Temperature Warning Device

Abstract

A reflective road stud, e.g. cat’s eye, comprising a temperature warning device is disclosed which changes the colour of the reflected light. The temperature warning device 1 comprises a housing 3 wit

Description

The invention relates to a temperature warning device, particularly for incorporation into a reflective road stud, such as a Cat's Eye type stud. Reflective road studs receive light from a vehicle's headlamps and reflect light back towards the driver of the vehicle. Such road studs are used extensively, in many countries, to delineate road edges, centre marking, carriageway lanes, slip roads and laybys. Millions of road studs are in use in the UK alone. They are particularly useful in poor visibility conditions, such as fog and at night, to indicate road edges etc. to drivers. Recent research developments in reflective road studs have included indicators to alert drivers to potentially hazardous road conditions, for example, ice. These reflective road studs may comprise moving components which can lead to problems with the operation of the studs. For example, sudden impacts, such as might be received when a vehicle drives over a stud, can cause loads in the moving parts, which, over time, may lead to damage. According to a first aspect of the invention there is provided a temperature warning device, comprising: a housing; a first chamber within the housing comprising a first part holding a first material, a second part holding a colour-change element and a flexible membrane separating the first and second parts; a second chamber within the housing holding a third material; at least one channel within the housing comprising a first end connected to an opening of the second part of the first chamber and a second end connected to an opening of the second chamber; at least one reflector unit within the housing accessible to light through the housing; wherein, in a temperature warning state, when an ambient temperature of the device is below a trigger temperature, the first material in the first part of the first chamber undergoes a phase change and increases in volume, the flexible membrane is extended into the second part of the first chamber, the colour-change element in the second part of the first chamber is pushed into the at least one channel, light from a light source enters the housing and is reflected back from the at least one reflector unit towards the light source and passes through the colour-change element in the at least one channel which effects a change of colour of the light. In a normal state, when the ambient temperature of the device isgreaterthan the trigger temperature, the first material in the first part of the chamber undergoes a phase change and decreases in volume, the flexible membrane retracts from the second part of the first chamber, the colour-change element in the second part of the first chamber is replaced in the at least one channel by the third material in the second chamber, light from a light source enters the housing and is reflected back from the at least one reflector unit towards the light source and passes through the third material in the at least one channel which does not effect a change of colour of the light. The trigger temperature may be in the range comprising 0 °C to 3.9 °C, preferably 0.5 °C to 3 °C, more preferably 0.9 °C to 2.1 °C. The trigger temperature could result in the formation of ice in the vicinity of the device, thus the change of colour of light reflected from the device warns a driver of possible icy road conditions. The colour-change element in the second part of the first chamber may comprise a second material which may be pushed into the at least one channel on extension of the flexible membrane into the second part of the first chamber. The second material in the second part of the first chamber may be a coloured liquid. The coloured liquid may be any of blue, pink, brown. The coloured liquid may tinted. The coloured liquid may be pigmented. The coloured liquid may be translucent. The coloured liquid may be an oil. The coloured liquid may have a refractive index substantially similar to the refractive index of the third material. The colour-change element in the second part of the first chamber may comprise an optical element which may be pushed into the at least one channel on extension of the flexible membrane into the second part of the first chamber. The optical element may be supported by the flexible membrane. The optical element may be pushed into the at least one channel by the flexible membrane on extension of the flexible membrane into the second part of the first chamber. The optical element may be supported by second material in the second part of the first chamber. The optical element may float on the second material in the second part of the first chamber. The optical element may be pushed into the at least one channel by the second material on extension of the flexible membrane into the second part of the first chamber. The second material in the second part of the first chamber may be a coloured liquid, such as a coloured oil. The optical element in the second part of the first chamber may be a coloured element. The coloured element may be any of blue, pink, brown. The coloured element may tinted. The coloured element may be pigmented. The coloured element may be translucent. The coloured element may be a plastic element. The at least one reflector unit within the housing may be accessible