Telescopic boom for operating machines and relative operating machine

Abstract

A telescopic boom (20) for operating machine, preferably a telehandler (10), which comprises: - a series of extending elements (21,...,26) having cross-section decreasing from an external base extending element (21), configured to be hinged to a supporting frame (11) of the operating machine, up to a last internal extending element (26), to the free end of which an operating head (260) is associated, wherein the series of extending elements (21,...,26) comprises: o a first group of consecutive extending elements (23,..., 26), which begins with a first extending element (23) and ends with said last extending element (26), and o a second group of extending elements (21,22), which begins with the base extending element (21) and ends with a terminal extending element (22) of the second group; - a double-acting oleodynamic actuator (27) operating between the terminal extending element (22) of the second group and the first extending element (23) of the first group and placed externally to the extending elements (21,...,26) of the series of extending elements (21,...,26); - a first chain or rope return system (28) configured to operate the transmission of the relative motion imposed by the actuator (27) to the extending elements (23,...,26) of the first group, in extraction and / or in retraction; and - a second chain or rope return system (29) configured to operate the transmission of the relative motion imposed by the same actuator (27), synchronously, to each extending element (21,22) of the second group, in extraction and / or in retraction.

Description

TECHNICAL FIELD

[0001] The present invention concerns a telescopic boom for mobile operating machines (for lifting loads), preferably telehandler, and the relative operating machine (i.e. the relative telehandler).PRIOR ART

[0002] As is known, known operating machines (or working machines) are equipped with a telescopic boom for lifting loads (i.e. things or people, depending on the needs) by means of suitable working tools, such as hooks, winches, jib extensions with hook and winch, man-baskets, jib extensions with man-basket, buckets, buckets with claw, concrete mixing buckets, sweepers, snow blades and other known working tools.

[0003] The telescopic boom is usually hinged to a supporting frame (i.e. the frame of the machine or a rotating turret supported by the frame of the machine) of the operating machine, with the possibility of oscillating around a substantially horizontal oscillation axis and, therefore, moving on a vertical plane from a lowered position, substantially horizontal, to a raised position, substantially close to the vertical, by means of a hydraulic jack.

[0004] The telescopic boom is formed by a plurality of extending elements (or sections) telescopically coupled to each other, of which a "fixed" base extending element, hinged to the supporting frame of the machine with respect to said oscillation axis, and one or more "mobile" extending elements with section decreasing towards the free end of the telescopic boom to which an operating head adapted to be attached to a tool holder plate is fixed.

[0005] For telescopic booms having a number of less than or equal to four "mobile" extending elements, the use of a double-acting jack is provided, acting between the base extending element and the first "mobile" extending element of the series (proximal to the base extending element), which jack is configured to operate the drive in translational motion, in extraction and retraction, of the first extending element, and a chain or rope (and pulley) return system that transmit - synchronously - the translation motion, in extraction and contraction, from the first extending element to the other extending elements of the series. For telescopic booms having more than four "mobile" extending elements, for example five extending elements, used to have a greater extension of the telescopic boom itself, it is known to use an additional hydraulic jack, as described in patent no. 102014902283655.

[0006] A drawback found in these telescopic booms having a large number of extending elements (greater than 4) is the fact of having to use an additional jack, which - as is known - implies having to provide a dedicated hydraulic control circuit, requiring further maintenance and cleaning interventions and represents a further point of vulnerability of the telescopic boom and of the operating machine.

[0007] An object of the present invention is to overcome the mentioned drawbacks of the prior art, within the context of a simple and rational solution and at a contained cost.

[0008] These objects are achieved by the features of the invention set forth in the independent claim. The dependent claims outline preferred and / or particularly advantageous aspects of the invention.DISCLOSURE OF THE INVENTION

[0009] The invention, in particular, makes available a telescopic boom for operating machine, preferably a telehandler, which comprises: a series of extending elements having cross-section decreasing from an external base extending element, configured to be hinged (at its own free end) to a supporting frame of the operating machine, up to a last internal extending element, to the free end of which an operating head is associated, wherein the series of extending elements comprises: ∘ a first group of (four) consecutive extending elements, which begins with a first extending element and ends with said last extending element, and ∘ a second group of extending elements, which begins with the base extending element and ends with a terminal extending element of the second group; a (single) double-acting oleodynamic actuator operating between the terminal extending element of the second group and the first extending element of the first group and placed externally to the extending elements of the series of extending elements; a first chain or rope return system configured to operate the transmission of the relative motion imposed by the oleodynamic actuator to the extending elements of the first group, in extraction and / or in retraction; and a second chain or rope return system configured to operate the transmission of the relative motion imposed by the same oleodynamic actuator, synchronously, to each extending element of the second group, in extraction and / or in retraction.

