Cable-driven robot

Abstract

The cable-driven robot (100) comprises a base structure (1); a plurality of cables (C; C1); a movable element (EM) held suspended by the plurality of cables (C; C1); a movement system (2) for moving the cables (C; C1) and therefore for moving the movable operating element (EM) in space, comprising a plurality of winding elements (4) of the cables (C; C1) triggerable in rotation to wind / unwind the cables (C; C1). At least one cable (C1) of the plurality of cables (C; C1) is realized comprising a central core (5) and an outer cladding sheath (6). The central core (5) is made of an electrically conductive material to transmit electric current and / or command signals to the end of the cable (C1) connected to the movable element (EM), while the outer cladding sheath (6) is made of a braided synthetic material so as to provide the cable (C1) with resistance to traction and bending loads.

Description

Technical Field

[0001] The present invention relates to the technical field related to parallel robots, and in particular to a cable-driven robot. Background Art

[0002] Cable-driven robots use cables to keep components or devices suspended and move them in three-dimensional space.

[0003] A cable-driven robot comprises a fixed base structure or frame, a movable element which is held suspended by a plurality of cables and which must be moved in three-dimensional space relative to the base structure by movement of the cables after the cables have been extended or shortened.

[0004] In this regard, the cable-driven robot includes a moving system for moving the cable, ie, a moving system for extending and shortening the cable.

[0005] The moving system of the cable (S) usually comprises a plurality of moving devices, one moving device for each cable.

[0006] Each moving device comprises a cable winding element, such as a drum, and motor means for triggering the winding element to rotate in one rotational direction or the other to wind or unwind the cable thereon, wherein the cable is wound or unwound around the winding element.

[0007] In this way, each cable connected to the movable element by a first end and to a drum at a second end can be shortened (wound on the drum) or lengthened (unwound from the drum) and can therefore change its length between the fixing point of the movable element and the corresponding drum by reducing or increasing it (extension).

[0008] Thus, by appropriately actuating the various motors, for example by triggering the rotation of the corresponding drums connected thereto, thereby extending or shortening the various cables, the movable element can be moved and displaced relative to the base structure and its position in the three-dimensional workspace can be changed.

[0009] The movable operating element may comprise, for example, a tool or a platform on which operating mechanisms are mounted and pre-arranged for performing certain working operations, such as picking up and releasing objects, or other types of operations or processes.

[0010] In this type of cable-driven robot, it is often necessary to have an electric current source available, or to transmit signals such as command or control signals directly to the movable element in order to be able to trigger and command various tools, devices or operating mechanisms pre-set thereon.

[0011] Currently, a first known solution consists in directly mounting and pre-arranging a battery or another type of electrical energy storage on the movable element. However, this solution is not optimal and is not completely satisfactory, as the weight of the battery may have an impact on the movement of the movable element.

[0012] Furthermore, once the battery is depleted, it must be replaced or, if the battery is rechargeable, recharged.

[0013] Another solution currently employed consists of using a suspended structure in the form of an overhead conveyor or an articulated arm that carries the supply cable to the movable element.

[0014] This type of solution also has various disadvantages.

[0015] Firstly, this type of solution requires a considerable volume, since the support structure for the electrical cables takes up space within the base structure on which the movable element is to move.

[0016] Secondly, the movement of the support structure of the supply cable must be coordinated with the support structure of the movable element in order to follow its spatial movement relative to the base structure. Summary of the Invention

[0017] Therefore, an object of the present invention is to provide a novel cable-driven robot that can overcome the above-mentioned disadvantages of the prior art.

[0018] Therefore, in particular, it is an object of the present invention to provide a cable-driven robot which is able to provide a power supply or command or control signals directly to a movable element in a simple and effective and reliable manner.