to light through an opening of the housing. The at least one reflector unit within the housing may be accessible to light through a transparent section of the housing. The at least one reflector unit may comprise a retroreflector unit. Such units reflect light back to the light source with minimum scattering. The at least one reflector unit may comprise at least one reflector and at least one lens having a first part, a second part and a slot therebetween and the channel may pass through the slot. The at least one reflector unit may comprise at least one reflector and at least one lens having a slot therethrough and the channel may pass through the slot. The at least one reflector unit may comprise at least one reflector and at least one lens and a slot therebetween and the channel may pass through the slot. The at least one reflector unit may comprise at least one reflector and at least one lens and a slot between the lens and an opening of the housing for the light and the channel may pass through the slot. The at least one reflector unit may comprise an array of reflectors and at least one lens and a slot therebetween and the channel may pass through the slot. The at least one reflector unit may comprise an array of reflectors and an array of corresponding lenses and a slot therebetween and the channel may pass through the slot. The slot may comprise opposing sides which are parallel. The slot may comprise opposing sides which slope inwards at any of a first end, a second end both first and second ends. The slot may comprise a tubular cross section. The at least one lens may comprise glass. The at least one lens may comprise a spherical glass bead. The at least one lens may comprise a non-spherical glass bead. The non-spherical glass bead may have first and second faces and a surface radius of the first face approximately twice that of the second face. Such a bead will be better at sending light to a receiver somewhat off-axis from the light source, e.g. sending light to a driver from headlamps of the driver's vehicle. The at least one lens may comprise plastic. The at least one plastic lens may comprise any of polycarbonate, polystyrene. The at least one plastic lens may have a scratchresistant coating. In the temperature warning state, light from the light source passes through the colour change element in the at least one channel. In the normal state, light from the light source passes through the third material in the at least one channel. In both states, it is desirable to have close to parallel rays of light from the at least one channel to the reflector and close to parallel rays of light from the at least one channel towards the light source. This will be affected by the different refractive indices of the colour-change element and the third material. The geometry of the at least one lens may be customised to accommodate different refractive indices of the colour-change element and the third material in the at least one channel. The geometry of the at least one lens may be customised to accommodate different refractive indices of the colour-change element and the third material in the at least one channel to provide reflected light from the device of an intensity that exceeds a threshold intensity value. The threshold intensity value may be set with reference to a minimum intensity value in relevant standards. The geometry of the at least one lens may be customised by adjusting a diameter of the lens. The geometry of the at least one lens may be customised by offsetting the reflector from the lens. The material of the at least one lens may be customised to accommodate different refractive indices of the colour-change element and the third material in the at least one channel. The material of the at least one lens may be customised to accommodate different refractive indices of the colour-change element and the third material in the at least one channel to provide reflected light from the device of an intensity that exceeds a threshold intensity value. The material of the at least one lens may be customised by adjusting a refractive index of the material. The at least one reflector may comprise a mirrored surface reflector. The mirrored surface reflector may be placed on a face of the at least one lens. The at least one reflector may comprise a corner cube reflector. The corner cube reflector may have a plurality of angled reflective surfaces. Incoming light may reflect off at least some of the surfaces to return towards the light source. The first material in the first part of the first chamber may comprise a liquid that undergoes a liquid to solid phase change and increases in volume below the trigger temperature. The first material may comprise any of water, deuterium, water / deuterium mix. The water / deuterium mix may have respective ratios (vol%) to cause a phase change at a chosen trigger temperature of the device. The third material in the second chamber may be a gas. The gas in the second chamber may be pressurised. The gas in the second chamber may comprise an inert gas. The gas in the second chamber may comprise any of air, nitrogen, helium, carbon dioxide. Using a gas such as nitrogen reduces chances of the gas reacting with the second material. The first part and the second part of the first chamber may have rigid walls. The flexible membrane may comprise a non-porous material. The flexible membrane may comprise an inert material. The flexible membrane may comprise a flexible elastomeric