[0010] Thanks to this solution, it is possible - effectively and economically - to solve the aforementioned problems of the prior art, in particular it is possible to use a single actuator for the movement of a large number of extending elements (up to, for example, eight extending elements), without thereby having to increase the capacity (size and weight) of the return systems.

[0011] A further advantage of the solution subject-matter of the invention is that the actuator, although single, is not particularly stressed or more stressed than those known and, therefore, does not require oversizing.

[0012] Still an advantage obtained by the present solution, is the fact that the extending elements that make up the first group (as well as the entire oleodynamic and / or electrical architecture thereof) define an identical and interchangeable block with shorter telescopic booms (with four extensions), with undoubted advantages in terms of keeping in stock components by the manufacturer (who may provide a substantially modular telescopic boom, in which the module formed by extending elements that make up the first group can be alternatively used for the realization of telescopic booms with five extending elements, in which the first extending element is hinged to the supporting frame, or of telescopic booms with more than five extending elements, in which the claimed base extending element is hinged to the supporting frame) and of structural validation of the telescopic boom.

[0013] In addition, an advantage due to the fact of putting the actuator to operate between the terminal extending element of the second group and the first extending element of the first group and of having a second chain or rope return system configured to operate the transmission of the relative motion imposed by the same actuator, synchronously, to each extending element of the second group (instead of, as could be hypothesized, putting the actuator between the base extending element and the proximal extending element) is the fact that (the flexible members of) the second return system, that is, operating between the base extending element and the proximal extending element) can be less oversized, that is, be of smaller sizes (than in the case hypothesized above). In fact, from structural calculations it can be noted that in order to have the same safety coefficient with the two configurations (i.e. the one claimed here and the one hypothesized) on (the flexible members of) the second return system (which, as a rule, must be >5) the quantity / capacity / size of (the flexible members of) the second return system should be tripled in the hypothesized case.

[0014] A further advantage of the solution subject-matter of the invention compared to the hypothesized solution is that the actuator is less stressed.

[0015] Advantageously, the oleodynamic actuator can have the free end of an own stem constrained to the first extending element of the first group and its own cylinder constrained to the terminal extending element of the second group, preferably near an end of the cylinder opposite the free bottom thereof (or vice versa can have the free end of an own stem constrained to the terminal extending element of the second group and its own cylinder constrained to the first extending element of the first group, preferably near an end of the cylinder opposite the free bottom thereof).

[0016] According to an aspect of the invention, the first return system may comprise a first turn of chains or ropes operating the relative extraction of the extending elements of the first group and a second turn of chains or ropes operating the relative retraction of the extending elements of the first group.

[0017] Furthermore, the second return system may comprise a respective first turn of chains or ropes operating the relative extraction of the extending elements of the second group and a respective second turn of chains or ropes operating the relative retraction of the extending elements of the second group.

[0018] Advantageously, at least one hydraulic and / or electrical circuit can be arranged at least partially inside the extending elements of the series and has an inlet section that enters in an extending element of the second group and an outlet section that exits from the last extending element of the first group at the operating head.

[0019] Also in this case, thanks to the aforementioned solution, the hydraulic / electrical circuit inside the telescopic boom contributes to the aforementioned modularity of the telescopic boom, in which the first group of extending elements, also hydraulically and / or electrically, has the same configuration for telescopic booms of different length.

[0020] Preferably, at least a portion of the hydraulic and / or electrical circuit may be housed in one or more flexible cable-carrying chains arranged within the extending elements of the series.

[0021] For the same purposes and advantages set out above, a further aspect of the invention makes available an operating machine, preferably a telehandler, which comprises: a supporting frame; a powertrain engaging the ground to allow movement of the operating machine; and a telescopic boom as described above, which is hinged to the supporting frame.

[0022] Preferably, the powertrain may comprise at least one front axle provided with two front wheels and connected to a front section of the supporting frame and at least one rear axle provided with two rear wheels and connected to a rear section of the supporting frame.

[0023] Still further, the powertrain may comprise at least one motor for driving the front wheels and / or the rear wheels in rotation.

[0024] Advantageously, the operating machine may comprise a hydraulic and / or electrical circuit for the movement and / or control of the telescopic boom and / or of a working tool fixed to the operating head of the telescopic boom.BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Further features and advantages of the invention will be more apparent after reading the following description provided by way of a non-limiting example, with the aid of the accompanying drawings. Figure 1 is a schematic side view of an operating machine, preferably a telehandler, according to the invention. Figure 2 is a side view of a telescopic boom according to the invention in a contracted position. Figure 3 is a longitudinal sectional view of Figure 2. Figure 4 is a first longitudinal sectional view of the telescopic boom of Figure 2 in an extended position. Figure 5 is a second longitudinal sectional view of the telescopic boom of Figure 2 in an extended position. BEST MODE TO IMPLEMENT THE INVENTION

[0026] With particular reference to these figures, globally indicated with 10 is an operating machine, preferably a telehandler or telescopic handler.

