Patent Description:
Telehandlers (short for "telescopic handlers") are widely used both in agriculture and in industry in view of their great versatility in use.

Telehandlers generally comprise a frame, a telescopic boom articulated on the frame and traction means adapted to move the frame and the boom with respect to the ground. In detail, the boom can be fitted with various operative tools, such as a bucket, pallet forks or a winch.

Under some circumstances, such operative tools are rotatable relative to the boom about an axis transversal to the boom. Rotation of the operative tools may be obtained by means of handling system comprising a cylinder, a stem sliding within the cylinder and a leverage, which is adapted to convert the translation of the stem into a rotational movement.

In detail, the stem slides along a predetermined stroke within the cylinder between a retracted position and an extended position. However, when the stem is in the retracted or in the extended position, its position is not locked with respect to the cylinder. As a result, the stem might slip beyond the extended position and away from the cylinder, thereby causing damage to the cylinder and stem assembly.

This risk increases when the boom and the operative tool attached thereto are required to handle high loads, due to the stresses acting on the stem.

Therefore, the need is felt to obtain an optimized handling system for a boom of a telehandler, which allows minimizing the risk of damage to the mechanical parts of the boom. Document <CIT> discloses an example of a handling system for a boom of a front loader comprising a stopper element on the boom.

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

The aforementioned aim is reached by a handling system, as claimed in the appended independent claims.

The aforementioned aim is also reached by a boom for a telehandler and by a telehandler comprising such boom.

Preferred embodiments of the invention are realized according to the claims dependent or related to the above independent claims.

With reference to <FIG>, numeral <NUM> indicates a telehandler, in particular for industrial or agricultural applications.

Telehandler <NUM> comprises a frame <NUM> and a plurality of wheels <NUM> for moving the frame <NUM> with respect to the ground. In addition, telehandler <NUM> is preferably provided with a driver's cockpit <NUM>.

Telehandler <NUM> further comprises a boom <NUM>, which is fitted in a movable manner to frame <NUM>. In particular, boom <NUM> is a telescopic boom, i.e. extendable or retractable along a direction A. Furthermore, boom <NUM> may be rotatable about a vertical axis Z and/or a horizontal axis Y of telehandler <NUM> (<FIG>).

In detail, boom <NUM> comprises a first end 5a, at which it is articulated on frame <NUM> and a second end 5b, which is opposite to first end 5a and adapted to be operatively connected with a not-shown operative tool of telehandler <NUM>, such as a bucket, pallet forks or a winch.

In the embodiment shown, boom <NUM> comprises a first stretch <NUM> on the side of first end 5a and a second stretch <NUM> on the side of second end 5b. In detail, second stretch <NUM> is hinged to first stretch <NUM> and is rotatable with respect to first stretch <NUM> about an axis W transversal to direction A. In further detail, when second stretch <NUM> is in the default position illustrated in <FIG>, it extends along a direction J that is transversal to direction A.

As shown in <FIG>, telehandler <NUM> comprises a handling system <NUM>, which is arranged at second end 5b. More precisely, handling system <NUM> is arranged at second stretch <NUM>.

Handling system <NUM> comprises, in turn, a cylinder <NUM>, a stem <NUM> sliding within cylinder <NUM> along a direction B and a lever <NUM> operatively connected to stem <NUM>. In detail, cylinder <NUM> may be a hydraulic or a pneumatic cylinder.

As shown in <FIG>, second stretch <NUM> is at least partially hollow and defines a cavity <NUM>. Preferably, cylinder <NUM> and stem <NUM> are completely housed inside cavity <NUM>. In addition, lever <NUM> is at least partially housed inside cavity <NUM>.

Stem <NUM> is slidable between an extended position and a retracted position with respect to cylinder <NUM>. In detail, stem <NUM> comprises a not-shown inner end, which is arranged inside cylinder <NUM> and an outer end, which is opposite to the inner end and is arranged outside cylinder <NUM>. When stem <NUM> is in the extended position, the outer end of stem <NUM> is placed at a first distance with respect to cylinder <NUM> (<FIG>); when stem <NUM> is in the retracted position, the outer end of stem <NUM> is placed at a second distance with respect to cylinder <NUM> (<FIG>). In detail, the second distance is smaller than the first distance.

