Patent Description:
This patent application relates to an improved radio-controlled vehicle.

In particular, the invention relates to an improved radio-controlled vehicle, which can safely operate on slopes with extreme inclinations, for example inclinations exceeding <NUM>°.

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 <NUM> 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 <NUM>°).

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. Document <CIT> discloses a radio-controlled vehicle comprising a frame having a longitudinal axis and comprising a left longitudinal member and a right longitudinal member; wherein the frame comprises, furthermore, a front guide and a rear guide, which transversely connect said right longitudinal member and left longitudinal member to one another; wherein each guide is a tubular body having an inner cavity and a longitudinal axis; each guide is connected to the left longitudinal member and to the right longitudinal member so as to be transverse, substantially perpendicular, to said longitudinal axis of the frame; wherein each guide has a left opening and a right opening, which establish a communication between the respective cavity and the outside in the area of a right end and a left end, respectively, of each guide; wherein the frame comprises a height adjustment unit; the radio-controlled vehicle comprising a left undercarriage and a right undercarriage; wherein each undercarriage comprises a support structure having a respective longitudinal axis, which, in use, is substantially parallel to the ground; wherein said adjustment unit is configured to vary the levelling of the vehicle.

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 radio-controlled vehicle according to the appended claims.

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

In <FIG>, number <NUM> indicates, as a whole, a radio-controlled vehicle comprising a frame <NUM>, a left undercarriage 3I and a right undercarriage 3II. Advantageously, the radio-controlled vehicle <NUM> is configured, as explained more in detail below, so as to ensure a correct operation even on extreme slopes, namely on slopes exceeding <NUM>°.

Hereinafter, the terms front, rear, right and left will be used with reference to the moving direction v of the radio-controlled vehicle <NUM> 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 <NUM> 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.

<FIG> is an exploded view of the radio-controlled vehicle <NUM> of <FIG>. The radio-controlled vehicle <NUM> comprises, in a known manner, a body <NUM>, a hydraulic assembly <NUM>, a motor <NUM>, a radiator <NUM>. Preferably, the radiator <NUM> comprises, in turn, a reversible fan <NUM>. Advantageously, the radio-controlled vehicle comprises a rollbar <NUM>, which is fitted around the body <NUM> and is configured to protect the radiator <NUM> and the reversible fan <NUM> against external hits.

Advantageously, the motor <NUM> is a common rail, turbo intercooler motor. The motor <NUM> is arranged at the front relative to the radiator <NUM>.

<FIG> and <FIG> show a detail of <FIG>, in particular the assembly consisting of the frame <NUM>, the left undercarriage 3I and the right undercarriage 3II, as explained more in detail below.

<FIG> show in detail a left undercarriage 3I. The components of the right undercarriage 3II are substantially equal to and mirror-like relative to the ones of the left undercarriage 3I. Each undercarriage 3I, 3II, in use, transfers to the ground the driving motion generated by the motor <NUM>.

Each undercarriage 3I, 3II comprises a support structure 10I, 10II, which has a longitudinal axis XI, XII and is configured to be connected to the frame <NUM> and to support all the operating units of the undercarriage, as explained more in detail below. According to <FIG>, the support structure <NUM>, 10II is divided, along the longitudinal axis XI, XII, into a front portion 11I, 11II, a central portion <NUM>, 12II and a rear portion 14I, 14II.

Furthermore, each undercarriage 3I, 3II comprises a driving wheel 15I, 15II, a plurality of idlers 16I, 16II and a track 18I, 18II, which is fitted around the idlers 16I, 16II and the driving wheel 15I, 15II. The driving wheel <NUM>, 15II meshes with the track 18I, 18II and operates the track in a known manner. In particular, the driving wheel <NUM>, 15II is hydraulically operated.

The support structure <NUM> comprises a bracket 19I, 19II to support the driving wheel 15I, 15II and arranged in the area of a central portion <NUM>, 12II of the support structure 10I, 10II.

