Field of the invention

The present invention relates to a guidance element with internal conduit between two constructional parts. The invention also relates to a construction comprising such a guidance element. Additionally, the invention relates to a method for manufacturing such a guidance element. Background

In general, an (electrical) connection between two parts moving relative to each other is needed for many applications. A large variety of solutions exists like "roll up" (e.g. vacuum cleaner), cable schlepp (e.g. forklift), telescopic guidance, etc. In an aircraft, such connections can be found at doors and in the landing gear. It is foreseen that some moving components have been "passive" until now, but may include some "active" subsystems in near future aircraft models. An example is a wing flap in which e.g. electrical (de-icing) equipment may be installed. Consequently, an electrical connection between the fixed wing and movable flap has to be installed. At the moment, no obvious solutions for this type of connection exist on the market.

In WO2009130473 an example of present available technology to route cables through/along pivots is given. In order to guide the cable along the pivot of the hinge, the cable is wound around the pivot axis with the winding axis coincident with the pivot axis of the links. Disadvantageously, this arrangement requires multiple

"complete windings" of the cable around the pivot axis, which requires a large winding radius for thick cables as the typical allowed bending radius is in the order of magnitude of 5-10 ^χ the cable diameter. This results in a relative large and bulky solution. Secondly, for this solution, the cables are allowed to "shave" as each winding can shave against adjunct windings/housing. Furthermore, the "effective length" of the cable changes when the pivot rotates due to winding/unwinding of the cable, also causing shaving of the cable with respect to its housing.

In US20130233967 a cable arrangement is disclosed in which the cable is routed through the pivot axis between the fixed part and the moveable part.

Disadvantageously, the cable arrangement of US20130233967 requires large joints for thick cables as a result of the allowable bending radius of 5-10 ^χ the cable diameter. This results in a relative large and bulky solution. Secondly, for this solution, the cables are "exposed" at the joints and possible shaving of the cable at the exposed section near the joint is not inherently prevented.

It is an object of the present invention to provide a guidance element and a method for manufacturing such a guidance element that overcome or mitigate the above detrimental effects.

Summary of the invention

The above object is achieved by a guidance element between two constructional parts, that are pivotable relative to each other around an intermediate pivot axis, comprising a flexible routing element, a first hinging part and second hinging part; the flexible routing element comprising at least a first flexible bellows or tube;

the at least first flexible bellows being attached to an inward surface of the first hinging part on a first end and being attached to an inward surface of the second hinging part on a second end of the flexible routing element;

the first and second hinging parts each being adapted with at least a first conduit and the at least first flexible bellows being arranged as flexible conduit, the conduits of the first and second hinging parts and the flexible conduit of the at least first flexible bellows forming a continuous first internal conduit between an entry on the first hinging part and an exit on the second hinging part;

the flexible routing element further comprising at least a first leaf spring, wherein the at least first leaf spring is arranged extending parallel to the length of the at least first flexible bellows, the at least first flexible bellows attached on a first portion of its periphery to an adjoining first edge of said at least first leaf spring;

the flexible routing element intersecting the intermediate pivot axis perpendicularly, the intermediate pivot axis coinciding with the width of the at least first leaf spring.

The invention provides that the guidance element is capable to function as a hinge element for a relative motion between two parts, e.g., a fixed part and a moveable part. The flexible routing element can bend when the orientation of the first hinging part relative to the second hinging part changes around the intermediate pivot axis. Since the flexible routing element is fixedly attached to the hinging parts and holds dimensionally stable leaf springs between them, the length of the flexible bellows does j

not change. Thus, any linear element inside the bellows will not be exposed to any changes in length.

Additionally, the leaf springs provide that the flexible bellows will follow the bending line of the leaf springs between the hinging parts. An linear element within the flexible bellows will bend accordingly without any movement with respect to the length of the flexible bellows, i.e., without shaving of the linear element on the interior of the bellows. In addition, the leaf springs prevent torsion of the flexible bellows and the linear element.

Since the flexible bellows provides a sealed channel between the first and second hinging parts, the linear element is screened from the environment. In this manner, the linear element is protected from exposure to dust, particles, moisture, and/or harsh environments.

