This application is a National Stage entry of International Application No. PCT/IB2013/001409, filed Jul. 2, 2013, which claims priority to Italian Patent Application No. MO2012A000170, filed Jul. 6, 2012. The disclosures of the prior applications are hereby incorporated in their entirety by reference.
The object of the invention is 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 means of suitable hydraulic jacks.
The telescopic arm is formed by a tubular outer arm and one or more coaxial slip-off elements, which have decreasing tubular section, are coupled telescopically and whose outgoing and ingoing movements need one or more 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 transfer system is used linking the first slip-off member (operated directly by the jack) to the subsequent ones, so that its outgoing or ingoing stroke is transmitted at the same time and in the same extent also to the other slip-off elements.
The last of said slip-off elements has, associated thereto, an operative head, aimed at supporting, by suitable connection means, the tools aimed at performing specific operations, for example, forks, hooks or the like, in order to move the loads from the ground to the height, or vice versa, or aerial work platforms to move one or more workers to a working area situated over 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, following the change of the length of the same arm as a result of the extension and return of various slip-off 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 slip-off elements, various constructive tricks are known, for example, the introduction of the flexible pipes into articulated pipe holding channels, of the same type as those used for electric cables.
The Industrial Patent Application N. MO2011A000333 filed on 23 Dec. 2011 by the Applicant, protects a “Method and apparatus for keeping flexible pipes or conduits situated side by side in an orderly way”, in which the latter are placed side by side and parallel and become integral by means of gluing, heat welding or with help of joining elements arranged at prefixed distance intervals. Consequently, the bundle of pipes obtained according to said method can be bent by 180° or more, and allows such a curve to move dynamically during the outgoing and ingoing movements of the slip-off member, without reciprocal movements among the single pipes.
Another known solution includes a pulley, associated to its slip-off member, 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 only to arms having at most three slip-off elements. Consequently, it is obvious that a considerable number of components are required, which must be placed correctly, so as not to interfere with the respective functions, to provide a telescopic arm with a system for moving the slip-off elements and a hydraulic circuit for supplying the tools situated at its end; obviously, the number of components and the respective location problems increase together with the increasing number of slip-off elements. In particular, the constructive solutions used so far for telescopic arms with four slip-off elements are not optimal, because:
Therefore, it is an object of the present invention to propose a telescopic arm for operating machines, in particular of the type with four slip-off elements, capable of overcoming the reported drawbacks of the prior art, related to the drive system of outgoing and ingoing movements of the latter, as well as the hydraulic circuit aimed at supplying the operative head and/or tool.
Another object of the invention is to obtain a telescopic arm, in which the above mentioned hydraulic circuit for supplying the operative head and/or tool is housed inside the slip-off elements, both for greater protection against unintentional pipe breaking and for better aesthetic neatness of the arm.
A further object of the invention is to obtain a telescopic arm, in which the operation logic of the slip-off elements drive system is compatible with the requirement of the configuration of the above mentioned hydraulic circuit, and is as simple and compact as possible.
The above mentioned objects are wholly obtained by a telescopic arm for operating machines, of the type including a tubular outer arm, hinge-articulated to a platform provided in said machine, four coaxial slip-off members having a tubular decreasing section, respectively, first, second, third and fourth member, from the biggest to the smallest one, and an operative head associated at the free end of said fourth slip-off member, with said telescopic arm being tiltable in a vertical plane, from a substantially horizontal position to a nearly vertical one and aimed at assuming a close configuration, in which said slip-off members are introduced one into another and housed in said outer arm, and an open configuration, in which the same slip-off members are at least partially extended to place the above mentioned operative head in a prefixed working area, with the same telescopic arm including:
The characteristics of the invention will become obvious from the following description of a preferred embodiment of the telescopic arm under discussion, in accordance with the contents of claims and with help of the enclosed drawings, in which:
With reference to the above mentioned figures, the reference numeral 1 indicates the telescopic arm under discussion, as a whole.
The telescopic arm 1 is aimed at fitting out known self-propelled operating machines (not shown), for example, used in building industry, agriculture, earthmoving or others.
Normally, the telescopic arm 1 is 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.
The telescopic arm 1 is formed, in a way known in itself, by a tubular outer arm 2 and four coaxial slip-off elements having decreasing tubular section, coupled in a telescopic way, from the biggest to the smaller one, respectively, first 10, second 20, third 30 and fourth 40.
