AU2007101236A4

AU2007101236A4 - Tactile Ground Surface Indicator

Info

Publication number: AU2007101236A4
Application number: AU2007101236A
Authority: AU
Inventors: Daniel Dedomenico
Original assignee: CTA Australia Pty Ltd
Current assignee: CTA Australia Pty Ltd
Priority date: 2007-07-05
Filing date: 2007-11-30
Publication date: 2008-07-31
Anticipated expiration: 2015-11-30
Also published as: AU2007101236B4

Description

Australian Patents Act 1990 Regulation 3.2 ORIGINAL COMPLETE SPECIFICATION STANDARD

PATENT

Invention Title "Tactile Ground Surface Indicator" The following statement is a full description of this invention, including the best method of performing it known to us:o Tactile Ground Surface Indicator The present invention relates to tactile indicators which are disposed on a ground surface to provide a tactile and/or visual indication to a person, particularly a blind or O vision-impaired person, walking on the surface.

Tactile ground surface indicators are specially configured protrusions which are positioned on walking surfaces. Such indicators are typically found in public areas in and around buildings and stairs, or at pedestrian crossings and the like, to forewarn pedestrians, particularly blind or vision-impaired persons, of an upcoming obstruction or hazard. When the person feels the tactile indicators under their feet, they are made aware that their next step should be taken with caution.

Tactile ground surface indicators can be located, for example, in approaches to steps or stairs, edges of railway platforms, traffic crossings, ramps and so forth.

In Australia the shape and configuration of tactile ground surface indicators is prescribed by Part 4 of Australian Standard AS/NZS 1428, entitled Design for Access and Mobility.

Consistent with that standard, tactile ground surface indicators according to preferred embodiments of the present invention provide areas of raised ground surface texture treatment, designed to provide blind or vision-impaired pedestrians with warning and/or directional orientation information.

It is generally important to configure a tactile ground surface indicator such that the risk of a person slipping when walking on or onto the indicator is minimised.

According to a first aspect of the present invention, there is provided a tactile ground surface indicator which is adapted to be fixed with respect to a ground surface, the indicator comprising an indicator portion which is arranged to be positioned over the ground surface and which comprises a bottom portion, an upper portion and a surrounding sloped side wall which extends upwardly and radially inwardly from the bottom portion to the upper portion, the indicator portion further comprising an upright wall extending I'\OPERWRFN- comple1 Twdrk 30413951 .doc. 30111107 S2 z around the periphery of the upper portion to be engageable with the sole of a person's shoe.

SPreferably, the upright wall projects outside a projected plane of the side wall.

Preferably, the upright wall is defined by an upwardly projecting lip.

Preferably, the upright wall projects from a top end of the side wall.

SPreferably, the upper portion is provided with a gripping pattern, the gripping pattern comprising a plurality of upright projections extending around a central upright axis of the indicator and positioned progressively radially outwardly therefrom to be engageable with the sole of the person's shoe when the person is standing on the indicator. Preferebly, upper ends the upright projections are arranged in a single plane which is transverse to the central upright axis.

In a preferred embodiment of the invention, an upper end of the upright wall lies in said single plane. In an alternative preferred embodiment of the invention, the upper end of the upright wall lies above said single plane.

In a preferred embodiment of the invention, upper ends of alternating ones of the upright projections in a radially inward direction from the upright wall lie in a common plane which is transverse to the central upright axis and upper ends of remaining ones of the upright projections lie below the common plane, and an upper end of upright wall lies in the common plane. Preferably, the upper ends of the remaining ones of the upright projections lie in another common plane arranged below and parallel to said common plane. In one embodiment of the invention, the upper end of every second one of the upright projections in said radially inward direction from the upright wall lies in said common plane. In another embodiment of the invention, every third one of the upright projections in said radially inward direction from the upright wall lies in said common plane.