[0027] The telehandler 10 is provided with a supporting frame 11 movable on the ground by means of a powertrain, for example provided with wheels 12, of which a pair of front wheels 12 supported by a front axle and a pair of rear wheels 12 supported by a rear axle, of which for example at least one of the two axles is oscillating (with respect to an oscillation axis parallel to a longitudinal axis of the supporting frame 11.

[0028] The supporting frame 11 supports at the top a telescopic boom 20, which will be better described below.

[0029] Furthermore, the supporting frame 11 supports a driver's car, e.g., placed to the side of the telescopic boom 13.

[0030] The supporting frame 11 is substantially rigid (viz., non-deformable under the usual work-loads to which it is subjected in use) and / or jointed.

[0031] The supporting frame 11 has for example an elongated shape along a longitudinal axis A (defining the longitudinal axis of the telehandler 10) and therefore has, at or near a first axial end thereof, a front section, and at or near an opposite second axial end thereof, a rear section.

[0032] In the present description, front refers to the portion of the telehandler 10 or of the supporting frame 11 which precedes (viz., it is placed at the front) in a forward direction of the telehandler 10 on the ground in a usual and preferred forward travel (viz., wherein the free end of the telescopic boom 20 is placed) and rear refers to the portion of the telehandler 10 or of the supporting frame 11 which follows (viz., it is placed at the back) in a forward direction of the telehandler 10 on the ground in the usual and preferred forward travel (or which precedes a backward travel).

[0033] The supporting frame 11 could provide ground support stabilisers, of which, for example, two front stabilisers and / or two rear stabilisers.

[0034] The stabilisers are configured to stabilise the ground support of the telehandler 10, e.g., by enlarging the ground support area (viz., the ground support quadrilateral) with respect to the ground support area (or track) defined by the wheels 12 during determined work steps / conditions of the telehandler 10.

[0035] The stabilisers are individually movably associated with the supporting frame 11 (e.g., tiltable and / or extendable), as known to the person skilled in the art, by means of specific actuators.

[0036] In particular, each stabiliser is configured to be able to be switched, alternatively, between at least one work position (preferably several work positions, depending on the tilt and / or extension thereof), wherein the stabiliser is supported on the ground (e.g., in addition to or in place of the ground support defined by one or more wheels 12), and at least one rest position, in which it is raised from the ground.

[0037] The telehandler 10, as mentioned, comprises a powertrain for driving the driving wheels 12 and, indirectly, for moving the telescopic boom 20.

[0038] The powertrain comprises at least one motor.

[0039] For example, the powertrain comprises (or consists of) an endothermic engine. Alternatively or additionally, the powertrain comprises (or consists of) an electric motor. It is also not excluded that the operating machine may be different from the one described above, for example being a crawler operating machine or other.

[0040] In general, the telescopic boom 20 comprises a series of extending elements 21,..., 26 (or sections) having cross-section decreasing from an external base extending element 21 (having a larger cross-section), configured to be hinged, at its own free end, to the supporting frame 11 of the operating machine, up to a last internal extending element 26 (having a smaller cross-section), to the free end of which an operating head 260 is associated.

[0041] The extending elements 21,..., 26 can be driven between a contracted position (in which all the extending elements 21,..., 26 are, mainly, one inside the other) and an extended position (in which all the extending elements 21,..., 26 are, mainly, extended or extracted with respect to the others).

[0042] The telescopic boom 20, i.e. the proximal base extending element 21, is hinged to the supporting frame 11 so as to be able to oscillate around a (single) oscillation axis, horizontal and / or orthogonal to the longitudinal axis A of the telehandler (and to the longitudinal axis of the telescopic boom 20), by means of a (double-acting) oleodynamic jack 200, for example hinged to the supporting frame 11 and to the base extending element 21 by means of respective hinges with hinge axes parallel and eccentric with respect to the oscillation axis.

[0043] The telescopic boom 20, preferably, is hinged - at the rear free end of the base extending element 21) to the supporting frame 11, for example above it, preferably at the rear section thereof.

[0044] The telehandler 10 may further comprise an attachment device for (releasable) attachment of one (interchangeable) working tool (at a time, for example chosen from a plurality of all selectively attachable working tools) to the operating head 260 of the telescopic boom 20 of the telehandler 10.

