ROAD MARKING STUDS

Abstract: In installing a road marking stud, a circular hole is bored in the road surface, a cylindrical metal case (10) which forms part ofthe stud is impacted into the hole, and an elastomeric body (12) having a reflective element (18) is fitted into the metal case (10).

Description: Road Harking Studs This invention relates to reflective studs for road marking and more particularly to methods of installing and removing such studs . In accordance with this invention, there is provided a method of installing a reflective road marking stud, comprising boring a circular hole in the road surface, inserting into the hole a cylindrical metal case which forms part of the stud, and is an interference fit within the hole, applying impact to the cylindrical metal case to force it into the hole, and then fitting an elastomeric body into the metal case, which body mounts a reflective element. Preferably the cylindrical metal case is open at both its top and bottom ends. Preferably the metal case has a radially outwardly projecting flange around its top end, but the hole which is drilled does not include an enlarged-diameter portion at the road surface for receiving this flange. Preferably a groove is formed around the outer periphery of the metal case immediately below this flange: then as the case is impacted into the hole, material from the road surface will be impacted by the flange and force into this groove. Also in accordance with this invention there is provided a method of removing a reflective road marking stud, which road stud comprises a cylindrical metal case into which fits an elastomeric body mounting a reflective element, the method comprising removing the elastomeric body and reflective element, then inserting a tool into the case through its open top and engaging the tool with a projection on the inner surface of the metal case, using the tool to apply an upwards force to the metal case via said projection to withdraw the metal case from the road. Preferably the projection on the inner surface of the case is used normally to hold in position the elastomeric body of the road stud relative to the metal case. Preferably this projection comprises an annular rib. The above-defined methods for installing or removing the road stud are preferably carried out by a worker on a platform at the rear of a road vehicle. Also in accordance with this invention, there is provided a road stud which comprises a cylindrical metal case, an elastomeric body which fits within the case and a reflective element which is mounted to the elastomeric body, the reflective element comprising a ring of transparent material provided with a reflective coating on its inner periphery. Preferably the reflective element extends a full 360° so that the stud will reflect light from any direction, thus being particularly suited to use at road junctions. Embodiments of this invention will now be described by way of examples only and with reference to the accompanying drawings, in which: FIGURE 1 is a cross-section through a road stud in accordance with this invention; FIGURE 2 is a plan view of the road stud of Figure 1; FIGURE 3 is an elevation of an apparatus for removing the road stud of Figure 1 from the road; FIGURE 4 is a diagramatic section through the apparatus of Figure 3 to show the manner in which it engages the metal case of the road stud; FIGURE 5 is a cross-section through a collar of the apparatus of Figures 3 and 4; FIGURE 6 is a plan view of the metal case of a modified road stud; and FIGURE 7 is a side view of the head of a modified apparatus for removing the case of Figure 6 from the road. Referring to Figures 1 and 2, there is shown a reflective stud for road marking, which comprises a generally cylindrical metal (e.g. steel) case 10 which is fitted by impact into a hole bored in the road. The stud further comprises a rubber body 12 which fits within the case 10 and has a peripheral groove which engages an annular rib 14 on the inside of the case 10. The rubber body 12 is in the general form of an inverted cup and has a circular recess 16 in its top, which receives a ring-shaped glass or plastics transparent member IS having a reflective coating 20 on its inner periphery. A plastics cap 22 fits over the top of the reflector member 18 and clamps the latter in place, a screw 24 passing through the cap 22 and being threaded into an insert 26 within the rubber body 12. The case 10 is formed with an outwardly projecting annular flange 20 around its top and its outer surface is formed with a peripheral groove 30 immediately below the flange 28. In order to fit the stud into the road, a hole is bored into the road surface, then pitch is applied to the hole and the case 10 (which is a press-fit relative to the hole) is impacted into the hole using an impact tool. The hole which is bored does not include an enlarged-diameter portion at the surface for receiving the flange 28. When the case is impacted into an e.g. tarmac surface, the tarmac will be forced into the peripheral groove 30. Preferably the flange 28 becomes recessed into the road surface as a result of the impacting. Once the case 10 has been fixed into the road, the rubber body 12 is fitted into the casing and finally the reflective member 18 is applied and fastened in place using the cap 22 and screw 24. If at any time the stud must be removed from the road, the reflective member 18 and rubber body 12 are removed and then the case 10 is extracted using a pulling apparatus, for example as shown in Figures 3 to 5. This apparatus includes a hollow metal tower 40 having a base 42 which fits over the top of the case 10 and over the surrounding road surface. Within the tower 40 there is a shaft 44 which passes through a collar 46 and carries a conical-section wedge 48. Three levers 50 are pivoted to the collar 46 and have notches 52 adjacent their free ends, to engage the rib 14 on the case 10 of the road stud. The apparatus includes a hydraulic cylinder for displacing the shaft 44 upwards, and with it the wedge 48, so that the wedge will bear on the levers 50 and displace them into engagement with the rib 14 of the case 10. Futher displacement of the shaft 44 will apply upwards force to the casing via the levers 50 and rib 14, to lift the case out of the road . Preferably the levers 50 are sprung-loaded in the radially inwards direction. Instead of the rib 14 of the case 10 extending fully around the periphery of the case, it may be interrupted at e.g. two points (as shown in Figure 6) or more points. Then for lifting the case out of the road, the shaft 44 of the lifting apparatus may carry a head 54 as shown in Figure 7, instead of the levers 50 and wedge 48. This head 54 has two (or more) radial projections 56 at or adjacent its lower end, which will pass through the interruptions in the rib 14: if the shaft 44 and head 54 are now turned, the projections 56 engage under the rib 14 so that the case 10 will be lifted when the shaft 44 is displaced upwards. Preferably the installation and removal of the road studs is carried out from a platform on the rear of a vehicle.

