GB2172921A - Road studs - Google Patents

Abstract

A reflective road stud 10 has an expandable spigot 34 projecting from its underside to engage in a hole in the road surface. The spigot has an outer spilt sleeve and an inner screw 46 and has a head 44 engaging in a recess 26 in the top of the stud and extends through the sleeve to receive an annular wedge 44 at the bottom of the sleeve which is drawn up into the sleeve as the screw is turned in one direction to expand the sleeve. The upper end of the split sleeve is spaced from the underside of the stud by collapsible abutments 40 to hold the stud and sleeve apart as the screw if first tightened to lock the spigot in the hole and an application of sufficient compressive force through the screw, to collapse allowing the stud to be tightened down onto the road surface. <IMAGE>

Description

SPECIFICATION Road studs This invention relates to roads for fixing to the road or other highway surface to act as traffic markers.

This invention provides a road stud comprising a body for mounting on a road surface, an expandable projection for insertion into a complementary hole in the road, means for mounting the body on the projection, for expanding the projection and/or drawing the projection towards the body and compressable means acting between the projection and body for spacing the projection from the body until a certain force is applied between the projection and body causing the spacing means to be compressed whereby the projection may be expanded in the hole in the road by the mounting means and the collapsible spacer means then compressed to allow the body to be drawn into engagement with the road surface to clamp the body to the surface.

Preferably the compressable spacer means comprise one or more collapsible abutments acting between the projection and the body, the collapsible abutment or abutments being arranged to hold the projection spaced from the body until certain force is applied thereto causing the abutment or abutments to collapse and allow the body to move towards the projection.

In one arrangement according to the invention the projection has a tapered bore extending therealong, the means for expanding the projection comprise an expansion member slidably engaging the bore, and means are provided to move the expansion member along the bore to expand the projection.

In the latter construction at least one longitudinal slot may be formed in the projection between the bore and the outer surface of the projection to facilitate expansion of the projection.

More specifically the projection is formed by two longitudinally split parts to facilitate expansion of the projection and the tapered bore may taper inwardly as the bore extends upwardly, and the means to move the expansion member may be arranged to draw the expansion member up the bore. The expansion member preferably has a threaded bore, the means to move the expansion member along the bore comprising a screw member extending from the body along the bore and into screw threaded engagement with the expansion member, the screw member being rotatable from above the road stud to draw the expansion member up the bore.

The collapsible abutment means may comprise a plurality of collapsible fingers arranged around the bore between the projection and the body so that, once the projection has been expanded to grip in the hole in the road, further rotation of the screw member causes the fingers to collapse and permit the body to be pulled against the road surface.

The expansion member may have a radial fin element which engages a slot in the projection, or between the longitudinally split parts of the projection, to prevent relative rotation of the expansion member and projection.

In any of the above arrangements means may be provided acting between the stud and the projection to restrain the stud from relative rotation with respect to the projection whilst permitting lengthwise movement of the stud with respect to the projection after collapse of the collapsible spacer means. In that construction the means to restrain the stud from rotation about the projection may comprise inter-engaging means on the underside of the stud and the adjacent end of the projection which permit relative sliding between the stud and projection in the lengthwise direction of the projection but prevent rotation of the stud with respect to the projection. The underside of the stud may have an annular collar to receive the end of the projection and inter-engaging means are provided between the collar and the adjacent end of the projection.The collar may have at least one abutment on its inner surface extending in the axial direction of the collar to engage in a corresponding slot in the adjacent end of the projection.

Preferably abutments are provided at diametrically spaced locations on the collar to engage in correspondingly diametrically spaced slots on the adjacent end of the projection.

It is further preferred that the collapsible spacer means are formed on the end of the projection and engage the road stud within the collar.

The following is a description of some specific embodiments of the present invention, reference being made to the accompanying drawings in which: Figure 1 is a perspective view, partially cut-away, of a road stud according to the present invention; Figure 2 is a side view of one spigot or half forming part of the road stud shown in Figure 1; Figure 3 is a top view of the spigot or half shown in Figure 2; Figure 4 is a view of the spigot half as seen in the direction IV in Figure 2; and Figure 5 is a similar view to that of Figure 1 showing a modified construction.

