Fastening element for fastening or fixing a display unit to a support device

Abstract

The invention relates to a fastening element which is used for fastening or fixing a display unit, preferably an electronic display unit, particularly preferably an electronic price and / or product information display unit, to a support device, which is preferably designed as a shelf rail, wherein the fastening element comprises at least one retractable and deployable blocking element, which is preferably designed as a pin, is held in its deployed position by a spring provided in the fastening element and which can be moved against the force of the spring to a retracted position. The invention is characterized in that the fastening element is implemented as a separate fastening module.

Description

Technical field background

[0001] German patent DE68902399T2 discloses an electronic display unit, also known as an Electronic Shelf Label or ESL, which, as part of its mounting element integrated into the ESL and used to attach the ESL to a shelf rail, features a retractable locking element. The locking element protrudes from the ESL housing and engages in a groove, recess, or hole of the corresponding shelf rail. The locking element can be retracted using a separate special tool that is brought into direct contact with the ESL, allowing the ESL to be removed from the shelf rail or repositioned along the rail. This secures the ESL in its designated position on the shelf rail, reliably preventing removal from the rail, theft of the ESL, and its repositioning along the shelf rail.This is only possible for those persons who have access to the special tool. GB2469352A is considered the closest prior art and discloses all the features in the preamble of claim 1.

[0002] However, the well-known ESL has proven to be disadvantageous in use because it absolutely requires a specially designed shelf rail to be used.

[0003] The invention therefore aims to provide an improved fastening element, an improved ESL and a system with such an ESL attached to a carrying device that is more flexible in its application. Summary of the invention

[0004] This problem is solved by a fastening element according to claim 4. The object of the invention is therefore a fastening element that serves to fasten or fix a display unit, preferably an electronic display unit, and particularly preferably an electronic price and / or product information display unit, to a support device, preferably designed as a shelf rail, wherein the fastening element has at least one retractable locking element, preferably designed as a pin, which is held in its extended position by a spring provided in the fastening element and can be moved against the force of the spring to a retracted position, wherein the fastening element is implemented as a separate module.

[0005] Furthermore, this problem is solved by an electronic display according to claim 1. The subject matter of the invention is therefore a display unit, preferably an electronic display unit, particularly preferably an electronic price and / or product information display unit, which has a housing, wherein the housing has a housing structure and the housing structure is designed to receive a fastening element implemented as a separate fastening module, wherein the fastening element serves to fasten the display unit to a support device, preferably designed as a shelf rail, and wherein the housing structure is designed as an outwardly open receiving shaft corresponding to a sleeve-shaped form of the fastening element.

[0006] Furthermore, this problem is solved by an electronic display according to claim 14. The subject matter of the invention is therefore a system comprising a display unit according to the invention and a support device, preferably designed as a shelf rail, to which the display unit is attached by means of the locking element of the fastening element incorporated in the housing structure of the display unit, wherein the support device has at least one recess into which the locking element has penetrated.

[0007] The invention thus provides a modularly usable fastening element that can be optionally inserted into the display unit and removed from it again.

[0008] The measures according to the invention therefore offer the advantage that the display unit can be flexibly used on different types of shelf rails. For example, the display unit with the attached fastening element can be used on a specially designed shelf rail that has a corresponding configuration to interact with the locking element in such a way that the display unit is locked against removal from the shelf rail, both with respect to its position along the rail and at the shelf rail itself. Likewise, the display can be used without the fastening element on a different type of shelf rail that does not have such special configurations.

[0009] This also results in the logistical and economic advantage that customer requirements can be flexibly accommodated with regard to the type of shelf rail to be installed. Despite the installation of different shelf rail types, the same display unit design is always used, albeit once with and once without the mounting element. Therefore, with regard to the display unit, which is the cost driver in the system, the aspect of "economy of scale" comes into play – that is, the cost advantage with higher production volumes of a single display unit design.

[0010] Further, particularly advantageous embodiments and developments of the invention will result from the dependent claims and the following description.

[0011] Preferably, the spring is designed as a coil spring. However, it can also be implemented as a leaf spring, an elastic band, or the like.

[0012] The display can be a simple paper or plastic-based label showing information about products, services, and / or prices. However, it is preferably an electronic display unit.

