The present invention relates to a self-propelled work vehicle.

As is known, the sector of self-propelled work vehicles includes vehicles that make it possible for an operator to carry out activities of a various nature at raised heights, for bridge maintenance or reinforcement, to repair pipes or infrastructure located several meters from the ground, etc.

This category of vehicles therefore has a self-propelled chassis (equipped with wheels or tracks) which is provided with telescopic arms and/or other lifting means, which in any case support a work platform, which is designed to accommodate one or more operators, who are thus brought to the desired height by the lifting means.

Along one side of the platform there is usually a control panel, which allows the operator to actuate the lifting means, to move the chassis and in general to move the platform itself and govern the operation of the machine.

Evidently, the ability to work at great heights entails highly critical issues in terms of safety for the operator on the platform, and it is therefore necessary to provide for many safety contrivances and various safety measures, in order to guard against the danger of falling or of other accidents (which could easily lead to serious injury or even death, given the peculiar working conditions involved).

First of all therefore, the platform usually constitutes the floor of a cage which, with a reticular structure provided with a gate, surrounds the operator. Furthermore, in order to enable levers, buttons and other controls arranged on the panel (and therefore move the platform), it is necessary to keep a pedal arranged proximate to the panel pressed down.

Such implementation solution is however not free of drawbacks.

In some unfortunate circumstances, it can happen that during the movement of the platform, and of the chassis in particular, the operator does not notice an obstacle behind him or her (a corner of a roof, a tree, etc.), which is approaching precisely because the platform is moving. The operator can therefore be struck by such obstacle, and sometimes the impact is such as to crush the operator against the panel, and one of the controls can be actuated inadvertently. If owing to trauma or as a consequence of the position assumed with the impact, the operator cannot or cannot manage to lift his or her foot from the pedal, it is easy to imagine how the consequences of the event just described, and of the unwanted activation of a command, could be serious or even fatal.

The aim of the present invention is to solve the above mentioned problems, by providing a self-propelled work vehicle provided with a lifted work platform, which adopts adequate contrivances for the safety of the operator who is called on to operate on that platform.

Within this aim, an object of the invention is to provide a self- propelled work vehicle in which the lifted platform is provided with an additional safety device, to minimize the injury to an operator as a consequence of an impact with an obstacle behind him or her.

Another object of the invention is to provide a self-propelled work vehicle that ensures a high reliability of operation.

Another object of the invention is to provide a self-propelled work vehicle that adopts an alternative technical and structural architecture to those of conventional vehicles.

Another object of the invention is to provide a self-propelled work vehicle that can be easily implemented using elements and materials that are readily available on the market.

Another object of the invention is to provide a self-propelled work vehicle that is of low cost and safely applied.

This aim and these and other objects which will become better apparent hereinafter are achieved by a self-propelled work vehicle according to claim 1 and by a safety device according to claim 10.

Further characteristics and advantages of the invention will become better apparent from the description of a preferred, but not exclusive, embodiment of the self-propelled work vehicle according to the invention, which is illustrated by way of non-limiting example in the accompanying drawings wherein:

Figure 1 is a schematic side view of a self-propelled work vehicle according to the invention;

Figure 2 is a perspective view of a detail of a self-propelled vehicle according to the invention, which shows the platform and two bars in the work position;

Figure 3 is a perspective view of the two bars of Figure 2; Figure 4 is a view from above of the two bars of Figure 2;

Figure 5 is a cross-sectional view of Figure 4, taken along the line V- V;

Figure 6 is an exploded perspective view of the two bars of Figure 2.

With particular reference to the figures, the reference numeral 1 generally designates a self-propelled work vehicle, which in Figure 1 is schematically shown in a possible embodiment (which does not limit the application of the invention).

The machine 1 comprises first of all a chassis 2 which can move over ground: to this end, the chassis 2 can be provided with a drive unit (of any type) and with wheels 3 and/or tracks, for the purpose of making it possible to move over the terrain of interest.

Furthermore, the chassis 2 supports an apparatus 4 for lifting a work platform 5 (in the known art in fact, this type of machine 1 is sometimes referred to as an "aerial platform"). The apparatus 4 can comprise various elements and systems, according to the specific requirements, which in any case are capable of lifting and moving the platform 5 according to various methods. Typically (but not exclusively), the apparatus 4 comprises one or more arms 6 which are mutually articulated and arranged in series, and are optionally telescopic: the first arm 6 can be coupled to the chassis 2 or to a rotating base 7 (which in turn is supported by the chassis 2), which gives a further degree of freedom to the system.

