GB2041047A

GB2041047A - Road Studs

Info

Publication number: GB2041047A
Application number: GB7943848A
Authority: GB
Original assignee: Simmons G M A
Current assignee: Simmons G M A
Priority date: 1978-12-21
Filing date: 1979-12-20
Publication date: 1980-09-03
Also published as: GB2041047B

Abstract

A road marking stud has a movable reflector (10) facing four lenses (2, 5) in a casing (1). The reflecting surfaces of the reflector facing the lenses have alternate different colour parallel stripes matching cylindrical lens elements (8) of the lenses and is slidably mounted. A bi-metallic strip (11) bows upwardly when the ambient temperature approaches freezing point to move the reflector and changes the colour of the stripes facing the lens elements so that the light from a vehicle head lamp illuminating the stud and reflected back also changes in colour as a warning to the vehicle driver. <IMAGE>

Description

SPECIFICATION Road Marking Studs The invention relates to studs for road marking of the kind which are set into a road surface and inculde reflective elements observable by a vehicle driver when the studs are illuminated by light from the vehicle head lamps.

According to the present invention, a road marking stud comprises a casing containing a lens with an exposed surface and a movable reflector arranged so that light directed onto the exposed surface is reflected back through the lens by a part of a reflecting surface of the reflector facing the lens, the reflecting surfaces having areas of different colours, and means responsive to changes in ambient temperature for moving the reflector relative to the lens to vary the colour of the reflecting part of the surface of the reflector.

The temperature responsive means preferably comprises a bi-metallic strip arranged to move the reflector and thus change the colour of the surface part reflecting light when the ambient temperature falls below a pre-determined value.

In gcneral the value is at or near OOC so that a change in colour of the reflected light is produced when ambient conditions may give rise to the formation of ice on a road surface in which the reflector is located.

In a preferred construction, four lenses are provided in pairs facing in opposite directions and the reflector has two reflecting surfaces, each facing one pair of lenses. The reflecting surfaces have alternate stripes in two different colours to register with parallel cylindrical lens elements of the lenses so that the colour of the stripe opposite each lens element changes as the reflector is moved.

Embodiments of the invention will now be described in detail with reference to the accompanying drawings wherein: Figure 1 shows a sectional plan view of a road marking stud according to the invention, Figure 2 shows a longitudinal section of part of the stud on the line A-A in Figure 1, Figure 3 shows a cross-section of the stud on the line B-B in Figure 1, and Figure 4 shows a cross-section of another embodiment of the invention.

The stud shown in Figures 1-3 comprises a casing 1 housing four lenses 2, 3, 4 and 5 arranged in oppositely facing pairs. Each lens is of generally cylindrical shape extending longitudinally of the casing with part spherical ends 6 protruding through apertures in opposite ends of the casing and forming light diffusers. The inward ends 7 of the lenses are shaped to form successive semi-cylindrical lens elements 8 with their axes horizontal. The ends 7 of the lenses are spaced apart adjacent the centre of the casing to leave a space 9 which accommodates a reflecting flag 10.

The flag 10 is a rectangular shaped plate and each of its surfaces is reflective and is provided with a succession of horizontal stripes alternately coloured and white/silver. Each stripe has a width equal to half the width of the lens element 8. The ends of the flag are mounted in guides 1 5 so that the flag is freely vertically slidable.

A bi-metallic element 11 is mounted in the base of the casing by rivetting its ends 12 to anchor points on the casing and walls, the element being so constructed that it bows downwardly under rising ambient temperature.

Under temperatures above a pre-determined critical value, e.g. OOC, the centre of the element lies within or below a recess 14 in the flag. When the ambient temperature falls to the critical value the element bows upwardly and raises the flag.

At the lowest position the white or silver stripes of the flag are opposite the lens element 8 with the result that light shining on the lenses from, for example, a vehicle head lamp is reflected back from the stripe through the lenses as white light. When the flag is raised by the element due to a fall in temperature below the critical value, the coloured stripes are progressively brought into register with the lens elements so that the reflected light is coloured.

Accordingly, a row of studs in a road surface normally show white light to the driver of an oncoming vehicle, but as the ambient temperature falls below the critical value and icing conditions are present, the studs show a coloured light to the driver. The colour intensity will deepen as the temperature falls due to the progressive increase in the area of the coloured stripes opposite to the lens elements.

The second embodiment of the invention is generally similar to that already described except for the form of the bi-metallic strip element. As shown in Figure 4, a generally U-shaped strip 20 is housed in a recess 21 in the base of the casing below the flag 10, one end being bent over and rivetted or pinned to the casing. The other end is shaped to provide an abutment 22 to engage the bottom edge of the flag and raise it as the arms of the U spread apart when the ambient temperature falls below the critical value.

Claims

1. A road marking stud comprising a casing containing a lens with an exposed surface and a movable reflector arranged so that light directed on to the exposed surface is reflected back through the lens by a part of a reflecting surface of the reflector facing the lens, the reflecting surface having areas of different colours, and means responsive to change in ambient temperature for moving the reflector relative to the lens to vary the colour of the reflecting part of the reflector.

