EP3174821B1

EP3174821B1 - Telescopic arm for operating machines

Info

Publication number: EP3174821B1
Application number: EP15762701.9A
Authority: EP
Inventors: Riccardo Magni
Original assignee: CMC SRL
Current assignee: CMC SRL
Priority date: 2014-07-30
Filing date: 2015-07-21
Publication date: 2018-05-09
Anticipated expiration: 2035-07-21
Also published as: WO2016016700A1; ES2679193T3; EP3174821A1

Description

DESCRIPTION OF THE INVENTION

The invention relates to a telescopic arm aimed at fitting out self-propelled operating machines used in many fields, for example, building industry, agriculture or others.
The telescopic arm is usually articulated to a platform of the operating machine, with possibility to tilt in a vertical plane from a substantially horizontal position to a nearly vertical one, by action of suitable hydraulic jacks.
It is composed of a tubular outer arm and one or more coaxial extensible sliding elements, having decreasing tubular section, coupled in a telescopic fashion, whose motion outwards and inwards is operated by usually hydraulic jacks.
In order to avoid the increase of the number of jacks or the use of multistage jacks, when there are more slip-off members, a chain or cable transfer system is used between the first extensible sliding element (operated directly by the jack) and the subsequent ones, so that their extension and return strokes are transmitted at the same time and with unitary mutual relationship also to the other extensible sliding elements.
The last of said extensible sliding elements is equipped with an operative head associated thereto. The operative head is aimed at supporting, by suitable connection means, tools for performing specific operations, for example, forks, hooks or the like designed to move loads from the ground upwards, or vice versa, or aerial work platforms, used to take one or more workers to a working area raised from the ground.
The operative head must have enough degrees of freedom with respect to the arm, so as to place the tool or the aerial work platform in the correct working position, whatever tilting angle the telescopic arm has assumed.
The tool, in turn, can be provided with moving elements and actuators which control such movements; for these reasons, the telescopic arm must be associated with a bundle of hydraulic pipes, capable of supplying, as well as allowing the return of the fluid under pressure to and from the operative head, thus permitting the change of the length of the same arm as a result of the extension and return of various extensible sliding elements,
Therefore, the hydraulic pipes mentioned above, must be of flexible type, for at least a part of their length.
In order to prevent the flexible pipes from assuming uncontrolled positions, which imply the risk of twisting, in particular during the returning step of the extensible sliding elements, various constructive tricks are known, for example, introduction of the flexible pipes into articulated pipe supporting channels, of the same type as those used for electric cables.
According to the Patent Application n. MO2011A000333 filed on 23/12/2011 by the same Applicant, the pipes are arranged one beside another and mutually parallel, so as to make them integral.
Consequently, the bundle of pipes obtained according to said method can be bent by 180° or more, and allows a dynamic positioning of such a curve during the extending and returning movements of the extensible sliding element, without reciprocal movements among the single pipes.
Another known solution includes a pulley, associated to its extensible sliding element, aimed at engaging the flexible pipes along the part, in which they are bent by 180°, keeping them stretched during the returning step.
The just mentioned solutions, concerning the above mentioned hydraulic circuit, are applied in the prior art only to arms with at most three extensible sliding elements.
The number of telescopic sliding elements influences the total length of the arm at its maximum extension and it does not allow to go below some determined values of length of the arm in closed position with the same length of extension. The last condition is particularly important, but it is hindered by the limitation of the prior art that requires a limited length of a telescopic arm having four extensible sliding elements, both in the closed position and the extended position.

WO2O141O08474 discloses such a machine.