Preferably, the upright projections are configured as ribs P:\OPER\MRFNc' complelt Tactile 30413951 doc 30111/07 According to a second aspect of the present invention, there is provided a tactile ground surface indicator which is adapted to be fixed with respect to a ground surface, the indicator comprising an indicator portion which is arranged to be positioned over the ground surface and which comprises a bottom portion, an upper portion and a surrounding sloped side wall which extends upwardly and radially inwardly from the bottom portion to the upper portion, the indicator portion further comprising a gripping portion extending around the periphery of the upper portion and projecting upwardly from the upper portion to be engageable with the sole of a person's shoe.

The gripping portion defines an edge or a protuberance which can catch and engage the sole of the person's shoe, particularly as moved against the tactile ground surface indicator in a direction having a sideways component, thereby preventing slipping, especially in the general plane defined by the side wall, and conferring improved anti-slip characteristics to the tactile ground surface indicator.

Preferably, the gripping portion projects outside the general plane defined by the side wall.

Preferably, the gripping portion is defined by an upright shoulder.

According to a preferred feature of the present invention, the gripping portion is positioned at a radially outermost extent of the upper portion to be immediately adjacent a top end of the side wall.

According to a preferred feature of the present invention, the side wall is smooth.

According to an alternative preferred feature of the present invention, the side wall is stepped.

In a preferred embodiment of the present invention, the indicator portion is generally circular. In such an embodiment, the side wall is frustoconical, whereby the general plane defined by the side wall is conical.

According to a preferred feature of the present invention, the gripping portion is OPER\MRFNcw complete Tacile 30413 9 51 doc 30111/07 0 continuous around the periphery of the upper portion. According to a further preferred feature of the present invention, the gripping portion is configured as a lip.

According to a further preferred feature of the present invention, the upper portion of the indicator portion comprises an upwardly facing surface which is surrounded by the Sgripping portion. According to a preferred feature of the present invention, the upwardly facing surface is provided with a gripping pattern. According to a further preferred feature of the present invention, the gripping pattern is defined by a plurality of upwardly extending portions. According to a preferred feature of the present invention, uppermost extents of the upwardly extending portions lie in a plane which is defined by a top end of the gripping portion.

According to a further preferred feature of the present invention, the upwardly extending portions are distributed substantially over the entirety of the upwardly facing surface.

According to a preferred feature of the present invention, adjacent ones of the upwardly extending portions define a radial pitch therebetween, the pitches being substantially equal.

According to a further preferred feature of the present invention, the upwardly extending portions are concentric and separate.

It will be appreciated that the indicator according to the invention may be part of an array of integrally formed indicators.

According to a third aspect of the present invention, there is provided an array of tactile ground surface indicators according to the first or second aspect, in which the indicators are integrally formed.

According to a preferred feature of the present invention, the tactile ground surface indicators of the array are integrally formed. According to a further preferred feature of the present invention, the indicators are formed on the upper surface of a sheet. The sheet may comprise a tactile ground surface indicator tile.