Any configuration of the apparatus 4, which the person skilled in the art will be able to recognize as appropriate to the use discussed herein or which in any case can be adopted in the sector of aerial platforms and/or of other self-propelled work vehicles 1 , should be understood as falling within the scope of protection claimed herein.

In turn, the platform 5 can also be provided according to various methods but in any case it is configured to accommodate at least one operator (who typically acts while remaining standing on it) and is provided with at least one control panel 8.

The panel 8 is designed for the movement of the platform 5 : that is to say, the panel 8 offers the possibility to control the movement of the chassis 2 (to move it over ground), to control the operation of the apparatus 4 (rotate the base 7, consequently rotate the arms 6 and retract/extend them, if the arms are telescopic, etc.), or the like.

In order to carry out the tasks indicated above, the panel 8 can therefore be actuated by the operator, when he or she is located on the platform 5 in a work station 9 in front of the panel 8.

The work station 9 may not be indicated on the platform 5, but it coincides with the area of space, immediately adjacent to the panel 8, which the operator is intended to occupy while he or she is on the platform 5 when he or she wishes to interact with the panel 8. It should likewise be noted that typically, at this work station 9, on the platform 5 there is a pedal (known in the art as a dead man's pedal or dead man's switch) which must be pressed and/or kept pressed in order to enable the correct operability of the panel 8, thus constituting a major safety measure for the operator.

The platform 5 therefore enables the operator (or operators) to carry out various activities, intervening on structures of various types located at different heights from the ground (by taking advantage of the possibility for lifting offered by the apparatus 4).

The protection claimed herein should be understood as being extended to any application and type of intervention, according to the specific requirements.

Up to this point, the machine 1 is effectively conventional, and can be provided with any technical contrivance or functionality that is common in the sector, while remaining within the scope of protection claimed herein.

According to the invention, the machine 1 comprises at least one rotatable bar 10, which is normally kept by respective elastic means 11 in a work position (the position in which the bar 10 is shown for example in Figure 2).

In the work position (which is maintained during normal interaction with the panel 8 by the operator), the bar 10 is substantially interposed, at a predefined height with respect to the platform 5, between the panel 8 and the work station 9. As can be seen in Figure 2, by virtue of the placement chosen when the operator stands in front of the panel 8 (in the work station 9), the operator is faced with the bar 10, which to some extent is interposed between him or her and the panel 8. The bar 10 can be parallel to the platform 5 and rotate about an axis perpendicular thereto (as in the accompanying figures), but it can also be partially inclined (and/or with an inclined rotation axis), so as to be kept in any case between the operator and the panel 8.

The predefined height at which the bar 10 is set is chosen so as not to impede interaction with the panel 8, while still ensuring the functionality that will be explained below.

The bar 10 is functionally associated with an electronic control and management unit, which is programmed with instructions for the execution of an emergency cycle designed to immediately stop the movement of the platform 5, following the detection of a rotation of the bar 10, with respect to the work position, by an extent that is greater than a predefined threshold value (a rotation of lesser extent being deemed acceptable).

By virtue of the chosen placement of the bar 10, explained above, a rotation thereof is typically the result of an impact with an obstacle, experienced by the operator from behind, of such violence as to hurl the operator against the panel 8. In such an eventuality therefore, the body of the operator is pressed against the bar 10 with an intensity that is such as to defeat the action of the elastic means 11 and automatically cause the rotation of the bar 10. This results in the activation of the emergency cycle and therefore the immediate arrest of the movement of the platform 5, which guards against more serious damage and achieves the set aim.

It should be noted that the electronic unit can be a controller, a computer, another form of hardware, reprogrammable or otherwise (for example with a microprocessor) and typically is the same electronic unit that is responsible for governing the entire machine 1 (and which will therefore be provided with additional instructions for the execution of the emergency cycle). The possibility is not ruled out however of having a dedicated electronic module, to be mounted on the machine 1 (or preexisting) and designed to interact with the other electronic and mechanical components, and the panel 8, in order to execute the emergency cycle.

It should be noted that the emergency cycle can include the provisions or actions (imparted by the electronic unit) that the person skilled in the art deems most appropriate, in order to safeguard the safety of the operator. Purely for the purposes of example, it is possible for the electronic unit to be programmed so that the cycle results in the arrest of the chassis 2 and/or of the apparatus 4 (and therefore, as desired, of the platform 5) by then executing all the necessary commands to bring the machine 1 and, especially, the operator on the platform 5 to conditions of safety.