[0013] Such an electronic display unit comprises electronics that serve to receive data and to display the image content transmitted with this data in a readable form on an electronic screen. Such electronics, including the communication behavior, i.e., the radio protocol used, and the screen, are disclosed, for example, in WO2015 / 124197 on pages 2-32, a disclosure which is hereby incorporated by reference. Preferably, extremely energy-efficient electrophoretic displays are used. However, active displays, such as LCD or OLED displays, can also be used. In addition to the battery-powered operation described therein, an electronic display unit can also be supplied with electrical energy via Near Field Communication (NFC) technology or Power-over-WiFi technology, etc.Data communication with electronic displays can be implemented not only wirelessly (e.g., via NFC, ZigBee, Bluetooth, or the proprietary radio protocol according to WO2015 / 124197, etc.) but also via wired connections, as is known, for example, from WO2017 / 153481 A1, which is also included by reference.

[0014] The electronics, the screen, and any electrical energy storage device are housed within the display unit's casing. The screen may be covered by a protective window, which then forms part of the casing, or it may itself serve as a casing component if the protective window is omitted. The casing can also consist entirely or partially of a transparent material that encloses and protects the screen.

[0015] The housing has fastening means that enable the display unit to be attached to the support structure or support device.

[0016] The support structure or device can be implemented in various ways. For example, it could be a table display that can be placed on or fixed to a shop counter. It is also possible to design the support structure as a clothing hanger that can be attached to a garment. However, for the sake of a concise description of the invention, the following discussion will focus exclusively on a shelf rail as the preferred embodiment of the support structure.

[0017] Along its longitudinal extent, the shelf rail can have a (e.g., lower) first mounting rail with a hook-shaped end section and a (e.g., upper) second mounting rail with hole-like, slot-like, or groove-like recesses arranged in a grid along the shelf rail, the two mounting rails being spaced apart such that the display unit can be inserted between them. A connecting web can be formed between the mounting rails, and further elements for attaching the shelf rail to a shelf, e.g., as its front end, can be provided.

[0018] To enable the display unit to form a (potentially force-fit) connection with the shelf rail, thus locking it in position, the housing's mounting elements, for example, have a (lower) groove into which the (lower) first mounting rail can engage with its hook-like end section. The display unit, initially inserted and held there by one housing section or end, can then be pressed into the shelf rail with its other housing section or end until the locking element of the mounting element engages in one of the preferably hole-like recesses of the second mounting rail. Since these recesses are arranged at equidistant intervals along the length of the shelf rail, i.e., in a grid pattern, it may be necessary to...It may be necessary to move the display unit slightly to the left or right so that the position of the blocking element coincides with the position of one of the recesses and can penetrate or snap into it.

[0019] The fastening element, as well as the housing structure into which it can be inserted, can be configured so that a permanent connection is established between the housing and the fastening module after the initial insertion. This can be achieved, for example, by one or more hooks that engage behind a lug and cannot be released again except by the application of a destructive force.

[0020] Preferably, the fastening element, implemented as a mounting module, is designed or shaped such that the mounting module can be inserted or plugged into a housing structure of the display unit that corresponds to the shape of the mounting module, and is particularly removable. This means that the outer shape of the mounting module is adapted to the shape of the housing structure; for example, both shapes are formed by curved shapes, particularly cylindrical shapes, that can be guided or slid into one another, or by angular shapes, particularly rectangular shapes. The shape of the housing structure can have a constant diameter along its longitudinal extent. Preferably, the shape of the housing structure has a contour that tapers inwards. The shape of the mounting module is also adapted to this contour and therefore has a wedge- or cone-like (truncated) shape.This facilitates the manual insertion of the mounting module into the housing structure and also ensures a machine assembly process. Furthermore, with a substantially rectangular cross-sectional shape, it can be advantageous to have chamfers at least along the longitudinal edges of the mounting module at the transition between its side surfaces, i.e., significantly shorter connecting surfaces, e.g., running at an angle of 45°, between the side surfaces.