P \OPERMRFNcw complete Tactile 30413951 doc 30/11/07 0 The present invention will now be described, by way of non-limiting example only, with Z reference to the drawings, in which: Cc Figure 1A is a perspective view of a tactile ground surface indicator according to a first embodiment of the invention; D 5 Figure lB is a top view of the indicator showing Figure IA; M, Figure IC is a cross-sectional elevation view taken through section J-J in Figure I B, showing deformable longitudinal ribs of a retaining portion of the indicator; Figure ID is a cross-sectional elevation view taken through section K-K in SFigure I B, showing channels of the retaining portion of the indicator; Figure 2A is a perspective view of the body portion of the tactile ground surface indicator; Figure 2B is a top view of the body portion shown in Figure 2A; Figure 2C is a cross-sectional elevation view taken through section D-D in Figure 213B; Figure 2D is a rotated side view of the body portion shown in Figures 2A to 2C; Figure 3A is a perspective view of the tactile ground surface indicator according to the first embodiment having an alternative retaining portion; Figure 3B is a top view of the indicator showing Figure 3A; Figure 3C is a cross-sectional elevation view taken through section F-F in Figure 3A; Figure 4A is an elevation view of a tactile ground surface indicator according to the first embodiment having an alternative form of stem and a further alternative retaining portion; Figure 4B is a cross-sectional elevation view taken through section D-D in Figure 4A, of the tactile ground surface indicator shown in Figure 4A, showing the alternative form of stem; Figure 4C is a perspective elevation view of the retaining portion shown in Figures 4A and 4B; Figure 5A is a perspective view of an indicator portion of the indicator according to the first embodiment; Figure 5B is a top view of the indicator portion shown in Figure Figure 5C is a cross-sectional elevation view taken through section D-D in P \OPER MRFNew complete Tctile 30413951 doe 30111/07 Figure Figure 5D is a view of detail E as shown in Figure Figure 5E is a rotated side view of the indicator portion shown in Figures 5A to Figure 6A is a perspective view of an indicator portion and stem of a tactile ground surface indicator according to a second embodiment of the invention; Figure 6B is a top view of the indicator portion shown in Figure 6A; Figure 6C is a cross-sectional elevation view taken through section E-E in Figure 6B; Figure 6D is a view of detail K as shown in Figure 6C; Figure 7A is a perspective view of an indicator portion and stem of a tactile ground surface indicator according to a third embodiment of the invention; Figure 78 is a top view of the indicator portion shown in Figure 7A; Figure 7C is a cross-sectional elevation view taken through section H-H in Figure 7B; Figure 7D is a view of detail N as shown in Figure 7C; Figure 8A is a perspective view of an indicator portion and stem of a tactile ground surface indicator according to a fourth embodiment of the invention; Figure 8B is a top view of the indicator portion shown in Figure 8A; Figure8C is a cross-sectional elevation view taken through section I-I in Figure 8B; and Figure 8D is a view of detail M as shown in Figure 8C.

A tactile ground surface indicator 1 according to a first embodiment of the invention, as depicted in Figure 1 A, comprises a body portion 3 which is moulded as a single piece from stainless steel, or machined from a solid bar of stainless steel, and, as can best be seen in Figures IC and 1D, comprises an indicator portion 5 which will be positioned above a ground surface, and a downwardly projecting portion in the form of a stem 7 which is receivable in a cavity, provided in the ground, which locates the indicator 1 in position.

The indicator 1 further comprises a generally elongate retaining portion 9, which is received over, and engaged with, the stem 7, the retaining portion, which is for holding the indicator 1 in the ground, being made from suitably deformable plastic, whereby the OPER\MRf\Ncw omplte Tclile 3041395 I.do 30/11/07 0 retaining portion comprises a deformable portion, as will be described in further detail Z later, which is configured to deform against an annular wall of the cavity when the CC indicator 1 is driven into the cavity.

ID 5 The retaining portion is moulded as a single piece of plastically-deformable plastic, and is cmoulded to, the stem 7. The retaining portion 9 is configured as a cap which covers the stem 7, the cap defining a recess 11 which is occupied by the stem 7. The retaining portion 9 has a generally circular outer transverse cross-sectional profile.

The exterior of the retaining portion is provided with a pair of opposed ridges or ribs 13 which extend linearly and longitudinally along the retaining portion 9 from a top end of the retaining portion 9. The ribs 13 are provided at diametrically opposite positions on the retaining portion 9. The ribs 13 protrude radially outwardly to be engageable with the annular wall of the cavity so as to deform against the wall when the indicator 1 is driven into the cavity, thus permanently locking the retaining portion in the cavity and fixing the indicator 1 in the ground. To this end, the outermost extents of the ribs 13 are spaced apart by a distance which slightly exceeds the diameter of the cavity.

The lower end 15 of the retaining portion 9 is tapered radially inwardly to facilitate driving of the indicator I into the ground.

The retaining portion 9 further comprises a pair of longitudinally extending channels 17 which are disposed at diametrically opposite positions on the exterior of the retaining portion 9 and extend generally linearly between the top and bottom ends of the retaining portion 9. The channels 17 define spaces into each some of the material of the retaining portion 9 can be displaced when the retaining portion 9 is driven into the cavity, under a radially inward pressure exerted by the cavity wall, giving rise to a radially outward biasing of the retaining portion against the cavity wall, which assists retention of the indicator 1 in the ground.

