Clamping device

Abstract

A detachable connecting element (100) between a lightweight panel (110) and a hinge (150) with two tabs (170, 180) comprises (a) a retaining frame (200) for a force-fit and form-fit connection with a lightweight panel (110) and (b) an insertion element (300) which can be inserted into a receiving pocket (250) provided in the retaining frame (200) in a form-fit manner, locked there in its final position, and released again. This insertion element is optionally designed as a tab of the hinge (150) or connected to such a tab. The retaining frame (200) has an outer contour with two substantially parallel top surfaces (210, 215) and four side surfaces arranged between them, wherein three of the side surfaces form part of a circumferential groove (220) which is designed to receive lightweight panel edge sections (112, 114, 116) which act as a spring in a form-fitting manner and the fourth side surface has the access (225) to the receiving pocket (250).In an assembly process, the retaining element is preferably bonded into a correspondingly designed recess in the lightweight panel in a form-fitting / force-fit manner. The connecting element is preferably used as a hinged connection for the access cover of an aircraft.

Description

[0001] The present invention relates to a holding device for attaching components to a lightweight panel, in particular for the interior paneling of vehicles and aircraft. BACKGROUND

[0002] Interior paneling, especially wall coverings, partition walls, and storage areas are important design and functional elements of interior spaces and also contribute to thermal and acoustic insulation. The wall elements and functional fixtures are often prefabricated as lightweight construction elements. The manufacture of such lightweight elements from sandwich panels with a honeycomb core has long been a practice, particularly in aircraft construction.

[0003] Based on the Wikipedia definition, a honeycomb sandwich panel (also abbreviated to honeycomb panel) is a (usually) three-layer composite sandwich construction consisting of two load-bearing face layers and a honeycomb-shaped support core. The support core, also known as a honeycomb, has a hexagonal basic shape and is made of cardboard, resin-impregnated paper, fiberglass, or thin aluminum foil. The face layers can be made of cardboard, plastic, fiberglass composites, or sheet metal. Various material combinations between the support core and face layers are possible; the support core and face layers are usually glued together.The sandwich panel adopts the principle of the double-T beam for the tensile structure, in that the thin cover layers with their large distance from the central surface ensure a large area moment of inertia and thus high bending stiffness, while the supporting core simultaneously creates shear stiffness and continuously supports the cover layers against buckling and wrinkling.

[0004] The honeycomb structure of the material creates high mechanical rigidity with comparatively low weight, making sandwich construction attractive for the aviation, boatbuilding, and aerospace industries, among others. Honeycomb panels are used in aircraft tailplanes and wings, lightweight ship hulls, surfboards, and truck bodies. Simple building interior doors utilize this construction method. For several years, polyurethane-fiberglass honeycomb panels have also been used in automobiles as spare tire covers, parcel shelves, and sliding headliners.

[0005] Despite all the advantages of lightweight construction, connecting sandwich panels to the supporting structure, other sandwich panels, or attaching additional elements to sandwich panels is difficult to achieve using conventional fasteners such as screws, nails, or spot bonding. The familiar point-based anchoring in or on the solid material, and thus the distribution of loads or forces across the material volume, is not readily possible here.

[0006] A hinge is a joint that rotates around an axis. It is used primarily as a fitting for flaps on furniture and containers, as well as a pivoting connecting link between a door (leaf) and a frame, or between a window (leaf) and a frame. For technical simplicity, the term "hinge" refers to both separable hinges (bands) and fixed hinges.

[0007] Essentially, a hinge consists of three elements: the joint element itself, which also defines the axis of rotation, and two tabs arranged as wings that pivot around the axis of rotation. Each of these is attached to a wing / frame, a flap / container, or a door. Typically, a hinge connects a stationary, first component with a second, pivoting component. However, it is also possible to connect two components that are not themselves stationary.