[0019] The above-mentioned objects are achieved by a cable-driven robot according to the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The following description will illustrate features of a preferred, but not exclusive, embodiment of a cable-driven robot of the present invention with reference to the accompanying drawings, in which:

[0021] - Figure 1 An overall schematic perspective view showing a cable-driven robot of the present invention;

[0022] - Figure 2 Partially in plan view and partially in section are shown particularly important elements of the cable-driven robot of the invention for transmitting power and / or command or control signals directly to the movable element;

[0023] - Figure 3 It is along Figure 2 View of cross-sectional plane II. DETAILED DESCRIPTION

[0024] Referring to the accompanying drawings, reference numeral (100) represents as a whole a cable-driven robot of the present invention.

[0025] Cable driven robot (100) Figure 1 Shown schematically.

[0026] It comprises: a base structure (1); a plurality of cables (C; C1) and a movable element (EM), wherein the movable element is kept suspended by the plurality of cables (C; C1).

[0027] The movable element (EM) is shown purely schematically in a stylized manner: it may consist of a clamping device, a tool, an instrument or another operating mechanism, which, in order to function, must be supplied with current and / or voltage or must receive command signals for performing determined operations and / or processes.

[0028] The movable element may also be a platform on which the above-mentioned mechanisms / tools / instruments are arranged.

[0029] The cable-driven robot further comprises a movement system (2) for moving the cable (C; C1) and, therefore, for moving the movable operating element (EM) in space relative to the base structure (1).

[0030] The moving system (2) comprises a plurality of winding elements (4) for the cable (C; C1), which can be triggered to rotate in order to wind / unwind the cable (C; C1).

[0031] In this regard, the cable (C; C1) comprises a first end fixed to the movable element (EM) and a second end connected to a corresponding winding element (4) of the movement system (2).

[0032] The cable-driven robot (100) described in the present invention is characterized in that at least one cable (C1) among a plurality of cables (C; C1) is implemented in the following manner.

[0033] At least one cable (C1) (see for example Figure 2 and Figure 3 ) is made to include a central core (5) and an outer cladding sheath (6).

[0034] In detail, the central core (5) is made of a conductive material to enable the transmission of electric current and / or command signals to the end of the cable (C1) connected to the movable element (EM), and the outer sheath (6) is made of a braided synthetic material to provide the cable (C1) with resistance to pulling and bending loads.

[0035] Thus, due to the special structure of the cable (C1), in particular due to the central core made of conductive material, the cable (C1) is used to suspend and move the movable element and can therefore directly provide the movable element with power and / or command signals for its operation without having to resort to accumulators or batteries pre-installed on the movable element or an external system.

[0036] Furthermore, due to the presence of the outer covering sheath (6) made of braided synthetic material, the cable (C1) has sufficient resistance to pulling and bending loads to which it may be subjected during winding of the cable on and / or unwinding of the cable from the respective winding element, thereby causing the movable operating element (EM) to move in space relative to the base structure (1).

[0037] The cable (C1) is made such that the outer covering jacket (6) comprises a first inner layer (61) consisting of a plurality of first strands (7) arranged around a central core (5) and braided with each other to form a first braid (610) wound around the central core (5).

[0038] Each of the plurality of first strands (7) is composed of a series of monofilaments (71) made of a high-density synthetic material woven together.

[0039] The monofilaments (71) made of synthetic material used have a high elastic modulus and a high strength-to-weight ratio in order to make the cable (C1) light but at the same time resistant to high loads (e.g. at least up to 1 to 2 kN) with very low elongation (elongation at break less than 2%).

[0040] In this regard, the monofilaments (71) of the series of monofilaments (71) forming the strands (7) of the first series of strands (7) are made of high density polyethylene.

[0041] Furthermore, in order to impart wear resistance to the cable (C1), the outer sheath (6) is made to include a second outer layer (62) consisting of a plurality of second strands (8), which are arranged around a plurality of first strands (7) forming the first inner layer (61) and are braided with each other to form a second braid (620) wound around a first braid (610) formed by the plurality of first strands (7) braided with each other.