An annular channel 19 is provided in the exterior of the stem 7, the channel 19 defining a space into which a complementarily configured, radially inwardly projecting portion 21, in P:\OPERMR F Nw complte Tlclile 30413951 doc 30111/07 0 the form of an annular rim, provided on the retaining portion 9 in the recess 11, is received.

Z The channel 19 defines a transversely extending portion which in turn defines an upper C€ shoulder 23, providing a downwardly facing surface 25. The channel 19 also defines a further transversely extending portion which in turn defines a lower shoulder 27, providing ID 5 an upwardly facing surface 29.

Similarly, the projecting portion 21 defines, on the retaining portion 9, a transversely extending portion which in turn defines an upper shoulder 30, providing a downwardly Sfacing surface 31. The projecting portion 21 also defines a further transversely extending portion which in turn defines a lower shoulder 33, providing an upwardly facing surface The downwardly facing surface on the retaining portion 9 abuts the upwardly facing surface on the stem 7 to restrain the body 3 from upward movement relative to the retaining portion 9. Similarly, abutment of the downwardly facing surface of the stem 7 with the upwardly facing surface of the retaining portion 9 prevents downward movement of the body 3 with respect to the retaining portion, as does abutment of the upper end of the retaining portion 9 with the underside of the indicator portion 5. Relative movement between the retaining portion 9 and body 3 is thus prevented.

It will be appreciated that the abutting surfaces need not face exactly upwardly and downwardly but rather need merely to have respective upwardly and downwardly facing components.

As can be seen in Figures 1C and ID, the recess 11 and stem 7, and particularly the channel 19 projecting portion 21, are complementarily profiled such that the retaining portion 9 is closely received over and fitted to the stem 7.

As will be clear from Figures IB and 1D, the channels 17 lie in an upright plane which is perpendicular to an upright plane in which the ribs 13 lie. The ribs 13 are thus provided intermediate the channels 17 around the exterior of the retaining portion 9.

P,%OPER\MRPNw compite Tcil 304 3951 doc 30/ 1/07 The indicator 1 may incorporate an alternative form of retaining portion, as shown in Figures 3A and 3C. The retaining portion 9' comprises opposed ridges or ribs 13' which, instead of extending longitudinally along the retaining portion extend around the retaining portion The ribs 13' each extend between the channels 17 and are provided at opposite sides of a longitudinally-extending plane passing through the channels, the ribs 13' thus defining a substantially annular deformable portion. The ribs 13' are provided approximately halfway down the retaining portion.

The tactile indicator 1 may incorporate an alternative form of stem and yet a further alternative form of retaining portion, as depicted in Figures 4A to 4C. The indicator 1 also comprises a body portion 3 (see Figure 4B) moulded as a single piece of stainless steel, or machined from a solid bar of stainless steel. The body portion 3 comprises an indicator portion 5, which is identical to the indicator portions of the first and second embodiments.

The body portion 3 further comprises a stem 7 and an elongate retaining portion 9" into which the stem 7 is lockingly receivable.

The retaining portion instead of being overmoulded to the stem 7, is formed separate from the body 3 and is constructed to receive lockingly the stem 7 during installation in the ground 7, as will be described in greater detail below.

The retaining portion a perspective view of which is shown in Figure 4B, is moulded as a single piece of plastically-deformable plastic. The retaining portion 9" takes the form of a generally cylindrical cap which is receivable over the stem 7, the cap having a recess 11 which is to be occupied by the stem 7.

The exterior of the retaining portion 9" is configured with a plurality of radially outwardly protruding portions, in the form of ribs or ridges 13" which are arranged axially along the retaining portion 9" and which each extend therearound. The ridges 13" provide a serrated longitudinal cross-sectional profile, affording the exterior of the retaining portion 9" a barbed configuration. As can be seen in Figure 4A, each ridge 13" extends upwardly and radially outwardly to define an annular edge 71.

P:kOPER\MRF\New complett Ticle 3D41395Idoc 30/11107 O The retaining portion 9" further comprises openings in the form of a pair of axially extending slots 73 disposed on opposite sides of the retaining portion the slots 73 ~providing communication between the outside of the retaining portion 9" and the recess 11.