Lever <NUM> is rotatable about an axis C transversal to direction B as a consequence of the movement of stem <NUM> within cylinder <NUM> (<FIG>). In other words, lever <NUM> is adapted to convert the translation of stem <NUM> within cylinder <NUM> into a rotational movement.

Handling system <NUM> further comprises a locking element <NUM>, which is hinged to boom <NUM> and is operatively connected to lever <NUM>. Locking element <NUM> is rotatable about an axis D, which is parallel to axis C.

In particular, locking element <NUM> may be directly or indirectly operatively connected to lever <NUM>. In other words, one or more elements may be interposed between lever <NUM> and locking element <NUM> without preventing lever <NUM> and connecting element <NUM> from being operatively connected to each other.

Furthermore, boom <NUM> comprises two stop portions <NUM>, <NUM>, which are adapted to limit the rotation of locking element <NUM> about axis D.

Advantageously, locking element <NUM> is rotatable between a first angular position, in which it is adapted to cooperate with stop portion <NUM> and to lock stem <NUM> in the extended position (<FIG>) and a second angular position, in which it is adapted to cooperate with stop portion <NUM> and to lock stem <NUM> in the retracted position (<FIG>).

Since locking element <NUM> is operatively connected to lever <NUM> and since lever <NUM> is adapted to rotate as a consequence of the movement of stem <NUM> within cylinder <NUM>, the rotation of locking element <NUM> is determined by the movement of stem <NUM> within cylinder <NUM>. In particular, each position of stem <NUM> within cylinder <NUM> between the extended and the retracted positions corresponds to an angular position of locking element <NUM> between the first and the second angular positions.

In detail, locking element <NUM> is adapted to contact stop portion <NUM> in the first angular position and to contact stop portion <NUM> in the second angular position. In further detail, stop portion <NUM> is adapted to prevent the rotation of locking element <NUM> beyond the first angular position in the rotational direction oriented from the second angular position to the first angular position. Similarly, stop portion <NUM> is adapted to prevent the rotation of locking element <NUM> beyond the second angular position in the rotational direction oriented from the first angular position to the second angular position.

Preferably, locking element <NUM> is rotatable between the first angular position and the second angular position by an angle of <NUM>° about axis D.

As shown in <FIG>, handling system <NUM> further comprises a connecting element <NUM>, which is operatively connected to lever <NUM> and to locking element <NUM>. In particular, connecting element <NUM> is adapted to transmit to locking element <NUM> the rotation of lever <NUM> about axis C.

Furthermore, as shown in <FIG>, lever <NUM> comprises a central portion 13a, a first arm 13b and a second arm 13c. In detail, first and second arms 13b, 13c extend from central portion 13a along two respective directions F, G transversal to each other. In other words, lever <NUM> is substantially V-shaped or boomerang-shaped.

More precisely, central portion 13a, first and second arms 13a, 13b form a single piece. In addition, first arm 13a and second arm 13b are rounded to each other.

Lever <NUM> is hinged to the outer end of stem <NUM> at central portion 13a; it is hinged to boom <NUM> at first arm 13b with a hinge <NUM> and it is hinged to connecting element <NUM> at second arm 13c.

In detail, hinge <NUM> is a fixed hinge and comprises a pin <NUM> defining axis C. In further detail, pin <NUM> protrudes from second stretch <NUM> and out of cavity <NUM> parallel to axis C (<FIG>).

As shown in <FIG>, the extension of first arm 13b along direction F is greater than the extension of second arm 13c along direction G. In addition, the distance between the point at which central portion 13a is hinged to stem <NUM> and hinge <NUM> is greater than the distance between the point at which central portion 13a is hinged to stem <NUM> and the point at which second arm 13c is hinged to connecting element <NUM>.