The track 18I, 18II has a closed band body and comprises an outer surface 20I, 20II, which, in use, comes into contact with the ground, and an inner surface <NUM>, 21II, which, in use, comes into contact with said idlers 16I, 16II and said driving wheel 15I, 15II.

The track 18I, 18II further comprises an annular projection 22I, 22II, which radially projects from said inner surface <NUM>, 21II towards the inside of the track 18I, 18II. In particular, the annular projection 22I, 22II has an annular housing 23I, 23II, which is laterally delimited by two lateral abutment walls, hereinafter indicated with inner abutment wall 24I, 24II and outer abutment wall 25I, 25II.

The annular projection 22I, 22II has an inner profile with a substantially V-shaped cross section.

The annular projection 22I, 22II divides the inner surface <NUM>, 21II of the track 18I, 18II into two bands, hereinafter indicated with inner band 26I, 26II and outer band <NUM>, 27II.

The inner band 26I, 26II and the outer band 27I, 27II are substantially parallel and equal to one another. In other words, the annular projection 22I, 22II engages an annular central portion of the inner surface <NUM>, 21II of the track 18I, 18II.

Advantageously, each undercarriage 3I, 3II comprises a pair of front idlers 28I, 28II, 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 18I, 18II. The pair of front idlers 28I, 28II is connected to the front portion 11I, 11II of the support structure <NUM>. Advantageously, the pair of front idlers 28I, 28II is connected to the front portion 11I, 11II of the support structure <NUM> by means of a tensioner system 29I, 29II, which can be adjusted so as to change the tension of the track 18I, 18II.

In particular, the tensioner system 29I, 29II comprises a fork 30I, 30II, which is connected to the pair of front idlers 28I, 28II, a hydraulic cylinder <NUM>, 31II, which connects the fork 30I, 30II to the front portion 11I, 11II of the support structure <NUM>, and elastic return elements <NUM>, 32II, which act between the fork 30I, 30II and the hydraulic cylinder <NUM>, 31II. The hydraulic cylinder <NUM>, 31II is configured to change the pre-load of the elastic return elements 32I, 32II upon the fork 30I, 30II.

The fork 30I, 30II comprises two arms <NUM>, which are connected in a known manner to the pair of front idlers 28I, 28II, and a hub <NUM> having an inner cavity <NUM>, where the hydraulic cylinder <NUM>, 31II is arranged. In particular, the elastic return elements <NUM>, 32II are helical springs fitted around the hydraulic cylinder <NUM>, 31II so as to form the tensioner system <NUM> at least partially housed inside the hub <NUM>. The hydraulic cylinder <NUM>, 31II, in the area of an end of its, is connected to the support structure 10I, 10II.

Each undercarriage 3I, 3II further comprises a pair of rear idlers 36I, 36II, 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 18I, 18II. The pair of rear idlers 36I, 36II is connected to the rear portion 14I, 14II of the support structure <NUM>.

Each undercarriage 3I, 3II further comprises a plurality of stabilization rollers 37I, 37II, which are connected to the central portion <NUM>, 12II of the support structure 10I, 10II. The pairs of stabilization rollers <NUM>, 37II are interposed, along the longitudinal axis XI, XII, between the pair of front idlers 28I, 28II and the pair of rear idlers 36I, 36II.

Each pair of stabilization rollers 37I, 37II comprises a pair of rollers <NUM>, 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 10I, 10II. Each roller <NUM> engages a respective band <NUM>, <NUM> of the track 18I, 18II. In particular, the pairs of stabilization rollers 37I, 37II engage a section of the track 18I, 18II in contact with the ground.

Each undercarriage 3I, 3II further comprises an anti-derailment plate <NUM>, which is connected to said support structure 10I, 10II and, in use, projects into the annular housing <NUM> of the annular projection 22I, 22II, substantially between the inner abutment wall <NUM> and the outer abutment wall <NUM>.

In particular, the anti-derailment plate <NUM> is connected to the central portion <NUM>, 12II of the support structure 10I, 10II and lies between the rollers <NUM> of each pair of stabilization rollers 37I, 37II.