[0008] A particularly common application in aircraft interiors is the hinged connection of an overhead compartment hatch to the actual overhead compartment. These interior elements are subject to high levels of stress during operation and are often made of the aforementioned lightweight material. The hinges should be compact and free of obstructive contours to allow for easy and complete loading. In addition, the connection between the hatch and the lightweight element should be detachable via the hinge, allowing for easy replacement of a damaged hatch. STATE OF THE ART

[0009] Various solutions to this problem of attaching a component to a lightweight construction element are known in the prior art. So-called inserts with threaded nuts, clamps, or locking elements are glued into oversized blind holes in the sandwich panel. An adhesive fills the space between the insert and the honeycomb fabric with a form-fitting fit and, once cured, transfers the applied load from the attachment point to the sandwich panel. It is easy to understand that such an attachment point represents a considerable weight and requires considerable effort to install. In addition, this type of attachment creates an interfering contour, since although the insert itself can be designed flush with the original cover layer, the attachment of the component then protrudes beyond the cover layer.

[0010] Also common are so-called clip connectors. Simply put, these provide a classic fastening element such as a nut, a clamp for a bolt, or a locking element, which is connected to a clamp. The clamp is pushed onto the edge of a sandwich panel and holds the fastening element in a desired position, e.g., relative to a pre-drilled through hole. This type of fastening is easy to install, but can only be used on the edges of a sandwich panel. This type of fastening also creates a large interference contour and is not very aesthetically pleasing, which is why it is usually used when the back of the sandwich panel is not visible.

[0011] The prior art document DE 10 2009 005 596 A1 describes a fitting component that can be inserted into furniture panels from the edge and that fits into a recess existing or created in the furniture panel. The fitting component can accommodate connecting elements to room or furniture walls.

[0012] Prior art US 3,728,758 shows a hinge equipped with a hinge tab that can be inserted into a self-locking bracket in a frame. The self-locking bracket is flush with the surface of the frame and has a pocket for receiving the hinge tab.

[0013] Document WO 97 / 44560 (=EP 0 898 636) similarly proposes inserting the hinge tabs of the frame-side hinge parts into hinge pockets in the door frame. These hinge pockets are provided in the vertical members of the frame and feature a locking device.

[0014] The object of the invention is to propose a connecting element for a hinge which does not require any inserts or clip connectors, has an aesthetic effect with the smallest possible interference contour and provides a large surface for the introduction of force into a lightweight construction element. DESCRIPTION OF THE INVENTION

[0015] This object is achieved by a connecting element together with a lightweight panel, a holding frame and an insertion element, wherein the connecting element is designed as a holding frame on the side of the lightweight element or a sandwich panel and as an insertion element on the hinge side, according to the features of independent claim 1. The subclaims describe further variants and embodiments.

[0016] The detachable connecting element according to the present invention serves to connect a lightweight panel (or a building element that uses a lightweight panel) of thickness s and a hinge that has two tabs. With reference to the above definition of hinge, the tab is the part of the hinge with which the hinge is attached to the frame / wing / casing / hatch. The connecting element comprises, on the one hand, a holding frame that is connected to the said lightweight panel in a force-fitting and form-fitting manner, and, on the other hand, an insert element. This insert element can be inserted in a form-fitting manner into a receiving pocket provided in the holding frame, locked there in its final position, and then released again. This insert element forms the actual tab of the hinge or can be attached to such a tab.

[0017] The support frame is characterized by its outer contour with two essentially parallel top surfaces and four side surfaces arranged between them. The outer shape can thus be described, in simplified form, as a box or cuboid. A characteristic feature is, among other things, that three of the side surfaces form part of a circumferential groove. The three side surfaces do not have to form right angles; they could also be arranged trapezoidally, with the fourth side surface then forming the base of the trapezoid. Equivalently, the three side surfaces could also form a kink-free arch or semi-arch without compromising the functionality described below.

[0018] The circumferential groove is part of a tongue-and-groove connection between the support frame and the lightweight panel. The groove positively accommodates the edge sections of the lightweight panel, which act as a tongue, with the fourth side surface providing access to the receiving pocket. A recess is therefore made in the lightweight panel, or more precisely, in one of its edges, for mounting the support element. This recess is dimensioned so that the edges of the recess (the edge sections of the lightweight panel) engage in the groove of the support frame as a tongue.

