GB2293845A - Improvments in road signs - Google Patents

Abstract

A road sign comprising a generally planar upper frame 2 to which a signboard can be attached, the upper frame having a horizontal lower edge to which a number of hinge lugs 11 are attached, and the upper frame having two leg frames attached to its lower edge by hinge portions (12) Fig. 2 cooperating with the hinge lugs. Each of the leg frames is hingeable from a closed position, wherein it lies substantially in the plane of the upper frame, to a deployed position wherein the leg frames are set at an angle of approximately 45 DEG on either side of the plane of the upper frame. The hinge lugs and the hinge portions include cooperating stop surfaces which limit the arc of travel of the leg frames relative to the upper frame. The parts are preferably made of plastics. <IMAGE>

Description

IMPROVEMENTS IN ROAD SIGNS The present invention relates to road signs, and is particularly concerned with providing a lightweight, robust, foldable road sign with an improved hinge configuration.

Many currently-used road signs are of a tripod design, which holds a sign indicating board at an acute angle to the vertical. The present invention seeks to provide an arrangement which supports a sign placard in a vertical plane, while providing a firm and rigid base for the sign with reduced stress levels in the sign components at the hinge.

According to the present invention, there is provided a road sign comprising a generally planar upper frame to which a signboard can be attached, the upper frame having a horizontal lower edge to which a number of hinge lugs are attached, and the upper frame having two leg frames attached to its lower edge by hinge portions cooperating with the hinge lugs, each of the leg frames being hingeable from a closed position, wherein it lies substantially in the plane of the upper frame, to a deployed position wherein the leg frames are set at an angle of approximately 45" on either side of the plane of the upper frame, wherein the hinge lugs and the hinge portions include cooperating stop surfaces which limit the arc of travel of the leg frames relative to the upper frame.

Advantageously, the road sign the hinge lugs each comprise a pair of stop surfaces arranged in orthogonal planes, and the hinge portions include a pair of stop surfaces arranged in planes inclined at an acute angle to each other.

Most preferably, each hinge lug comprises a horizontal bearing plate from which a central downwardly depending web extends; and pairs of hinge plates extend to either side of the web and are penetrated by a pair of bores extending parallel to the planes of the web and the bearing plate, and the hinge portions comprises a number of similar hinge plates penetrated by an aligned bore, the hinge plates situated on one side of the central web of each of the hinge lugs and the hinge plates of one of hinge portions being arranged with their bores in alignment to receive a pivot pin.

An embodiment of the present invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 is a perspective view showing the general layout of the road sign; Figures 2a and 2b are front and back views, respectively, of one of the leg portions of the sign; Figure 3a is a rear view of the upper framework of the sign; Figure 4 is a perspective view showing the cross-sectional arrangement of the members making up the upper frame shown in Figure 3; Figures 5a, Sb and Sc are side, front and underneath views, respectively, of a hinge lug attached to the lower edge of the upper frame; Figures 6a, 6b and 6c are side, front and top views of hinge portions attached to the upper part of the leg frames; Figure 7 is a perspective view of an attachment clip; and Figures Sa and Sb are front and side views of a further attachment clip.

Referring now to Figures 1 to 3, the sign of the present invention comprises a generally planar upper frame 2, to which a signboard can be attached. The upper frame 2 comprises four generally vertical members 3. 4, 5 and 6 joined by lower, intermediate and upper cross-members 7, 8 and 9 respectively. Bracing webs 10 may be added at intersections of the members, to assist in maintaining the rectangular form of the panel. To the lower edge of the sign panel, as shown in Figure 3, there are fixed on lower transverse member 7 four hinge lugs 11, shown in greater detail in Figures 5a to 5c. The purpose of these hinge lugs will be explained in detail later.

