GB2221234A

GB2221234A - Grooved paving slabs

Info

Publication number: GB2221234A
Application number: GB8817917A
Authority: GB
Inventors: Allan Geddes Dodds
Original assignee: University of Nottingham
Current assignee: University of Nottingham
Priority date: 1988-07-27
Filing date: 1988-07-27
Publication date: 1990-01-31
Anticipated expiration: 2008-07-27
Also published as: GB8817917D0; GB2221234B

Abstract

A paving slab has an upper surface provided with a plurality of grooves substantially identical in shape, each groove comprising two sloping surfaces, one surface being substantially vertically oriented with respect to the horizontal and the other surface being oriented at an angle of less than 45 DEG to the horizontal. The slab provides a blind person with directional information.

Description

IMPROVEMENTS IN OR RELATING TO PAVING SLABS The present invention relates to paving slabs and more particularly to tactile paving slabs for blind people, Blind people often have difficulty in identifying landmarks in their environment as they travel due to the relative paucity of tactile and audible cues. One solution to this problem is to provide them with tactile warning of impending approach to these landmarks. One existing tactile warning is that developed by the Department of Transport which is currently in use at zebra and PEdestrian LIght CONtrolled (Pelicon) cssings. It consists of a blistered pattern which can be felt underfoot.

A disadvantage with the blistered pattern is that though it gives the blind person a knowledge of location it does not possess any means for indicating to the traveller any directional information.

It is an object of the present invention to provide a paving slab which provides a blind person travelling with directional information.

The present invention provides a tactile paving slab for blind people in which the upper surface of the slab is provided with a plurality of grooves the grooves forming a surface which is more resistive to the movement of a guidance stick in a first direction than in a second, opposite direction.

In a preferred embodiment the upper surface of the paving slab is cast with a plurality of grooves each groove being substantially identical in shape and being formed in a modified V-shape comprising two sloping surfaces, one surface being substantially vertically oriented with respect to the horizontal and one surface being oriented to form a surface at less than 45o to the horizontal.

In a particular embodiment the whole upper surface of the slab is formed with grooves.

Preferably the grooves are substantially wider in comparison to their depth.

Embodiments of the present invention will now be described, by way of example with reference to the accompanying drawings in which: Figure 1 shows a directional tactile paving slab according to the present invention in cross-sectional elevation; and Figure 2 shows the paving slab of Figure 1 in plan view showing the upper surface.

With reference now to the drawings the upper surface of a slab 10 is provided with a sawtooth pattern 20. The pattern is continuous, as shown in Figure 2, over the whole surface of the slab 10.

The principle derives from the observation that the sawtooth pattern 20 possesses different tactile characteristics depending upon which direction it is explored. For example, if it is approached with a cane it will produce either a gentle, rattling sound which the traveller can take notice of as he passes over it, or it will cause the cane tip to snag to such an extent that he is forced to stop momentarily. These messages can be used either to inform him that he should be anticipating a landmark or crossing-point, or that he should stop before an impending hazard such as a flight of stairs.

The directional surface on the block shown in Figures 1 and 2 and the detail inset consists of a square block of concrete A mm square of B mm depth. The sawtooth pattern is superimposed upon the surface, adding a further depth of C mms. There are N sawtooths per block, each sawtooth having a slope of D degrees and a width of E mms. The top 22 of each sawtooth is flattened to provide material stability, and this produces a platform of F mm width. It is additionally possible to incorporate contrasting stripes into the material, which would be of benefit to the partially sighted.

In a particular embodiment the dimensions of the slab are as follows: A. 400 mm B. 45 mm C. 5 mm D. 250 E. 23 mm F. 2 mm The surface may be reproduced by casting the concrete slab integrally with the grooves or alternatively if a slightly softer surface is required the grooves may be reproduced in a rubberised sheet material which may be provided with an adhesive backing for fixing to existing slabs. This has the advantage that existing slabs, for example at the bottom or the top of stairs need not be removed prior to the tactile surface being laid, it being only necessary to clean and roughen the existing slabs or concrete and stick an appropriate number of directional tactile sheets down in desired positions.

The grooves shown in Figures 1 and 2 are parallel to the edges of the block but they could be moulded (or stuck) to form a diagonal which could be of use for example at a corner position. The grooves do not have to be straight but could be curved which again could be advantageous.

The directional tactile slabs (or sheets) therefore provide a blind or partially sighted person with information not only of the presence of a hazard or desired objective such as a front door but also on its relative position.

Claims

1. A tactile paving slab for blind people in which the upper surface of the slab is provided with a plurality of grooves the grooves forming a surface which is more resistive to the movement of a guidance stick in a first direction than in a second, opposite direction.

2. A slab according to claim 1 wherein the upper surface is provided with a plurality of grooves substantially identical in shape, each comprising two sloping surfaces, one surface being substantially vertically oriented with respect to the horizontal and the other surface being oriented at an angle of less than 450 to the horizontal.

3. A paving slab having an upper surface provided with a plurality of grooves substantially identical in shape, each comprising two sloping surfaces, one surface being substantially vertically oriented with respect to the horizontal and the other surface being oriented at an angle of less than 450 to the horizontal.

4. A slab according to any one of the preceding claims wherein the upper surface between each groove is flattened.

5. A slab according to any one of the preceding claims wherein the grooves are substantially wider than they are deep.

6. A slab according to any one of the preceding claims cast in concrete.

7. A slab according to any one of claims 1 to 5 wherein the grooves are reproduced in a rubberised sheet fixed to a slab.

8. A slab according to any one of the preceding claims wherein the grooves are straight.

9. A slab according to any on of claims 1 to 7 wherein the grooves are curved.

10. A slab according to any one of the preceding claims wherein the upper surface incorporates contrasting stripes.

11. A rubberised sheet suitable for fixing to a paving slab comprising a surface provided with a plurality of grooves, the grooves forming a surface which is more resistive to the movement of a blind person's guidance stick in a first direction than in a second opposite direction.

12. A sheet according to claim 11 having an adhesive backing for fixing the sheet to existing slabs.

13. A sheet according to either one of claims 11 and 12 having a surface configured to provide a paving slab having an upper surface according to anyone of claims 1 to 4 and 7 to 9 when secured in place.

14. A tactile paving slab for blind people substantially as hereinbefore described with reference to the accompanying drawings.