[0019] This circumferential groove is most easily realized as a flat projection of the parallel cover surfaces beyond the side surfaces, whereby the side surfaces form the depth limit (the bottom) of the groove. This design with flat, protruding cover surfaces also results in a flat design and thus a minimal interference contour.

[0020] The clear distance d between the parallel cover surfaces in the area of the groove is chosen so that it matches the thickness or strength s of the lightweight panel. As is obvious from the tongue and groove principle, the thickness s of the lightweight panel intended for connection is chosen such that d ≈ s and at the same time d > s. In other words, the clear gap d of the groove is chosen to be only slightly larger than the thickness s of the lightweight panel. This allows the lightweight panel to be pushed into the groove parallel to its surface, achieving a clamp fit or a form fit with a small air gap. This dimensioning specification is applicable to all lightweight panels commonly used in the area of application. The air gap is dimensioned so that adhesive bonding is reliably possible. The connection between the holding frame and the lightweight panel is therefore preferably achieved by surface bonding of the lightweight panel in the groove.This can be done with commercially available two-component adhesives or with special adhesives as required for the respective lightweight panel.

[0021] Preferably, the receiving pocket, which will accommodate the insert element when assembled, has a substantially cuboid-shaped inner contour. This embodiment, which is visually reminiscent of a drawer / drawer structure, is also explained in the accompanying drawings. The receiving pocket or the complementary insert element could also have the basic shape of a trapezoid or a triangle. Technically equivalent, it is also conceivable to use one or more connecting bolts as inserts instead of a drawer, which can be inserted into corresponding holes in the support frame.

[0022] As is technically evident from the context, the receiving pocket will have one or more guide elements that guide the insert element in the insertion direction during assembly and, when installed, serve to transfer loads from the insert element to the support frame transversely to the insertion direction. The guide elements can be implemented as surface elements of the receiving pocket, e.g., as grooves, channels, or flat elements with corresponding complementary structures on the insert element.

[0023] In particular, one of the cover surfaces can also span the receiving pocket and thus be designed as a guide element. It is also technically possible for both cover surfaces to span the receiving pocket, thus both covering surfaces being designed as guide elements. The receiving pocket would thus be, for example, an opening in the support frame with a rectangular cross-section that extends in the plane of the lightweight panel (after assembly).

[0024] The lockable and detachable connection between the holding frame and the insert element can be achieved by the receiving pocket or the insert element having a latch that is designed as a movable or rotatable component and can be brought into a positive and detachable connection with a complementary counterpart in the insert element or in the receiving pocket. In other words, the latch can be provided in one or the other component. It is not excluded that both solutions can be combined, for example to increase security against tampering. The latch is preferably designed as a tongue-shaped locking element in the insert element. The latch is pushed back during insertion and can then engage in a spring-locking manner in a designated opening in the holding frame and fix the insert element in an end position.

[0025] Plastic is the preferred material for both the retaining frame and the insert element. In particular, it can be made from injection-moldable thermoplastic or a fiber-reinforced thermoplastic, or as a combination of different thermoplastics with varying elasticity. For example, the latch can be made from a softer plastic than the rest of the insert element. It is also possible and conceivable to manufacture the retaining frame and / or insert element from metal if the load on the hinge requires it. A material mix, such as a metal retaining frame with a plastic insert element, is also possible.

[0026] If one wants to describe the procedure by which a connecting element is inserted according to the type described above, one obtains the following steps: Providing a lightweight panel. It can be part of the interior fittings of a luggage compartment, a cabinet, or a frame. Providing a support frame with the features described above, in particular the groove running around three sides; providing a recess in the aforementioned lightweight panel that is slightly larger than the dimensions of the groove of the support frame. This can be done by sawing, punching, or similar processes. Applying adhesive in the groove and / or on the edge sections of the lightweight panel along the recess. In this case, in particular, sufficient adhesive can be provided to locally fill a honeycomb structure exposed in the recess, thus anchoring it in the plane of the lightweight panel.Insert the retaining frame into the recess so that the edge sections of the lightweight panel are positioned as a tongue in the groove of the retaining frame; ensure the intended final position of the retaining frame and lightweight panel until the adhesive cures. Ensuring this includes steps such as position control, re-measurement, and fixation using suitable holding devices such as clamps or gauges. Insert a hinge with an insert element into the receiving pocket of the retaining frame.