In the embodiment shown, proceeding along first arm 13b along direction F and away from central portion 13c, the extension of first arm 13b perpendicularly to direction F progressively decreases and then progressively increases. On the other hand, proceeding along second arm 13c along direction G and away from central portion 13a, the extension of second arm 13c perpendicularly to direction G progressively decreases.

As shown in detail in <FIG>, locking element <NUM> comprises a main portion <NUM> and two flange portions <NUM>.

In detail, main portion <NUM> comprises a central portion 20a and two lateral portions 20b, which extend from central portion 20a at two respective opposite ends thereof along a direction E of locking element <NUM>. In further detail, central portions 20a and lateral portions 20b are planar and rounded to one another. In addition, lateral portions 20b are perpendicular to central portion 20a. In other words, main portion <NUM> is U-shaped.

In particular, when locking element <NUM> is fitted to boom <NUM>, direction E and axis D are parallel to each other.

Each lateral portion 20b comprises, in turn, an abutment portion <NUM>, which is adapted to abut against second stop portion <NUM> when locking element <NUM> is in the second angular position (<FIG> and <FIG>). In detail, each abutment portion <NUM> is planar and is arranged at the end of the respective lateral portion 20b opposite to central portion 20a.

Flange portions <NUM> extend from central portion 20a on the same side of lateral portions 20b and are interposed between lateral portions 20b along direction E. In addition, flange portions <NUM> are spaced from each other along direction E and are identical to each other. Preferably, flange portions <NUM> are arranged symmetrically with respect to a median plane of main portion <NUM> along direction E.

As shown in <FIG>, main portion <NUM> is hinged to boom <NUM> and flange portions <NUM> are hinged to connecting element <NUM>.

In detail, main portion <NUM> is formed with two holes <NUM> through which locking element <NUM> is hinged to boom <NUM>. In further detail, each lateral portion 20b is formed with a respective hole <NUM>. As illustrated in <FIG>, holes <NUM> are through and concentric holes.

In addition, each flange portion <NUM> is formed with a respective hole <NUM>, through which locking element <NUM> is hinged to connecting element <NUM>. As illustrated in <FIG>, holes <NUM> are through and concentric holes.

Furthermore, as shown in <FIG>, connecting element <NUM> is substantially a rod comprising a first end 17a and a second end 17b, which are opposite to each other. In detail, first end 17a is hinged to second arm 13c of lever <NUM> and second end 17b is hinged to flange portions <NUM> through holes <NUM>.

As illustrated in <FIG>, locking element <NUM> is fitted to boom <NUM> in such a manner that main portion <NUM> and flange portions <NUM> face boom <NUM> and define a seat <NUM> with respect to second end 5b. More precisely, central portion 20a faces boom <NUM> on the side from which lateral portions 20b and flange portions <NUM> extend. In addition, main portion <NUM> is arranged completely external with respect to cavity <NUM>.

More precisely, seat <NUM> is delimited by central portion 20a on the side from which lateral portions 20b and flange portions <NUM> extend. Seat <NUM> is further delimited by lateral portions 20b on the side of flange portions <NUM> and second end 5b of boom <NUM>.

Furthermore, stop portions <NUM> and <NUM> can be variously conformed for the purpose of limiting the rotation of locking element <NUM> between the first and the second angular positions.

In the embodiment shown, stop portion <NUM> comprises hinge <NUM>, which acts as a detent. In detail, the portion of hinge <NUM> arranged externally with respect to cavity <NUM> is adapted to act as an abutment for locking element <NUM>, when locking element <NUM> is in the first angular position (<FIG>). In further detail, such portion of hinge <NUM> is adapted to abut against lateral portions 20b of locking element <NUM>.

Alternatively or in addition, stop portion <NUM> comprises a portion of end 5b of boom <NUM>. In detail, when locking element <NUM> is in the first angular position, locking element <NUM> abuts against end 5b. In further detail, flange portions <NUM> are adapted to contact end 5b, when locking element <NUM> is in the first angular position (<FIG>).