Each undercarriage 3I, 3II further comprises a front slide 40I, 40II and a rear slide <NUM>, 41II, which are connected to the support structure 10I, 10II. The front slide 40I, 40II and the rear slide <NUM>, 41II transversely project from a same side of the support structure 10I, 10II. Each slide 40I, 40II, <NUM>, 41II has a hollow tubular body <NUM> with a longitudinal axis YA and YB, respectively, which is transverse, substantially perpendicular, to the longitudinal axis XI, XII of the support structure 10I, 10II. Each slide 40I, 40II, <NUM>, 41II is configured to be coupled, in use, to a respective guide of the frame <NUM> of the radio-controlled vehicle <NUM>, as explained more in detail below.

Advantageously, the bracket 19I, 19II of the driving wheel <NUM> is interposed between the pair of front idlers <NUM>, 28II and the pair of rear idlers 36I, 36II. In particular, the bracket 19I, 19II for said driving wheel 15I, 15II is interposed, along the longitudinal axis XI, XII of the support structure 10I, 10II, between the front slide 40I, 40II and the rear slide <NUM>, <NUM>.

Therefore, the track 18I, 18II of each undercarriage 3I, 3II follows a triangular path. In this way, the stability of the radio-controlled vehicle <NUM> increases, as the centre of gravity is located between the pair of front idlers 28I, 28II and the pair of rear idlers 36I, 36II.

<FIG> and <FIG> show in detail the assembly consisting of the frame <NUM>, the left undercarriage 3I and the right undercarriage 3II.

According to <FIG> and <FIG>, the frame <NUM> has a longitudinal axis X, which substantially lies on a symmetry plane of the radio-controlled vehicle <NUM>. The frame <NUM> comprises a left longitudinal member 42I, a right longitudinal member 42II, a front guide 43A and a rear guide 43B.

The front guide 43A and the rear guide 43B connect the left longitudinal member 42I and the right longitudinal member 42II to one another in a transverse, substantially perpendicular manner.

Each guide 43A, 43B is a tubular body <NUM> 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 <NUM>.

Each guide 43A, 43B has a left opening 45I and a right opening 45II, 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 40I, 40II and the rear slide <NUM>, <NUM> of the left undercarriage 3I are coupled in a sliding manner to the front guide 43A and to the rear guide 43B, respectively, of the frame <NUM>. In particular, the front slide 40I, 40II is inserted into the left opening 45I of the front guide 43A and the rear guide <NUM>, 41II is inserted into the left opening 45I of the rear guide 43B.

The front slide 40I, 40II and the rear slide <NUM>, <NUM> of the right undercarriage 3II are coupled in a sliding manner to the front guide 43A and to the rear guide 43B, respectively, of the frame <NUM>. In particular, the front slide 40I, 40II is inserted into the right opening 45II of the front guide 43A and the rear guide <NUM>, 41II is inserted into the right opening 45II of the rear guide 43B.

Advantageously, the frame <NUM> comprises an adjustment unit <NUM>, which is configured to adjust the relative position between the left undercarriage 3I and the frame <NUM> and, similarly, between the right undercarriage 3II and the frame <NUM>.

According to <FIG>, the adjustment unit <NUM> 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 3I and the right undercarriage 3II. In particular, each cylinder 47A, 47B comprises a left piston 48A and a right piston 48II. Each piston 48I, 48II can selectively project out of the respective left opening 45I or right opening 45II of the corresponding guide 43A, 43B, as explained more in detail below.

According to <FIG>, each cylinder 47A, 47B comprises a tubular body <NUM> 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 48I, 48II. In particular, each cylinder 47A, 47B comprises two cylinder-heads 50I, 50II opposite one another, each fixed to a respective end of the tubular body <NUM>.