[0045] The telescopic boom 20 thus interchangeably supports, via the operating head 260 (and the attachment device), a working tool, for example, chosen from a group of working tools comprising forks (see fig. 1), forks with spreader and shifter, grippers of various types, hooks, winches, jib extensions (for example with hook and winch), man-baskets, jib extensions with man-basket, buckets, buckets with claw, concrete mixing buckets, sweepers, snow blades and other known working tools.

[0046] The series of extending elements 21,...,26 comprises a first group of consecutive extending elements 23,... ,26, preferably in a number less than or equal to four, or in a number comprised between one and four, even more preferably in a number equal to four.

[0047] This first group of extending elements 23,...,26 begins with a first extending element 23 of the first group and ends with said last extending element 26 (provided with the operating head 260.

[0048] In the example, the first group of extending elements 23,...,26 comprises a first extending element 23, a second extending element 24, consecutive to the first extending element 23, a third extending element 25, consecutive to the second extending element 24 and the last (or fourth) aforementioned extending element 26, consecutive to the third extending element 25.

[0049] The series of extending elements 21,...,26 also comprises a second group of consecutive extending elements 21,22, preferably in a number less than or equal to four, i.e. in a number comprised between one and four, even more preferably in a number equal to two (in the example).

[0050] Said second group of extending elements 21, 22 begins with said base extending element 21 (hinged to the supporting frame 11) and ends with a terminal extending element 22 of the second group, which precedes the first extending element 23 of the first group that is consecutive to it.

[0051] In the example, the terminal extending element 22 of the second group is consecutive (and adjacent) to the base extending element 21 and, in turn, the first extending element 23 of the first group is consecutive to said terminal extending element 22, i.e. the terminal extending element is directly interposed (without interposition of other extending elements) between the base extending element 21 and the first extending element 23 of the first group.

[0052] It is not excluded, however, that one or two additional extending elements can be interposed (in a smaller number equal to 2) between the terminal extending element 22 and the base extending element 21.

[0053] In any case, the terminal extending element 22 of the second group is adjacent to (and accommodates in its inside) directly the first extending element 23 of the first group. Each extending element 21,..., 26 has a substantially box-like / tubular shape, internally hollow, i.e. each extending element 21,...,26 has a respective axial cavity, fully developed, which is open at the opposite ends (front external and rear internal).

[0054] The series of extending elements 21,...,26 that make up the telescopic boom 20 is driven, between the contracted position and the extended position, by means of a (single) double-acting oleodynamic actuator 27, i.e. a jack or hydraulic cylinder.

[0055] Preferably, the actuator 27 operates (i.e. is interposed) between the terminal extending element 22 of the second group and the first extending element 23 of the first group, i.e. is directly connected / joined to the terminal extending element 22 of the second group and the first extending element 23 of the first group.

[0056] For example, the actuator 27 is placed externally to the extending elements 21,...,26 of the series, preferably arranged above them.

[0057] The actuator 27 comprises, in particular, a cylinder within which a stem (or piston) slides and is switchable between a contracted position and an extended position.

[0058] The maximum stroke of the piston with respect to the stem is equal to the maximum stroke allowed to each extending element 21,...,26 of the series with respect to the contiguous extending element.

[0059] For example, the free end of the stem of the actuator 27 is constrained, for example rigidly fixed, to the first extending element 23 of the first group (for example to an external terminal section, proximal to the free end thereof) and the cylinder is constrained, for example rigidly fixed, to the terminal extending element 22 of the second group.

[0060] For example, the cylinder is constrained to the terminal extending element 22 near an end of the cylinder opposite the free bottom thereof (which is placed at a non-zero distance from the terminal extending element 22 so as to be able to slide externally to the base extending element 21, for example by presenting a roller or roll adapted to roll on it), for example to an external terminal section of the terminal extending element 22, proximal to free end thereof.

[0061] The telescopic boom 20 also comprises a first chain or rope return system 28 associated with the first group of extending elements 23,...,26, which is configured to operate the transmission of the relative translational motion imposed by the actuator 27 to the extending elements 23,...,26 of the first group, in extraction and / or in retraction.

[0062] In practice, the first return system 28 is configured to drive synchronously with the extraction and retraction stroke (of the stem with respect to the cylinder) of the actuator 27 a corresponding stroke (of equal extent), in extraction and retraction, of the extending elements 23,...,26 of the first group, i.e. of all these extending elements 23,...,26 of the first group (simultaneously).

[0063] In detail, with each stroke (of any extent) of extension of the actuator 27, thanks to the first return system 28, each extending element 23,... , 26 of the first group performs a corresponding (and of the same extent) stroke of extension with respect to the extending element 23,..., 26 of the first group that precedes it (in the series).