According to an aspect, the invention provides a guidance element as described above, wherein the flexible routing element comprises a second leaf spring, the second leaf spring arranged extending parallel to the length of the at least first flexible bellows and the at least first leaf spring, the second leaf spring attached on a second portion of the periphery of the at least first flexible bellows to an adjoining edge of said leaf spring, wherein the second portion of the periphery of the at least first flexible bellows is diametric to the first portion, the intermediate pivot axis, the intermediate pivot axis coinciding with the width of the first and second leaf springs.

According to an aspect, the invention provides a guidance element as described above, wherein the internal conduit is arranged receiving and guiding an linear [linear] element, and the flexible bellows being arranged as flexible conduit through which the linear element is to extend between the first and second hinging parts.

According to an aspect, the invention provides a guidance element as described above, wherein each leaf spring is a substantially rectangular plate, and the flexible bellows overlaps each leaf spring at the adjoining edge.

According to an aspect, the invention provides a guidance element as described above, wherein the first and second hinging parts are coupled by a pair of flexible bars structures on opposite sides of the flexible routing element, substantially in the plane of the at least one leaf spring.

According to an aspect, the invention provides a guidance element as described above, wherein the flexible bars structure is embodied as a first pair of crossing bars attached to a rigid linkage part of the first hinging part and to a central connector body that substantially coinciding with the pivot axis, and as a second pair of crossing bars attached to a rigid linkage part of the second hinging part and to the central connector body.

According to an aspect, the invention provides a guidance element as described above, comprising an auxiliary folded plates stack with each plate being parallel to the pivot axis, each plate of the stack having an internal opening in which the flexible routing element is positioned.

According to an aspect, the invention provides a guidance element as described above, wherein the auxiliary folded plates stack is positioned inbetween the flexible bars structures at the opposite sides of the flexible routing element.

According to an aspect, the invention provides a guidance element as described above, wherein the first hinging part is configured with an outward surface for attaching one of the two constnictional parts, the second hinging part is configured with an outward surface for attaching the other of the two constructional parts.

According to an aspect, the invention provides a guidance element as described above, wherein at least one of the first and second hinging parts is curved between its respective outward and inward surfaces.

According to an aspect, the invention provides a guidance element as described above, wherein the first and second hinging parts are each provided with contact surfaces in proximity of the respective inward surface, the contact surfaces being configured to abut each other under a maximum pivot angle between the first and second hinging parts around the pivot axis.

According to an aspect, the invention provides a guidance element as described above, wherein the maximum pivot angle is between 45° and about 120°.

According to an aspect, the invention provides a guidance element as described above, wherein the contact surfaces and the flexible bars staicture on each side of the flexible routing element are in a respective common plane.

According to an aspect, the invention provides a guidance element as described above, wherein the flexible routing element comprises a second flexible bellows, and the first and second hinging parts comprise corresponding second internal conduits.

According to an aspect, the invention provides a guidance element as described above, wherein the second flexible bellows is attached on a first portion of its periphery to an adjoining second edge of said at least first leaf spring, the second edge opposite to the first edge of the leaf spring.

According to an aspect, the invention provides a guidance element as described above, wherein the second flexible bellows is attached on a first portion of its periphery to the periphery of the first flexible bellows at a position diametrically opposite the adjoining first edge of the first leaf spring.

According to an aspect, the invention provides a guidance element as described above, wherein the flexible routing element comprises a second leaf spring, the second leaf spring arranged extending parallel to the lengths of the first and second flexible bellows and the at least first leaf spring, the second leaf spring attached on a second portion of the periphery of the second flexible bellows to an adjoining edge of said second leaf spring, wherein the intermediate pivot axis coincides with the width of the first and second leaf springs.

According to an aspect, the invention provides a guidance element as described above, wherein the flexible routing element comprises a second and third leaf spring, parallel to the length of the first and second flexible bellows and the at least first leaf spring; the second leaf spring being attached to the periphery of the first flexible bellows and the third leaf spring being attached to the periphery of the second flexible bellows, in a manner that the first leaf spring is intermediate the second and third leaf springs, the widths of the first, second and third leaf springs are parallel to each other, and the intermediate pivot axis coincides with the widths of the first, second and third leaf springs.

