Patent Description:
Work vehicles usually comprises joysticks configured to allow the control of different work elements such as blades or booms of this latter.

An example of work vehicle is represented by mini excavators which are machines designed for mainly light application and for a discontinuous work. Typically, an operator climbs on the machine and gets out of this latter very frequently to check the operation area and to discuss with colleagues about dig operations. Because of this reason and to keep the product cost at low level, many similar work machines are equipped with a simple protection structure instead of a real cab. This structure is called "canopy".

When the work machine is equipped with a canopy instead of the cab, the operator compartment is consequently not equipped with any heating system since the operator area protected by the canopy structure is open to the environment. However, in some areas the temperature of environment may be cold and therefore, it is known to provide joystick which can be warmed upon request of the operator; indeed such warming will offer a thermal comfort and benefit to the operators. This latter will perceive a feeling of comfort especially in cold and wet days. In fact, it is frequent that operators do not wear gloves during operations and therefore the adoption of a warming system have the result of a better warm perception and global wellness for the operator.

Usually, joysticks comprise a pair of shells which are manufactured in polymeric materials like ABS, PA, or similar and which are coupled to each other to define a cavity configured to house a solid rod which is configured to operate the electric/hydraulic/pneumatic circuit which control the work element of the work machine.

In view of the above, known heatable joysticks usually comprise electric means installed inside the cavity defined the aforementioned pair of shells. Electric means comprises electric resistance configured to transform electrical energy to thermal energy which is transmitted from the cavity to joystick shells which consequently warm up the surface in contact with the hand of the user, providing thermal comfort improvement to this latter. The temperature can be adjusted through a dedicated controller, and switched on/off on demand.

However, the use of electrical energy is provided by the battery of the vehicle and/or given by the internal combustion engine. Therefore the energy demand of the vehicle is increased and consequently its consumption.

Therefore, the need is felt to provide temperature adjustable joysticks for work machines which at the same time do not increase the fuel/energy consumption of the vehicle.

An aim of the present invention is to satisfy the above mentioned needs in a cost effective and optimized way.

<CIT> discloses a joystick for a work vehicle.

The aforementioned aim is reached by a joystick and a work vehicle as claimed in the appended set of claims.

<FIG> discloses a work vehicle, e.g. a mini excavator <NUM>, as known in the art essentially comprising a main body <NUM> movably carried by an undercarriage <NUM> movable on the ground, e.g. by tracks. Main body <NUM> is further provided with an operator station <NUM> comprising control means <NUM> for operating a work element, e.g. a bucket <NUM> carried by a system of booms <NUM>, and being open to the environment. As shown, operator station <NUM> may further be protected by a canopy <NUM> extending over operator's seat.

Control means <NUM> advantageously comprise at least a joystick <NUM> according to the invention, disclosed in greater detail in <FIG> and <FIG>.

As known in the art, joystick <NUM> essentially comprises an handle <NUM> defining an external surface 11a suitable for allowing a comfortable grip for the user. The handle <NUM> is preferably realized in two shells 11b, 11c which can be coupled one to the other; more preferably shells 11b, 11c are hollows and, when connected to each other, define an internal volume <NUM> as described in the following.

According to the described embodiment, each of shells 11b, 11c defines a lower portion <NUM>, an intermediate portion <NUM> and an upper portion <NUM>, preferably fixedly connected one to the other and, more preferably realized monolithically.

Lower portion <NUM> and intermediate portion <NUM> have each preferably a semi-cylindrical shape however, intermediate portion <NUM> has a diameter lower than the diameter of lower portion <NUM>. Upper portion <NUM> has a substantial semi-ellipsoidal shape and defines a first semi-rectangular opening 16a provided with joint corners and a second semi-rectangular opening 16b having a shape similar to first semi-rectangular opening 16b and preferably centered with respect to this latter; in particular first semi-rectangular opening is realized in a front side of upper portion <NUM> and second semi-rectangular opening 16b is realized in a rear side opposite to the aforementioned front side of upper portion <NUM>.

According to the exemplary shape which has been described above, shells 11b, 11c, when connected, defines an inner volume <NUM> comprising a lower volume portion 12a which is substantially cylindrical, an intermediate volume portion 12b which is substantially cylindrical and has an internal diameter lower than portion 12a and an upper volume portion 12c which is substantial ellipsoidal and which opened to the environment thanks to a rectangular opening <NUM>.

Lower and intermediate volume portions 12a, 12b are sized to house a solid rod for controlling the related control circuit (not shown) and/or electrical wires related to such control circuit or simply additional electrical wires.

More preferably, shells 11b, 11c have a symmetrical shape, defining external handle surface 11a, with respect to a sagittal plane passing through handle <NUM> and they advantageously may be realized in polymeric material. Shells 11b, 11c may be connected to each other thanks to known means, e.g. threaded means such as screws.