[0064] Furthermore, with each stroke (of any extent) of contraction of the actuator 27, thanks to the first return system 28, each extending element 23,...,26 of the first group performs a corresponding (and of equal extent) stroke of contraction with respect to the extending element 23,...,26 of the first group that precedes it (in the series).

[0065] The first return system 28 preferably comprises a first turn 281 of chain(s) or rope(s) (external to the telescopic boom) operating the relative extraction of the extending elements 23,...,26 of the first group and a second turn 282 of chain(s) or rope(s) (internal to the telescopic boom) operating the relative retraction of the extending elements 23,...,26 of the first group.

[0066] For example, the first turn 281 comprises a first flexible member 2811 (for example a chain or a rope) configured to drive in extraction translation the second extending element 24 (with respect to the first extending element 23).

[0067] The first flexible member 2811 has a first end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, in order to be able to adjust the traction) to a section of the terminal extending element 22 of the second group, and a second opposite end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, in order to be able to adjust the traction) to the internal rear end of the second extending element 24 and, in addition, is wound around a pulley or toothed wheel rotatably coupled to the first extending element 23 of the first group.

[0068] The thrust exerted by the actuator 27 on the first extending element 23 causes the translation of the pulley or toothed wheel, which in turn pulls the second end of the first flexible member 2811 that drags with it the second extending element 24, in extraction with respect to the first extending element 23.

[0069] Furthermore, the first turn 281 comprises a second flexible member 2812 (for example a chain or a rope) configured to drive in extraction translation the third extending element 25 (with respect to the second extending element 24).

[0070] The second flexible member 2812 has a first end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, so as to be able to adjust the traction) to a section of the first extending element 23 of the first group, and a second opposite end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, so as to be able to adjust the traction) to the internal rear end of the third extending element 25 and, in addition, is wound around a pulley or toothed wheel rotatably coupled to the second extending element 24 of the first group.

[0071] The thrust exerted by the actuator 27 on the first extending element 23 (which causes, as mentioned above, through the first flexible member 2811 the translation of the second extending element 24) causes the translation of the pulley or toothed wheel, which in turn pulls the second end of the second flexible member 2812 that drags with it the third extending element 25, in extraction with respect to the second extending element 24. Again, the first turn 281 comprises a third flexible member 2813 (for example a chain or a rope) configured to drive in extraction translation the fourth and last extending element 26 (with respect to the third extending element 25).

[0072] The third flexible member 2813 has, in turn, a first end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, so as to be able to adjust the traction) to a section of the second extending element 24 of the first group, and a second opposite end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, so as to be able to adjust the traction) to the internal rear end of the last extending element 26 and, in addition, is wound around a pulley or toothed wheel rotatably coupled to the third extending element 25 of the first group.

[0073] The thrust exerted by the actuator 27 on the first extending element 23 (which causes, as mentioned above, through the first flexible member 2811 and the second flexible member 2812, the translation of the third extending element 25) causes the translation of the pulley or toothed wheel, which in turn pulls the second end of the third flexible member 2813 that drags with it the last extending element 26, in extraction with respect to the third extending element 25.

[0074] For example, the flexible members 2811,2812 and 2813 of the first turn 281 are arranged outside and above the telescopic boom 20.

[0075] Furthermore, the second turn 282 comprises, in turn, a first flexible member 2821 (for example a chain or a rope) configured to drive in contraction translation the second extending element 24 (with respect to the first extending element 23) of the first group. The first flexible member 2821 has a first end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, in order to be able to adjust the traction) to a section of the terminal extending element 22 of the second group, and a second opposite end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, in order to be able to adjust the traction) to the inner rear end of the second extending element 24 and, in addition, is wound around a pulley or toothed wheel rotatably coupled to (behind) the first extending element 23 of the first group.

[0076] The traction exerted by the actuator 27 on the first extending element 23 causes the translation of the pulley or toothed wheel, which in turn pulls the second end of the first flexible member 2821 that drags with it the second extending element 24, in contraction with respect to the first extending element 23.

[0077] Furthermore, the second turn 282 comprises a second flexible member 2822 (for example a chain or a rope) configured to drive in contraction translation the third extending element 25 (with respect to the second extending element 24).

[0078] The second flexible member 2822 has a first end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, so as to be able to adjust the traction) to a section of the first extending element 23 of the first group, and a second opposite end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, so as to be able to adjust the traction) to the inner rear end of the third extending element 25 and, in addition, is wound around a pulley or toothed wheel rotatably coupled behind the second extending element 24 of the first group.