[0042] Each of the plurality of second strands (8) is composed of a series of monofilaments (81) made of a high-tenacity synthetic material braided with each other.

[0043] The monofilaments (81) of the series of monofilaments (81) forming the strands (8) of the second series of strands (8) are made of polyester, in particular 100% polyester.

[0044] Since the outer sheath has a double layer, the cable (C1) will have a high resistance to both bending and pulling loads, with minimal elongation, while also being abrasion resistant.

[0045] exist Figure 3 In the preferred but non-exclusive embodiment shown in , the first inner layer (61) of the outer sheath (6) is formed by 8 strands (7) braided with each other, the strands having monofilaments (71) made of high-density polyethylene, and the second outer layer (62) of the outer sheath (6) is formed by 14 strands (8) braided with each other, the strands having monofilaments (81) made of 100% polyester.

[0046] It is also possible to make two outer sheaths with different numbers of strands.

[0047] In a further preferred aspect, the cable (C1) is made such that the central core (5) comprises a plurality of wires (51) made of an electrically conductive material.

[0048] Specifically, a plurality of conductive wires (51) made of a conductive material forming a central core (5) are spirally wound around each other.

[0049] This makes it possible to provide the cable ( C1 ) with greater flexibility and thus facilitate its winding / unwinding from the respective winding element.

[0050] The plurality of wires (51) made of a conductive material forming the central core (5) include copper wires.

[0051] Alternatively, in another possible embodiment of the cable (C1), the central core (5) may be composed of a plurality of galvanized steel wire strands (51) helically wound around each other.

[0052] In a further preferred aspect, the cable (C1) may comprise an intermediate sheath (50) made of insulating material, sandwiched between the central core (5) and the outer cladding (6) sheath of the cable (C1).

[0053] For example, the intermediate sheath (50) made of insulating material may be made of rigid PVC.

[0054] Furthermore, in order to provide greater resistance to wear, the cable (C1) can be made to include a covering layer (not shown in detail in the drawings) arranged around the outer sheath (6) of the cable (C1) made of polyurethane.

[0055] Still other particular aspects of the invention relate to the way in which the cable movement system (2) can be implemented.

[0056] For example, Figure 1As shown, although very schematically, the cable movement system (2) comprises a plurality of movement devices (20), at least one of which is implemented to include:

[0057] a frame (21) pivotally hinged to a portion (11) of the base structure (1) about a vertical hinge axis (V) such that the frame (21) can rotate relative to the base structure (1) about the vertical hinge axis (V);

[0058] a motor (3) mounted on a frame (21);

[0059] and at least one winding / unwinding element (4) (e.g., a drum) for a corresponding cable (C; C1) of the plurality of cables (C; C1), the at least one winding / unwinding element being mounted on a frame (21) and rotatable by a motor (3).

[0060] In this way, for the cable (C1), such as the one realized as described above, it will not be necessary to use a deflection element or a cable guide element, since it will always be correctly oriented towards the movable element, since during the movement of the movable element in space, the frame pivots relative to the base structure, i.e. can rotate relative to a part of the base structure around a vertical hinge axis, and the cable will not be deflected or twisted.

[0061] Thus, the winding element of the cable, when rotating with the frame relative to the base structure, will automatically adjust its orientation and position to the position that the movable element will occupy from time to time, in effect automatically aligning with the actual position occupied by the movable element.

[0062] Essentially, the cable portion comprised between the movable element and the winding element will always be substantially perpendicular to the axis of rotation of the winding element.

[0063] This will prevent unwanted additional stress from being applied to the cable due to bending or twisting, which could cause wear and degradation of the cable over time.

[0064] As is clear from the above description, the cable-driven robot object of the present invention will successfully provide current supply and / or command signals directly to the movable element by utilizing at least one of the cables used to keep the same movable element suspended and moving, thereby avoiding the problems highlighted in the introduction that exist in the prior art.