The main object of the present invention is to obviate the limitation indicated in the prior art, in particular for machines capable of mounting telescopic arms, whose maximum length is more than 30 m, maintaining at the same time the length of the same arm in the closed position quite limited without losing anything in terms of performance and effectiveness of the machine also in connection with efficiency characteristics of the hydraulic circuit feeding the operative head and/or the tool which is to be manipulated by the arm.
The above mentioned objects are wholly obtained by a telescopic arm for operating machines as described and claimed in the following description and claims.
The characteristics of the invention will become more apparent from the following description of a preferred, but non only embodiment of the invention, illustrated by way of not limiting example with help of the enclosed figures, in which:

Fig. 1 is a schematic side view, shown partially in section along an axial plane, of the arm in an open configuration, with the extended sliding elements;
Fig. 2 is a schematic side view in enlarged scale of a closed configuration with the returned sliding elements;
Figs. 3 and 4 exemplify, in a schematic side view partially in section along an axial plane and with some parts not shown, two configurations of the extension and removal sequence;
Figs. 5 and 6 exemplify, in a schematic side view partially in section along an axial plane and with some parts not shown, two configurations of the extension and removal sequence.

With reference to the above mentioned Figures, the reference numeral 1 indicates a telescopic arm for operating machine, of the type including a plurality of coaxial extensible sliding elements, which is constrained, in the region of its own base end, to a platform, not shown in the Figures, associated to said operating machine. The telescopic arm 1 is constrained to an outer base element 2, which is hinged to said platform, not shown, by means of an articulation pin 13. The outer base element 2 has a tubular form. The extensible sliding elements of the telescopic arm 1 are arranged telescopically in coaxial relationship and have a cross-section decreasing from the first to the last element, the free end of this last element is provided with an operating head 3 equipped with a suitable hydraulic supply obtained by a bundle of pipes, which runs along the whole telescopic arm 1, so as to allow the hydraulic operation of different types of tools that can be mounted thereon.
The extensible sliding elements of said plurality are aimed at assuming, on command, mutual positions which allow the telescopic arm 1 as a whole to have any configuration or length, comprised between two extreme configurations: a closed configuration (C), in which they are at least partially inserted one into another to define a minimum overall length of the telescopic arm 1, shown schematically in Figure 2, and an open configuration (A), in which they are mutually positioned in such a way to define the maximum extension or overall length of the telescopic arm (1) and vice-versa.
The telescopic arm 1 includes: a synchronous driving system, for length extension and retraction of the extensible sliding elements, which is partially supported outside of the same telescopic arm 1 and a hydraulic circuit, mainly housed within said telescopic arm 1 and consisting of hydraulic conduits which include fixed pipes and hoses, respectively, which are kept stretched, in the extension and retraction motion of the extensible sliding elements, by corresponding idle pulleys supported by the latter.
The above mentioned plurality of extensible sliding elements consists of five extensible sliding elements in all and comprises as follows, at least one coaxial extensible sliding base element 500, which is coupled to the external base element 2 and to which a first extensible sliding element 100 is coupled, wherein these elements can be extracted consecutively from one another in the axial direction.
A second extensible sliding element 200, a third extensible sliding element 300 and a fourth extensible sliding element 400 are coupled in succession and to the first extensible sliding element 100.
There are provided a first hydraulic actuator 11, placed externally with respect to the telescopic arm 1 and operating, upon command, between the outer base element 2 and the coaxial extensible sliding base element 500, and a second hydraulic actuator 12 operating between the coaxial extensible sliding base element 500 and the first extensible sliding element 100.
Overall, the telescopic arm 1 is at least adjustable around the articulation pin 13, by which it is hinged to the platform of the operating machine, not shown in the enclosed Figures.