[0079] The traction exerted by the actuator 27 on the first extending element 23 (which causes, as mentioned above, through the first flexible member 2821, the translation of the second extending element 24) causes the translation of the pulley or toothed wheel, which in turn pulls the second end of the second flexible member 2822 that drags with it the third extending element 25, in contraction with respect to the second extending element 24. Finally, the second turn 282 comprises a third flexible member 2823 (for example a chain or a rope) configured to drive in contraction translation the fourth and last extending element 26 (with respect to the third extending element 25).

[0080] The third flexible member 2823 has, in turn, a first end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, so as to be able to adjust the traction) to a section of the second extending element 24 of the first group, and a second opposite end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, so as to be able to adjust the traction) to the inner rear end of the last extending element 26 and, in addition, is wound around a pulley or toothed wheel rotatably coupled behind the third extending element 25 of the first group.

[0081] The traction exerted by the actuator 27 on the first extending element 23 (which causes, as mentioned above, through the first flexible member 2821 and the second flexible member 2822, the translation of the third extending element 25) causes the translation of the pulley or toothed wheel, which in turn pulls the second end of the third flexible member 2823 that drags with it the last extending element 26, in contraction with respect to the third extending element 25.

[0082] For example, the flexible members 2821,2822 and 2823 of the second turn 282 are arranged inside and below the telescopic boom 20.

[0083] Particularly, for the purposes of the present invention, the telescopic boom 20 comprises a second chain or rope return system 29 associated with the second group of extending elements 21, 22, which is configured to operate the transmission of the relative translational motion imposed by the same actuator 27, synchronously, to each extending element 21,22 of the second group, in extraction and / or in retraction.

[0084] In practice, the second return system 29 is configured to drive synchronously with the extraction and retraction stroke (of the stem with respect to the cylinder) of the actuator 27 a corresponding stroke (of equal extent), in extraction and retraction, of the extending elements 21,22 of the second group, or of all these extending elements 21,22 of the second group (simultaneously).

[0085] In detail, with each stroke (of any extent) of extension of the actuator 27, thanks to the second return system 29, each extending element 21,22 of the second group performs a corresponding (and of equal extent) stroke of extension with respect to the extending element 21,22 of the second group that precedes it (in the series).

[0086] Furthermore, with each stroke (of any extent) of contraction of the actuator 27, thanks to the second return system 29, each extending element 21,22 of the second group performs a corresponding (and of equal extent) stroke of contraction with respect to the extending element 21,22 of the second group that precedes it (in the series).

[0087] The second return system 29 and the first return system 28, moreover, are also synchronous with each other, that is, at each stroke (of any extent) of contraction or extension of the actuator 27, each extending element 21,22 of the second group performs a corresponding (and of equal extent) stroke of contraction or extension (respectively) with respect to each extending element 23,..., 26 of the first group.

[0088] The second return system 29 preferably comprises a first turn 291 of chain(s) or rope(s) (internal with respect to the telescopic boom) operating the relative extraction of the extending elements 21,22 of the second group and a second turn 292 of chain(s) or rope(s) (external with respect to the telescopic boom) operating the relative retraction of the extending elements 21,22 of the second group.

[0089] For example, the first turn 291 comprises a first flexible member 2911 (for example a chain or a rope) configured to drive in extraction translation the terminal extending element 22 with respect to the base extending element 21.

[0090] The first flexible member 2911 of the first turn 291 has a first end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, so as to be able to adjust the traction) to a section of the base extending element 21 of the second group, and a second opposite end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, so as to be able to adjust the traction) to the internal rear end of the first extending element 23 of the first group and, in addition, is wound around a pulley or toothed wheel rotatably coupled to the terminal extending element 22 of the second group.

[0091] The thrust exerted by the actuator 27 on the terminal extending element 22 with respect to the first extending element 23 causes the traction of the first flexible member 2911, which drags with it the terminal extending element 22 in extraction with respect to the base extending element 21.

[0092] Furthermore, the second turn 292 comprises, in turn, a first flexible member 2921 (for example a chain or a rope) configured to drive in contraction translation the terminal extending element 22 of the second with respect to the base extending element 21.

[0093] The first flexible member 2921 of the second turn 292 has a first end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, so as to be able to adjust the traction) to the inner rear end of the first end section 23 of the first group, and a second opposite end that is fixed (rigidly, for example in a manner that can be adjusted / regulated, so as to be able to adjust the traction) to a section of the base extendable element 21 and, in addition, is wound around a pulley or toothed wheel rotatably coupled (anteriorly) to the terminal extending element 22 of the second group.

[0094] The traction exerted by the actuator 27 on the terminal extending element 22 with respect to the first extending element 23 causes the traction of the first flexible member 2921, which drags with it the terminal extending element 22 in contraction with respect to the base extending element 21.

