without the top box 2 fastened thereto .

The device 1 comprises a first rigid element 4 integrally fastenable to the upper part of the supporting frame 30 and therefore to the motorcycle 3, which first element 4 is provided with one or more sliding guides 40 oriented in the longitudinal direction of the motorcycle, and a second rigid element 5 provided with arms fastening to the top box 5, which second element 5 is provided with one or more slides 50 intended to be engaged in the sliding guides 40 such to cooperate therewith by a translation movement. Said slides 50 are in the form of longitudinal struts with such a section to slidably telescopically engage the guides 40. Said guides are made as tubular and with an inner section intended to slidably house the slides 50. The slides 50, namely the struts are connected at least at one head end, with each other and to one of the arms 5 fastening to the top box respectively, said arms being retained in the position overlapping the slides 50 and at a given vertical distance therefrom and from the corresponding sliding guides 40.

The device is composed of a rigid material of any type provided with enough mechanical strength, preferably metal, particularly steel.

The first element 4 comprises a rigid plate 41 for fastening to the supporting frame 30, to which the sliding guides 40 are fastened, visible also in figure 3. The plate is provided with holes in standard positions for being fastened by means of screws to the supporting frame 30. The fastening of the sliding guides 40 to the plate 41 can be made in any currently known manner, preferably by means of a plurality of spacing elements, in the example of the figures four cylindrical spacing elements 42.

The sliding guides 40 in the example of the figures are composed of two tubular elements placed parallel to the front-to-back travel axis of the motorcycle 3 and side by side with each other. The two tubular elements are engaged with each other by means of one or more connection elements, particularly two connection elements placed at the opposite ends of the tubular elements, such to form a single element like a O, shown in the right portion of figure 3, fastenable to the plate 41 by means of said spacing elements 42. The components of the first element 4 are visible in figures 3, 4 and 5 showing top, front and side views respectively of the sliding guides.

The sliding guides can have different configurations, for example can be composed of elements at least partially opened and/or divided into several sections etc.

In the example in the figure the tubular elements have a square section, but it is possible to provide different sections, for example polygonal or circular or elliptical sections.

The slides in the example of the figures are composed of two elongated elements 50, intended to be slidably fitted into the sliding guides, namely inside the tubular elements 40.

The two elongated elements 50 have a section along a plane perpendicular to the front-to-back travel axis of the motorcycle 3 corresponding to the section of the inner cavity of the tubular elements 40 along such plane, with slightly smaller dimensions such to enable the sliding.

The second element 5 is composed of two U-shaped elements, placed on vertical planes parallel with each other and to the front-to-back travel axis of the motorcycle 3, whose lower arms are the elongated elements 50 composing the slides.

The upper arms are provided with holes for fastening the top box 2.

The two U-shaped elements are engaged with each other by a connection element. The components of the second element 5 are visible in figures 6, 7 and 8 showing top, front and side views respectively of the second element 5.

The end wall provided in each tubular element is the abutment element defining the extreme position, on which the head of the respective elongated element is intended to abut in the maximum insertion condition.

There are provided means for removably locking the second element 5 with respect to the first element 4, which comprise two openings 51 provided in the second element 5, visible in figures 7 and 8, two movable pins 41 provided in the first element 4 and intended to selectively engage the openings for alternatively placing the top box 2 in the extreme forward position or in the extreme backward position.

The pins 41 protrude outwardly from the tubular elements 40 such to be able to be removed by the user and are urged towards the inserted condition by elastic means such as springs or the like, such that they are removed from the opening where they are inserted in by overcoming the force of the elastic means, thus releasing the slides that therefore can slide into the sliding guides, allowing the top box 2 to be moved.

On the element connecting the two U-shaped elements a fastening end of a rod-like element 6 is fastened, which thus is fastened to the second element 5. The rod-like element 6 is arranged parallel to the front-to-back travel axis of the motorcycle 3, and it passes through a hole 42 provided into one of the two connection elements of the first element 4. The rod-like element 6 extends beyond said hole 42, and at the free end it is provided with an enlarged head 60, such that the extreme forward position is defined as corresponding to the condition of maximum removal of the second element from the first one, such condition being defined by the abutment of the enlarged head 60 of the rod-like element 6 against the edges of the hole 42 provided in the first element.

Figures 9 to 11 show a variant embodiment of the device 1 according to the present invention. In these figures like parts or parts having the same function are denoted by the same reference numerals used in the embodiment of figures 1 to 8 and only the characteristics making the second embodiment different from the first one will be described, the further characteristics being equal to or similar to those of the previous embodiment or anyway transferable from the first embodiment to this second embodiment without the need for inventive step.

The second embodiment is different from the first embodiment mainly because between the slides 50 and the sliding guides 40 there are provided release removable locking means , operated by a manual control .

Such means can be of any known type. In the example of figures 9 to 11, a preferred solution is shown inspired by release removable locking mechanisms used in handles of trolley cases or the like.

Inside the slide 50 which is made as tubular there is provided a slider 150 slidably mounted and at one side thereof facing a side wall of the slide 50 it has a cam track wherein there is provided a recess 250 connected by an inclined portion to the peripheral surface with a greater diameter of the slider 150.

The slider 150 is controlled so as to slide between two positions by means of a button 350 through a control rod 450 that in turn acts against the action of a spring 550 that firmly urges the slider in the position where the cam track coincides with the portion with a greater diameter of the slider.