Claims: CLAIMS 1) A method of installing a reflective road marking stud, comprising boring a circular hole in a road surface, inserting into the hole a cylindrical metal case which forms part of the stud, and is an interference fit within the hole, applying impact to the cylindrical metal case to force it into the hole, and then fitting an elastomeric body into the metal case, which body has mounted thereon a reflective element. 2) A method according to claim 1, in which the cylindrical metal case is open at both its top and bottom ends. 3) A method according to claim 1 or 2, in which the metal case has a radially outwardly projecting flange around its top end, but the hole which is drilled does not include an enlarged - diameter portion at the road surface for receiving this flange. 4) A method according to claim 3, in which a groove is formed around the outer periphery of the metal case immediately below said flange, such that as the metal case is impacted into the hole, material from the road surface is impacted by the flange and forced into said groove. 5) A method of removing a reflective road marking stud from a road or other surface, which road stud comprises an open-topped cylindrical metal case into which fits an elastomeric body having a reflective element mounted thereon, the method comprising removing the elastomeric body and reflective element, then inserting a tool into the case through its open top and engaging the tool with a projection on the inner surface of the metal case, using the tool to apply an upwards force to the metal case via said projection so as to withdraw the metal case from the road or other surface. 6) A method according to claim 5, in which said projection is used normally to hold in position the elastomeric body of the road stud relative to the metal case. 7) A method according to claim 5 or 6, in which the projection on the inner surface of the case comprises an annular rib. 8) A road stud comprising a cylindrical metal case, an elastomeric body which fits within the case and a reflective element which is mounted to the elastomeric body, the reflective element comprising a ring of transparent material provided with a reflective coating on its inner periphery. 9) A road stud according to claim 8, in which the reflective element extends a full 360° relative to the axis of the case. 10) A road stud according to claim 8 or 9, in which the case has a radially inwardly projecting member and said elastomeric body has a complementary peripheral groove for receiving said projecting member.

Inventors: SHERWIN GILLIAN, SHERWIN GODFREY PETER, SHERWIN, GILLIAN, SHERWIN, GODFREY, PETER
Applicants: SHERWIN GILLIAN, SHERWIN GODFREY PETER, SHERWIN, GILLIAN, SHERWIN, GODFREY, PETER
Application year: 1991
Main classification: E01C23
IPC codes: E01C23, E01F9