membrane. The housing of the device may be impact-resistant. The housing of the device may comprise a rubber material. The housing may be depressible. The housing may be sealed. This will reduce ingress of dirt etc. into the device. The housing may form a flexible insert for a road stud. The housing may be shaped to fit with a housing of an existing road stud. The housing may comprise a flexible rubber dome shaped to fit within a shoe of a Cat's Eye road stud attached to a road surface. This will enable the temperature warning device to be retrofitted to existing Cat's Eyes road studs easily, thereby upgrading road stud capabilities on a highways network. The temperature warning device may further comprise at least one wireless communication module which is placed in a communication state when the device is in the temperature warning state. The at least one wireless communication module may be placed in a communication state by extension of the flexible membrane. The at least one wireless communication module may be placed in a communication state by extension of a further flexible membrane of the device. The at least one wireless communication module may be placed in a communication state by displacement of colour-change element from the second part of the first chamber into the at least one channel. The at least one wireless communication device may communicate a temperature warning signal to a vehicle passing near to or over the device. The at least one wireless communication device may communicate a temperature warning signal to a communication network, such as a communication network of a highways network. The wireless communication module may comprise an radio frequency identification (RFID) module. The RFID module may comprise an antenna which is switched on when the temperature warning device is in the temperature warning state. According to a second aspect of the invention there is provided a road stud comprising a temperature warning device according to the first aspect of the invention. Embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a schematic representation of a first embodiment of a temperature warning device according to the first aspect of the invention; Figure 2 is a cross sectional view through the temperature warning device of Figure 1 in a temperature warning state; Figure 3 is a schematic representation of a second embodiment of a temperature warning device according to the first aspect of the invention, and Figure 4 is a cross sectional view through the temperature warning device of Figure 3 in a temperature warning state. Referring to Figure 1, a first embodiment of a temperature warning device 1 is shown. This comprises a housing 3. In this embodiment, the housing 3 comprises a rubber material and is impact-resistant and depressible. The housing 3 is in two parts and is sealed by fasteners to reduce ingress of dirt etc. into the device 1. The housing 3 comprises a flexible rubber dome shaped to fit within a shoe of a Cat's Eye road stud (not shown) attached to a road surface (not shown). Referring to Figure 2, the temperature warning device 1 is shown in a temperature warning state. The device 1 further comprises, within the housing 3, a first chamber 5, a second chamber 7, a channel 9, a first reflector unit 11, a second reflector unit (not shown) and a wireless communication module (not shown). It will be appreciated that other embodiments of the temperature warning device may comprise one or more than two reflector units. The first chamber 5 comprises rigid walls providing a first part 13 holding a first material 15 and a second part 17 holding a colour-change element, which, in this embodiment, is a second material 19. The first material 15 comprises a liquid that undergoes a liquid to solid phase change and increases in volume below the trigger temperature of the device 1. In this embodiment, the first material comprises a water / deuterium mix, having respective ratios (vol%) to cause the liquid to solid phase change at a chosen trigger temperature of the device 1. It will be appreciated that the first material may comprise any of water, deuterium. The second material 19 in the second part 17 of the first chamber 5 is a coloured oil, in this embodiment, blue. The blue coloured oil may be tinted or pigmented and is translucent. The blue coloured oil has a refractive index as close to possible as the refractive index of a third material in the second chamber 7. A flexible membrane 21 is attached to the housing 3 and separates the first and second parts 13, 17 of the first chamber 5. The flexible membrane 21 comprises a flexible elastomeric membrane. The second chamber 7 is separated from the first chamber 5 by the channel 9. The second chamber holds a third material 23. In this embodiment, the third material is a gas comprising air. The channel 9 comprises a first end 25 connected to an opening 27 of the second part 17 of the first chamber 5 and a second end 29 connected to an opening 31 of the second chamber 7. The first reflector unit 11 and the second reflector unit are retroreflector units, which reflect light back to a light source with minimum scattering. Components of the first reflector unit 11 will now be described, however, the second reflector comprises the same components. The first reflector unit 11 comprises a reflector 33 and a lens having a first lens part 35, a second lens part 37and a slot 39 therebetween comprising opposing parallel sides. The channel 9 passes through the