According to an aspect, the invention provides a guidance element as described above, wherein the guidance element is a 3D printed structure.

According to an aspect, the invention provides a guidance element as described above, wherein the 3D printed structure consists of a metal.

The present invention also provides a guidance element between two

constructional parts, that are pivotable relative to each other around an intermediate pivot axis, comprising a flexible routing element, a first hinging part and second hinging part; the flexible routing element comprising a flexible bellows or tube; the flexible bellows being attached to an inward surface of the first hinging part on a first end and being attached to an inward surface of the second hinging part on a second end of the flexible routing element; the first and second hinging parts each being adapted with a respective conduit and the flexible bellows being arranged as flexible conduit, the conduits of the first and second hinging parts and the flexible conduit of the flexible bellows forming a continuous internal conduit between an entry on the first hinging part and an exit on the second hinging part; the flexible routing element further comprising two leaf springs, wherein the leaf springs are arranged extending parallel to the flexible bellows, the flexible bellows being positioned between two leaf springs and attached on opposite portions of its periphery to an adjoining edge of each leaf spring; the flexible routing element intersecting the intermediate pivot axis perpendicularly, the intermediate pivot axis coinciding with the width of the leaf springs.

Additionally, the present invention provides an air vehicle or space craft comprising a fixed constructional part and a moveable constaictional part, the fixed part being coupled to the moveable part by at least one guidance element as described above.

According to an aspect, the invention provides an air vehicle or spacecraft as described above, wherein the first hinging part is mechanically connected to the fixed part and the second hinging part is mechanically connected to the moveable part.

According to an aspect, the invention provides an air vehicle or spacecraft as described above, wherein the fixed part is coupled to the moveable part by multiple guidance elements, arranged in a series connection between the fixed and moveable parts.

According to an aspect, the invention provides an air vehicle or spacecraft as described above, wherein an linear element is arranged the linear element is one selected from a group comprising electrical cable, electrical wire, optical fibre, hydraulic or fluid line, and a line for pressurized gas or air, or a combination thereof.

According to an aspect, the invention provides an air vehicle or spacecraft as described above, wherein the fixed part is a wing and the moveable part is a flap.

According to an aspect, the invention provides an air vehicle or spacecraft as described above, wherein the fixed part is either a wing or a fuselage and the moveable part is a landing gear.

Moreover, the present invention provides a method for manufacturing a guidance element as defined above, comprising 3D printing of the arrangement of the first hinging part, second hinging part, flexible bellows and leaf springs for creating the guidance element. According to an aspect, the invention provides a method as described above, wherein the 3D printing comprises 3D metal printing of said arrangement.

Advantageous embodiments are further defined by the dependent claims. Brief description of drawings

The invention will be explained in more detail below with reference to drawings in which illustrative embodiments thereof are shown. They are intended exclusively for illustrative purposes and not to restrict the inventive concept, which is defined by the appended claims.

Figure 1 shows a perspective view of a guidance element in accordance with an embodiment of the invention;

Figure 2 shows a cross-section of the guidance element according to an embodiment of the invention;

Figure 3 shows a perspective view of a flexible routing element arrangement according to an embodiment of the invention;

Figure 4 shows a cross-section of the flexible routing element arrangement of Figure 3; Figure 5 shows a perspective view of a guidance element in accordance with an embodiment of the invention;

Figure 6 shows a cross-section of the guidance element of Figure 5, and

Figures 7A - 7D show cross-section views of respective alternative embodiments of the flexible routing element.

Detailed description of embodiments

Figure 1 shows a perspective view of a guidance element in accordance with an embodiment of the invention.

The guidance element 100 comprises a first hinging part 105, a second hinging part 110 and a flexible routing element 115.

The flexible routing element 1 15 comprises a flexible bellows 130 or an flexible tube. The flexible bellows 130 is connected on a first end to a proximate end 106 of the first hinging part 105, and on a second end to a proximate end 111 of the second hinging part 1 10. The first and second hinging parts 105, 110 each comprise a respective distal end 107; 112 that is arranged for mechanically connecting with a first constructional part (not shown) and a second constructional part (not shown), respectively.