Referring to Figure 1, a road stud, generally indicated by the reference numeral 10, comprises a moulded body 12 having a generally rectangular or square, horizontally extending skirt 14 and a raised central portion 16 provided with reinforcing webs 18.

A row of reflective elements 22 mounted in a plastics carrier 24 are moulded in one side of the body 12 so that the inserts face generally horizontally but are inclined slightly upwardly to reflect vehicle lights. A further carrier (not shown) may be moulded into the opposite side of the body. Other suitable ways of securing reflective elements to the body may be employed. A hole 26 is formed in a central boss 28 depending from the portion 16 and has an upwardly facing shoulder 30. Also, four downwardly facing recesses 32 are formed in the lower face of the boss 28 around the hole 26.

Referring also to Figures 2 and 3, the stud further comprises a spigot 34 formed by two identical generally C-sectioned spigot halves which together form a central bore 36 along the spigot. Over about the lower half of the spigot, the bore tapers (at 38) outwardly to the lower end of the spigot.

The upper end of the spigot is provided with four upwardly extending deformable fingers 40 which are a sloppy fit in the recesses 32. The fingers 40 are longer than the depth of the recesses 32 so that the spigot is spaced from the boss 28. The outer surface of the spigot 34 is formed with circumferential ribs 42 over about the lower twothirds of the length of the spigot An annuiar wedge 44 is located in the tapered bore 38 at the lower end of the spigot, the wedge having a complementary taper to the taper of the bore 38. To pull the wedge 44 up the bore to expand the spigot 34, a screw 46 extends through the bore and engages a screw thread 48 in the wedge 44, the shoulder at the head 49 of the screw 46 engaging the shoulder 30 in the boss 28.The upper end of the head 48 is flush with the upper surface of the raised portion 16 of the body 12 and has a square recess 50 to receive a brace.

The lower portion of each spigot half 39 is provided with a pair of longitudinal slots 52 to bifurcate the lower portion. The slots provide for two important functions. Firstly, they facilitate radial expansion of the lower end of each spigot half, in addition to the radial expansion permitted by the spigot 34 being formed as two halves. Secondly,the wedge 44 is formed with a pair of complementary radially extending fins 44a (see Figure 5) which slide along the slots as the wedge is drawn up the spigot and prevent rotation of the wedge.

To fit the road stud to a road surface, firstly a hole is drilled in the road to accommodate the spigot 34 snugly, and then the stud is layed in position, with the spigot 34 in the hole and the underside of the skirt 14 resting on the road surface.

Then, the screw 46 is rotated with a brace to draw the wedge 44 up the tapered bore 38 and expand the spigot width-ways so that the ribs 42 bite into the road and secure the spigot in the hole in the road. Then, upon further rotation of the screw 46, the fingers 40 begin to collapse in the recesses 32 and the body 12 is drawn by the screw towards the now-fixed spigot to hold the body 12 firmly against the road surface.

The stud may be supplied, ready for use, with the wedge 44 connected to the spigot halves 39 by a thin shearable connection, this connection being broken when the wedge is drawn up the spigot.

In the modification of Figure 5, the underside of the stud 10 is formed with a downwardly extending integral collar 60 to receive and encircle the upper end of the projection 34. The collar is formed on the inner side with axial extending abutments or keys 61 and diametrically spaced locations across the collar to engage corresponding slots 62 formed on the head of the projection 34 which engages in the collar. The inter-engagement of abutments 61 in the slot prevents the stud from rotating with respect to the projection and thus with respect to the road surface one projection has been locked in its hole in the road whilst permitting the stud to move axially down the projection as the stud is screwed on to the projection. The collapsible abutments 40 at the top of the projection engage the underside of the stud within the collar and hold the projection initially when the screw 46 is turned to cause the projection 34 to expand in its hole in the road. Once the projection has expanded into locking engagement with the hole, further turning of the screw 46 forces the stud body downwardly causing the abutments 40 to collapse. The body can then be tightened further down onto the road surface to form a tight engagement between the underside of the stud and the road surface and at the same time the stud is locked against turning with respect to the road surface by the inter-engagement of the abutments 61 in the collar with the slots in the head of the projection.