[0095] Furthermore, the telehandler 10 comprises a control and command unit for the movement of the telescopic boom 20 and / or the working tool (and / or parts thereof), i.e. configured to control and command the movement, for example individually and / or simultaneously, of one or more uses, each of which is defined by an actuation member, for example the (single) actuator 27 (responsible for the extension and contraction of the telescopic boom 20), the jack 200 (responsible for the tilt of the telescopic boom 20) and / or any service actuators (responsible for the movement of the working tool and / or parts thereof).

[0096] The control and command unit, in particular, comprises a hydraulic circuit 30 (oleodynamic), which has a "fixed" part, i.e. arranged on board the supporting frame 11, and a "mobile" part, i.e. arranged on board the telescopic boom 20.

[0097] The hydraulic circuit 30, i.e. the fixed part thereof, comprises a valve distributor comprising one or more sections, each of which is connectable to a respective use, i.e. to the actuator 27 and to the jack 200 (in the example) and to a service actuator placed at the operating head 260 and / or the working tool mounted thereto.

[0098] The hydraulic system 30, i.e the fixed part thereof, further comprises a supply apparatus, which is configured to supply a flow rate of operating fluid to the valve distributor.

[0099] The supply apparatus comprises, in turn, a pump, which is connected to (and is driven by) the motor of the powertrain (or by a dedicated motor, for example electric).

[0100] For example, the pump is a fixed displacement pump (and rotates at the same revolutions as the motor of the powertrain).

[0101] However, it is not ruled out that the pump could be a variable displacement pump or of other types depending on the construction requirements.

[0102] A supply channel is connected to the pump through which the operating fluid is sent from the pump to the valve distributor, viz., it is supplied at high pressure to the various sections of the valve distributor.

[0103] The supply system further comprises a low-pressure (oil) tank to which the discharges of the uses (i.e. the actuator 27, the jack 200, the service actuators and other uses) are connected, via one or more discharge channels.

[0104] The pump is, for example, configured to draw operating fluid from said tank or from another suitable tank.

[0105] The hydraulic circuit 30, i.e. the movable part thereof, has at least one tube or tube bundle 31 (oleodynamic), which is used to fluidically supply the actuator 27 and / or the service actuator placed at the operating head 260 and / or the working tool mounted thereto, i.e. which connects the service actuator (in a releasable manner) with the valve distributor. For example, the tube or a tube bundle 31 comprises an external branch, which is (for example rigid) fixed to the base extending element 21 and fluidically connected to the actuator 27 for the oleodynamic operation thereof.

[0106] The tube or a tube bundle 31, moreover, has an internal branch, which is arranged at least partially inside the extending elements 21,...,26 of the series that makes up the telescopic boom 20 and has an inlet section that enters in an extending element of the second group, preferably the terminal extending element 22, for example in a front (external) terminal section thereof.

[0107] The internal branch of the tube or tube bundle 31 then comprises an outlet section that exits from the last extending element 26 of the first group at the operating head 260, and is provided with one or more releasable hydraulic fittings for connection to further service pipes to the service actuator, for the oleodynamic operation thereof.

[0108] The internal branch of the tube or tube bundle 31 develops inside the extending elements 21,...,26 of the series that makes up the telescopic boom 20 from the inlet section to the outlet section and comprises: a first portion (preferably flexible) that is inserted between the terminal extending element 22 of the second group and the first extending element 23 of the first group (in the gap between them), for example above the first extending element 23, and slides behind towards the rear end thereof, where it has a connecting curve (at 180°) and, with it, joins a second portion, preferably rigid, which is arranged inside the first extending element 23 of the first group (and rigidly fixed thereto), for example passing inside the internal cavity thereof; the front end of the second portion is then extended axially by a third portion (preferably flexible) that axially crosses the extending elements 24,..., 26 of the first group and ends with the aforementioned outlet section.

[0109] At least one of said portions, in particular at least one between the first and third portion (of the internal branch) of the tube or tube bundle 31 of the hydraulic circuit 30 is housed in a respective cable-carrying chain 32, for example in plastic, flexible and arranged inside the extending elements of the series (22 and 24,..., 26), to accompany (and keep orderly and free of crushing points / elbows) the relative portions of the tube or tube bundle 31, alternately passing between a stretched configuration (when the telescopic boom 20 is fully extended) and a configuration folded on itself, with gentle curves, (when the telescopic boom 20 retracts).

[0110] The control and command unit, in particular, may comprise an electrical circuit, which - similarly to the hydraulic circuit 30 - has a "fixed" part, i.e. arranged on board the support frame 11, and a "mobile" part, i.e. arranged on board the telescopic boom 20.

[0111] The electrical circuit is for example an electrical power line and / or an electrical / electronic signal line.