The first hinging part 105, the second hinging part 1 10 and the flexible routing element 115 are each provided with an internal conduit 101 for receiving and guiding the linear element. The flexible bellow is arranged as flexible conduit through which the linear element extends between the first and second hinging parts.

The linear element relates to any kind of linear connecting element between a point in the first constructional part and a point in the second constructional part, and comprises a cable, wire, optical fibre or flexible tube for transport of fluid.

The first and second constructional parts are arranged to be pivotable around an intermediate pivot axis A of the guidance element 100, i.e., the guidance element provides a hinge with one degree-of-freedom for a rotation around intermediate pivot axis A.

For example, the first constructional part is a fixed part such as a wing, and the second constructional part is a moveable flap mechanically coupled to the wing by means of the guidance element 100.

The flexible routing element 1 15 is located at a position that the intermediate pivot axis A perpendicularly crosses the flexible routing element 115, at substantially the center region of the flexible routing element 115. According to this set-up, when the second constructional part is to move with respect to the first constructional part, the second hinging part will move with respect to the first hinging part around the intermediate pivot axis, and the flexible bellows will bend between the first and second hinging parts substantially without displacement from the position of the intermediate pivot axis.

In an embodiment the flexible routing element 1 15 comprises the flexible bellows 130 and a pair of leaf springs 132. The leaf springs are arranged on opposite sides of the flexible bellows, the width of the leaf springs oriented along the direction of the pivot axis A. An embodiment of the flexible routing element 1 15 will be described in more detail with reference to Figure 3 and 4.

The first and second hinging parts 105, 1 10 each comprise a pair of rigid linkage parts 103; 1 13, arc shaped, at the end 106; 11 1 proximate to the flexible routing element 115, on opposite sides of the flexible routing element along the direction of the pivot axis A.

Each rigid linkage part 103, 1 13 is optionally provided with a contact surface 104; 1 14 on a front end and back end. The contact surfaces on the first hinging part 105 are configured to abut the contact surfaces of the opposing second hinging part 1 10 when the first and second hinging part are under a maximum pivot angle a. In this manner rotation of the first hinging part with respect to the second hinging part beyond a mechanically safe maximum is prevented.

In the direction of the pivot axis A on opposite sides of the flexible routing element 115 a flexible side bar structure 120; 121 is arranged that couple the rigid linkage parts on the respective side of the guidance element 100 in order to provide additional sideways translational stiffness.

In an embodiment each flexible side bar structure 120; 121 comprises two pairs of cross-bars 123, 124 and a central connector 125, forming two crosses on each side of the pivot axis. One pair of crossbars is connected on one end to a bar connection surface of the rigid linkage part of the first hinging part and on another end with the central connector. The other pair of crossbars is connected on one end to a bar connection surface of the rigid linkage part of the second hinging part and on another end with the central connector. The center position of the central connector coincides with the position of the pivot axis A.

In this embodiment, both first and second hinging parts 105, 1 10 are curved along the direction of the internal conduit 101, forming a curved guidance element. It will be appreciated that alternatively, one or both of the first and second hinging parts may have a straight shape.

The internal conduit 101 can be arranged for receiving a linear element such as cable, wire, fiber or pipe. Alternatively the internal conduit 101 can be used per se for transport of fluid, either liquid or gas.

Figure 2 shows a cross-section of the guidance element according to the embodiment of Figure 1 in a length direction. In Figure 2 elements with the same reference number as shown in, and described with reference to, Figure 1 refer to corresponding elements.

The internal conduit 101 for holding and guiding the linear element or transport of fluid (indicated by dashed line 140) extends from the distal end 107 of the first hinging part 105 to the distal end 112 of the second hinging part 1 10, such that the linear element 140 extends through the first hinging part, the flexible bellows 130 and the second hinging part 1 10.

Figure 3 shows a perspective view of a flexible routing element arrangement according to an embodiment of the invention.

The flexible routing element 1 15 comprises the flexible bellows 130 and a pair of leaf springs 132a, 132b. The leaf springs are arranged on opposite sides of the flexible bellows and are oriented lengthwise along the length of the flexible bellows.

The leaf springs are further oriented with their width along one common direction C perpendicular to the length of the flexible bellows.