Each piston 48I, 48II comprises a rod <NUM>, which is mounted so as to slide, in a known manner, through a respective cylinder-head 50I, 50II. Each piston 48I, 48II comprises a head <NUM>, which is fixed to an inner end of the rod <NUM> and can slide, in a fluid-tight manner, inside the tubular body <NUM>. In particular, the right piston 48II comprises a right rod <NUM>, which is mounted so as to slide through the right cylinder-head 50II. Similarly, the left piston 48I comprises a left rod <NUM>, which is mounted so as to slide through the left cylinder-head 50I. The heads <NUM> of the right piston 48II and of the left piston 48I, respectively, are arranged beside one another so as to delimit, inside the cavity of the cylinder, an inner chamber <NUM>.

The head <NUM> of the left piston 48I laterally delimits, with the respective cylinder-head 50I, a left chamber 54I with a variable volume, based on the position of the left piston 48I along the respective axis ZA, ZB.

The head <NUM> of the right piston 48II laterally delimits, with the respective cylinder-head 50II, a right chamber 54II with a variable volume, in function of the position of the right piston 48II along the respective axis ZA, ZB.

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

Each cylinder 47A, 47B comprises, furthermore, a pair of secondary ducts 56I, 56II, each configured to introduce oil into the left chamber 54I and, respectively, into the right chamber 54II.

Each cylinder 47A, 47B further comprises a valve element <NUM>, which is configured to deflect the oil flow between the primary duct <NUM> and the secondary ducts 56I, 56II, and vice versa. By so doing, the oil can be selectively and alternatively directed between the inner chamber <NUM> and the right 51I and left chamber 54II, thus causing the movement of each piston 48I, 48II along the longitudinal axis ZA, ZB. <FIG> show an example of a valve element <NUM>, which of course can be replaced by equivalent systems, which, in particular, are suited to deflect the flow of a fluid from a duct <NUM> (56I, 56II) to the other one 56I, 56II (<NUM>) and to enable the selective emptying of the chambers <NUM>, <NUM> of the cylinder.

Each rod <NUM> of each cylinder 47A, 47B is configured to extend through a respective slide of a corresponding undercarriage. Each rod <NUM> 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 <NUM>. Therefore, by selectively operating each cylinder 47A, 47B, it is possible to adjust the relative position between each undercarriage 3I, 3II and the frame <NUM>. In this way, depending on the slope of the ground, the base of support of the radio-controlled vehicle <NUM> can be changed so as to increase the stability of the radio-controlled vehicle <NUM>.

According to <FIG> and <FIG>, the frame <NUM> comprises a motor housing <NUM>. Advantageously, the motor housing <NUM> is interposed, along the longitudinal axis X of the frame <NUM>, between the front guide 43A and the rear guide 43B. According to <FIG> and <FIG>, the frame <NUM> comprises a division bar <NUM> and the motor housing <NUM> is laterally delimited by a respective portion of the left longitudinal member 42I and of the right longitudinal member 42II, by the rear guide 43B and by the division bar <NUM>.

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

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

The frame <NUM> comprises, furthermore, a hydraulic assembly housing <NUM>, which is arranged at the front relative to the motor housing <NUM>. In other words, the hydraulic assembly housing <NUM> is interposed between the division bar <NUM> and the front guide 43A.

Advantageously, the radio-controlled vehicle <NUM> comprises a common rail, turbo intercooler motor <NUM>. Advantageously, the motor <NUM> is installed at the centre relative to the frame <NUM>, namely between the front guide 43A and the rear guide 43B. Therefore, the stability of the radio-controlled vehicle <NUM> is increased relative to known radio-controlled vehicles where the motor is installed in a projecting manner.

Advantageously, the radiator <NUM> with the reversible fan <NUM> is arranged at the back of the motor <NUM>, relative to the longitudinal axis X of the frame <NUM>.

Advantageously, the rollbar <NUM> is installed at the back of the motor <NUM> and is fitted around the radiator <NUM> and the reversible fan <NUM>. The rollbar <NUM>, besides protecting the body <NUM>, is configured to protect the radiator <NUM> and the reversible fan <NUM>.

