Technical Field

The present disclosure relates to a display device, which is particularly suited for holding thin, flexible sheets of printed matter.

Background

US3310901 and US4519152A disclose a display device comprising a front part and a back part, which are adapted to be assembled in mating pivotal relationship with one another. A spring extends between the back and front parts to bias the front part between an open position and a closed position. In the open position, a sheet that is to be displayed can be received and in the closed position, the sheet is clamped between the back part and a free portion of the front part.

There is a need for a further improved display device. In particular, there is a need for a device which is better suited to hold a thin, flexible sheet of printed matter. Moreover, there is a need for a display device which facilitates the task of posting a sheet of printed matter, especially when very large sheets are to be posted. Summary

It is thus an object to provide display device and a method of posting a thin, flexible sheet of printed matter, which is improved as compared to the prior art. In particular, objects include providing a device and method which can achieve a more secure mounting of a thin, flexible sheet of printed matter and/or which facilitate the task of posting such sheet.

The invention is defined by the appended independent claims, with embodiments being set forth in the dependent claims, in the following description and in the attached drawings.

According to a first aspect, there is provided a display device for posting a thin, flexible sheet of printed matter. The display device comprises a base part and a front part. The front part is pivotable relative to the base part between an open position, wherein the sheet may be inserted into or removed from the display device, and a closed position, wherein the sheet is clamped between the front part and the base part. The base part presents a base part clamping surface, which extends at an angle of more than 45 ^° , preferably more than 80 ^° or about 90 ^° , relative to a display plane, and the front part presents a corresponding front part clamping surface, which is adapted to provide a clamping force in a direction that is normal to the base part clamping surface.

The thin, flexible sheet may be a sheet having a weight of about 80-

180 g/m ² , preferably 90-170 g/m ² . Such a sheet may be a paper sheet, a cardboard sheet, a coated paper sheet, a laminated sheet having a core of paper, woven or nonwoven material, or a polymer film.

The display surface is a surface which is parallel to a display surface of the sheet. This display surface may be an imaginary surface, e.g. in the case when the display device merely forms a frame, or it may be an actual surface, when the display device is provided with a panel or grid providing support in a direction normal to the display surface.

A display device as described above provides enhanced fixation of the sheet as compared prior art display devices. This is particularly advantageous when posting very large sheets, such as sheets having sides on the order of more than 1 .5 m, or preferably 2 m. Tests have shown good performance on a sheet having a height of 2 m and a width of 6 m. Display devices according to the present disclosure may be used for posting sheets having side lengths of up to 15 m or even up to 20 m.

The display device may further comprise a first recess portion, which is recessed relative to a display plane, whereby the base part clamping surface is formed at least partially in the first recess portion.

The front part clamping surface may be formed on a clamping protrusion which is closer to a free end of the front part than to a hinge portion of the front part.

The front part clamping surface may be convex and may preferably present a portion which is parallel with the base part clamping surface. The display device may further comprise an auxiliary support shoulder, which protrudes beyond the display surface and which preferably presents an angle of 90 ^° +/- 10 ^° relative to the display surface.

Such a support shoulder may facilitate the posting of the sheet, as it may provide additional support for a rolled-up or folded sheet while the sheet is being attached to the display device.

The auxiliary support shoulder may be spaced from the display surface by at least the first recess portion.

The base part and/or the front part may be formed as an integrated extruded part.

The display device may further comprise at least one spring element, which is arranged to bias the front part towards the base part when the front part is in the closed position.

At least one of the base part clamping surface and the front part clamping surface may present a ridge or protrusion extending towards the other one of the base part clamping surface and the front part clamping surface.

Such a protrusion may act against a smooth surface, against another protrusion or against a recess or groove in the opposing surface. Hence, improved clamping may be achieved.

The front part may present a secondary clamping surface, which is adapted to provide a secondary clamping force in a direction that is normal +/- 30 ^° , preferably +/- 15 ^° or +/- 5 ^° to the display plane.

