PRIORITY CLAIM

This application claims priority from Italian Patent Application No. 102017000036800 filed on April 4, 2017, the disclosure of which is incorporated by reference.

TECHNICAL FIELD

This patent application relates to an improved frame, an improved undercarriage and an improved radio-controlled vehicle .

In particular, the invention relates to an improved frame, an improved undercarriage and an improved radio- controlled vehicle, which can safely operate on slopes with extreme inclinations, for example inclinations exceeding 60° .

BACKGROUND ART

It is known to use radio-controlled vehicles for maintenance activities to be carried out in green areas in rough places, such as for example road and motorway edges. Known radio-controlled vehicles usually have a weight exceeding 1000 kg and risk rolling over in case of extreme slopes, which are further inaccessible to normal means.

Generally, radio-controlled vehicles comprise: a frame to support the motor and the other operating units, and two undercarriages, which are arranged on the sides of the frame and are provided with tracks, which transmit the motion to the ground so as to move the radio-controlled vehicle. Furthermore, known radio-controlled vehicles are operated by motors which, according to anti-pollution rules that are becoming stricter and stricter, in the next years will have to be replaced by other types of less polluting motors, such as for example common rail, turbo intercooler motors. However, common rail, turbo intercooler motors are larger and have greater weights than currently used motors and cannot be installed in existing vehicles, as their use would cause the rollover of the radio-controlled vehicle when it is being used, especially in case of extreme slopes.

In other words, existing frames and undercarriages are not suitable for the installation of larger and heavier motors and, therefore, cannot ensure the safety of the radio- controlled vehicle during the operation on extreme slopes (for example exceeding 60°) .

In particular, known radio-controlled vehicles have the drawback that, during the execution of normal activities on extreme slopes, the tracks can come out of their seat, thus causing a series of troubles, such as the standstill of the machine and the interruption of the activities. Therefore, the operator is forced to reach the vehicle and fix the tracks putting them back into place. In these conditions the safety of the operator is subjected to a great risk, as the conditions of the ground on which the operator has to intervene are often very difficult and full of obstacles. This phenomenon obviously is stronger in case of installation of a larger and heavier motor, such as for example a common rail, turbo intercooler motor.

DISCLOSURE OF INVENTION

An object of the invention is to provide a frame which ensures the safety of the radio-controlled vehicle during the operation on extreme slopes, namely which can accommodate larger and heavier motors than the ones currently used (in particular, motors that are designed to fulfil anti ^¬ pollution requirements, such as for example common rail, turbo intercooler motors) and allows the centre of gravity of the radio-controlled vehicle to be lowered as much as possible, so as to increase the compactness and the stability thereof .

An object of the invention is to provide an undercarriage which ensures the safety of the radio- controlled vehicle during the operation on extreme slopes, namely which prevents the tracks from coming out of their seat .

An object of the invention is to provide a radio- controlled vehicle which ensures safety during the operation on extreme slopes and preferably is operated by a low- emission motor compliant with anti-pollution rules, such as for example a common rail, turbo intercooler motor.

According to the invention, there is provided a frame according to the appended claims.

According to the invention, there is provided an undercarriage according to the appended claims.

According to the invention, there is provided a radio- controlled vehicle according to the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described with reference to the accompanying drawings, which show a non-limiting embodiment thereof, wherein:

- figure 1 is a perspective view of a radio-controlled vehicle according to the invention;

- figure 2 is an exploded view of the radio-controlled vehicle of figure 1;

- figure 3 shows a detail of figure 2;

- figure 4 is a plan view of the detail of figure 3;

- figure 5 is a plan view of a first detail of the radio-controlled vehicle of figure 1;

- figure 6 is a lateral view of the detail of figure 5;

- figure 7 is a section according to lines VII-VII of figure 6;

- figure 8 is an exploded view of a detail of figure 5; - figures 9 to 11 are respective partially sectional, lateral and plan views of a further detail of the radio- controlled vehicle of figure 1.

BEST MODE FOR CARRYING OUT THE INVENTION

In figure 1, number 1 indicates, as a whole, a radio- controlled vehicle comprising a frame 2, a left undercarriage 31 and a right undercarriage 311. Advantageously, the radio- controlled vehicle 1 is configured, as explained more in detail below, so as to ensure a correct operation even on extreme slopes, namely on slopes exceeding 60°.

Hereinafter, the terms front, rear, right and left will be used with reference to the moving direction v of the radio-controlled vehicle 1 when driving forward. In order to distinguish two substantially equal components, hereinafter, the components on the left of the symmetry plane of the radio-controlled vehicle 1 are indicated with suffix I, whereas the components on the right are indicated with suffix II. Similarly, the front components are indicated with suffix A and the rear components are indicated with suffix B.

