French Patent Application No. 2 717 941, fig. 2, dis- closes a sign of this type, which, however, is inexpedi- ent because it includes a relatively large number of com- ponents, including a fixing plate having keyhole-shaped openings.

The object of the invention is to provide an improved sign of the above-mentioned type, which may be manufac- tured with a relatively limited number of components, and which allows temporary attachment of one or more sign plates, which have already been secured to the base parts, until the time when a more effective attachment of the sign plate is desired, also while any other sign plates are secured to the base part.

This is achieved according to the invention in that the locking device is shaped as a substantially flat and elongated body having a reception opening for a respec- tive engagement means, said reception opening being formed with a first portion which provides a first pull- out resistance on the engagement means, and a second por-

tion which provides a second and greater pull-out resis- tance on the engagement means, and that the locking de- vice provides the first pull-out resistance in the first position A and the second pull-out resistance in the sec- ond position B.

According to a preferred embodiment, the reception track may be defined by a wall portion which can form an en- gagement face for the sign plate, and which comprises openings for the engagement means. This provides a stable support of the sign plate in the mounted position.

If the sign comprises a plurality of sign plates, the locking device is preferably adapted to affect all en- gagement means with the first pull-out resistance and the second pull-out resistance, respectively, by said move- ment. When all sign plates have been mounted, a more per- manent attachment of the sign plates may be provided by means of the locking device until one or more of the sign plates are to be replaced.

In order to be able to provide the variable pull-out re- sistance, the reception opening is preferably formed with an elongated slot which forms the second portion, and which, at one end, terminates in a transverse, elongated slot to form the first portion.

In addition, the sign preferably comprises separate end members which define the reception track, and which can give the reception track a length which just allows the movement from position A to position B. The end members have an insertion opening for a tool by means of which the locking device may be moved. Thus, the sign has no directly accessible operating parts by means of which un- authorized persons can move the locking device.

The invention will be explained more fully below with reference to an embodiment shown in the drawing. In the drawing: fig. 1 shows a horizontal cross-section through the sign, seen from above, mounted on a wall, fig. 2 shows a locking device, seen from the front, for the attachment of three sign plates, fig. 3 shows an end member, seen from the front, which forms the upper and lower boundaries of the sign, fig. 4 shows an alternative embodiment of the locking de- vice, seen in perspective view, fig. 5 shows a component for the locking device in fig. 4 seen from the front, and fig. 6 shows a section on an enlarged scale of the lock- ing device of fig. 4, seen from the front.

In fig. 1, the reference numeral 1 indicates a wall face having mounted thereon a sign according to the invention intended to display a text in the form of e. g. a name or a directional indication. In the embodiment shown, the sign comprises two elongated base parts 5', 5"which are made of an elongated extruded profile, and which are se- cured to the wall face 1 mutually spaced by means of screws (not shown) which are passed through threaded holes 3. The sign is defined at the upper edge and the lower edge by respective end members 4, of which one end member 4 is shown in front view in fig. 3. The shown end member 4 has a central portion 8 with a through opening 9 for an attachment screw by means of which the end member may be secured to the wall face 1. The end member 4 addi-

tionally has protruding portions 7 which extend outwards on each side of the central portion 8. As will appear from fig. 1, the end member 4 is formed so that its cen- tral portion 8 may be inserted into the space between the two base parts 5', 5"fastened by screws.

The base parts 5', 5"comprise an internal elongated track 6 which is defined at the upper edge of the sign and at the lower edge of the sign by the protruding por- tions 7 on a respective end member 4. The protruding por- tions 7 are shaped such that a suitable tool, such as a small screwdriver, may be inserted into the track 6 ei- ther from above or from below, as will be explained more fully below. In addition, each base portion 5', 5"is formed with a number of openings 12 which extend along the track 6, and which give access to the interior of the track 6 from the front side of the track 6 opposite the wall face 1.