An operative head 3, associated to the free end of said fourth slip-off member 40, is aimed at supporting, by means of suitable connection means, tools aimed at performing specific operations; said connection means and tools, of known type, have not been shown, since not directly relevant to the invention. The telescopic arm 1, in accordance with the invention, is provided with a system 100 for moving synchronously and with the same extent said slip-off elements 10, 20, 30, 40 in their outgoing and ingoning strokes.
In a close configuration C of the telescopic arm 1 (
The system 100, supported in part outside of the telescopic arm 1 and in part inside it, includes:
The above mentioned first rope driving means 110, according to the preferred embodiment, include in turn:
The above mentioned second rope driving means 120, in the shown example, include in turn:
The telescopic arm 1 includes also a hydraulic circuit 200 housed therein, aimed at being connected to an outer hydraulic system 166, associated to the respective operating machine and comprising, in known way, high pressure pumps, selector valves and whatever is necessary to obtain fluid under pressure to be introduced into the hydraulic circuit 200 and supply, thereby, hydraulic actuators of the operative head 3 and/or the tool mounted thereon.
According to the prior art, the hydraulic circuit 200 is formed by feed pipes and return pipes, which allow to return the fluid from the operative head 3 toward said hydraulic system.
The hydraulic circuit 200 is suitably positioned inside the telescopic arm 1, so as not to interfere with the above mentioned second rope driving means 120, and includes:
The first support 214, which binds the first pulley 212 to the first slip-off member 10 is advantageously provided with first spring tensioner 215, which allows the pulley 212 to make small resilient movements in a direction parallel to the longitudinal axis X of the telescopic arm 1, so as to avoid anomalous tensile stresses on the first flexible pipes 211 (
Likewise, the second support 224, which binds the second pulley 222 to the third slip-off member 30 is provided with second spring tensioner 225 (see again
A “U”-profile channel-like holder 22 is fastened inside the second slip-off member 20, so as to hold and protect lower branches 221i of said second flexible pipes 221, delimited by their engagement with said second pulley 222 (
The channel-like holder 22 avoids interferences between said lower branches 221i and the mentioned fifth chain C5, which is situated directly underlying (
The channel-like holder 22 is supported only at its rear part, while the fore cantilevered end is provided with wheels 23 aimed at rolling on the lower horizontal walls of the tubular elements that form the third and fourth slip-off members 30, 40 (
This prevents the channel-like holder 22 from downward bending and the subsequent third and fourth slip-off elements 30, 40 from being unintentionally hit during their return movement.
The channel-like holder 22 is functionally more advantageous with the maximum extent of said lower branch 221i, that is, when the telescopic arm 1 is in close configuration C (
It appears obvious from the above description how the constructive and functional aspects of the system 100, for moving synchronously and with the same extent said slip-off elements 10, 20, 30, 40, are combined in best way with those of the hydraulic circuit 200, having the inner pipes kept stretched and in order, so as to obtain an original telescopic arm 1 with four slip-off elements, having peculiar characteristics, which make it advantageous with respect to the prior art solutions.
The configuration of the hydraulic circuit, with two groups of hydraulic conduits connected in series, each of which is provided with its own pulley for keeping stretched the respective flexible pipes, meets the functional requirements and allows a high protection against unintentional pipe breaking and better aesthetic neatness of the arm.
The channel-like holder provided in the second of the slip-off elements gives an important functional contribution to the “coexistence” of many members inside the slip-off elements, by preventing anomalous and potentially dangerous interference in the most packed area.
It is anyway understood that what above, has been described as a pure, non limiting example, therefore, possible constructive variations and/or changes of details remain within the same protective scope defined by the claims below.
Number | Date | Country | Kind |
---|---|---|---|
MO2012A0170 | Jul 2012 | IT | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/IB2013/001409 | 7/2/2013 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2014/006474 | 1/9/2014 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
2571858 | Garland | Oct 1951 | A |
4034875 | Pugh | Jul 1977 | A |
20030205547 | Dupre et al. | Nov 2003 | A1 |
Number | Date | Country |
---|---|---|
3447095 | Jul 1986 | DE |
Entry |
---|
International Search Report of PCT/IB2013/001409 dated Oct. 24, 2013. |
Number | Date | Country | |
---|---|---|---|
20150151954 A1 | Jun 2015 | US |