The slots 73 are located at approximately the same axial position along the retaining portion 9" as the ridges 13".

_The stem 7 has a lower portion 7A, an upper portion 7B and a tapered step 7C between the upper and lower portions. The diameter of the lower portion 7A is less than that of the recess, whereas the diameter of the upper portion 7B is slightly greater than that of the recess.

The inner wall of the recess 7 is further provided with a plurality of circumferential grooves 75 which lockingly receive circumferential ribs 77 formed on the stem 7, as will be described in further detail below.

Installation of the tactile ground surface indicator 1 depicted in Figures 4A to 4C commences with drilling a cavity into the ground, the cavity having approximately the same diameter and depth as the retaining portion The retaining portion 9" is then inserted into the cavity. Each edge 71 is a trailing edge when the retaining portion 9" is inserted, whereby any engagement between it and the cavity wall during insertion will not hinder insertion.

Next, the lower end of the stem 7 of the body portion 3, which is tapered to facilitate insertion, is introduced into the open upper end of the retaining portion 9" and forced down through the recess 7, whereby the tapered step 7C and upper portion 7B engage the inner wall of the recess 7 to cause the walls of the retaining portion including the ridges 13", to be displaced radially outwardly such that the tips 71 are forced against the annular wall of the cavity, whereupon the ridges 13" serve as barbs which engage with the annular wall and will resist pulling forces which may otherwise be sufficient to remove the indicator 1 from the ground, thus locking the retaining portion in the cavity. Because the ridges 13" are plastic, they will deform slightly when forced against the annular wall. The radially outward displacement of the ridges 13" is enabled, or at least facilitated, by the slots 73.

P \OPER'\MRJ~R.I c omplete Tlaile 30413951.doc .30/11/07 Upon insertion of the stem 7 into the recess II, the ribs 75 are received in the grooves 77.

Cc As can be seen from Figure 4A, the ribs 77 and grooves 75 are complementarily profiled such that the body portion 3 and the retaining portion 9" are locked together. Since the retaining portion 9" is made out of plastic, the retaining portion 9" is resiliently flexible to a sufficient extent to enable the inner wall of the recess 11 to be displaced radially outwardly to allow passage of the ribs 73 past the grooves 75 during insertion of the stem 7, until the stem 7 has been fully inserted, whereupon the grooves 75 align with the appropriate respective ribs 73 and the inner wall contracts slightly so that the ribs 73 are received in the grooves The indicator portion 5 of indicator 1 according to the first embodiment is illustrated in Figures 5A to SE. The indicator portion 5, which is provided as a single piece, has a generally circular transverse cross section and comprises a bottom portion 56, defining a downwardly facing surface 58 arranged to abut the ground surface, an upper portion 57 and a sloped or tapered smooth side wall 59, extending upwardly and radially inwardly from the bottom portion 56 to the upper portion 57 and being inclined at an angle of approximately 350 to 450 from the downwardly facing surface 58. The diameter of the bottom portion is 35 millimetres.

The upper portion 57 is defined by an upwardly facing surface 61, which is bounded by an upper end of the side wall and which in this embodiment is level with the upper end of the side wall. The diameter of the upwardly facing surface 61, and thus the upper portion, is millimetres. The distance between the downwardly facing surface 58 and the upper portion 57 is 4 to 5 millimetres.

A circular rim or lip 60 is provided at a radially outermost position on the upper surface 61 and extends upwardly from the upper surface 61 to define a shoulder or wall 62 which protrudes outside of the conical plane defined by the side wall 59, i.e. by extrapolation in the upwardly and radially inwardly direction in which the side wall 59 extends. The wall 62 comprises an edge 64 which lies outside of the conical plane. The lip 60 has a height of 0.5 millimetres.

P:\OPER\MRFANe complet Tactile 04131951 doc- 30/ /07 o The wall 62, particularly its edge 64, is able to catch and engage the sole of the person's shoe, particularly as moved against the tactile ground surface indicator in a direction pc, having a sideways component, thereby preventing slipping, especially in the general plane defined by the side wall, and conferring improved anti-slip characteristics to the tactile ground surface indicator.