It should be made clear that it is possible to program the electronic unit so as to allow the normal functionality of the machine 1 and of the panel 8 to be restored only after having returned the bars 10 to the work position and after a diagnostic check has verified that all the buttons or levers of the panel 8 are released (and that the pedal is pressed).

In particular, the machine 1 comprises at least one sensor 12 which is functionally associated with the electronic unit and is configured to directly or indirectly detect a rotation of the bar 10, with respect to the work position, by an extent that is greater than the preset threshold value. Such information is immediately transferred to the electronic unit so that, as has been seen, it can activate the emergency cycle.

The sensor 12 can be capable of continuously measuring any rotation of the bar 10, but it can also be chosen to be capable of simply detecting a rotation by an extent that is greater than the preset threshold value. Furthermore, although below a specific embodiment of the sensor 12 will be explained, it should be noted that the sensor can be of any type and can be adapted to measure various physical values (directly or indirectly correlated to the rotation of the bar 10) according to various principles and technologies.

In an embodiment of significant practical interest, illustrated in the accompanying figures for the purposes of non-limiting example of application of the invention, the machine 1 comprises two bars 10, which are kept in mutual alignment by the respective elastic means 11 when they are in the work positions (as can be seen in Figure 2). In such arrangement the two bars 10 resemble a sort of swing gate and, except where otherwise indicated, the construction details that will be supplied for one bar 10 should be understood as relating to each bar 10.

The electronic unit is therefore programmed with instructions for the execution of the emergency cycle following the detection of a rotation of any one of the bars 10 with respect to the work position, by an extent that is greater than a predefined threshold value.

It is emphasized that the cycle can be activated as a consequence of the rotation of just one of the bars 10 (since this could in any case mean that the body of the operator has been pressed against the panel 8 by an obstacle behind him or her) or of both. The first case could arise when the operator is not in the center of the work station 9 and/or the impact suffered pushes him or her in a direction that is not perpendicular to the orientation of the bars 10 and to the panel 8.

In this case too, the sensor 12 can be capable of measuring any physical value correlated to the angular position of each bar 10.

More specifically, in the preferred embodiment (which does not limit the application of the invention), each bar 10 is supported rotatably by the platform 5, directly or indirectly, at a first end 10a; furthermore, in the work positions the second ends 10b of the bars 10, which are opposite to the first ends 10a, are arranged so as to face each other at a predefined distance. The sensor 12 is therefore arranged substantially at one of the second ends 10b and is designed to monitor the distance between them.

Thus, the choice to monitor the distance from each other makes it possible to adopt a single sensor 12 for monitoring both of the bars 10. In fact, evidently even the rotation of just one bar 10 (just as with a rotation of both) results in a variation of the distance between the second ends 10b, which can in fact be detected by a single sensor 12 in order to activate the emergency cycle. Figure 4 shows in dotted lines two possible arrangements assumed by the bars 10, following rotation from the initial work position (the position of the bars 10 shown in solid lines).

The scope of protection claimed herein in any case includes the choice to use a sensor 12 for each bar 10, where the specific requirements make such choice preferable or in any case applicable.

Even more specifically, the sensor 12 is a magnetic sensor, which is inserted in the second end 10b of one of the bars 10 and is directed toward a magnet 13, inserted in the second end 10b of the other bar 10 (as can be clearly seen in Figures 4-6). It should be noted that the bars 10 can have a niche at the second ends 10b, to accommodate the sensor 12 and the magnet 13, or, as in the accompanying figures, each bar 10 can be tubular and therefore be passed through longitudinally by a through duct 14 (which also lightens the weight of the whole), which hosts the sensor 12 or the magnet 13 in an end portion (which is open outward). In this latter embodiment the tubular bar 10 can be internally coated with a layer 15 of protective foam, which in fact surrounds the duct 14.

It is possible for example to maintain the second ends 10b at less than 20mm distant from each other, calibrating the electronic unit to react (activating the emergency cycle) when the sensor 12 detects that its distance from the magnet 13 (and therefore the distance between the second ends 10b of the bars 10) has exceeded the value of 20 mm (optionally providing for some millimeters of tolerance), corresponding to a rotation that exceeds the tolerated amount (typically a few degrees).