On one edge each leaf spring is attached to the wall of the flexible bellows.

Within the guidance element 100, the common direction C coincides with the pivot axis A. An upper side of the flexible routing element 115A is configured to be connected to the proximate end 106 of the first hinging part 105 and a lower side 1 15B is configured to be connected to the proximate end 111 of the second hinging part 1 10.

If the second hinging part 110 is pivoted with respect to the first hinging part 105 around the pivot axis A, a bending force B is exerted on the leaf springs 132a, 132b causing elastic bending of the leaf springs and of the flexible bellows 130. Since the flexible bellows is connected to the leaf springs, the flexible bellows will show a similar bending as the leaf springs due to the bending force. As the flexible routing element is intersected perpendicular by the pivot axis A, the flexure of the flexible routing element (and flexible bellows) will be 'simple' lateral bending without movement of the central axis of the flexible routing element relative to the position of the pivot axis. As a result, an linear element 140 within the flexible bellows 130 will only bend and not slide or shave along the internal wall of the internal conduit 101 in the flexible bellows. This prevents wear of the linear element 140.

By providing a pair of leaf springs on opposite sides of the flexible bellows provide enhanced longitudinal and in-plane bending stiffness which prevents longitudinal shaving of an linear element when present within the internal conduct.

Figure 4 shows a cross-section of the flexible bellows arrangement of Figure 3 in a length direction. In Figure 4 elements with the same reference number as shown in, and described with reference to, any of Figures 1 - 3 refer to corresponding elements. As seen in detail here, the leaf spring 132b is a substantially rectangular plate. The flexible bellows 130 is attached to a longitudinal edge of each leaf spring.

According to this embodiment, the flexible bellows overlaps the plate over the longitudinal edge and is attached to a major surface 133 of the leaf spring 132b; 132a.

Figure 5 shows a perspective view of a guidance element 150 in accordance with an embodiment of the invention.

In Figure 5 elements with the same reference number as shown in, and described with reference to, any of Figures 1 - 4 refer to corresponding elements.

The guidance element 150 of this embodiment is to a large extent similar to the guidance element as shown in figures 1 and 2. Additionally, the guidance element 150 comprises an auxiliary stack 155 of folded plates 160 that is mounted between the proximate ends 106 and 111 of the first and second hinging parts 105,110. The folded plates that make up the stack 155, are each provided with a central opening (see figure 6, reference 165) of which the position corresponds with the position of the flexible bellows and the leaf springs. Through the central openings in the folded plates 160, the flexible bellows and the leaf springs extend between the two hinging parts 105, 110.

The plates are folded along respective folding lines that are substantially parallel to the pivot axis A. As a result, the auxiliary stack 155 provides an additional resistance to torsion of the first hinging part 105, relative to the second hinging part 110.

Figure 6 shows a cross-section of the guidance element of Figure 5.

Figures 7A - 7D show top views of respective alternative embodiments of the flexible routing element.

Next to the embodiment of the flexible routing element 115 comprising one flexible bellows arranged inbetween a pair of leaf springs parallel to the length of the flexible bellows as described above, the invention provides alternative embodiments of the flexible routing element. In Figure 7A a top view of a flexible routing element is shown in which the flexible routing element comprises one flexible bellows 130 and one leaf spring 132a. The leaf spring is attached at the periphery of the flexible bellows. The width of the leaf spring extends radially from the flexible bellows. Within the guidance element, the intermediate pivot axis A coincides with the width of the leaf spring 132a and crosses the center of the flexible bellows 130.

Figure 7B shows a top view of another alternative embodiment. The flexible routing element comprises first and second flexible bellows 130a, 130b and one leaf spring 132a.

The lengths of the first and second flexible bellows and the leaf spring are parallel to each other, the leaf spring is attached on opposite side edges to the first flexible bellows and the second flexible bellows, respectively.

Within the guidance element, the intermediate pivot axis A coincides with the width of the leaf spring 132a and crosses the center of the first flexible bellows 130a and the second flexible bellows 130b.

The first and second hinging parts 105, 1 10 comprise two internal conduits that each are in communication with a respective one of the first and second flexible bellows to form a first and second conduit, respectively, between the constructional parts.