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

Advantageously, the adjustment unit <NUM> enables an adjustment of the relative position between the left undercarriage 3I and the frame <NUM> and, similarly, between the right undercarriage 3II and the frame <NUM>. By so doing, the base of support of the radio-controlled vehicle <NUM> can e changed depending on the relative use conditions, so as to increase its stability.

Advantageously, the fact that the adjustment unit <NUM> comprises cylinders with a double rod <NUM>, which are arranged inside one single guide, allows the operating elements of the undercarriages 3I, 3II 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 <NUM> can be minimized and the protection of the cylinders <NUM> 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 <NUM>, the housings described above can be obtained in the frame <NUM>. These housings allow the motor <NUM> and the radiator <NUM> to be positioned in lower positions, namely closer to the ground, compared to traditional radio-controlled vehicles. Furthermore, the motor housing <NUM> 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 <NUM> described above, besides being more compact and protecting the adjustment unit <NUM> from dirt or the like, allows the motor <NUM> to be housed in a lower position, thus increasing the stability of the radio-controlled vehicle <NUM>. Furthermore, the particular compactness of the front guides 43A and of the rear guides 43B of the frame <NUM> 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 <NUM>, namely the position of the motor <NUM> between the front guide 43A and the rear guide 43B, relative to the longitudinal axis of the frame <NUM>, increases the stability of the radio-controlled vehicle <NUM> compared to known radio-controlled vehicles where the motor is arranged at the back and projects. In addition, the central position of the motor <NUM> also affects the configuration of the left undercarriage 3I and of the right undercarriage 3II.

Indeed, thanks to the central position of the motor <NUM>, the driving wheel 15I, 15II of the undercarriage can be arranged between the pair of front idlers 28I, 28II and the pair of rear idlers 36I, 36II. In this way, the compactness and the stability of each undercarriage 3I, 3II are increased.

Furthermore, the anti-derailment plate <NUM> arranged inside the annular projection 22I, 22II of each track 18I, 18II forbids the derailment of the track 18I, 18II. In case of extreme slopes, the anti-derailment plate <NUM> comes into contact with the outer annular abutment wall or the inner annular abutment wall, thus bringing the track 18I, 18II back to its ordinary use position.

Claim 1:
A radio-controlled vehicle (<NUM>) comprising a frame (<NUM>) having a longitudinal axis (X) and comprising a left longitudinal member (42I), a right longitudinal member (42II); wherein the frame (<NUM>) comprises, furthermore, a front guide (43A) and a rear guide (43B), which transversely connect said right longitudinal member (42II) and left longitudinal member (<NUM>) to one another; wherein each guide (43A; 43B) is a tubular body having an inner cavity (44A; 44B) and a longitudinal axis (WA; WB); each guide (43A; 43B) is connected to the left longitudinal member (42I) and to the right longitudinal member (42II) so as to be transverse, substantially perpendicular, to said longitudinal axis (X) of the frame (<NUM>); wherein each guide (43A; 43B) has a left opening (45I) and a right opening (45II), which establish a communication between the respective cavity (44A; 44B) and the outside in the area of a right end and a left end, respectively, of each guide (43A; 43B); wherein the frame (<NUM>) comprises an adjustment unit (<NUM>), which comprises, in turn, a first cylinder (47A) housed inside the front guide (43A) and a second cylinder (47B) housed inside the rear guide (43B); wherein each cylinder (47A; 47B) comprises a plurality of rods (<NUM>; 51II), each capable of sliding and selectively projecting outwards from the respective guide (43A; 43B) through said left opening (45I) or said right opening (45II); the radio-controlled vehicle comprising a left undercarriage (3I) and a right undercarriage (3II); wherein each undercarriage (3I; 3II) comprises a support structure (10I; 10II) having a respective longitudinal axis (XI; XII), which, in use, is substantially parallel to the ground; wherein said adjustment unit (<NUM>) is configured to vary, in use, the distance between the longitudinal axis of the frame (X) and the longitudinal axis of each undercarriage (XI, XII), so as to consequently change the base of support of the radio-controlled vehicle (<NUM>).