Stop portion <NUM> comprises a detent <NUM> arranged at second stretch <NUM> and extending transversally to direction J towards the outside of second stretch <NUM>. Detent <NUM> is completely external with respect to cavity <NUM> and comprises an abutment portion <NUM> (<FIG>). In detail, abutment portion <NUM> is adapted to contact abutment portion <NUM> of locking element <NUM> when locking element <NUM> is in the second angular position (<FIG> and <FIG>).

The operation of the locking element <NUM> according to the invention and described as above is the following. In particular, the operation will be described starting from a condition in which locking element <NUM> is in the first angular position (<FIG>).

In this condition, stem <NUM> is in the extended position and locking element <NUM> abuts against first stop portion <NUM>. In particular, lateral portions 20b abut against hinge <NUM> and/or flange portions <NUM> abut against a portion of end 5b.

Therefore, the rotation of locking element <NUM> beyond the first angular position in the rotational direction oriented from the second angular position to the first angular position is prevented.

When it is necessary to operate the operative tools fitted to boom <NUM>, stem <NUM> moves from the extended position toward the retracted position and the outer end of stem <NUM> moves closer to cylinder <NUM> along direction B. Accordingly, lever <NUM>, which is hinged to stem <NUM> rotates about axis C. In detail, with reference to <FIG>, lever <NUM> rotates clockwise about axis C.

As a consequence of the rotation of lever <NUM> and because of the fact that locking element <NUM> is operatively connected to lever <NUM> through connecting element <NUM>, locking element <NUM> rotates about axis D toward the second angular position.

When stem <NUM> reaches the retracted position, locking element <NUM> is in the second angular position. In this condition, locking element <NUM> abuts against second stop portion <NUM>. In detail, abutment portion <NUM> of locking element <NUM> abuts against abutment portion <NUM> of detent <NUM> (<FIG> and <FIG>).

Therefore, the rotation of locking element <NUM> beyond the second angular position in the rotational direction oriented from the first angular position to the second angular position is prevented.

In view of the foregoing, the advantages of handling system <NUM>, of boom <NUM> and telehandler <NUM> according to the invention are apparent.

In particular, handling system <NUM> comprises locking element <NUM>, which is rotatable between the first angular position, in which it is adapted to lock stem <NUM> in the extended position and the second angular position, in which it is adapted to lock stem <NUM> in the retracted position.

Accordingly, the risk of damage to the mechanical parts of boom <NUM> is minimized. In fact, since the rotation of locking element <NUM> beyond the first angular position in the rotational direction from the second angular position to the first angular position is prevented, stem <NUM> cannot slip beyond the extended position and away from cylinder <NUM>. The risk of damages is reduced also when boom <NUM> and the operative tools attached thereto are subjected to high loads.

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

Claim 1:
Handling system for a boom (<NUM>) of a telehandler (<NUM>) comprising:
- a cylinder (<NUM>) and a stem (<NUM>) adapted to slide within said cylinder (<NUM>) along a first direction (B);
- a lever (<NUM>) operatively connected to said stem (<NUM>) and adapted to rotate about a first axis (C) as a result of the sliding of said stem (<NUM>) within said cylinder (<NUM>); said first axis (C) being transversal to said first direction (B); and
- a locking element (<NUM>), to be hinged to a boom (<NUM>) and is operatively connected to said lever (<NUM>); said locking element (<NUM>) being rotatable about a second axis (D) parallel to said first axis (C);
wherein said locking element (<NUM>) is rotatable between:
- a first angular position, in which it is adapted to cooperate with a first stop portion (<NUM>) of said boom (<NUM>) and to lock said stem (<NUM>) in an extended position with respect to said cylinder (<NUM>); and
- a second angular position different than the first angular position, in which it is adapted to cooperate with a second stop portion (<NUM>) of said boom (<NUM>) and to lock said stem (<NUM>) in a retracted position with respect to said cylinder (<NUM>);the handling system is characterized in that it further comprises a connecting element (<NUM>), which is operatively connected to said lever (<NUM>) and said locking element (<NUM>); said connecting element (<NUM>) being adapted to transmit to said locking element (<NUM>) the rotation of said lever (<NUM>) about said first axis (C).