Figure 7C shows a top view of an embodiment of the flexible routing element which comprises first and second flexible bellows 130a, 130b and one leaf spring 132a as shown and described with reference to Figure 7B. In addition, in this embodiment, the flexible routing element comprises a second and third leaf spring 132b, 132c.

The length of second and third leaf springs is parallel to the length of the first and second flexible bellows and the at least first leaf spring. The second leaf spring 132b is attached to the periphery of the first flexible bellows 130a and the third leaf spring 132c is attached to the periphery of the second flexible bellows 130b, in a manner that the first leaf spring 132a is intermediate the second and third leaf springsl32b, 132c. The widths of the first, second and third leaf springs are parallel to each other. Within the guidance element the intermediate pivot axis A coincides with the widths of the first, second and third leaf springs 132a, 132, 132c and crosses the respective center of the first and and second flexible bellows 130a, 130b..

Figure 7D shows a top view of a flexible routing element that comprises a first and second flexible bellows 130a, 130b and a first and second leaf spring 132a, 132b.

In this embodiment, the first and second flexible bellows 130a, 130b are longitudinally attached to each other at their peripheries. In addition, the first leaf spring 132a is longitudinally attached to the first flexible bellows 130a and the second leaf spring 132b is longitudinally attached to the second flexible bellows 130b. The first and second leaf springs 132a, 132b and the first and second flexible bellows 130a, 130b are arranged in-line in a manner that the pair of the first and second flexible bellows are inbetween the first and second leaf springs. The in-line arrangement is coinciding with the intermediate pivot axis within the guidance element.

The first and second hinging parts comprise a pair of internal conduits that each are in communication with one of the first and second flexible bellows to form a first and second conduit, respectively, between the constructional parts.

The guidance element according to the invention can be manufactured from separate components that are mechanically connected. Preferably however, the guidance element is manufactured by a 3D manufacturing technique such as 3D (laser) printing.

The guidance element is preferably made from metal. In an embodiment, the guidance element is manufactured by 3D printing of metal. Optionally, the 3D printing step may be followed by an annealing or tempering step.

The guidance element according to the present invention provides that a bending radius of a guided element comprising cable, wire or tube is inherently respected, and "shaving" and torsion of the guided element are prevented.

Due to the distributed compliance of the flexible routing inside the guidance element, the linear element such as a cable or wiring or flexible tube is not subject to an instant "sharp" bending. Instead, the linear element is bend with a flexure equally distributed over the length of the flexible bellows, and thus is respecting the allowable minimum bending radius. Furthermore, as the flexible leaf springs have hardly any compliance in longitudinal direction, elongation of the internal conduit in the flexible bellows is not possible, preventing shaving between routing and linear element. Also the internal conduit is only subjected to a bending deformation around the considered axis of rotation, resulting in no torsional deformations. At last, the flexible bellows fully surrounds the linear element protecting it from the outside environment.

Besides advantages with respect to properly routing linear elements between a fixed part and a movable part, the guidance element according to the present invention has the advantage that no components move relative to one another. As of this, no lubricants are required and no wear takes place, resulting in a high durability and low levels of maintenance.

It will be appreciated that the coupling between the first and second constructional parts can comprise a single guidance element or multiple guidance elements that are coupled in a series. In this manner, the coupling between the first and second constructional parts can have one or more intermediate pivot axes, each allowing an individual rotation defined by the orientation of the respective pivot axis.

In the foregoing description of the figures, the invention has been described with reference to specific embodiments thereof. It will, however, be evident that various modifications and changes may be made thereto without departing from the scope of the invention as summarized in the attached claims.

In addition, modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention includes all embodiments falling within the scope of the appended claims.

In particular, combinations of specific features of various aspects of the invention may be made. An aspect of the invention may be further advantageously enhanced by adding a feature that was described in relation to another aspect of the invention.

It is to be understood that the invention is limited by the annexed claims and its technical equivalents only. In this document and in its claims, the verb "to comprise" and its conjugations are used in their non-limiting sense to mean that items following the word are included, without excluding items not specifically mentioned. In addition, reference to an element by the indefinite article "a" or "an" does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements. The indefinite article "a" or "an" thus usually means "at least one".