Figure 2 is an exploded view of the radio-controlled vehicle 1 of figure 1. The radio-controlled vehicle 1 comprises, in a known manner, a body 4, a hydraulic assembly 5, a motor 6, a radiator 7. Preferably, the radiator 7 comprises, in turn, a reversible fan 8. Advantageously, the radio-controlled vehicle comprises a rollbar 9, which is fitted around the body 4 and is configured to protect the radiator 7 and the reversible fan 8 against external hits.

Advantageously, the motor 6 is a common rail, turbo intercooler motor. The motor 6 is arranged at the front relative to the radiator 7.

Figures 3 and 4 show a detail of figure 2, in particular the assembly consisting of the frame 2, the left undercarriage 31 and the right undercarriage 311, as explained more in detail below.

Figures 5 to 8 show in detail a left undercarriage 31. The components of the right undercarriage 311 are substantially equal to and mirror-like relative to the ones of the left undercarriage 31. Each undercarriage 31, 311, in use, transfers to the ground the driving motion generated by the motor 6.

Each undercarriage 31, 311 comprises a support structure 101, 10II, which has a longitudinal axis XI, XII and is configured to be connected to the frame 2 and to support all the operating units of the undercarriage, as explained more in detail below. According to figure 8, the support structure 101, 10II is divided, along the longitudinal axis XI, XII, into a front portion 111, 11II, a central portion 121, 1211 and a rear portion 141, 1411.

Furthermore, each undercarriage 31, 311 comprises a driving wheel 151, 1511, a plurality of idlers 161, 1611 and a track 181, 1811, which is fitted around the idlers 161, 1611 and the driving wheel 151, 1511. The driving wheel 151, 1511 meshes with the track 181, 1811 and operates the track in a known manner. In particular, the driving wheel 151, 1511 is hydraulically operated.

The support structure 10 comprises a bracket 191, 1911 to support the driving wheel 151, 1511 and arranged in the area of a central portion 121, 1211 of the support structure 101, 10II.

The track 181, 1811 has a closed band body and comprises an outer surface 201, 2011, which, in use, comes into contact with the ground, and an inner surface 211, 2111, which, in use, comes into contact with said idlers 161, 1611 and said driving wheel 151, 1511.

The track 181, 1811 further comprises an annular projection 221, 2211, which radially projects from said inner surface 211, 2111 towards the inside of the track 181, 1811. In particular, the annular projection 221, 2211 has an annular housing 231, 2311, which is laterally delimited by two lateral abutment walls, hereinafter indicated with inner abutment wall 241, 2411 and outer abutment wall 251, 2511.

The annular projection 221, 2211 has an inner profile with a substantially V-shaped cross section.

The annular projection 221, 2211 divides the inner surface 211, 2111 of the track 181, 1811 into two bands, hereinafter indicated with inner band 261, 2611 and outer band 271, 2711.

The inner band 261, 2611 and the outer band 271, 2711 are substantially parallel and equal to one another. In other words, the annular projection 221, 2211 engages an annular central portion of the inner surface 211, 2111 of the track 181, 1811.

Advantageously, each undercarriage 31, 311 comprises a pair of front idlers 281, 2811, which are coaxial to one another relative to an axis which is transverse, substantially perpendicular, to the longitudinal axis of the undercarriage .

Each front idler engages a respective band of the track 181, 1811. The pair of front idlers 281, 2811 is connected to the front portion 111, 11II of the support structure 10. Advantageously, the pair of front idlers 281, 2811 is connected to the front portion 111, 11II of the support structure 10 by means of a tensioner system 291, 2911, which can be adjusted so as to change the tension of the track 181, 1811.

In particular, the tensioner system 291, 2911 comprises a fork 301, 3011, which is connected to the pair of front idlers 281, 2811, a hydraulic cylinder 311, 3111, which connects the fork 301, 3011 to the front portion 111, 11II of the support structure 10, and elastic return elements 311, 3211, which act between the fork 301, 3011 and the hydraulic cylinder 311, 3111. The hydraulic cylinder 311, 3111 is configured to change the pre-load of the elastic return elements 321, 3211 upon the fork 301, 3011.