Advantageously, the wall 62 confers upon the indicator 1 an RI3 anti-slip rating in accordance with Australian Standard AS 4586:2004.

To enhance gripping further, a gripping pattern 63 is provided on the upper surface 61, the gripping pattern 63 comprising a plurality of ribs in the form of concentric rings extending upwardly from the upper surface 61. The upper ends or tips of the rings, which define the uppermost extent of the gripping pattern 63, lie in a plane which is millimetres above the upper portion 57, or the plane defined by the upwardly facing surface 61 and are coplanar with the top end of the circular lip 60 and the upper edge 64.

The concentric rings 65 each have a thickness of 0.4 millimetres, as does the lip 60. The concentric rings 65 have a radial pitch P of 1.1 millimetres, each ring 65 thus having a thickness which is approximately 35% of the radial pitch P. Annular spaces 66 are defined between the rings 65, the annular spaces having a radial dimension of 0.7 millimetres, as does the annular space defined between the lip 60 and the outermost ring A disc-shaped portion 67 is located on the centre of the upwardly facing surface 61 and extends upwardly therefrom to end flush with the upper ends of the rings 65. The disc-shaped portion 67 has a diameter of 3mm.

In the following description of the second, third and fourth embodiments, the same reference numerals as used in respect of the first embodiment will be used to designate common features.

The tactile ground surface indicator 1' according to the second embodiment is illustrated in Figures 6A to 6D. The indicator 1' is identical to the indicator 1 of the first embodiment p:\OPERMhRF\Ncw compl3 Ttilc 30413951 4doc 30/1 1/07 though the upwardly facing surface 61 is positioned 1i.0mm, instead of 0.5mm, below the edge 64, whereby the plane in which the upper ends or tips of the concentric rings 65 lie is Cc, 0.5 mm below the edge 64. The lip 60' thus extends upwardly 1.0 mm from the surface 61 and 0.5 mm from the upper end of the side wall 59.

IND CThe tactile ground surface indicator 1" according to the third embodiment is illustrated in __Figures 7A to 7D. The indicator 1" is identical to the indicator 1' of the second embodiment though, in addition to the lip 60' extending upwardly 1.0 mm from the Ssurface 61, every second ring 65 in a radially inward direction thereafter also has a height of 1.0 mm (instead of 0.5 mm), and the disc-shaped portion 67' also has a height of 1.0 mm (instead of 0.5 mm).

The tactile ground surface indicator according to the fourth embodiment is the same as the indicator 1' according to the second embodiment though, in addition to the lip extending upwardly 1.0 mm from the surface 61, each third ring 65 in a radially inward direction thereafter also has a height of 1.0 mm (instead of 0.5 mm).

Other embodiments are envisaged in which every nth ring after the lip in a radially inward direction is raised such that its upper end is flush with the upper end of the lip 60, for example embodiments in which n 3 or 4.

The rings (and lip) in each embodiment are sufficiently narrow and sufficiently spaced so as to exert enough upward pressure on the sole of the shoe of a person stepping on the indicator to cause the sole to be deformed such that sole material is received into the spaces defined between the rings, thus creating an interlocking effect to prevent slippage in the plane of the upper portion (which extends perpendicular to the central upright axis of the indicator). Advantageously, the rings (and lip), owing to their annularity, provide uniform resistance to slipping in all directions in that plane.

The effect of varying the heights of the rings in accordance with the preferred embodiments is to vary the degree of resistance to slipping according to the requirement of the particular application, whilst maintaining the omnidirectionality of that resistance P:\OPERMRFNcw complete Tactlle3041395 Idoc 30/11107 0 In the described embodiments, the wall 62 is continuous around the periphery of the upper portion but other embodiments are envisaged in which the wall is discontinuous but Snevertheless arranged around the periphery of the upper portion, e.g. breaks (spaces) could be provided at intervals along the lip 60 to define a castellated wall.

_It will be appreciated that the upright wall may, in a simplified embodiment, be defined by the outer circumferential wall of a solid disc-shaped portion substantially covering the S upper portion and extending upwardly therefrom.