The second hydraulic actuator 12, which operates between the coaxial extensible sliding base element 500 and the first element extensible sliding element 100, is arranged externally with respect to the telescopic arm 1 in opposite position with respect to the first hydraulic actuator 11, and has the outer end of its stem 121 constrained to the withdrawing arm 100, while it has its cylinder 122 constrained firmly to the coaxial extensible sliding base element 500 in the region of its fore end, The bottom side end of the cylinder 122 is free to overlap, at least partially, the outer cylindrical surface of the outer base element 2 and to run with respect thereto in a direction parallel to the axis of the telescopic arm 1.
The bottom side end of the cylinder 122 of the second hydraulic actuator 12 is provided with sliding means, through which it is adapted to slide freely on the outer surface of the outer base element 2 with a total stroke corresponding to the total stroke of the coaxial extensible sliding base element 500 with respect to the outer base element 2.
The sliding means, associated to the bottom side end of the cylinder 122 of the second hydraulic actuator 12 are constituted by a sliding pulley or roller 123 pivoted freely to the same end and guided to run freely in the parallel direction with respect to the axis of the telescopic arm 1, along a portion of the outer surface of the outer base element 2. The pulley or roller 123 is spaced apart from the point in which the coaxial extensible sliding base element 500 joins the corresponding fore end of the cylinder 122. Therefore, its total stroke with respect to the outer base element 2 is not less than the total stroke of the coaxial extensible sliding base element 500 with respect to the same outer base element 2.
The whole telescopic arm 1 includes a system for operating the extensible sliding elements, not driven directly by the first and said second hydraulic actuators 11 and 12, which comprises chain and/or cable transmission means, which are operated as a result of the synchronous and proportional strokes, imposed to the related extensible sliding elements by said hydraulic actuators, during extension and retraction.
There are first cable transmission means, operated as a result of the extending motion of the extensible sliding elements operated by the first and second actuators 11 and 12 and aimed at making the remaining extensible sliding elements perform their respective extension movements synchronous and proportional to the one of the same extensible sliding element.
Similar second cable transmission means are provided to impose respective synchronous and proportional return movements.
The hydraulic circuit for supplying the telescopic arm 1 comprises first fixed hydraulic conduits 4, coming from outside and housed externally with respect to the outer base element 2.
The ends of said fixed conduits 4 are equipped with connections 5, which lead to the inside of the wall of the outer base element 2, between the latter and the coaxial extensible sliding base element 500. The first ends of the first flexible conduits 6 are sealingly connected to the connections 5, whereas the second ends of the first flexible conduits are sealingly connected to the corresponding ends of second fixed conduits 7 arranged firmly inside the coaxial extensible sliding element 500.
The second ends of the second fixed conduits 7 are bent backwards, by an angle of 180°, and are sealingly connected to the corresponding flexible conduits 8, wound around a first idling pulley 9, by which they are routed to the subsequent extensible sliding elements with a repeating pattern of what has been illustrated before, and according to which the second ends of the flexible conduits 8 are sealingly connected to the third fixed conduits 15, integral with the second extensible sliding element 200. The corresponding flexible conduits 16 are sealingly connected to the folded ends of the third fixed conduits 15, with the flexible conduits 16 being wound around a second idling pulley 19, by which they are routed to the next remaining extensible sliding elements.
The extension and the return of the extensible sliding elements are carried out with a proportional electric control directly from the cab of the operating machine, to whose platform the same telescopic arm 1 is hinged.
The sliding sequence is pre-determined: the second hydraulic actuator 12 is operated first; which causes the proportional dragging and consequently motion outwards of the extensible sliding elements 100, 200, 300 and 400. Then the first hydraulic actuator 11 is operated, which concludes the outward motion and extension, thus making the coaxial base sliding element 500 go out.
On the contrary, the return sequence includes the operation of the first hydraulic actuator 11, and then the return of the coaxial base sliding element 500 and then the activation of the second hydraulic actuator 12, which causes the return of the extensible sliding elements 100, 200, 300 and 400.
Cable reel sensors (usually a micro-switch at the outlet and one at the inlet) are provided so as to reset the system.
The advantages of the invention derive substantially from the size reduction of the telescopic arm in the closed position with the possibility to obtain the same maximum length in its maximum extension configuration, especially for maximum heights over 30 m.