Hence, additionally enhanced attachment of the sheet may be achieved.

According to a second aspect, there is provided a display holder comprising at least one display device as described above.

Preferably, such a display holder may comprise at least three display devices.

The display holder may comprise at least two separate display devices which are longitudinally aligned and separately openable and closeable.

According to a third aspect, there is provided a method of posting a thin, flexible sheet of printed matter. The method comprises providing a display device comprising a base part, and a front part, wherein the front part is pivotable relative to the base part between an open position, wherein the sheet may be inserted into or removed from the display device, and a closed position, wherein the sheet is clamped between the front part and the base part. The method further comprises arranging at least part of the sheet in a display plane, such that an edge portion of the sheet extends beyond an edge of a display surface, pivoting the front part towards the closed position, such that the edge portion is folded over the edge, and clamping the edge portion between the front part and the base part by a clamping force which presents an angle of less than 90 ^° relative to the display plane.

The method may further comprise resting the sheet on a support shoulder, which extends beyond the display plane while the front part is in the open position.

The method may further comprise providing the sheet in a rolled-up or folded state, at least partially attaching a leading edge portion of the rolled-up or folded sheet to a display device extending in parallel with said leading edge, and alternately rolling out or unfolding the sheet in a direction away from the leading edge portion and clamping edge portions along said direction away from the leading edge portion.

Brief Description of the Drawings

Fig. 1 is a schematic elevation view of a display holder 1 for posting a sheet 4 of printed matter.

Figs 2a-2c are schematic sectional views of a display device 2, which forms part of the display holder 1 in Fig. 1 .

Figs 3a-3b are schematic sectional views of the display device 2 illustrated in Figs 2a-2c.

Fig. 4 schematically illustrates a sectional view of an alternative embodiment of the display device 2'.

Detailed Description

Fig. 1 schematically illustrates a display holder 1 polygonal frame structure composed of a plurality of display devices 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k, 21, which are held together by brackets 3a, 3b. In Fig. 1 , display devices 2a, 2I; 2c, 2d; 2f, 2g; 2i, 2j used to form corners are formed with 45 ^° cut ends and 90 ^° ends, while display devices 2b, 2e, 2h, 2k provided there between are formed only with 90 ^° ends. However, the angles may be selected arbitrarily.

It is understood that the display holder may be formed from an arbitrary number of display devices 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k, 2I.

In one basic embodiment, the display holder may be formed with only four display devices, all of which may be 45 ^° cut at both ends.

In yet another embodiment, the display holder may be formed with three display devices, all of which may be 60 ^° cut at both ends.

In yet another embodiment, the display holder may be formed with six display devices, two of which may extend over substantially an entire side length and thus be e.g. 45 ^° cut at both ends. Four of the display devices may be 45 ^° cut at one end and the remaining two display devices may be formed with 90 ^° ends.

Analogously, the display holder 1 may be formed of display devices having a suitable length, i.e. a length that is sufficiently short to be

manipulated by hand. Typically, display device length may be on the order of 0.5-2 m, preferably around 1 m.

It may be desirable to adapt the hardness (i.e. spring constant) of the springs to the length of the display device, such that longer display devices comprise a higher number of springs, which are softer, while a shorter display device comprises a smaller number of springs, but which are harder.

The display devices 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k, 2I may be arranged to abut each other at the short sides. Alternatively, a space between abutting short sides may be provided. Such space may be on the order of 0.5- 5 mm. optionally, a sealing device, such as a sealing strip, may be provided to prevent moisture from entering the display holder 1 . A space between adjacent display devices may be such that the display devices may be manipulated individually without engaging each other. The display devices 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k, 21 may be held together by corner brackets 3a and straight brackets 3b so that a substantially self-supporting frame is provided.

Alternatively, or additionally, the display devices 2a, 2b, 2c, 2d, 2e, 2f, 2g, 2h, 2i, 2j, 2k, 21 may be attached to a panel 5, as will be described in more detail with reference to Fig. 3b.