slot 39. The first reflector unit 11 is accessible to light through an opening (not shown) of the housing 3. The second lens part 37 is adjacent the opening of the housing 3. The reflector 33 comprises a mirrored surface reflector, which is placed as a coating on a face of the first lens part 35. In this embodiment, the reflector is a white reflector. The first lens part 35 and the second lens part 37 comprise glass. Together the first lens part 35 and the second lens part 37 form a lens which is a non-spherical bead. The non-spherical glass bead may have first and second faces and a surface radius of the first face approximately twice that of the second face. Such a bead will be better at sending light to a receiver somewhat off-axis from the light source, e.g. sending light to a driver from headlamps of the driver's vehicle. The wireless communication module comprises an RFID module. The RFID module comprises an antenna which is switched on when the temperature warning device is in the temperature warning state, by extension of the flexible membrane 21. The RFID module may communicate a temperature warning signal to a vehicle passing near to or over the device and a temperature warning signal to a communication network of a highways network. In a temperature warning state, when an ambient temperature of the temperature warning device 1 is below the trigger temperature, the first material 15, the water / deuterium mix, in the first part 13 of the first chamber 5 undergoes a liquid to solid phase change and increases in volume. The water / deuterium mix expands by approximately 10% when the liquid to solid phase change occurs. The trigger temperature is within a range comprising 0 °C to 3.9 °C, preferably 0.5 °C to 3 °C, more preferably 0.9 °C to 2.1 °C. The liquid to solid phase change and increase in volume of the first material 15 causes the flexible membrane 21 to be extended into the second part 17 of the first chamber 5. Second material 19 in the second part 17 is pushed into the channel 9. Light from a light source, for example the headlamps of a vehicle, enters the first reflector unit 11, passes through the second lens part 37, through the channel 9 and through the first lens part 35. The light is reflected from the reflector 33 and passes back through the first lens part 35, the channel 9 and the second lens part 37 and exits through the opening in the housing 3. The channel 9 holds the second material 19, which is a blue coloured oil, and the light passes through the second material 19 which effects a change of colour of the light to blue when the ambient temperature of the temperature warning device 1 is below the trigger temperature. The trigger temperature could result in the formation of ice in the vicinity of the device 1, thus the change of colour to blue of light reflected from the device 1 warns a driver of possible icy road conditions. Light from the light source, for example the headlamps of the vehicle, also enters the second reflector unit and a change of colour of the light to blue is effected when the ambient temperature of the temperature warning device 1 is below the trigger temperature. In another embodiment of the invention, light reflected from only one of the reflector units changes colour. In a normal state (not shown), when the ambient temperature of the temperature warning device 1 is greater than the trigger temperature, the first material 15 in the first part 13 of the first chamber 5 undergoes a solid to liquid phase change and decreases in volume. The flexible membrane 21 retracts from the second part 17 of the first chamber 5 and second material 19 in the second part 17 of the first chamber 5 is replaced in the channel 9 by the third material, e.g. is pushed out of the channel 9 by the pressurised air 23 in the second chamber 7. Light from a light source, for example the headlamps of a vehicle, enters the first reflector unit 11, passes through the second lens part 37, through the channel 9 and through the first lens part 35. The light is reflected from the reflector 33 and passes back through the first lens part 35, the channel 9 and the second lens part 37 and exits through the opening in the housing 3. The channel 9 holds air and the light passes through the air which does not effect a change of colour of the light when the ambient temperature of the temperature warning device 1 is above the trigger temperature. Referring to Figure 3, a second embodiment of a temperature warning device 40 is shown. This comprises a housing 42 in the form of a road stud. In this embodiment, the housing 42 is in two parts and is sealed by fasteners to reduce ingress of dirt etc. into the device 40. The housing 42 comprises a first substantially plate-like part, adapted for fastening to a road surface (not shown) and a dome-shaped second part which, in use, is raised above the road surface to reflect incident light. Referring to Figure 4, the temperature warning device 40 is shown in a temperature warning state. The device 40 further comprises, within the housing 42, a first chamber 44, a second chamber 46, a first channel 48, a second channel 50, a first reflector unit 52, a second reflector unit 54 and a wireless communication module (not shown). It will be appreciated that other embodiments of the temperature warning device may comprise one or more than two reflector units. The first chamber 44 comprises rigid walls providing a first part 56 holding a first material 58 and a second part 60 holding