Moreover, another embodiment exists which comprises an array of indicators/indicator portions configured with the upright wall, and possibly also the gripping pattern, as described above, such as a sheet or tile having an upper surface into which having the indicators are formed.

It will also be appreciated that the indicators according to the embodiments need not be provided with deformable retaining portions but rather any means of fixing them in position over the ground surface. Furthermore, the alternative stem and retaining portion configurations disclosed for the first embodiment are equally applicable to the further embodiments.

Manufacture of the indicator 1 illustrated in Figures 1A to 3C firstly comprises moulding of the body portion 3, including the indicator portion 5, from stainless steel, or machining it from a solid billet of stainless steel.

With the body portion 3 arranged upside down, the stem 7 is then centrally positioned in a mould which defines the external configuration of the retaining portion the flat underside of the indicator portion 5 abutting a lower end of the mould to close that lower end. Molten plastic is then injected into the space between the mould and the stem, through a suitable opening provided in the mould. The plastic is then allowed to cool and set, whereupon the finished indicator 1 is removed from the mould.

Owing to the aforementioned abutment of surfaces on the retaining portion 9/9' and stem 7, P:\OPER.\MRFNcw complece Tactile 3041395I.doc 30111/07 0 the retaining portion 9/9' is permanently fixed to the stem 7.

z cc While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only, and not by way of limitation. It will be apparent to a person skilled in the relevant art that various changes in form and detail can be made therein without departing from the spirit and scope of the _invention. Thus, the present invention should not be limited by any of the above described exemplary embodiments.

Throughout this specification and the claims which follow, unless the context requires otherwise, the word "comprise", and variations such as "comprises" and "comprising", will be understood to imply the inclusion of a stated integer or step or group of integers or steps but not the exclusion of any other integer or step or group of integers or steps.

PKOPER\MRFN N -mpl Tik 3041 3951 I.doc 30/11/07

Claims

2. A tactile ground surface indicator according to claim 1, wherein the upright wall projects outside a projected plane of the side wall.
3. A tactile ground surface indicator according to claim 1 or claim 2, wherein the upright wall is defined by an upwardly projecting lip.
4. A tactile ground surface indicator according to any one of the preceding claims, wherein the upright wall projects from a top end of the side wall.
5. A tactile ground surface indicator according to any one of the preceding claims, wherein the upper portion is provided with a gripping pattern, the gripping pattern comprising a plurality of upright projections extending around a central upright axis of the indicator and positioned progressively radially outwardly therefrom to be engageable with the sole of the person's shoe when the person is standing on the indicator.
6. A tactile ground surface indicator according to claim 5, wherein upper ends the upright projections are arranged in a single plane which is transverse to the central upright axis.
7. A tactile ground surface indicator according to claim 6, wherein an upper end of the upright wall lies in said single plane.
8. A tactile ground surface indicator according to claim 6, wherein an upper end of the upright wall lies above said single plane. P \OPER\MRF\ ew complete Tactile 304139S1 doc 30 11107 -17- o 9. A tactile ground surface indicator according to claim 6, wherein upper ends of alternating ones of the upright projections in a radially inward direction from the upright C€ wall lie in a common plane which is transverse to the central upright axis and upper ends of remaining ones of the upright projections lie below the common plane, and wherein an upper end of upright wall lies in the common plane. A tactile ground surface indicator according to claim 9, wherein the upper ends of the remaining ones of the upright projections lie in another common plane arranged below Sand parallel to said common plane.
11. A tactile ground surface indicator according to claim 9 or claim 10, wherein the upper end of every second one of the upright projections in said radially inward direction from the upright wall lies in said common plane.
12. A tactile ground surface indicator according to claim 9 or claim 10, wherein the upper end of every third one of the upright projections in said radially inward direction from the upright wall lies in said common plane.
13. A tactile ground surface indicator according to any one of the preceding claims, wherein upright projections are configured as ribs.
14. A tactile ground surface indicator substantially as hereinbefore described with reference to the drawings and/or Examples. P:\OPER\MRPNN complete Tacile 30439581 dw 30111/07