Each of the leg frames 20 of the sign comprises a pair of vertical legs 21 situated at the extreme ends of a central cross-member 22, and extending upwardly and downwardly therefrom. Extending upwardly from intermediate parts of the cross-member 22 are bracing legs 23, and the legs 21 and bracing legs 23 each carry at their upper end a hinge portion 12. The spacing of the legs 21 and 23 is so arranged that the hinge portions 12 can mate with respective hinge lugs 11 of the upper sign frame 2, effectively preventing relative movement of the parts along the hinge axis.

As is clear from the general arrangement shown in Figure 1, the upper sign frame has attached to its lower edge two leg frames, the leg frames being hingeable from a closed position, substantially in the plane of the upper frame 2, to a deployed position wherein the leg frames are set at an angle of approximately 45" on either side of the plane of the upper frame 2. Such an arrangement provides a firm and stable base for the upper frame 2.

The hinge lugs 11 and hinge portions 12 will now be described in greater detail with reference to Figures 5 and 6 of the drawings.

Referring to Figures 5a, 5b and 5c, the lower transverse frame member 7 of the upper frame 2 has attached thereto a number of horizontal plates 25, from which a central downwardly depending web 26 extends substantially in the plane of the upper frame 2. Extending from either side of the web 26 are pairs of hinge plates 27, each pair of hinge plates being penetrated by aligned bores 28.

The hinge elements 12 attached to the legs 21 and bracing legs 23 of the leg frames each comprise a number of similar hinge plates 27a penetrated by aligned bores 28a. The hinge plates 27 and 27a of the hinge lugs 11 and hinge elements 12 are arranged so as to be able to interdigitate with the bores 28 and 28a in alignment to receive a pivot pin. Each leg frame engages the plates 27 to one side of the central webs 26 of the lugs 11 of the upper frame 2.

The shaping of the plates 27a of the hinge elements 12 is such that, when the leg frames 20 are in their deployed positions, the plates 25 of the hinge lugs 11 are supported on first flat edge surfaces30c of the plates 27a, and a second flat edge surface 30b bears against the web 26. When the leg frames 20 are in their retracted position, a third flat' edge surface 30a of each plate 27a engages the central web 26 of the hinge lugs 11.

The profile of the edges of the plates 27a between third and second edge surfaces 30a and 30b is so arranged that, as the leg frame 20 swings from its retracted position to its deployed position, the edge of plate 27a between third and second edge surfaces 30a and 30b momentarily engages the central web 26, causing a resilient deflection. As the central web 26 springs back to its original form, the force it exerts on the plates 27a tends to urge the leg frames 20 towards either their deployed or their retracted positions, acting as an 'over-centre' toggle.

Thus, the resilient deflection of the webs 26 is used to retain the leg frames 20 in their retracted or deployed positions.

The parts of the sign frame are generally constructed from injection-moulded plastics material, preferably recycled plastics material. The cross-sectional shape of the frame elements of the upper frame is shown in Figure 4, the cross-sectional shape being a generally divergent channel section with outwardly extending flanges on its free edges, and transverse stiffening webs being positioned at intervals along the channel section. The cross-sectional shape of the leg frames is a substantially rectangular channel section, with internal stiffening webs positioned both transversely and diagonally within the channel section.

In order to attach signboards to the upper frame, clips such as are shown in Figures 7 and 8 may be used. Openings may be provided in the elements of the upper frame 2 at prearranged intervals, and corresponding openings can be formed in signboards. To attach such a signboard to the upper frame 2, the barbed studs 35 of the clip 36 of Figure 8 may be introduced through the opening in the signboard so that flange 37 lies against the surface of the signboard. The barbed studs 35 are then pushed through an opening in a member in the upper frame 2, and the clip of Figure 7 is then placed over the barbed studs 35. The opening 38 in the clip of Figure 7 is so dimensioned that the barbed studs may enter the opening 38 by resiliently deflecting towards each other, and as the barbs emerge from the opening 38, the studs 35 spring away from each other to snap-engage with the clip of Figure 7. To release such a clip, the barbs may be squeezed together and urged back through the opening 38 of the clip of Figure 7.