a colour-change element, which, in this embodiment, is a second material 62. The first material 58 comprises a liquid that undergoes a liquid to solid phase change and increases in volume below the trigger temperature of the device 40. In this embodiment, the first material comprises water. It will be appreciated that the first material may comprise any of deuterium, a water / deuterium mix. The second material 62 in the second part 60 of the first chamber 44 is a coloured oil, in this embodiment, blue. The blue coloured oil may be tinted or pigmented and is translucent. The blue coloured oil has a refractive index as close to possible as the refractive index of a third material in the second chamber 46. A flexible membrane 64 is attached to the housing 42 and separates the first and second parts 56, 58 of the first chamber 44. The flexible membrane 64 comprises a flexible elastomeric membrane. The second chamber 46 is separated from the first chamber 44 by the first and second cavities 48, 50. The second chamber holds a third material 66. In this embodiment, the third material is a gas comprising air. The first and second channels 48, 50 each comprise a first lower end connected to an opening of the second part 60 of the first chamber 44 and a second upper end connected to an opening of the second chamber 46. The first and second reflector units 52,54 are retroreflector units, which reflect light back to a light source with minimum scattering. The first reflector unit 52 comprises a first array of corner cube reflectors 68 and a first lens 70 and a slot therebetween. The first channel 48 passes through the slot. The second reflector unit 54 comprises a second array of corner cube reflectors 72 and a second lens 74 and a slot therebetween. The second channel 50 passes through the slot. The first and second lenses 70, 74 comprise plastic, such as any of polycarbonate, polystyrene. The first and second lenses 70, 74 may have a scratch-resistant coating. The wireless communication module comprises an RFID module. The RFID module comprises an antenna which is switched on when the temperature warning device is in the temperature warning state, by extension of the flexible membrane 64. The RFID module may communicate a temperature warning signal to a vehicle passing near to or over the device and a temperature warning signal to a communication network of a highways network. In a temperature warning state, when an ambient temperature of the temperature warning device 40 is below the trigger temperature, the first material 58, water, in the first part 56 of the first chamber 44 undergoes a liquid to solid phase change and increases in volume. The trigger temperature is within a range comprising 0 °C to 3.9 °C, preferably 0.5 °C to 3 °C, more preferably 0.9 °C to 2.1 °C. The liquid to solid phase change and increase in volume of the first material 58 causes the flexible membrane 64 to be extended into the second part 60 of the first chamber 44. Second material 62 in the second part 60 is pushed into the first and second channels 48, 50. Light from a light source, for example the headlamps of a vehicle travelling towards the first reflector unit 52, enters the housing 42 by passing through the first lens 70 and passes through the first channel 48. The light is reflected from the first array of reflectors 68 and passes back through the first channel 48 and the first lens 70 and exits the housing 44. The first channel 48 holds the second material 62, which is a blue coloured oil, and the light passes through the second material 62 which effects a change of colour of the light to blue when the ambient temperature of the temperature warning device 40 is below the trigger temperature, providing a warning to a driver of possible icy road conditions. Similarly, light from a light source, for example the headlamps of a vehicle travelling towards the second reflector unit 54, enters the housing 42 by passing through the second lens 74 and passes through the second channel 50. The light is reflected from the second array of reflectors 72 and passes back through the second channel 50 and the second lens 74 and exits the housing 44. The second channel 50 holds the second material 62, which is a blue coloured oil, and the light passes through the second material 62 which effects a change of colour of the light to blue when the ambient temperature of the temperature warning device 40 is below the trigger temperature, providing a warning to a driver of possible icy road conditions. In a normal state (not shown), when the ambient temperature of the temperature warning device 40 is greater than the trigger temperature, the first material 58 in the first part 56 of the first chamber 44 undergoes a solid to liquid phase change and decreases in volume. The flexible membrane 64 retracts from the second part 60 of the first chamber 44 and second material 62 in the second part 60 of the first chamber 44 is replaced in the first and second cavities 48, 50 by the third material, e.g. is pushed out of the channels 48, 50 by the pressurised air 66 in the second chamber 46. Light from a light source, for example the headlamps of a vehicle travelling towards either reflector unit 52, 54, passes through the first or second channel 48, 50. The channels 48, 50 hold air and the light passes through the air which does not effect a change of colour of the light when the ambient temperature of the temperature warning device 40 is above the trigger temperature.