As shown in fig. 1, a detachable sign plate 10 is ar- ranged in front of the base parts 5', 5", said sign plate carrying the text or the message which is to be dis- played. The sign plate 10 is preferably shaped as a rec- tangular flat plate with an outwardly directed text-car- rying surface and with an oppositely disposed surface which, as shown, is directed inwards toward the base parts 5', 5". The sign plate 10 has two protruding en- gagements means on the internal surface, both of which are generally designated by the reference numerals 15 and 18 in the drawing, where the numeral 15 indicates a pin- shaped root part, while the numeral 18 indicates a head arranged at the end of the root part 15. The heads 18 of the engagement means are passed through the openings 12 which are dimensioned so as to allow free insertion of the heads 18 into the track 12. It will be appreciated from fig. 1 that several such sign plates 10 may be

placed above each other according to the extent of the base parts 5', 5"in a direction out of the plane of the paper.

The interior of each track 6 accommodates a flat and elongated locking device 20 of a relatively flexible plastics material, such as e. g. injection moulded POM, which is shown in greater detail in fig. 2 and whose function is to secure the engagement means 15,18 to the base parts 5', 5". For this purpose, the locking device 20 has a plurality of reception openings, which each are indicated by the reference numerals 25 and 28, and which in number correspond to the preselected number of sign plates to be carried by the base parts 5', 5". Three such reception openings are thus shown in the drawing, corre- sponding to three sign plates 10 which each have an en- gagement means 15,18 at each edge. The reception open- ings are each composed of a first elongated slot 28 ex- tending in the longitudinal direction of the track 6 when the locking device 20 is installed correctly, and of a second slot 25 extending transversely to the first slot 28. The first slot 28 and the second slot 25 thus form a cross-shaped opening in the locking device 20, where the point of intersection of the slots forms the centre of the cross. By dimensioning the slots 25,28 suitably relative to the head 18 of the engagement means and by selecting a suitable flexibility of the locking device 20, a snap engagement may be established between the locking device 20 and an engagement means when the head 18 of the engagement means has been passed completely through the point of intersection of the slots. It will be appreciated that the material of the locking device 20 in the area around the point of intersection is deformed slightly elastically during the insertion of the head 18.

When the head 18 of the engagement means 15 has been passed through the reception opening at the point of in- tersection of the slots 25,28 from the front side of the locking device 20, as shown in fig. 1, the root part 15 extends through the point of intersection of the slots 25,28 and the head 18 engages the rear side of the lock- ing device 20, whereby the locking device 20 gives the sign plate 10 a first pull-out resistance, which ensures that the sign plate 10 can be retained temporarily, while any further sign plates 10 are mounted in a corresponding manner above or below.

As mentioned, the locking device 20 is embedded in the track 6, said locking device 20 being also so mounted as to be movable in the longitudinal direction of the track 6 between a first position A and a second position B, po- sition A corresponding to a position in which the point of intersection of the slots is disposed directly oppo- site a respective opening 12 in the base part. In posi- tion B, the locking device 20 is displaced so that the point of intersection of the slots has been moved down relative to the respective opening. In this position, the root part 15 of the engagement means now extends through the slot 28, while the head 18 is secured on the rear side of the locking device 20 in the area of the slot 28 which is most remote from the transverse slot 25. The locking device 20 will be less resilient in this area than in the area at the point of intersection of the slots 25,28, thereby providing a greater pull-out resis- tance which greatly protects against unintentional with- drawal of the sign plate 10.