[0027] The described connecting element and the described assembly method are particularly suitable for the articulated connection of a closure lid to a luggage compartment in an aircraft, land vehicle, or watercraft. Generally speaking, two connecting elements can also be used for the articulated connection of two components made of lightweight panels, with both hinge tabs being designed as insert elements or connected to an insert element, and a retaining frame being provided in each of the two components made of lightweight panels.

[0028] In general, a lightweight panel should preferably be understood as a sandwich panel with a honeycomb core, but also - technically equivalent - lightweight fiberboard or other thin panels for which the combination of holding frame and insert element described here can be used advantageously because a classic screw connection of the hinge is not possible or not desired.

[0029] This process description does not include all potentially necessary control, adjustment, or maintenance steps. However, this does not detract from the completeness of the description, as these intermediate steps do not affect the core inventive idea. DESCRIPTION OF THE CHARACTERS

[0030] The invention will now be explained by way of example with reference to the accompanying drawings. Figure 1 shows a schematic drawing of a hinge with the essential elements. Figure 2 shows a perspective view from the front (in relation to the installation position) of a support frame 200 Figure 3 shows a slide-in element in perspective from below Figure 4 shows the installation process of a holding frame with inserted insert element of a hinge into the recess of a lightweight panel

[0031] A hinge 150 as in Figure 1shown includes, in addition to the joint element 160, which defines the rotation or pivot axis of the hinge, the two lateral tabs 170 and 180.

[0032] Figure 2 shows a support frame 200 in a preferred, flat design. The cover surfaces 210 and 215 mark two parallel planes at a distance d. The circumferential groove 220 can be seen on three sides, formed by the projecting cover surfaces 210 and 215 and the side surfaces 212, 214, 216. The side surfaces lie behind the front edges of the cover surfaces and thus form the bottom of the groove 220. Figure 2The receiving pocket 250 is semi-open, with a closed cover surface 215 on the underside (in the drawing) and an opening on the top, which gives the upper cover surface 210 a U-shape. As described above, the upper cover surface 210 could also be closed, or the lower cover surface 215 could be designed analogously to the upper cover surface 210. Guide elements 230, 235, here designed in the form of longitudinal grooves in the insertion direction 290, serve as insertion aids and for load transfer during use. In addition to the three-sided groove 220, the access 225 for the insertion element 300 is indicated on the fourth side (at the front in the drawing).

[0033] Figure 3 shows an insert element 300, designed to complement the receiving pocket 250. The spring-loaded locking element or latching element is provided with the reference symbol 310.

[0034] Figure 4shows an assembly situation in which a holding frame 200 is inserted into the recess 120 in a lightweight panel 110. Adhesives or other connecting means are omitted. The edges of the recess, including both the seams at the cut edges of the recess 120 in the plane of the lightweight panel surface and the cut surfaces, are designated as edge sections 112, 114, 116. The hinge is shown with its joint element 120 as well as the cut second tab 180.