[0112] For example, the movable part of the electrical circuit comprises an electrical cable or a bundle of (flexible) electrical cables that follows the above-described path of the tube or tube bundle 31 of the hydraulic circuit 30 and has an inlet section that enters in an extending element of the second group, preferably the terminal extending element 22, for example in a front (external) terminal section thereof and an outlet section that exits from the last extending element 26 of the first group at the operating head 260, and is provided with one or more releasable electrical fittings for connection to further electrical cables or bundles of electrical cables serving the service actuator and / or other electrical utilities serving the working tool, for its operation and / or electronic control and / or for its safety, as known to the person skilled in the art.

[0113] The extension and contraction of the telescopic boom 20, as structured, is therefore commanded by the single actuator 270, which produces the relative (synchronous) and proportional sliding of all the extending elements 21,...,26 of the series, i.e. the (synchronous and proportional) extraction and retraction with respect to the base extending element 21 of all the extending elements 22,...,26 of the first group and of the second group, driven by the respective return systems 28,29.

[0114] The invention thus conceived is susceptible to many modifications and variants, all falling within the same inventive concept.

[0115] Moreover, all details can be replaced by other technically equivalent elements.

[0116] In practice, the materials used, as well as the contingent shapes and sizes, can be whatever according to the requirements without for this reason departing from the scope of protection of the following claims.

Claims

1. A telescopic boom (20) for operating machine, preferably a telehandler (10), which comprises: - a series of extending elements (21,...,26) having cross-section decreasing from an external base extending element (21), configured to be hinged to a supporting frame (11) of the operating machine, up to a last internal extending element (26), to the free end of which an operating head (260) is associated, wherein the series of extending elements (21,...,26) comprises: ∘ a first group of consecutive extending elements (23,..., 26), which begins with a first extending element (23) and ends with said last extending element (26), and ∘ a second group of extending elements (21,22), which begins with the base extending element (21) and ends with a terminal extending element (22) of the second group; - a double-acting oleodynamic actuator (27) operating between the terminal extending element (22) of the second group and the first extending element (23) of the first group and placed externally to the extending elements (21,...,26) of the series of extending elements (21,...,26); - a first chain or rope return system (28) configured to operate the transmission of the relative motion imposed by the actuator (27) to the extending elements (23,...,26) of the first group, in extraction and / or in retraction; and - a second chain or rope return system (29) configured to operate the transmission of the relative motion imposed by the same actuator (27), synchronously, to each extending element (21,22) of the second group, in extraction and / or in retraction.

2. The telescopic boom (20) according to claim 1, wherein the actuator (27) has the free end of an own stem constrained to the first extending element (23) of the first group and its own cylinder constrained to the terminal extending element (22) of the second group, preferably near an end of the cylinder opposite the free bottom thereof.

3. The telescopic boom (20) according to claim 1, wherein: - the first return system (28) comprises a first turn (281) of chains or ropes operating the relative extraction of the extending elements (23,...,26) of the first group and a second turn (282) of chains or ropes operating the relative retraction of the extending elements (23,...,26) of the first group; and - the second return system (29) comprises a respective first turn (291) of chains or ropes operating the relative extraction of the extending elements (21,22) of the second group and a respective second turn (292) of chains or ropes operating the relative retraction of the extending elements (21,22) of the second group.

4. The telescopic boom (20) according to claim 1, wherein at least one hydraulic (30) and / or electrical circuit is arranged at least partially inside the extending elements (21,...,26) of the series and has an inlet section that enters in an extending element (21,22) of the second group and an outlet section that exits from the last extending element (26) of the first group at the operating head (26).

5. The telescopic boom (20) according to the preceding claim, wherein at least a portion of the hydraulic (30) and / or electrical circuit is housed in one or more flexible cable-carrying chains (32) arranged inside the extending elements of the series.

6. An operating machine, preferably a telehandler (10), which comprises: a supporting frame (11); a powertrain (12) engaging the ground to allow movement of the operating machine; and a telescopic boom (20) according to any one of the preceding claims hinged to the supporting frame (11).

7. The operating machine according to claim 6, wherein the powertrain comprises at least one front axle provided with two front wheels (12) and connected to a front section of the supporting frame (11) and at least one rear axle provided with two rear wheels (12) and connected to a rear section of the supporting frame (11).

8. The operating machine according to the preceding claim, wherein the powertrain comprises at least one motor for driving the front wheels (12) and / or the rear wheels (12) in rotation.

9. The operating machine according to claim 7, comprising a hydraulic (30) and / or electric circuit for the movement and / or control of the telescopic boom (20) and / or of a working tool fixed to the operating head (260) of the telescopic boom (20).

Images