[0021] The mounting module and the housing structure can also be designed such that the mounting module, which is inserted into the housing structure with sufficient pressure, snaps into place, for example, by means of a plug-in or clamp mechanism. This mounting mechanism can be understood as a type of plug connection, such that the mounting module can be removed from the housing structure again by applying sufficient tensile force to overcome the connection's resistance. In connection with this type of mounting of the mounting module in the housing structure, a preferred embodiment should be noted in which the plug-in or clamp mechanism is accessible from outside the housing of the display unit. In this case, the plug-in or clamp action can be dimensioned or designed such that it cannot be overcome by simply pulling on the mounting module manually.Only by using a tool that releases the plug or clamp mechanism can the mounting module be removed from the housing structure. This design is advantageous when a temporarily irreversible hold of the mounting module in the housing structure is desired, one that cannot be overcome by the average user without the use of force.

[0022] Furthermore, the housing structure as well as the mounting module can be designed without any plug-in or clamp mechanism, so that the mounting module can simply be inserted into the housing structure without any holding effect from such a mechanism and essentially works flush with the housing structure and can be easily removed from there by applying a pulling force (or even by shaking it out), without having to overcome any minimum force caused by a plug-in or clamping effect.

[0023] Another aspect concerns retracting the locking element into its retracted position. This could be achieved, for example, by a special external component or tool that moves the locking element through direct or indirect mechanical actuation. However, it has proven particularly advantageous to use a magnetic or magnetizable component, especially a ferromagnetic component, preferably implemented as the locking element itself, to move the locking element. This allows the locking element to be moved into its retracted position against the spring force by applying an external magnetic force to the magnetic or magnetizable component. The external magnetic force can be generated, for example, by a separate device with an electromagnet or by a permanent magnet.This device is held against the display unit, and the external magnetic force can displace and / or rotate the magnetic or magnetizable component provided in the mounting module. The component can be coupled to the locking element, i.e., connected to it, or simply positioned against it. Through coupling with the locking element, the movement of the magnetic or magnetizable component is converted into a translational or rotational movement of the locking element, so that the locking element moves from the extended position to the retracted position, simultaneously tensioning the spring that interacts with the locking element. As soon as the external magnetic force is removed, the spring force of the tensioned spring moves the locking element back into the extended position. Preferably, the locking element itself constitutes the magnetic or magnetizable component.This means that the magnetic force applied by the external device acts directly on the locking element. Preferably, the locking element is made of ferromagnetic steel. This ensures the most robust and durable single-piece construction possible.

[0024] It has proven particularly advantageous if the fastening module has an outer sleeve or cage that houses both the spring and the locking element, and if the locking element protrudes from the sleeve, at least in the extended position, for example, at the head end. If the magnetic or magnetizable component is separate from the locking element, then it is advantageous if the magnetic or magnetizable component, as well as any other components or parts necessary for the function, are also housed within the sleeve so that they are protected by the sleeve. The sleeve wall can be solid, perforated, or at least left open on one side, i.e., not completely enclosing the interior of the sleeve.

[0025] Another aspect concerns the spring's support. The spring, supported by the sleeve, holds the locking element in the extended position. The spring is not supported anywhere on the housing of the display unit containing the mounting module, but is structurally and functionally located within the sleeve, ensuring the mounting module remains fully functional even outside the display unit. For example, the spring can be supported on the inside of the sleeve at its base, or it can interact with another component that is itself supported on the inside of the sleeve and from there interacts with the locking element. Preferably, the spring sits on a pin only a few millimeters long, which is formed at the base or foot of the sleeve. The other end of the spring interacts directly with the locking element, or via an intermediate element within the sleeve.The spring is dimensioned so that, in an essentially fully or at least partially relaxed state, i.e., at least slightly pre-tensioned state, it holds the locking element in its extended position.

[0026] Another aspect concerns the mobility of the locking element within the mounting module. The locking element is guided inside the sleeve by a guide, in particular a box-like, tube-like, slide-like, or rail-like guide, and can be moved along this guide between the extended and retracted positions. This measure also takes into account the fact that the mounting module functions autonomously. The aforementioned mechanical guidance of the locking element essentially ensures that the locking element is guided and held at a suitable angle or orientation to allow it to interact reliably with the support structure when used as intended in a display unit. The guide also helps to absorb lateral forces acting on the part of the locking element that protrudes from the mounting module.Preferably, the sleeve with its walls forms a box- or tube-like guide, and the locking element itself has, at least with its portion located within the sleeve, a slide-like guide that is essentially adapted to the box- or tube-like guide, thus allowing the locking element to slide within the sleeve between the extended and retracted positions. Furthermore, the slide-like guide formed by the locking element can also accommodate the spring, preferably in the form of a coil spring, within its interior. The spring then interacts at its first end—as previously discussed—with the sleeve and at its second end with the locking element. It is thus positioned between these two boundaries and laterally constrained by the slide-like guide, if necessary.The spring is also held in place by a wall of the sleeve, preventing it from shifting laterally when tensioned. These components, which spatially surround the spring, thus form a kind of spring cage that holds the spring in its intended position within the mounting module.