Figs 2a-2c schematically illustrate a display device 2, with a front part 22 in three different positions relative to a base part 21 .

The base part 21 may be formed as an elongate member having a profile which as a non-limiting example may be designed as illustrated in Fig. 2a.

The base part may be an extruded member of metal, e.g. aluminum, steel or magnesium or of a polymer material.

The base part 21 profile may comprise a first portion 2101 , which may extend from a pivot portion 21 1 towards a display surface 213. The first portion 2101 may also carry a spring seat 212, which may be formed as a concave surface adapted for receiving one end of a spring 23, such as a leaf spring. The spring seat 212 may be spaced from the first portion 2101 in a direction perpendicular to the display surface.

Between the first portion 2101 and the display surface 213, there may be formed a recess 215, which is recessed in relation to the display surface 213 and open in a direction perpendicular to the display surface 213. The recess may be formed by a second portion 2102 of the base part 21 profile. This second portion 2102 may extend from the first portion 2101 and in a direction opposite to a normal of the display surface 213, so as to form a wall of the recess 215. For example, the second portion may, but need not, extend substantially perpendicular to the display surface 213. The second portion 2102 may also extend past at least one of its connection to the first portion 2101 and the display surface 213, such that a support shoulder 218 is provided.

A third portion 2103 of the base part 21 profile may extend from another end of the second portion 2102 and away from the display surface, so as to form a second recess 21 6, which may be open in a direction parallel with the display surface and perpendicular to the first recess 215. When arranged as a frame enclosing a display surface 213, this second recess 21 6 may be open in an outward direction, away from the display surface 213. This second recess 21 6 may be used for assembly of the base part 21 with other base parts using such brackets 3a, 3b as are described with reference to Fig. 1 . The brackets may be attached to the base part 21 by a fixating device, such as screws, nut-and-bolt or rivet connectors.

A fourth portion 2104 of the base part 21 profile may provide a bottom of the first recess 2105. This fourth portion may extend substantially parallel with, and spaced from, the display surface 213.

A fifth portion 2105 of the base part 21 profile may be spaced from the second portion 2102. This fifth portion 2105 may provide a wall of the first recess 215 and may thus be spaced from the second portion 2102 by a distance corresponding to a length of the fourth portion 2104. The fifth portion 2105 and the second portion 2102 may extend substantially in parallel with each other and perpendicular to the display surface 213.

A sixth portion 2106 of the base part 21 profile may extend from the part of the fifth portion that is closest to the display surface 213 and in parallel with the display surface 213. This sixth portion 2106 may form part of the display surface 213.

A seventh portion 2107 of the base part profile may extend from the intersection between the fourth part 2104 and the fifth part 2105 and in parallel with the sixth portion 2106, such that a third recess 217 is formed by the fifth portion 2105, the sixth portion 2106 and the seventh portion 2107. This third recess 217 may be open in a direction parallel with the display surface 213, perpendicular to the first recess 215 and optionally opposite to the second recess 21 6. When arranged as a frame enclosing a display surface 213, this third recess 217 may be open in an inward direction, towards the display surface 213.

The third recess may be used for receiving an edge portion of a panel

5 (Fig. 3b) or other support member forming part of, and/or supporting, the display surface 213. The pivot portion 21 1 may be provided as a convex surface, which may be substantially cylindrical so as to operate as a hinge pin with a center of rotation C.

The description will now focus on the front part 22. The front part 22 may be formed as a generally U-shaped part having a pivot portion 221 which is designed to interact with the pivot portion 21 1 of the base part 21 . The pivot portion 221 of the front part may thus comprise a concave surface portion that has substantially the same curvature as the convex surface of the pivot portion 21 1 of the base part 21 . However, it is noted that the convex surface may instead be arranged on the front part 22 and the concave one may be arranged on the base part 21 .

At the opposite end of the front part 22 profile, there may optionally be provided a lever 224 for facilitating operation of the display device 2. As an alternative, the display device, in particular the front part 22, may be designed to be tamper proof, as disclosed in US4519152A.