During the mounting of the sign plate on the base parts 5', 5", the engagement means 15,18 are passed through the openings 12, as mentioned, and are pressed into a re- spective reception opening in the locking device 20, said

locking device 20 having been moved in advance to the po- sition A by means of a special tool which may be moved into the track 6, as mentioned above. Because of the de- scribed snap engagement with the engagement means 15,18 a first pull-out resistance is provided in position A, ensuring that a certain modest pull-out force has to be applied to the sign plate in order to pull the engagement means 15,18 out of engagement with the locking device 20 again, which is expedient when one of the sign plates is adjusted, while light attachment of the other sign plates 10 is still desired. When all sign plates 10 have been mounted correctly, fixing proper of the sign plates 10 may be established by moving the locking device 20 to po- sition B in which, as stated above, a relatively great pull-out resistance is ensured, whereby, in other words, a relatively considerably greater pull-out force has to be applied to the sign plate in order to disengage the engagement means 15,18 from the base part 5', 5". Since access to the locking device 20 can be achieved only by means of e. g. a small special tool, the sign is hereby protected to a great extent against e. g. vandalism where a person tries to remove one or more of the sign plates 10.

Figure 4 shows an alternative and presently preferred em- bodiment of the locking device 20. This embodiment is in- tended to avoid blocking, to some extent, of the movabil- ity of the locking device in the reception track as a consequence of temperature-caused expansions of the con- stituent materials. In the embodiment shown, the base part 5', 5"as well as an elongated subcomponent 31 of the locking device 20 shown in fig. 5 may thus be made of e. g. aluminium, said subcomponent 31 comprising a plural- ity of holes 33 in connection with which a respective component 34 of a plastics material is mounted.

Figure 6 shows a section on an enlarged scale of the locking device 20 in fig. 4, and it appears from this how the component 34 is shaped. It will be appreciated that the component 34 is secured to the elongated subcomponent 31 by clipping or in another conventional manner.

As mentioned, the component 34 is preferably made of a plastics material and is provided with elastic resilience to provide the previously mentioned first and second pull-out resistances on a sign plate with the engagement means described with reference to fig. 1.

As shown, the component 34 defines a reception opening 30 for the head 18 of the engagement means. More particu- larly, the reception opening is defined by two opposed and protruding elastically resilient lugs 35 arranged at a mutual distance which is slightly smaller than the di- mension of the head 18. When the head 18 is inserted in a direction perpendicular to the plane of the paper, the lugs 35 will be bent slightly to return to the starting position when the head 18 has been moved past them.

Hereby, a first pull-out resistance is provided on the engagement means.

The component 34 moreover comprises two opposed gripping flaps 38 provided with relatively less resilience in the mentioned direction perpendicular to the plane of the pa- per. This desired less resilience may e. g. be obtained by suitable dimensioning of the cross-sectional dimension of the gripping flaps 38 relatively to the lugs 35. Hereby, a second and greater pull-out resistance may be provided on the engagement means when the head 18 is held by the gripping flaps 38. As shown, the gripping flaps prefer- ably form an inner section 38'with a shape corresponding to the cross-sectional shape of the pin-shaped root part

18 of the engagement means, said gripping flaps forming a constriction in front of the section 38'.

In use, the locking device 20 is moved, as described be- fore, with the head 18 of the engagement means in engage- ment with the rear side of the lugs 35 and the flaps 38, respectively. When the root part 15 is inserted into the section 38', the flaps 38 yield slightly sideways in the direction of the arrow P to return to the starting posi- tion when the root part 18 is present in the section 38'. Effective attachment of the engagement means is provided hereby, which may be expedient when the sign is used e. g. on board ships, thereby avoiding noise from the sign caused by the machines of the ship. It will be appreci- ated that the dimension of the flaps 38 perpendicular to the plane of the paper may advantageously be selected to correspond to the length of the root part 15.

It should be stressed that the sign shown in the drawing must not necessarily be secured to a vertical wall, but that it may very well be secured to an inclined face or to a bracket plate. If the latter solution is selected, a corresponding sign may be secured on the opposite side of the bracket plate, whereby two signs according to the in- vention may be carried back to back on the bracket plate.

It should moreover be mentioned that the number of base parts may be selected freely, as optionally just one may be selected. Further, each sign plate may just have a single protruding engagement means, in which case the sign preferably just has one locking device. Rotation of the sign plate around the engagement means will in this case be prevented by the end member 4.