Claims

1. Detachable connecting element (100) for connecting a lightweight panel (110) of thickness s to a hinge (150) comprising two tabs (170, 180), wherein the lightweight panel (110) has a recess with lightweight panel edge sections (112, 114, 116) in the edge region; the detachable connecting element (110) comprising - a retaining frame (200) provided for force-fitting and form-fitting connection to the lightweight panel (110); and - an insertion element (300) which can be inserted in a form-fitting manner into a receiving pocket (250) provided in the retaining frame (200), locked in the end position and releasable again, wherein this insertion element forms a tab of the hinge (150) or can be fastened to one of the tabs (170, 180); wherein the retaining frame (200) has an outer contour with two substantially parallel cover surfaces (210, 215) and four side surfaces arranged between them, wherein three of the side surfaces form part of a circumferential groove (220), which is designed to receive lightweight panel edge sections (112, 114, 116) acting as positive-locking springs, and the fourth side surface has the access (225) to the receiving pocket (250); and wherein the clear distance d between the parallel cover surfaces (210, 215) in the region of the groove (220) is selected in relation to the thickness s of the lightweight panel (110) such that d ≈ s applies and thus the lightweight panel (110) can be inserted into the groove (220) with its surfaces parallel and a clamping fit or a form fit with a small air gap is achieved there.

2. Connecting element (100) according to claim 1, characterized in that the circumferential groove (220) is designed as a flat projection of the parallel cover surfaces (210, 215) beyond the side surfaces, whereby the side surfaces form the depth limitation (212, 214, 216) of the groove.

3. Connecting element (100) according to claim 1 to 2, characterized in that the connection of the retaining frame (200) to the lightweight panel (110) is achieved by bonding the lightweight panel (110) in the groove (220).

4. Connecting element (100) according to claim 1 to 3, characterized in that the receiving pocket (250) has an essentially cuboid, trapezoidal or triangular inner contour.

5. Connecting element (100) according to claim 1 to 4, characterized in that that the receiving pocket (250) has guide elements (230, 235) which guide the insertion element (300) in the insertion direction (290) during assembly and, in the assembled state, serve to transfer the load from the insertion element (300) into the retaining frame (200) transversely to the insertion direction (290).

6. Connecting element (100) according to claim 1 to 5, characterized in that one of the cover surfaces (210, 215) also spans the receiving pocket and is designed as a guide element.

7. Connecting element (100) according to claim 1 to 5, characterized in that both cover surfaces (210, 215) span the receiving pocket over a large area and are designed as guide elements.

8. Connecting element (100) according to claim 1 to 7, characterized in that the receiving pocket (250) or the insertion element (300) has a latch which is designed as a movable or rotatable component and can be brought into a form-fitting and releasable connection with a complementary counterpart in the insertion element (300) or in the receiving pocket (250) in a form-fitting and releasable connection.

9. Connecting element (100) according to claim 8, characterized in that the latch is designed as a tongue-shaped locking element (310) in the insertion element (300), which engages in a spring-locking manner in an opening provided for this purpose in the holder frame (200) and fixes the insertion element (300) in an end position.

10. Connecting element (100) according to claim 1-9, characterized in that the retaining frame is made of plastic, in particular a thermoplastic, a fiber-reinforced thermoplastic, or a combination of different thermoplastics with different elasticities.

11. Method for attaching a connecting element (100) according to claim 1-10, comprising the following steps of: - providing a lightweight panel (110); - providing a retaining frame (200) having the features of the characteristic parts of claims 1 to 3; - providing a recess (120) in said lightweight panel (110) which is slightly larger than the dimensions of the groove (220) of the retaining frame (200); - applying adhesive in the groove (220) and / or on the lightweight panel edge sections (112, 114, 116) along the recess (120); - inserting the retaining frame (200) into the recess (120) so that the lightweight panel edge sections (112, 114, 116) are arranged as springs in the groove (220) of the retaining frame; - ensuring the intended end position of the retaining frame (200) and lightweight panel (110) until the adhesive has hardened; - inserting a hinge (150) with an insertion element (300) into the receiving pocket (250) of the retaining frame (200).

12. Use of a connecting element (100) according to claims 1-10 for the articulated connection of a closure cover to a luggage compartment in an aircraft, a land vehicle or a watercraft.

13. Use of two connecting elements (100) according to claims 1-10 for the articulated connection of two components made of lightweight panels (110), characterized in that both tabs (170, 180) are each designed as an insertion element (300) or are connected to an insertion element, and a retaining frame is provided in each of the two components made of lightweight panels.

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