Claims

A telescopic arm (1) for an operating machine, of the type including a plurality of coaxial extensible sliding elements, wherein the telescopic arm is constrained, in the region of its own base end, to a platform, associated to said operating machine, by means of a outer base element (2), hinged to said platform; said extensible sliding elements being arranged telescopically in coaxial relationship and having a cross-section decreasing from the first to the last element, the free end of this last element being provided with an operating head (3) with a hydraulic supply; the extensible sliding elements of said plurality being designed to switch, upon command, between two extreme configurations: a closed configuration (C), in which they are at least partially inserted into one another to define a minimum overall length of the telescopic arm (1), and an open configuration (A), in which they are mutually positioned in such a way to define a maximum overall length of the telescopic arm (1); the telescopic arm (1) including: a synchronous driving system, for length extension and retraction of said extensible sliding elements, which is partially supported outside of the same telescopic arm (1); a hydraulic circuit, mainly housed within said telescopic arm (1) and consisting of hydraulic conduits which include fixed pipes and hoses, respectively, which are kept stretched, during the extension and retraction motion of said extensible sliding elements, by corresponding idle pulleys supported by the latter, said plurality comprising, at least one coaxial extensible sliding base element (500), which is coupled to the outer base element (2) and to which a first said extensible sliding element (100) is coupled, wherein these elements can be extracted consecutively from one another in the axial direction; with a second extensible sliding element (200), a third extensible sliding element (300) and a fourth extensible sliding element (400) coupled in succession to said first extensible sliding element (100); there being provided a first hydraulic actuator (11), placed outside the telescopic arm (1) and operating between the outer base element (2) and the coaxial extensible sliding base element (500), and a second hydraulic actuator (12) operating between the coaxial extensible sliding base element (500) and the first extensible sliding element (100); characterized in that the second hydraulic actuator (12), operating between the coaxial extensible sliding base element (500) and the first extensible sliding element (100), is arranged outside with respect to the telescopic arm (1) and has an end of its stem (121) secured to the extensible sliding arm (100), and has its cylinder (122) firmly attached, in the region of its own fore end, to the coaxial extensible sliding base element (500) and its bottom side end free to overlap, at least partially, the outer surface of the outer base element (2) and to slide with respect to it, in a direction parallel to the axis of the telescopic arm (1).
A telescopic arm according to claim 1, characterized in that said bottom side end of the cylinder (122) of the second hydraulic actuator (12) is equipped with sliding means, through which it is adapted to slide freely on the outer surface of the outer base element (2) with a total stroke corresponding to the total stroke of the coaxial extensible sliding base element (500) with respect to the outer base element (2).
A telescopic arm according to claim 2, characterized in that said sliding means, associated to said bottom side end of the cylinder (122) of the second hydraulic actuator (12), consist of a sliding pulley or roller (123) freely pivoted to said end and driven to slide freely in a direction parallel to the axis of the telescopic arm (1) along a portion of the outer surface of the outer base element (2).
A telescopic arm according to claim 1, characterized in that said hydraulic circuit for the supply of the telescopic arm (1) includes first fixed hydraulic conduits (4), coming from the outside and housed in part externally with respect to the outer base element (2); the ends of said fixed conduits (4) being equipped with connections (5) which lead to the inside of the wall of the outer element of the base (2), between this latter and the coaxial extensible sliding base element (500); first ends of the first flexible conduits (6) being sealingly connected to said connections (5) whereas second ends of the first flexible conduits are sealingly connected to corresponding ends of second fixed conduits (7) arranged firmly inside the coaxial extensible sliding element (500); second ends of said second fixed conduits (7) being bent backwards and being sealingly connected with corresponding flexible conduits (8) which wind around a first idling pulley (9) through which they are routed to the said subsequent extensible sliding elements.
A telescopic arm according to claim 1, characterized in that it includes a system for driving said extensible sliding elements which are not driven directly by said first and second hydraulic actuators (11) and (12) cable transmission means, which are operated as a consequence of the synchronous and proportional strokes applied to the related extensible sliding elements by said hydraulic actuators, during extension and retraction motion.