In an alternative embodiment. signboards may be attached to the upper frame by means of threaded fasteners. Particularly, a clip similar in shape to that shown in Figure 7 may have a threaded shank extending perpendicularly downwards from its centre section instead of the opening shown in the Figure. A threaded nut may be engageable with the shank, after it has passed through the upper frame and signboard, to secure the structure. In a further alternative embodiment, a threaded fastener having an enlarged head provided with a conical taper at the junction of the head and the shank may be used. The head may be of plastics material, and may be fixed, for example by ultrasonic welding, to the rear face of the signboard.

In the accompanying drawings, the upper frame 2 is shown as having substantially rectangular formation. To this rectangular upper frame, triangular, circular or rectangular signboards may be attached using snap-engaging clips or other attachment devices. To attach larger sign boards, the upper frame 21 can be extended by joining two upper frame members together, one in its position shown in Figure 1 and the other inverted. The two frames are joined by superimposing the frame members 8 and 9 over frame members 9 and 8 respectively.

Hooks 40 may be provided on the frame 2 or leg frames 20 for the attachment of ballast weights such as sandbags.

It is also foreseen that the leg frames 20 may be provided with cooperating engaging portions to retain them in their retracted position in addition to the retaining effect of the hinges. In an advantageous embodiment, horizontal rods may extend between each leg 21 of the leg frame 20 and its adjacent bracing leg 23, and resilient hooks may be provided on one or more of the rods to engage a corresponding rod in the other leg frame.

Claims (6)

1. A road sign comprising a generally planar upper frame to which a signboard can be attached, the upper frame having a horizontal lower edge to which a number of hinge lugs are attached, and the upper frame having two leg frames attached to its lower edge by hinge portions cooperating with the hinge lugs, each of the leg frames being hingeable from a closed position, wherein it lies substantially in the plane of the upper frame, to a deployed position wherein the leg frames are set at an angle of approximately 45C on either side of the plane of the upper frame, wherein the hinge lugs and the hinge portions include cooperating stop surfaces which limit the arc of travel of the leg frames relative to the upper frame.

2. A road sign according to claim 1, wherein the hinge lugs each comprise a pair of stop surfaces arranged in orthogonal planes, and the hinge portions include a pair of stop surfaces arranged in planes inclined at an acute angle to each other.

3. A road sign according to claim 1 or claim 2, wherein each hinge lug comprises a horizontal bearing plate from which a central downwardly depending web extends, and pairs of hinge plates extend to either side of the web and are penetrated by a pair of bores extending parallel to the planes of the web and the bearing plate, and the hinge portions comprises a number of similar hinge plates penetrated by an aligned bore, the hinge plates situated on one side of the central web of each of the hinge lugs and the hinge plates of one of hinge portions being arranged with their bores in alignment to receive a pivot pin.

4. A road sign according to claim 3, wherein the hinge plates of the hinge portion are so shaped that, when the leg frames 20 are in their deployed positions, the bearing plates 25 of the hinge lugs engage first flat edge surfaces 30c of the hinge plates 27a, and second flat edge surfaces 30b of the hinge plates 27a bear against the central web 26, and when the leg frames 20 are in their retracted position, a third flat edge surface 30a of each hinge plate 27a engages the central web 26 of the hinge lug 11, and the profiles of the edges of the plates 27a between the third and second edge surfaces 30a and 30b is so arranged that, as the leg frame 20 swings from its retracted position to its deployed position, portions of the edges of hinge plates 27a between faces 30a and 30b momentarily engage the central web 26 to cause a resilient deflection of the web.

5. A road sign according to any preceding claim, wherein the leg frames 20 are provided with cooperating engaging portions to retain them in their retracted position.

6. A road sign substantially as described herein, with reference to Figures 1 to 6 or Figures 7 and 8 of the accompanying drawings.