Moreover, at the opposite end of the front part 22 profile, there is provided a clamping flange 225, which may be substantially planar or curved inwardly, towards the pivot portion 221 . This clamping flange 225 provides a clamping surface 226, which is to cooperate with a clamping surface 214 provided in the first recess 215, such as on the fifth portion 2105 of the base profile 21 .

The clamping surface 226 may comprise a portion that is substantially parallel to a portion of the clamping surface 214 of the first recess 215.

The portions of the clamping surfaces 226, 214 that interact extend at an angle a of more than 45 ^° to the display surface, preferably at more than 80 ^° or about 90 ^° .

A secondary clamping surface 227 may be provided on the front part 22, this secondary clamping surface 227 being adapted for interaction with an edge portion of the display surface 213.

A transition between the display surface 213 and the clamping surface

214 of the base part 21 may be rounded with a bending radius of less than 3 mm, preferably less than 2 mm, less than 1 mm or less than 0.5 mm. Similarly, a transition between the clamping surface 226 and the secondary clamping surface 227 on the front part 22 may be rounded with a bending radius of less than 3 mm, preferably less than 2 mm, less than 1 mm or less than 0.5 mm. Preferably, the transitions at the base part 21 and the front part 22 present bending radii which differ by less than 20 %, preferably less than 10 %, from each other.

In the illustrated embodiment, at the base part 21 , there is an angle of about 90 ^° between the display surface 213 and the clamping surface 214. Moreover, at the front part 22, the clamping surface 226 and the secondary clamping surface 227 meet at an angle of about 90 ^° . The clamping surface 226 presents a short portion which is planar, just next to the transition, and the clamping surface 226 then becomes concave. The planar portion may be less than 30 %, preferably less than 15 % or less than 5 % of the length of the clamping flange 225, as seen in the cross sectional view.

Optionally, the clamping surface 214 may be provided with an elongate ridge or a plurality of protrusions that are arranged to interact with one or more ridges, protrusions or recesses on/in the clamping surface 214, or vice versa.

The front part 22 may also comprise an inwardly, towards the base part 21 extending spring flange 222, which presents a spring seat 223 for interaction with the other end of the spring 23.

The spring 23 may be formed of piece of resilient material, such as spring steel, which may have a slightly curved cross section, as illustrated and a length, along a length direction of the display device 2, which is shorter than that of the display device. Preferably, the length of the spring 23 may be on the order of 1 /40 to 1 /5 of that of the display device, and, if needed, several springs 23 may be arranged spaced from each other along the length of a display device 2.

A first end of the spring 23 may be received in the spring seat 212 of the base part 21 and a second end of the spring 23 may be received in the spring seat 223 of the front part 22, such that the spring 23 provides an expanding force between the spring seats 212, 223. The first end of the spring 23 may be moveable along the concave surface of the spring seat 212, such that the spring 23, when oriented in a first direction may provide a biasing force which biases the front part 22 towards an open position, as indicated in Fig. 2a, when oriented in a second direction, the spring 23 may instead bias the front part 22 towards the closed position, as indicated in Fig. 2c.

Hence, the front part 22 may provide a snap-over action between the open position (Fig. 2a) and the closed position (Fig. 2c).

The operation of the display device may be as follows when a thin, flexible sheet 4 of printed matter is to be posted.

The front part 22 is opened by pivoting about the hinge axis C away from the base part 21 . If provided, the lever 224 may be used for opening the front part 22 without the aid of a tool.

An edge portion 42, which may be about 0.5 to 4 cm, preferably about 1 -3 cm in length, is arranged to extend past an edge of the display surface

213 and out over the first recess 215, i.e. past the sixth portion 2106.

Optionally, at this point, the edge portion 42 may be pre-folded, by hand or using a tool, such that a crease 41 is formed.