According to the disclosed embodiment, joystick <NUM> may further comprises guide means <NUM> configured to control the centering of the above mentioned elements (rod and/or wires) inside volumes 12a, 12b. In particular, guide means <NUM> may comprise a support plate <NUM> being substantially a plate circular disc provided with a central opening 18a and at least a circumferential opening 18b realized around central opening 18a. In the described embodiment, plate 18a comprises a central opening 18a and a pair of circumferential openings 18b each extending for about <NUM>° around opening 18a and being consequently one opposed to the other with respect to this latter. According to the above defined configuration, the rod may be housed through opening 18a while possible electrical wires may pass through openings 18b.

Advantageously joystick <NUM> may comprises switch means <NUM> configured to control related circuits, e.g. electrical control circuit for operating bucket <NUM> or to move body <NUM> with respect to carriage <NUM>. According to the described embodiment, switch means <NUM> may comprise a plurality of buttons <NUM> carried by a support element <NUM> having a shape complementary to rectangular openings 16a, 16b and housed inside these latter and upper volume portion 12c.

As known in the art, handle <NUM> may be fixedly connected to a sleeve <NUM>, realized in polymeric elastic material, which is configured to cooperate with lower portions <NUM> of shells 11a, 11b to main body <NUM>. In particular, sleeve <NUM> may be provided with a circular opening <NUM> having a shape complementary to the shape of lower portions <NUM> of shells 11a, 11b. According to the described configuration, each of lower portions <NUM> of shells 11a, 11b further defines half of a groove <NUM> configured to cooperate with an edge 24a of opening <NUM> of sleeve <NUM> to mechanically connect handle <NUM> with sleeve <NUM>.

According to the invention, handle <NUM> comprises hydraulic conditioning means configured to allow the passage of a conditioning liquid fluid into joystick <NUM> to regulate the temperature of handle <NUM>, i.e. of external surface 11a.

Hydraulic conditioning means are configured to fluidly connect joystick <NUM> with a hydraulic conditioning circuit of the work vehicle <NUM> so as to spill part of a conditioning fluid of the hydraulic conditioning circuit <NUM> and make this latter circulate in joystick <NUM> for regulating the temperature of handle <NUM>.

Preferably, as disclosed schematically in <FIG>, hydraulic condition means advantageously define a fluid connection between joystick <NUM> and engine cooling fluid of a an engine circuit <NUM> of vehicle <NUM>. In this way, hydraulic condition means are configured to heat handle <NUM> so as to reach a temperature above a preset value.

As known, an engine cooling circuit <NUM> essentially comprises a radiator <NUM>, a first conduit <NUM> and a second conduit <NUM> fluidly connecting respectively an internal combustion engine <NUM> of the vehicle with radiator <NUM> upstream to this latter and radiator <NUM> with engine <NUM> upstream to this latter, and a pump <NUM> configured to allow the circulation of coolant fluid from engine <NUM> to radiator <NUM> and to radiator <NUM> to engine <NUM>. As known, coolant fluid will heat in engine <NUM>, passes through conduit <NUM> to radiator <NUM> in which it is cooled and then through conduit <NUM> to engine <NUM> to cool this latter and heat itself.

According to the above, hydraulic conditioning means comprises a system of conduit <NUM> carried by joystick <NUM> and fluidly connected to engine cooling circuit <NUM> so as to spill part of heated cooling fluid of engine <NUM> to heat handle <NUM>. In particular, system of conduit <NUM> comprises a first opening 40a fluidly connected to first conduit <NUM> and a second opening 40b fluidly connected to second conduit <NUM>. Advantageously, as shown in <FIG>, conduits <NUM> are housed in handle <NUM>, i.e. in shells 11b, 11c.

Advantageously, as shown in <FIG> and <FIG>, first opening 40a is realized in one of shells 11b, 11c and second opening 40b is realized in the other of shells 11b, 11c and conduits <NUM> comprises a single conduit <NUM> comprising a first portion 41a realized in one of shells 11b,11c and a second portion 41b realized in the other shell 11b, 11c.

Shells 11b, 11c each comprises (see <FIG> and <FIG>) an opening 42b, 42c configured to allow, when shells 11b 11c are connected, the fluidic communication between first and second portions 41a, 41b of conduit <NUM>. In particular openings 42b, 42c may be realized in a lateral edge of respective shells 11b, 11c and may comprise coupling means <NUM> configured to allow their matching. In particular, as shown in detail in <FIG>, shell 11b may comprise a male coupling means <NUM>, i.e. a protrusion 43a and shell 11c may comprise a female coupling means <NUM>, i.e. a complementary shape seat 43b. Coupling means <NUM> may further comprises tight means <NUM>, such as an O-ring.

Preferably portions 41a, 41b of conduit <NUM> are realized in intermediate portion <NUM> of shells 11b, 11c and may have a geometry realizing a plurality of "U" laterally adjacent one to the other along a longitudinal axis of intermediate portion <NUM> and being placed so that they are one opposite to the other, realizing, when seen laterally, a sort of continuous "S" shape, i.e. a "zig-zag" shape, as clearly depicted in <FIG>.

Because of the above described complicated shape, conduit <NUM> may be realized in shells 11b, 11c thanks to an additive manufacturing process.