Claims (17)

1. A road stud comprising a body for mounting on a road surface, an expandable projection for insertion into a complementary hole in the road, means for mounting the body on the projection, for expanding the projection and/or drawing the projection towards the body and compressable spacer means acting between the projection and body for spacing the projection from the body until a certain force is applied between the projection and body causing the spacing means to be compressed whereby the projection may be expanded in the hole in the road by the mounting means and the compressable spacer means then compressed to allow the body to be drawn into engagement with the road surface to clamp the body to the surface.

2. A road stud as claimed in Claim 1, wherein the compressible spacer means comprise one or more collapsible abutments acting between the projection and the body, the collapsible abutment or abutments being arranged to hold the projection spaced from the body until certain force is applied thereto causing the abutment or abutments to collapse and allow the body to move towards the projection.

3. A road stud as claimed in Claim 1 or Claim 2, wherein the projection has a tapered bore extending therealong, the means for expanding the projection comprising an expansion member slidably engaging the bore, and means being provided to move the expansion member along the bore to expand the projection.

4. A road stud as claimed in Claim 3, wherein at least one longitudinal slot is formed in the projection between the bore and the outer surface of the projection to facilitate expansion of the projection.

5. A road stud as claimed in Claim 3 or Claim 4, wherein the projection is formed by two longitudinally split parts to facilitate expansion of the projection.

6. A road stud as claimed in any of Claims 3 to 5, wherein the tapered bore tapers inwardly as the bore extends upwardly, and the means to move the expansion member is arranged to draw the expansion member up the bore.

7. A road stud as claimed in Claim 6, wherein the expansion member has a threaded bore, the means to move the expansion member along the bore comprising a screw member extending from the body along the bore and into screw threaded engagement with the expansion member, the screw member being rotatable from above the road stud to draw the expansion member up the bore.

8. A road stud as claimed in Claim 7, wherein the collapsible abutment means comprise a plurality of collapsible fingers arranged around the bore between the projection and the body so that, once the projection has been expanded to grip in the hole in the road, further rotation of the screw member causes the fingers to collapse and permit the body to be pulled against the road surface.

9. A road stud as claimed in Claim 7 or Claim 8, wherein the expansion member has a radial fin element which engages a slot in the projection, or between the longitudinally split parts of the projection, to prevent relative rotation of the expansion member and projection.

10. A road stud as claimed in any of the proceeding claims having means acting between the stud and the projection to restrain the stud from relative rotation with respect to the projection whilst permitting lengthwise movement of the stud with respect to the projection after collapse of the collapsible spacer means.

11. A reflective road stud as claimed in Claim 10, wherein the means to restrain the stud from rotation about the projection comprise inter-engaging means on the underside of the stud and the adjacent end of the projection which permit relative sliding between the stud and projection in the lengthwise direction of the projection but prevent rotation of the stud with respect to the projection.

12. A reflective road stud as claimed in Claim 11, wherein the underside of the stud has an annular collar to receive the end of the projection and inter-engaging means are provided between the collar and the adjacent end of the projection.

13. A reflective road stud as claimed in Claim 12, wherein the collar has at least one abutment on its inner surface extending in the axial direction of the collar to engage in a corresponding slot in the adjacent end of the projection.

14. A reflective road stud as claimed in Claim 13, wherein abutments are provided at diametrically spaced locations on the collar to engage in correspondingly diametrically spaced slots on the adjacent end of the projection.

15. A reflective road stud as claimed in Claim 13 or Claim 14, wherein the collapsible spacer means are formed on the end of the projection and engage the road stud within the collar.

16. A reflective road stud substantially as described with reference to and as illustrated in Figures 1 to 4 of the accompanying drawings.

17. A reflective road stud substantially as described with reference to and as illustrated in Figure 5 of the accompanying drawings.