[0027] The movement of the locking element can be limited by the base of the sleeve or by a bottom-mounted end stop of the sleeve. Preferably, the fastening module has a top-end cover with a cover opening, through which the locking element protrudes, at least in its extended position. The cover protects the interior of the fastening module from contamination and the like. The cover opening can also, for example, essentially form-fitting around the locking element to minimize the gap between the opening edge and the locking element required for its movement, without impairing the locking element's mobility. In this context, it can also be advantageous if the locking element has two different widths when viewed longitudinally.For example, a relatively slender, possibly pin-shaped, end section of the locking element can be provided, the dimensions of which are adapted to the shape of the recess in the support device and are designed to penetrate into one of the recesses in the support device. This slender end section can transition into a wider part of the locking element, which is located predominantly inside the sleeve and is adapted, for example, to the ceiling opening in order to slide within it. Preferably, the wider part of the locking element transitions into the slide-like guide of the locking element.

[0028] It has proven particularly advantageous if the fastening module has a side wall adjacent to the cover, in which a side wall opening is recessed and shaped in such a way that the locking element can be inserted into or removed from the fastening element. This measure ensures that the individual parts of the fastening module can be assembled and inserted into the module as easily as possible. At the same time, it ensures that a malfunctioning fastening module can be disassembled as easily as possible, cleaned if necessary, and that defective parts can be replaced. Such a fastening module is therefore extremely easy to maintain.Preferably, the side wall opening is designed to be so large that, when the mounting module is inserted into the shaft, the slide-like guide of the locking element is guided through the sleeve on three sides and, on the remaining fourth side (i.e., where the side wall opening is recessed), through the wall of the housing of the display unit. This represents an extremely material-saving design for the mounting module.

[0029] Regarding the display unit, it should be noted that the housing structure can advantageously be designed as an outwardly open receiving shaft corresponding to the aforementioned sleeve-shaped form of the mounting module. If the dimensions of the housing's receiving shaft and those of the mounting module's sleeve are matched with sufficient accuracy, reliable and, above all, virtually backlash-free positioning of the display unit on the support structure can be ensured. This primarily concerns the positional accuracy perpendicular to the positioning surface of the support structure or mounting device, where the rear of the display unit is positioned when the display unit is inserted into the support structure.

[0030] However, the depth of the housing structure can also be crucial for the reliable function of the mounting module. Therefore, it remains advantageous if the housing structure, particularly the mounting slot, is designed and dimensioned so that, when the mounting module is fully inserted, its locking element protrudes beyond an outer edge of the housing structure, at least in its extended position. This ensures that the locking element can interact with the support structure as intended. Naturally, the length of the portion of the locking element protruding beyond the edge must be dimensioned accordingly to reliably engage the recess in the support device when extended.

[0031] To achieve the longest possible operating life for the display unit, unaffected by environmental influences such as dust and liquids, it can be advantageous for the housing, and especially its structure—specifically the mounting slot—to seal the display unit. This measure allows the mounting element, which is problematic in conventional display units, to be closed or sealed without having to forgo the mounting element itself, as it can be used as a separate mounting module. Furthermore, this measure enables the creation of a completely sealed housing. With the exception of the battery compartment, which houses the batteries and allows for their removal for replacement, the housing can be fully encapsulated.To manufacture the encapsulated housing, the components of the display unit can first be inserted into open housing parts and the housing parts can then be inseparably joined together.

[0032] In particular, with the aforementioned two-sided open design of the housing shaft, the housing shaft can be easily rinsed with cleaning fluid, such as water, if it becomes contaminated.

[0033] Thus, a display unit with a fastening element implemented as a fastening module and inserted into the housing structure can form a display unit-fastening module sub-system for use in the system defined above according to the invention.