The fork 301, 3011 comprises two arms 33, which are connected in a known manner to the pair of front idlers 281, 2811, and a hub 34 having an inner cavity 35, where the hydraulic cylinder 311, 3111 is arranged. In particular, the elastic return elements 311, 3211 are helical springs fitted around the hydraulic cylinder 311, 3111 so as to form the tensioner system 29 at least partially housed inside the hub 34. The hydraulic cylinder 311, 3111, in the area of an end of its, is connected to the support structure 101, 10II.

Each undercarriage 31, 311 further comprises a pair of rear idlers 361, 3611, which are coaxial to one another relative to an axis which is transverse, substantially perpendicular, to the longitudinal axis of the undercarriage. Each rear idler engages a respective band of the track 181, 1811. The pair of rear idlers 361, 3611 is connected to the rear portion 141, 1411 of the support structure 10.

Each undercarriage 31, 311 further comprises a plurality of stabilization rollers 371, 3711, which are connected to the central portion 121, 1211 of the support structure 101, 10II. The pairs of stabilization rollers 371, 3711 are interposed, along the longitudinal axis XI, XII, between the pair of front idlers 281, 2811 and the pair of rear idlers 361, 3611.

Each pair of stabilization rollers 371, 3711 comprises a pair of rollers 38, which are coaxial to one another relative to an axis Y which is transverse, substantially perpendicular, to the longitudinal axis XI, XII of the support structure 101, 10II. Each roller 38 engages a respective band 26, 27 of the track 181, 1811. In particular, the pairs of stabilization rollers 371, 3711 engage a section of the track 181, 1811 in contact with the ground.

Each undercarriage 31, 311 further comprises an anti- derailment plate 39, which is connected to said support structure 101, 10II and, in use, projects into the annular housing 23 of the annular projection 221, 2211, substantially between the inner abutment wall 24 and the outer abutment wall 25.

In particular, the anti-derailment plate 39 is connected to the central portion 121, 1211 of the support structure 101, 10II and lies between the rollers 38 of each pair of stabilization rollers 371, 3711.

Each undercarriage 31, 311 further comprises a front slide 401, 4011 and a rear slide 411, 4111, which are connected to the support structure 101, 10II. The front slide 401, 4011 and the rear slide 411, 4111 transversely project from a same side of the support structure 101, 10II. Each slide 401, 4011, 411, 4111 has a hollow tubular body 49 with a longitudinal axis YA and YB, respectively, which is transverse, substantially perpendicular, to the longitudinal axis XI, XII of the support structure 101, 10II. Each slide 401, 4011, 411, 4111 is configured to be coupled, in use, to a respective guide of the frame 2 of the radio-controlled vehicle 1, as explained more in detail below.

Advantageously, the bracket 191, 1911 of the driving wheel 15 is interposed between the pair of front idlers 281, 2811 and the pair of rear idlers 361, 3611. In particular, the bracket 191, 1911 for said driving wheel 151, 1511 is interposed, along the longitudinal axis XI, XII of the support structure 101, 10II, between the front slide 401, 4011 and the rear slide 411, 4111.

Therefore, the track 181, 1811 of each undercarriage

31, 311 follows a triangular path. In this way, the stability of the radio-controlled vehicle 1 increases, as the centre of gravity is located between the pair of front idlers 281, 2811 and the pair of rear idlers 361, 3611.

Figures 3 and 4 show in detail the assembly consisting of the frame 2, the left undercarriage 31 and the right undercarriage 311.

According to figures 3 and 4, the frame 2 has a longitudinal axis X, which substantially lies on a symmetry plane of the radio-controlled vehicle 1. The frame 2 comprises a left longitudinal member 421, a right longitudinal member 4211, a front guide 43A and a rear guide 43B.

The front guide 43A and the rear guide 43B connect the left longitudinal member 421 and the right longitudinal member 4211 to one another in a transverse, substantially perpendicular manner.

Each guide 43A, 43B is a tubular body 49 having an inner cavity and a longitudinal axis. Each guide 43A, 43B is connected to the right and left longitudinal member so as to be transverse, substantially perpendicular, to the longitudinal axis of the frame 2.

Each guide 43A, 43B has a left opening 451 and a right opening 4511, which establish a communication between the respective cavity and the outside in the area of a left end and of a right end, respectively, of each guide 43A, 43B.

The front slide 401, 4011 and the rear slide 411, 4111 of the left undercarriage 31 are coupled in a sliding manner to the front guide 43A and to the rear guide 43B, respectively, of the frame 2. In particular, the front slide 401, 4011 is inserted into the left opening 451 of the front guide 43A and the rear guide 411, 4111 is inserted into the left opening 451 of the rear guide 43B.