2. A road marking stud according to claim 1 wherein the areas of different colours are formed by alternate stripes of two colours.

3. A road marking stud according to claim 2 wherein the reflector is in the form of a rectangular plate slidable in guides in the reflector casing.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Road Marking Studs The invention relates to studs for road marking of the kind which are set into a road surface and inculde reflective elements observable by a vehicle driver when the studs are illuminated by light from the vehicle head lamps. According to the present invention, a road marking stud comprises a casing containing a lens with an exposed surface and a movable reflector arranged so that light directed onto the exposed surface is reflected back through the lens by a part of a reflecting surface of the reflector facing the lens, the reflecting surfaces having areas of different colours, and means responsive to changes in ambient temperature for moving the reflector relative to the lens to vary the colour of the reflecting part of the surface of the reflector. The temperature responsive means preferably comprises a bi-metallic strip arranged to move the reflector and thus change the colour of the surface part reflecting light when the ambient temperature falls below a pre-determined value. In gcneral the value is at or near OOC so that a change in colour of the reflected light is produced when ambient conditions may give rise to the formation of ice on a road surface in which the reflector is located. In a preferred construction, four lenses are provided in pairs facing in opposite directions and the reflector has two reflecting surfaces, each facing one pair of lenses. The reflecting surfaces have alternate stripes in two different colours to register with parallel cylindrical lens elements of the lenses so that the colour of the stripe opposite each lens element changes as the reflector is moved. Embodiments of the invention will now be described in detail with reference to the accompanying drawings wherein: Figure 1 shows a sectional plan view of a road marking stud according to the invention, Figure 2 shows a longitudinal section of part of the stud on the line A-A in Figure 1, Figure 3 shows a cross-section of the stud on the line B-B in Figure 1, and Figure 4 shows a cross-section of another embodiment of the invention. The stud shown in Figures 1-3 comprises a casing 1 housing four lenses 2, 3, 4 and 5 arranged in oppositely facing pairs. Each lens is of generally cylindrical shape extending longitudinally of the casing with part spherical ends 6 protruding through apertures in opposite ends of the casing and forming light diffusers. The inward ends 7 of the lenses are shaped to form successive semi-cylindrical lens elements 8 with their axes horizontal. The ends 7 of the lenses are spaced apart adjacent the centre of the casing to leave a space 9 which accommodates a reflecting flag 10. The flag 10 is a rectangular shaped plate and each of its surfaces is reflective and is provided with a succession of horizontal stripes alternately coloured and white/silver. Each stripe has a width equal to half the width of the lens element 8. The ends of the flag are mounted in guides 1 5 so that the flag is freely vertically slidable. A bi-metallic element 11 is mounted in the base of the casing by rivetting its ends 12 to anchor points on the casing and walls, the element being so constructed that it bows downwardly under rising ambient temperature. Under temperatures above a pre-determined critical value, e.g. OOC, the centre of the element lies within or below a recess 14 in the flag. When the ambient temperature falls to the critical value the element bows upwardly and raises the flag. At the lowest position the white or silver stripes of the flag are opposite the lens element 8 with the result that light shining on the lenses from, for example, a vehicle head lamp is reflected back from the stripe through the lenses as white light. When the flag is raised by the element due to a fall in temperature below the critical value, the coloured stripes are progressively brought into register with the lens elements so that the reflected light is coloured. Accordingly, a row of studs in a road surface normally show white light to the driver of an oncoming vehicle, but as the ambient temperature falls below the critical value and icing conditions are present, the studs show a coloured light to the driver. The colour intensity will deepen as the temperature falls due to the progressive increase in the area of the coloured stripes opposite to the lens elements. The second embodiment of the invention is generally similar to that already described except for the form of the bi-metallic strip element. As shown in Figure 4, a generally U-shaped strip 20 is housed in a recess 21 in the base of the casing below the flag 10, one end being bent over and rivetted or pinned to the casing. The other end is shaped to provide an abutment 22 to engage the bottom edge of the flag and raise it as the arms of the U spread apart when the ambient temperature falls below the critical value. Claims

4. A road marking stud according to claim 1 and 2 wherein the lens has a plurality of parallel semi-cylindrical lens elements adjacent the reflector surface, the diameter of each lens element being twice the width of the reflector stripes.

5. A road marking stud according to claims 14 having four lenses arranged in pairs facing opposite directions, the reflector being provided with two reflecting surfaces, each surface facing one pair of lenses.

6. A road marking stud according to any of claims 1-5 wherein the temperature responsive means is a bi-metallic strip.

7. A road marking stud according to claim 6 wherein the bi-metallic strip is fixed to the casing at opposite ends and engages the reflector intermediate its ends for movement thereof.

8. A road marking stud according to claim 6 wherein the bi-metallic strip is U-shaped, and is secured to the casing at the end of one leg, the free end of the other leg being engageable with, the reflector for movement thereof.

9. A road marking stud constructed and arranged substantially as hereinbefore described and shown in Figures 1-3, or with Figure 4 of the accompanying drawings.