[0034] In summary, the solution according to the invention differs fundamentally from known solutions where the housing must have an opening into the interior of the display unit, from which the blocking element protrudes. The solution according to the invention thus eliminates the known problem that the mostly electronic components within the display unit, as well as the mechanical components of the fastening element, are exposed to external environmental conditions without protection. The solution according to the invention therefore ensures that, for example, liquids or even dusty or granular foreign substances can no longer penetrate the interior of the display unit housing, and thus the function of the electronics and the readability of the display can no longer be impaired.

[0035] Even if substances penetrating the fastening module according to the invention cause the blocking element to malfunction or become inoperative, it can be restored to working order by simple and quick cleaning. Situations in which a malfunction of the fastening element would necessitate the replacement of the entire display unit, as is the case with known solutions, can thus be avoided.

[0036] Finally, it should be mentioned that the locking element can also have several separate extensions that can be moved simultaneously between the extended and retracted positions. The locking element can also be contained multiple times within the fastening element. The fastening element can be adapted accordingly in terms of its size and shape. Furthermore, the indicator device can be designed to accommodate multiple fastening elements.

[0037] These and other aspects of the invention will become apparent from the figures discussed below. Character description

[0038] The invention is explained in more detail below with reference to the accompanying figures and exemplary embodiments, to which, however, the invention is not limited. In the various figures, identical components are provided with identical reference numerals. They show schematically: Fig. 1 shows a display unit and a disassembled mounting element from a first perspective; Fig. 2 shows the display unit and the disassembled mounting element according to the Figure 1 From a second perspective, Fig. 3 shows the display unit and the assembled mounting element in perspective according to the Figure 1 , Fig. 4 the display unit with inserted modular mounting element in perspective according to the Figure 1Fig. 5 shows the display unit inserted into a shelf rail and secured there with the help of the fastening element in a third perspective; Fig. 6 shows the use of a special tool for removing the display unit from the shelf rail; Fig. 7 shows the back of the display unit with the battery compartment open and a view of the inserted fastening element; Fig. 8 shows a magnification of a detail area of ​​the Figure 7 , Fig. 9 the assembled fastening element, Fig. 10 the fastening element disassembled into individual parts, Fig. 11 a sleeve of the fastening element in a first perspective, Fig. 12 the sleeve in a second perspective. Description of the exemplary implementations

[0039] In the Figure 1An electronic display unit 1 is shown in the viewing direction from an oblique rear view. The unit has an outwardly open housing structure on its upwardly oriented side, wherein the housing structure is implemented as a receiving shaft 2 with a substantially rectangular cross-section and serves to receive a mounting element, designed as a mounting module 3, which is separate from the display unit 1. This mounting module 3 is located in the Figure 1 This can be seen in an exploded view showing the components of the fastening module 3, which will be discussed in more detail later. Also, the Figure 2 This combined representation, consisting of the display unit 1 and the mounting module 3, is shown, however, from the viewing direction from a slanted front.

[0040] In the Figure 3 is now in the direction of consideration according to the Figure 1The assembled mounting module 3 can be seen above the receiving shaft 2, and the Figure 4 In the same viewing direction, the display unit 1 shows the mounting module 3 inserted into the receiving slot 2.

[0041] As a further consequence, in the Figure 5 The display unit 1, inserted into a shelf rail 4, is visualized. The display unit 1 and the shelf rail 4 are shown here from the side. Such a shelf rail 4 is typically attached to the front end of a shelf in a retail store, which explains the meaning of the following orientation terms "top" and "bottom" according to common usage. Accordingly, "top" means against the direction of gravity and "bottom" means in the direction of gravity. If the display unit 1 is positioned differently than shown in the diagram, the display unit 1 will be positioned at the front end of a shelf in a retail store. Figure 5As displayed, these directional indications refer to other pages or parts of display unit 1.

[0042] In general, it can be stated that the display unit 1 has a screen 5 on its front, which, together with an invisible, i.e., internally arranged, electronics, is housed in a casing 6.

[0043] On the rear side of the display unit 1, the housing 6 has a battery receiving area 7A for receiving batteries (not visible), which is separated from a screen bezel area 7B of the housing 6 that surrounds the screen 5 from the rear. Between these two areas 7A and 7B of the housing 6, a first (upper) groove 8 and a second (lower) groove 9 are formed. The two grooves extend along the transition between the two areas 7A and 7B and run between the two lateral ends of the battery receiving area 7A. In the middle of the upper groove 8 is the receiving slot 2, so that the mounting module 3 is visible from above and at least part of a locking element 11 of the mounting module 3, which is designed as a pin 10 at its end, projects beyond an outer edge of the receiving slot 2, as shown in the Figures 4 and 5 can be seen.