Usefully, and while not ruling out other practical methods of implementation, the elastic means 11 comprise a torsion spring 16, which is wound around an articulation pivot 17 of the bar 10 (preferably with the interposition of a bushing 18). Therefore it is the (constraining) elastic reaction of the spring 16 that keeps the respective bar 10 in the work position.

Advantageously, the platform 5 is substantially constituted by the floor of a reticular cage 19 for protecting the operator. As can be seen for example from Figure 2, each bar 10 is supported so that it can rotate by the cage 19 (which is preferably open above).

More specifically, the pivot 17 is rigidly accommodated in a box 20 which is fixed to the cage 19 and is inserted rotatably in a bracket 21 which is to the first end 10a of the bar 10. As can be seen in Figure 6, the box 20 has a side wall 20a, while at the opposite side it is open. The spring 16 is inserted with an end limb in the duct 14 of the bar 10 and keeps the latter pressed against the wall 20a, thus defining a stroke limit that effectively coincides with the work position. At the opposite side however, as noted the box 20 is open, in order to allow the rotation of the bar 10.

The machine 1 can likewise be completed with further useful elements, such as for example an optical signaling device 22 (a lamp or the like), an acoustic signaling device, etc., which is actuated by the electronic unit as part of the emergency cycle, in order to emanate an immediate and recognizable signal that the critical condition that the bar 10 is designed to detect has occurred.

It should be emphasized that the protection claimed herein relates firstly to a self-propelled work vehicle 1 according to what is claimed up to this point. However, the object of the present discussion and the scope of protection defined by it also relates to a safety device, which can be applied on vehicles 1 of the type described in the foregoing pages, and which therefore comprise a chassis 2 which can move over ground and which supports an apparatus 4 for lifting a work platform 5, the latter being configured to accommodate at least one operator and being provided with at least one control panel 8 which is designed for the movement of the platform 5 and can be operated by the operator, when the latter is located on the platform 5 in a work station 9 in front of the panel 8.

The device according to the invention, which can therefore be marketed separately from the machine 1 and optionally implemented on preexisting vehicles 1, comprises therefore at least one bar 10 and at least one electronic control and management unit according to what is described up to this point.

Operation of the machine 1 (and of the safety device) according to the invention has already been effectively described in the foregoing pages, but a brief summary is given below in any case.

According to methods that are traditional per se, the machine 1 can be used to enable an operator to carry out operations, maintenance, repairs and activities in general, on structures of various types located several meters above the ground, which would otherwise be unreachable. To this end in fact, the operator can enter the cage 19 and, after taking up position on the platform 5 at the work station 9, can interact with the panel 8 in order to move the chassis 2 over ground and lift (move) the platform 5, bringing himself or herself to the exact point where they need to be.

During the movement of the platform 5, the invention offers an additional and particularly useful safety measure (in addition to the presence of the cage 19, to the pedal described above, etc), which is activated in the event of accidental impact with an obstacle that strikes the operator from behind.

In such an eventuality in fact, the operator is pushed forward, toward the panel 8: but by doing this, the operator inevitably pushes against the bars 10, which, in the work position, are located between the panel 8 and the work station 9. The push exerted by the operator can defeat the elastic reaction exerted by the elastic means 11 and therefore the bars 10 are made to rotate (to this end, the weight of the bars 10 will be kept sufficiently low). The electronic unit (through the sensor 12 or in another way) can detect whether the rotation exceeds the preset threshold value and, in such case, take action as a consequence, immediately activating the emergency cycle, which arrests the platform 5, thus minimizing the injury inflicted on the operator (i.e. preventing further injury from being inflicted in addition to the injuries deriving from the impact with the obstacle).

It should be noted finally that the invention is easy to implement, requiring the simple mounting of one or two bars 10, suitably positioned, and the programming of an emergency cycle for the electronic unit: this renders the solution described herein certainly low cost and attractive for any type of customer. Furthermore, the simplicity is an assurance of reliability over time as well. The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims. Moreover, all the details may be substituted by other, technically equivalent elements.

In the embodiments illustrated, individual characteristics shown in relation to specific examples may in reality be substituted with other, different characteristics, existing in other embodiments.

In practice, the materials employed, as well as the dimensions, may be any according to requirements and to the state of the art.

The disclosures in Italian Patent Application No. 102019000014619 from which this application claims priority are incorporated herein by reference.

Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly, such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.