The front slide 401, 4011 and the rear slide 411, 4111 of the right undercarriage 311 are coupled in a sliding manner to the front guide 43A and to the rear guide 43B, respectively, of the frame 2. In particular, the front slide 401, 4011 is inserted into the right opening 4511 of the front guide 43A and the rear guide 411, 4111 is inserted into the right opening 4511 of the rear guide 43B.

Advantageously, the frame 2 comprises an adjustment unit 46, which is configured to adjust the relative position between the left undercarriage 31 and the frame 2 and, similarly, between the right undercarriage 311 and the frame 2.

According to figure 3, the adjustment unit 46 comprises a front cylinder 47A, which is housed inside the front guide 43A, and a rear cylinder 47B, which is housed inside the rear guide 43B. Each cylinder 47A, 47B comprises two pistons, which are operated simultaneously, so as to operate both the left undercarriage 31 and the right undercarriage 311. In particular, each cylinder 47A, 47B comprises a left piston 48A and a right piston 4811. Each piston 481, 4811 can selectively project out of the respective left opening 451 or right opening 4511 of the corresponding guide 43A, 43B, as explained more in detail below.

According to figures 9 to 11, each cylinder 47A, 47B comprises a tubular body 49 having a longitudinal axis ZA, ZB and is a double-acting cylinder. In particular, each cylinder 47A, 47B is configured to simultaneously operate two opposite pistons 481, 4811. In particular, each cylinder 47A, 47B comprises two cylinder-heads 501, 5011 opposite one another, each fixed to a respective end of the tubular body 49.

Each piston 481, 4811 comprises a rod 51, which is mounted so as to slide, in a known manner, through a respective cylinder-head 501, 5011. Each piston 481, 4811 comprises a head 52, which is fixed to an inner end of the rod 51 and can slide, in a fluid-tight manner, inside the tubular body 49. In particular, the right piston 4811 comprises a right rod 51, which is mounted so as to slide through the right cylinder-head 5011. Similarly, the left piston 481 comprises a left rod 51, which is mounted so as to slide through the left cylinder-head 501. The heads 52 of the right piston 4811 and of the left piston 481, respectively, are arranged beside one another so as to delimit, inside the cavity of the cylinder, an inner chamber 53.

The head 52 of the left piston 481 laterally delimits, with the respective cylinder-head 501, a left chamber 541 with a variable volume, based on the position of the left piston 481 along the respective axis ZA, ZB.

The head 52 of the right piston 4811 laterally delimits, with the respective cylinder-head 5011, a right chamber 5411 with a variable volume, in function of the position of the right piston 4811 along the respective axis ZA, ZB.

Each cylinder 47A, 47B further comprises a primary duct 55, which is configured to introduce oil into the inner chamber 53.

Each cylinder 47A, 47B comprises, furthermore, a pair of secondary ducts 561, 5611, each configured to introduce oil into the left chamber 541 and, respectively, into the right chamber 5411.

Each cylinder 47A, 47B further comprises a valve element 57, which is configured to deflect the oil flow between the primary duct 54 and the secondary ducts 561, 5611, and vice versa. By so doing, the oil can be selectively and alternatively directed between the inner chamber 53 and the right 511 and left chamber 5411, thus causing the movement of each piston 481, 4811 along the longitudinal axis ZA, ZB. Figures 9 to 11 show an example of a valve element 57, which of course can be replaced by equivalent systems, which, in particular, are suited to deflect the flow of a fluid from a duct 55 (561, 5611) to the other one 561, 5611 (55) and to enable the selective emptying of the chambers 53, 55 of the cylinder .

Each rod 51 of each cylinder 47A, 47B is configured to extend through a respective slide of a corresponding undercarriage. Each rod 51 is configured to extend through the respective guide and the respective slide, so as to cause the movement of a corresponding undercarriage transversely, in particular perpendicularly, to the longitudinal axis X of the frame 2. Therefore, by selectively operating each cylinder 47A, 47B, it is possible to adjust the relative position between each undercarriage 31, 311 and the frame 2. In this way, depending on the slope of the ground, the base of support of the radio-controlled vehicle 1 can be changed so as to increase the stability of the radio-controlled vehicle 1.

According to figures 3 and 4, the frame 2 comprises a motor housing 60. Advantageously, the motor housing 60 is interposed, along the longitudinal axis X of the frame 2, between the front guide 43A and the rear guide 43B. According to figures 3 and 4, the frame 2 comprises a division bar 61 and the motor housing 60 is laterally delimited by a respective portion of the left longitudinal member 421 and of the right longitudinal member 4211, by the rear guide 43B and by the division bar 61.