The cam track cooperates with a round-shaped locking tooth, particular a spherical one 650 that in turn is intended to be engaged into a fitting hole 140 of a plurality of fitting holes provided at predetermined distances in the wall of the sliding guide 40, through a slot 750 provided in the shell wall of the tubular slide in a position coinciding with the fitting holes 140.

The recess 250 formed by the cam track is commensurate to the diameter or the dimensions of the locking tooth or locking sphere 650, such that by operating the button 350 the slider causes the recess to coincide with the locking tooth 650 that enters within and releases the relative sliding between the guide 40 and the slide 50. Once the locking is released, the button can be released and the rounded locking tooth or sphere slides along the inner wall of the guide till it coincides with a following hole 140. The return action of the spring exerted on the slider causes it to urge the locking tooth 650 into the hole 140. A further advantageous characteristic of the second embodiment provides that at the free ends of the two U-shaped elements formed by an arm 5 and the associated slide 50 respectively, said arm and said slide are connected to each other by a spacing element 850. The thickness of such spacing element corresponds to the distance between the arm 5 and the slide 50 and it makes the combination of arms 5 and slides 50 more rigid. To this end, since the slides are inside the guides, said elements are fastened by screw elements 950 having an enlarged head into the slide and are screwed by passing through the spacing elements 850 in the arms 5.

On the contrary the sliding guides 40 have an upper longitudinal slit 240 with a width equal to the one of the spacing elements and that allows them to freely longitudinally slide together with the slides 50.

Claims

1. Device (1) for mounting a top box (2) to a supporting frame (30) , which supporting frame (30) is firmly fastened on a motorcycle (3) at the back of the rider seat with respect to the travel direction and that comprises a first rigid element (4) integrally fastenable to the upper part of the supporting frame (30) , which first element is provided with one or more sliding guides (40) , and a second rigid element (5) provided with means for fastening to the top box (2) , which second element is provided with one or more slides (50) intended to be engaged in the sliding guides (40) ,

characterized in that

said guide and slide combination (40, 50) being placed relative to the longitudinal extension of the motorcycle and having such a length to determine two extreme positions of the top box of which one is an extreme forward position (2, 2') in the direction of the rider seat, where the top box is moved as close as possible to the center of gravity of the motorcycle (2') or to a position substantially vertically coinciding with the rear wheel (2) , with reference to the position along the longitudinal axis and an extreme backward position in a direction opposite to the rider seat, where the top box is placed at such a distance from the rider seat to allow a passenger to sit.

2. Device (1) according to claim 1, wherein in the extreme forward position the top box (2) does not protrude beyond the rear edge of the supporting frame (30) .

3. Device (1) according to claim 1, wherein said sliding guides (40) are composed of tubular elements (40) arranged parallel to the front-to-back travel axis of the motorcycle (3) and said slides (50) are composed of elongated elements (50) intended to be slidably telescopically fitted in said sliding guides (40) , which elongated elements (50) have a section along a plane perpendicular to the front-to-back travel axis of the motorcycle (3) corresponding to the section of the inner cavity of said tubular elements (40) along such plane .

4. Device (1) according to claim 1, wherein there are provided means for removably locking the second element (5) with respect to the first element (4) .

5. Device (1) according to claim 4, wherein said locking means comprise openings (51) provided in the second element (5) and one or more movable pins (41) provided in the first element (4) and intended to selectively engage one or more of the openings (51) .

6. Device (1) according to claim 4 or 5, characterized in that said removable locking means are of the release locking type (150, 250, 650, 140, 750), comprising a manual member (350, 450) controlling the locking conditions that operate counteracting an elastic member (550) that firmly urges said means in the locking condition.

7. Device (1) according to one or more of the preceding claims, wherein there are provided means for automatically moving in a motorized manner the top box (2) between the extreme forward position and the extreme backward position.

8. Device (1) according to one or more of the preceding claims, wherein, when the top box (2) is in the extreme forward position (2, 2'), the second element (5) and/or the top box itself are in such a position to prevent the compartment under the saddle from being opened.

9. Device (1) according to one or more of the preceding claims, wherein there is provided an abutment element defining the extreme backward position composed of an end wall provided in each tubular element (40) , against which the respective elongated element (50) is intended to abut in the maximum insertion condition.

10. Device (1) according to claim 9, wherein the abutment element that defines the extreme forward position is composed of a rod-like element (6) fastened at one fastening end to the second element (5) and arranged parallel to the front-to-back travel axis of the motorcycle (3) , which rod-like element (6) passes through a hole (42) provided in the first element (4) and it is provided at the free end with an enlarged head (60) .

11. Method for modifying motorcycle attitude changes caused by a top box or the like, which top box is mounted on a frame provided at the rear end of the motorcycle and which method provides to mount the top box in a manner movable between two extreme positions of which one is a forward position and one is a backward position and lockable in one of said two extreme positions and possibly also in a plurality of intermediate positions, the extreme forward position (2, 2') being in the direction of the rider seat, where the top box is moved as close as possible to the center of gravity of the motorcycle (2') or to a position substantially vertically coinciding with the rear wheel (2) , with reference to the position along the longitudinal axis and an extreme backward position in a direction opposite to the rider seat, where the top box is placed at such a distance from the rider seat to allow a passenger to sit.

12. Method according to claim 11, wherein in at least one of the intermediate positions and/or in the extreme forward position the top box overlaps the saddle of the motorcycle preventing it from being lifted.