The front part 22 is pivoted about the hinge axis C towards the base portion 21 , as is seen in Fig. 2b, such that the clamping flange 225 forces the edge portion 42 into the recess 215.

During this phase, the spring 23 provides a bias force between the spring seats 212, 223, such that the front part 22 is pivoted biased towards the base part 21 .

At a final phase of the pivoting, the clamping surface 226 contacts at least part of the edge portion 42 and forces it towards the clamping surface

214 of the base part 21 , such that a clamping force directed in a direction normal to the clamping surfaces 214, 226 is provided. The base part 21 and the front part 22 may be designed such that in the closed position, there is a clearance between the clamping surfaces 214, 226, which less than the thickness of the sheet. For example, the clearance may be less than a minimum allowed sheet thickness. As further examples, the clearance may be 0 (zero) or even slightly negative. In the latter case, the base part 21 and/or the front part 22 may be flexible. For example, the clamping flange 225 may be flexible. In the alternative, the spring 23 and interacting pivoting portions 21 1 , 221 may allow some displacement of the front part 22 in a direction parallel with the display surface and away from the clamping surface 214 of the base part 21 .

When the front part 22 is in the clamping position, as illustrated in Fig. 2c, the spring 23 continues to bias the front part 22 towards the base part 21 , such that the clamping force is maintained.

Optionally, at this point a second clamping surface 227 on the front part 22 may clamp a portion of the sheet 4 against the display surface 213, such that an additional clamping force, directed in a direction normal to the display surface 213 is provided.

As illustrated in Fig. 3a, when posting a sheet 4, the support shoulder 218 may be used to support a sheet while it is being posted.

For example, once the front parts 22 of the display holder 1 have been opened, a roll 4' of sheet may be placed and supported at least partially on a shoulder 218 of a horizontally oriented lower display device 2g, 2h, 2i (Fig. 1 ), while its leading edge is being extracted and attached to at least one vertically oriented display device 2d, 2e, 2f; 2j, 2k, 2I. The roll 4' may then be moved horizontally along the horizontally oriented lower display device 2g, 2h, 2i

(Fig. 1 ), while supported on the shoulder 218 and while the sheet is rolled out. As the sheet is rolled out horizontally past the end of one horizontally oriented display device 2a, 2b, 2c, 2g, 2h, 2i, that display device may be closed. When the sheet is entirely rolled out, its remaining vertical edge is attached to the corresponding vertically oriented display device or devices.

For example, if the sheet is to be installed from left to right in Fig. 1 , the vertically oriented display devices 2j, 2k, 2I would be the first ones which are closed so as to lock the sheet's leading edge. As the sheet is then rolled out, the horizontally oriented display devices 2a, 2i would next be closed, followed by horizontally oriented display devices 2b, 2h, horizontally oriented display devices 2c, 2g and finally vertically oriented display devices 2d, 2e, 2f.

Referring to Fig. 3b, a panel 5 or grid may be placed inside a frame formed of display devices 2, as illustrated in Fig. 1 . An edge portion of such a panel 5 may be received wholly or partially in the third recess 217. Optionally, part of the edge portion of the panel 5 may be provided with a recess 51 with a depth which may be sufficient to accommodate the thickness of the sixth and/or seventh portions 2106, 2107 of the base part 21 profile. Hence, the part of the display surface 213 formed by the base part 21 may be flush with at least part of the remaining display surface.

The panel 5 may be a homogenous member of wood or wood based material, such as a fiber board. As one alternative, the panel 5 may be formed of a sandwich panel, comprising e.g. front and back sheets separated by a core. As yet another alternative, the panel may be formed by a corrugated sheet of e.g. metal or polymer material.

Fig. 4 schematically illustrates an alternative way of joining together display devices 2'. The base part 21 ' here comprises bracket retainers 2130a, 2130b, forming a slot which is open in the longitudinal direction of the display device 2', into which the bracket 3 may be inserted. The bracket may be optionally be provided with an additional a fixating device, such as screws, nut-and-bolt or rivet connectors.