In particular, the motor housing 60 is in a front position relative to the rear guide 43B.

The frame 2 further has a radiator housing 62, which is configured to house a radiator 7. Advantageously, the rear guide 43B is interposed, along the longitudinal axis of the frame 2, between the motor housing 60 and the radiator housing 62. In particular, the radiator housing 62 projects at the back relative to the rear guide 43B.

The frame 2 comprises, furthermore, a hydraulic assembly housing 63, which is arranged at the front relative to the motor housing 60. In other words, the hydraulic assembly housing 63 is interposed between the division bar

61 and the front guide 43A.

Advantageously, the radio-controlled vehicle 1 comprises a common rail, turbo intercooler motor 6.

Advantageously, the motor 6 is installed at the centre relative to the frame 2, namely between the front guide 43A and the rear guide 43B. Therefore, the stability of the radio-controlled vehicle 1 is increased relative to known radio-controlled vehicles where the motor is installed in a projecting manner.

Advantageously, the radiator 7 with the reversible fan

8 is arranged at the back of the motor 6, relative to the longitudinal axis X of the frame 2.

Advantageously, the rollbar 8 is installed at the back of the motor 6 and is fitted around the radiator 7 and the reversible fan 8. The rollbar 9, besides protecting the body

4, is configured to protect the radiator 7 and the reversible fan 8.

Advantageously, the radio-controlled vehicle 1 described above has an entire configuration, namely a combination between the arrangement of the components of the undercarriages and of the frame 2, which is such as to reduce the height and lower the position of the motor 6 relative to traditional radio-controlled vehicles. Furthermore, the arrangement of all the components of the radio-controlled vehicle 1 allows the motor 6 to be installed in a central position, this increasing the stability of the vehicle.

Advantageously, the adjustment unit 46 enables an adjustment of the relative position between the left undercarriage 31 and the frame 2 and, similarly, between the right undercarriage 311 and the frame 2. By so doing, the base of support of the radio-controlled vehicle 1 can e changed depending on the relative use conditions, so as to increase its stability.

Advantageously, the fact that the adjustment unit 46 comprises cylinders with a double rod 51, which are arranged inside one single guide, allows the operating elements of the undercarriages 31, 311 to be compacted inside the front guide 43A and the rear guide 43B, respectively. In this way, the space taken up by the adjustment unit 46 can be minimized and the protection of the cylinders 47 can be increased, as they are completely contained inside the respective slides and guides. Thanks to the reduction of the dimensions of the adjustment unit 46, the housings described above can be obtained in the frame 2. These housings allow the motor 6 and the radiator 7 to be positioned in lower positions, namely closer to the ground, compared to traditional radio- controlled vehicles. Furthermore, the motor housing 60 can have sizes that allow it to accommodate motors that are larger than the motors traditionally used in these vehicles, such as for example a common rail, turbo intercooler motor.

Therefore, the frame 2 described above, besides being more compact and protecting the adjustment unit 46 from dirt or the like, allows the motor 6 to be housed in a lower position, thus increasing the stability of the radio- controlled vehicle 1. Furthermore, the particular compactness of the front guides 43A and of the rear guides 43B of the frame 2 allows motors to be housed, which have sizes that are larger than those of the motors traditionally used in known radio-controlled vehicles, such as for example a common rail, turbo intercooler motor.

Moreover, the central position of the motor 6, namely the position of the motor 6 between the front guide 43A and the rear guide 43B, relative to the longitudinal axis of the frame 2, increases the stability of the radio-controlled vehicle 1 compared to known radio-controlled vehicles where the motor is arranged at the back and projects. In addition, the central position of the motor 6 also affects the configuration of the left undercarriage 31 and of the right undercarriage 311.

Indeed, thanks to the central position of the motor 6, the driving wheel 151, 1511 of the undercarriage can be arranged between the pair of front idlers 281, 2811 and the pair of rear idlers 361, 3611. In this way, the compactness and the stability of each undercarriage 31, 311 are increased .

Furthermore, the anti-derailment plate 39 arranged inside the annular projection 221, 2211 of each track 181, 1811 forbids the derailment of the track 181, 1811. In case of extreme slopes, the anti-derailment plate 39 comes into contact with the outer annular abutment wall or the inner annular abutment wall, thus bringing the track 181, 1811 back to its ordinary use position.

Therefore, the radio-controlled vehicle 1 described above ensures a safe operation even on extreme slopes, for example on slopes exceeding 60°, and enables the installation of larger and heavier motors than the motors currently used in known radio-controlled vehicles.