Claims

1. A cable-driven robot (100), comprising: Base structure (1); Multiple cables (C; C1); a movable element (EM) held in suspension by said plurality of cables (C; C1); a movement system (2) for moving the cable (C; C1) and, therefore, for moving the movable element (EM) in space relative to the base structure (1), the movement system comprising a plurality of winding elements (4) for the cable (C; C1) which can be driven in rotation to wind / unwind the cable (C; C1), wherein the cable (C; C1) comprises a first end connected to the movable element (EM) and a second end connected to a corresponding winding element (4) of the movement system (2); At least one cable (C1) of the plurality of cables (C; C1) is manufactured in such a manner as to comprise a central core (5) and an outer cladding sheath (6), wherein the central core (5) is made of an electrically conductive material so as to be able to transmit an electric current and / or a command signal to the end of the cable (C1) connected to the movable element (EM); wherein the outer sheath (6) is made of a braided synthetic material to provide the cable (C1) with resistance to pulling and bending loads, characterized in that the outer sheath (6) comprises a first inner layer (61), the first inner layer comprising a plurality of first strands (7), the plurality of first strands (7) being arranged around the central core (5) and braided with each other to form a first braid (610) wound around the central core (5), wherein each of the plurality of first strands (7) is composed of a series of monofilaments (71), the series of monofilaments being made of a high-density synthetic material braided with each other, wherein the monofilaments (71) made of the high-density synthetic material in the series of monofilaments (71) of the strands (7) forming the first series of strands (7) are composed of a high-density The invention relates to a method for manufacturing a protective layer of the present invention for protecting a plurality of first strands (7) from the wear of the wearer and for protecting a plurality of second strands (8) from the wearer. The protective layer comprises a plurality of second strands (8) arranged around the plurality of first strands (7) forming the first inner layer (61) and braided with each other to form a second braid (620) wound around the first braid (610) formed by the plurality of first strands (7) braided with each other, wherein each of the plurality of second strands (8) is composed of a series of monofilaments (81) made of a high-tenacity synthetic material braided with each other, wherein the monofilaments (81) made of a high-tenacity synthetic material in the series of monofilaments (81) of the strands (8) forming the second series of strands (8) are made of polyester.

2. The cable-driven robot (100) according to claim 1, wherein: The central core (5) comprises a plurality of wires (51) made of a conductive material.

3. The cable-driven robot (100) according to claim 2, wherein: The plurality of conductive wires (51) made of a conductive material forming the central core (5) are spirally wound around each other.

4. The cable-driven robot (100) according to any one of the preceding claims 2 and 3, wherein: The plurality of wires (51) made of conductive material forming the central core (5) include copper wires.

5. The cable-driven robot (100) according to claim 1, wherein: The central core (5) is composed of a plurality of galvanized steel wire strands (51) that are spirally wound around each other.

6. The cable-driven robot (100) according to claim 1, comprising an intermediate sheath (50) made of insulating material, the intermediate sheath being sandwiched between the central core (5) and the outer cladding sheath (6) of the cable (C1).

7. The cable-driven robot (100) according to claim 6, wherein: The intermediate sheath (50) made of insulating material is made of PVC.

8. The cable-driven robot (100) according to claim 1, comprising a covering layer arranged around the outer covering sheath (6) of the cable (C1) made of polyurethane.

9. The cable-driven robot (100) according to claim 1, wherein: The moving system (2) of the cables comprises a plurality of moving devices (20), at least one of the plurality of moving devices being implemented as comprising: a frame (21) pivotally hinged to a portion (11) of the base structure (1) about a vertical hinge axis so that the frame (21) can rotate relative to the base structure (1) about the vertical hinge axis; a motor (3) mounted on the frame (21); and at least one winding / unwinding element (4) of a corresponding cable (C; C1) of the plurality of cables (C; C1), the at least one winding / unwinding element being mounted on the frame (21) and rotatable by the motor (3).

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