[0044] As in the Figure 5As can be seen, the shelf rail 4 has a (lower) first mounting rail 12 with a hook-like end section 13 that runs along its entire length, and a (upper) second mounting rail 14 with hole-like recesses 15 that are located equidistantly from each other along the width of the longitudinal extent of the shelf rail 4, with the pin 10 shown inserted into one of these hole-like recesses 15. Viewed from below, the hook-like end section 13 engages in the lower groove 9 and holds the display unit 1 there, both fixed from below and at a constant distance from the shelf rail 4. The lower mounting rail 12 only allows for random movement.Positioning of the display unit 1 along the longitudinal extension of the shelf rail 4, whereby of course this movement is only possible if the pin 10 has not penetrated into one of the hole-like recesses 15.

[0045] The also shows Figure 5 a system that has at least one display unit 1 inserted into the shelf rail 4.

[0046] In the Figure 6The figure now shows how a special tool 16 is positioned on the lower half of the display unit 1 and how, with the aid of a magnetic force generated by the special tool, the ferromagnetic locking element 11 is moved into its retracted position. The display unit 1, thus unlocked at its upper edge from the shelf rail 4, can still be held at its lower edge by the shelf rail 4 and tilted out of the shelf rail 4 to the left at its upper edge and removed from the shelf rail 4. The special tool 16 has a magnet (not shown in detail) whose magnetic force is dimensioned or selected such that the force is sufficient to move the locking element over the distance defined by the geometry of the display unit 1 between the locking element and the magnet.

[0047] The Figure 7The display unit 1 is shown with the housing wall of the battery compartment 7A removed from housing 6. This reveals two batteries 17, which are connected by contact elements 18. The mounting slot 2, into which the mounting module 3 is inserted, is positioned between the batteries 17. As can be clearly seen in this view, the housing wall of the battery compartment 7A forms part of the mounting slot 2 at the rear. Also clearly visible in this view is a spiral spring 19, which is located inside the mounting module 3 and holds the locking element 11 in its extended position in its essentially relaxed state (except for a slight preload). It should also be mentioned that the spiral spring 19 is also present in the Figures 1 and 2 It can be seen, but is only roughly schematically indicated there as a cylinder.

[0048] In the Figure 7It can also be seen that the bottom 20 of the receiving shaft 2 has a bottom opening 21 through which a fastening mechanism 22 of the fastening module 3 is guided. In this case, the fastening mechanism 22 is formed by two hooks 23 which are mounted on elastically bendable arms 24, the hooks 23 being oriented away from each other so that they grip the bottom 20 on its outside, thereby fixing the fastening module 3 in the receiving shaft 2. A detail section 25 shows in the Figure 8 This situation is further illustrated by the assignment of the aforementioned reference symbols.

[0049] The fastening module 3 is in its assembled state in the Figure 9 and its disassembled state in the Figure 10 to be seen. Here, a sleeve 26 with an essentially rectangular cross-section is shown in detail. When inserted into the sleeve 26, the Figure 9also that the spiral spring 19 interacts with the locking element 11 at the head end and with a bolt 27 at the foot end. The in the Figure 10 The blocking element 11, which can be seen in detail, has a slide-like guide 28 into which the spiral spring 19 can be inserted, the slide-like guide being dimensioned in its width, length and depth such that it is longitudinally displaceable within the sleeve 26, which forms a box-like guide for the blocking element 11, between the retracted position and the extended position.

[0050] At its head end, the sleeve 26 has a cover 29 which has a cover opening 30, the shape of which corresponds to the shape of the part of the blocking element 11 passing through it, as shown in the Figure 9 can be seen.

[0051] The Figures 11 and 12The figures show only the sleeve 26 of the fastening module 3 from two different perspectives. The sleeve 26 is open on one side so that the spiral spring 19, together with the locking element 11, can be inserted from there. This is clearly visible in the perspective of the Figure 12 Visible. Side sleeve walls 31 each have a guide lug 32 that engages around or behind the inserted blocking element 11 to prevent it from falling out. A transverse sleeve wall 33, which connects the side sleeve walls 31, has a central recess 34 and wall edges 35 that are beveled towards the recess 34. These edges are formed in the area of ​​the inserted spiral spring 19 and serve to guide and position the spiral spring 19 when it is inserted.