Advantageously conduit <NUM> extends in shells 11b, 11c of at least two times with respect to the longitudinal extension of intermediate portion <NUM> and has a diameter which is about half of the thickness of shell 11b, 11c and extends circumferentially around almost all the extension of the respective shell 11b, 11c.

According to a further aspect of the invention, one between joystick <NUM> or circuit <NUM> may further comprise flow regulation means <NUM> configured to regulate the flow of conditioning fluid passing in joystick <NUM> so as to variably regulate the temperature of handle <NUM> according to the desire of the operator.

Advantageously, flow regulation means <NUM> comprise a thermostatic adjusting valve <NUM> configured to regulate the flow of fluid passing from first conduit <NUM> to opening 40a. Preferably, thermostatic adjusting valve <NUM> may be an electro-actuated valve and vehicle <NUM> may comprise control means (not shown) e.g. a switch or a button, electrically connected to a control unit (not shown), e.g. the ECU of vehicle <NUM>, electrically connected to valve <NUM> and configured to regulate the flow which may flow through this latter. In particular control unit comprises elaboration means configured to run code means suitable for operating a control method as described below. More preferably control means may be buttons <NUM> carried by support <NUM> placed in upper portion <NUM> of handle <NUM>.

Alternatively thermostatic adjusting valve <NUM> may be a mechanically actuated valve operated by a mechanical command linked to said switch or button.

The operation of a joystick <NUM> as described above is the following.

When the operator activates mechanically or electronically the warming function of joystick <NUM>, flow regulation means <NUM> allows the passage of a preset flow to joystick <NUM>.

Making reference to hydraulic scheme shown in <FIG>, heated engine cooling fluid coming from engine <NUM> will therefore flow towards opening 40a of joystick <NUM> and then pass into handle <NUM> in particular through first portion 41a of conduit <NUM>, through openings 42b, 42c, through second portion 41b of portion <NUM> and opening 40b of joystick <NUM>. When flow out from joystick <NUM> engine cooling fluid will flow to second conduit <NUM>, downstream with respect radiator <NUM> and then again into engine <NUM>, forced by pump <NUM>.

The passage of heated engine cooling fluid into conduit <NUM> inside handle <NUM> will transmit thermal energy through shells 11b, 11c thereby increasing the temperature of handle <NUM> so that when the operator touch surface 11a he will perceive a comfortable temperature.

If the operator wants a hotter handle <NUM> it will be sufficient to regulate the flow of fluid through regulation means <NUM>, i.e. electronically or mechanically.

The present invention further relates to a method for controlling the temperature of a handle of a joystick as described above and comprising essentially the following steps:.

The reach of the preset temperature may be detected thanks to the use of temperature sensors (not shown) carried by joystick <NUM> or estimated proportionally to the flow passing through flow regulation means <NUM>.

In view of the foregoing, the advantages of a joystick <NUM> according to the invention are apparent.

Thanks to hydraulic conditioning means it is possible to control the temperature of handle <NUM>, in particular to heat this latter, taking advantage of the thermal energy of a conditioning fluid of a conditioning circuit already present in the vehicle, thereby avoiding energy waste due to known Joule-effect electrical conditioning means.

Moreover, thanks to the peculiar geometry of conduit <NUM>, which can be obtained economically thanks to additive manufacturing, it is possible to define an optimized profile of conduit <NUM> inside handle <NUM> so as to generate a comfortable heating of handle surface 11a.

The incorporation of conduit <NUM> inside shells 11b, 11c allows to have a light, economical and compact joystick reducing waste of material. The use of additive manufacturing further optimize the production of this latter and allows the creation of conduits <NUM> of any desired geometry according to the shape of handle <NUM>.

Further, flow regulation means <NUM> allow to regulate the temperature of handle <NUM> according to operator's desires.

It is clear that modifications can be made to the described joystick <NUM> which do not extend beyond the scope of protection defined by the claims.

As said, hydraulic conditioning means may be provided to heat or cool handle <NUM> or even to both these functions according to operator's necessity.

Moreover it is clear that the shape of components of joystick <NUM> and number of this latter in the vehicle can be varied.

Further, it is clear the hydraulic circuit <NUM> as described may be any conditioning circuit of the vehicle comprising different elements.

Claim 1:
Joystick (<NUM>) for a work vehicle (<NUM>), said joystick (<NUM>) comprising a handle (<NUM>) defining an external surface (11a) configured to allow the grip by an operator of said work vehicle (<NUM>), said joystick (<NUM>) comprising hydraulic conditioning means configured to allow the passage of a conditioning fluid into said joystick (<NUM>) to regulate the temperature of said handle (<NUM>);
the joystick is characterized in that said hydraulic conditioning means are configured to fluidly connect said joystick (<NUM>) with a hydraulic conditioning circuit (<NUM>) of said work vehicle (<NUM>) so as to spill part of a conditioning fluid of said hydraulic conditioning circuit (<NUM>) and make this latter circulate in said joystick (<NUM>) for regulating the temperature of said handle (<NUM>).