[0052] Finally, it should be noted once again that the figures described in detail above are only exemplary embodiments, which can be modified in various ways by a person skilled in the art without departing from the scope of the invention. For the sake of completeness, it should also be noted that the use of the indefinite articles "a" or "an" does not preclude the possibility that the features in question may be present multiple times.

Claims

1. A display unit (1), - preferably an electronic display unit (1), - particularly preferably an electronic price and / or product information display unit (1), which comprises a housing (6) with a housing structure (2), wherein the housing structure (2) is designed to receive a fastening element (3) which is realized as a separate fastening module, wherein the fastening element (3) serves to fasten the display unit (1) to a supporting device, which is preferably designed as a shelf rail (4), characterized in that the housing structure (2) is designed as a receiving shaft (2) that is open towards the outside, corresponding to a sleeve-shaped form of the fastening element (3).

2. The display unit (1) according to claim 1, wherein the housing structure (2) is realized in such a manner, in particular dimensioned in depth in such a manner, that when the fastening element (3) is fully inserted into it (3), a locking element (10) of the fastening element (3), at least in its extended position, protrudes beyond an outer edge of the housing structure (2) at the location of the housing structure (2).

3. The display unit (1) according to any of the preceding claims, wherein the housing structure (2) seals the display unit (1).

4. A fastening element (3) for fastening or fixing a display unit (1), - preferably an electronic display unit (1), - particularly preferably an electronic price and / or product information display unit (1), to a supporting device, which is preferably designed as a shelf rail (4), wherein the fastening element (3) is realized as a separately insertable fastening module and comprises at least one retractable and extendable locking element (10), which is preferably designed as a pin, which is held in its extended position by a spring (19), which is provided in the fastening element (3), and can be moved against the force of the spring (19) to a retracted position, characterized in that the fastening element (3) comprises a sleeve-shaped form and is designed or shaped in such a manner that it can be inserted or plugged, in particular in a removable manner, into a housing structure (2) of the housing (6) of the display unit (1) according to any of claims 1 to 3 that corresponds to the shape of the fastening element (3).

5. The fastening element (3) according to claim 4, wherein a magnetic or magnetizable component, in particular a ferromagnetic component, which is particularly preferably realized by the locking element (10) itself, is provided for moving the locking element (10), so that by means of the action of an external magnetic force on the magnetic or magnetizable component, the locking element (10) can be moved into the retracted position against the force of the spring (19).

6. The fastening element (3) according to claim 4 or claim 5, which comprises an outer sleeve (26) or a cage in which both the spring (19) and the locking element (10) are received, and the locking element (10) protrudes out of the sleeve (26) at least in the extended position.

7. The fastening element (3) according to claim 6, wherein the spring (19), which is supported on the sleeve (26), holds the locking element (10) in the extended position.

8. The fastening element (3) according to claim 6 or claim 7, wherein the locking element (10) is guided in the interior of the sleeve (26) by means of a guide, in particular a box-like, tube-like, sledge-like or rail-like guide (28), and can be shifted along this guide between the extended position and the retracted position.

9. The fastening element (3) according to any of claims 4 to 8, which comprises a head-side cover (29) with a cover opening (30), wherein the locking element (10) protrudes through the cover opening (30) at least in its extended position.

10. The fastening element (3) according to claim 9, which comprises a side wall (31, 33) adjacent to the cover (29), in which a side wall opening is recessed, which is designed or shaped in such a manner that the locking element (10) can be inserted into the fastening element (3) or removed from there.

11. The display unit (1) according to any of claims 1 to 3, wherein the display unit (1) comprises a fastening element (3) according to any of claims 4 to 10, which is inserted into the housing structure (2) and realized as a fastening module.

12. A system, which comprises - a display unit (1) according to claim 11, and - a supporting device (4), which is preferably designed as a shelf rail (4), to which the display unit (1) is fastened by means of the locking element (10) of the fastening element (3), which is received in the housing structure (2) of the display unit (1), wherein the supporting device (4) comprises at least one recess (15), into which the locking element (10) is entered.

Images