Claims

1. A temperature warning device, comprising:a housing;a first chamber within the housing comprising a first part holding a first material, a second part holding a colour-change element and a flexible membrane separating the first and second parts;a second chamber within the housing holding a third material;at least one channel within the housing comprising at least one first end connected to an opening of the second part of the first chamber and at least one second end connected to an opening of the second chamber;at least one reflector unit within the housing accessible to light through the housing;wherein, in a temperature warning state, when an ambient temperature of the device is below a trigger temperature, the first material in the first part of the first chamber undergoes a phase change and increases in volume, the flexible membrane is extended into the second part of the first chamber, the colour-change element in the second part of the first chamber is pushed into the at least one channel, light from a light source enters the housing and is reflected back from the at least one reflector unit towards the light source and passes through the colour-change element in the at least one channel which effects a change of colour of the light.

2. A temperature warning device according to claim 1 in which, in a normal state, when the ambient temperature of the device is greater than the trigger temperature, the first material in the first part of the chamber undergoes a phase change and decreases in volume, the flexible membrane retracts from the second part of the first chamber, the colour-change element in the second part of the first chamber is replaced in the at least one channel by the third material in the second chamber, light from a light source enters the housing and is reflected back from the at least one reflector unit towards the light source and passes through the third material in the at least one channel which does noteffect a change of colour of the light.

3. A temperature warning device according to claim 1 or claim 2 in which the trigger temperature is in the range comprising 0 °C to 3.9 °C, preferably 0.5 °C to 3 °C, more preferably 0.9 °C to 2.1 °C.

4. A temperature warning device according to any of claims 1 to 3 in which the colour-change element in the second part of the first chamber is a second material comprising a coloured liquid which is pushed into the at least one channel on extension of the flexible membrane into the second part of the first chamber.

5. A temperature warning device according to any of claims 1 to 3 in which the colour-change element in the second part of the first chamber is an optical element which is pushed into the at least one channel on extension of the flexible membrane into the second part of the first chamber.

6. A temperature warning device according to claim 5 in which the optical element in the second part of the first chamber is supported by second material in the second part of the first chamber and is pushed into the at least one channel by the second material on extension of the flexible membrane into the second part of the first chamber.

7. A temperature warning device according to any preceding claim in which the at least one reflector unit comprises at least one reflector and at least one lens having a first part, a second part and a slot therebetween and the channel passes through the slot.

8. A temperature warning device according to any of claims 1 to 6 in which the at least one reflector unit comprises at least one reflector and at least one lens having a slot therethrough and the channel passes through the slot.

9. A temperature warning device according to any of claims 1 to 6 in which the atleast one reflector unit comprises at least one reflector and at least one lens and a slot therebetween and the channel passes through the slot.

10. A temperature warning device according to any of claims 1 to 6 in which the at least one reflector unit comprises at least one reflector and at least one lens and a slot between the lens and an opening of the housing for the light and the channel passes through the slot.

11. A temperature warning device according to any of claims 7 to 10 in which the slot comprises opposing sides which are any of parallel, slope inwards at a first end, slope inwards at a second end, slope inwards at both first and second ends.

12. A temperature warning device according to any of claims 7 to 11 in which the geometry of the at least one lens is customised to accommodate different refractive indices of the second material and the third material in the at least one channel.

13. A temperature warning device according to claim 12 in which the geometry of the at least one lens is customised to accommodate different refractive indices of the second material and the third material in the at least one channel to provide reflected light from the device of an intensity that exceeds a threshold intensity value.

14. A temperature warning device according to any of claims 7 to 13 in which the material of the at least one lens is customised to accommodate different refractive indices of the second material and the third material in the at least one channel.

15. A temperature warning device according to claim 14 in which the material of the at least one lens is customised to accommodate different refractive indices of the second material and the third material in the at least one channel to provide reflected light from the device of an intensity that exceeds a threshold intensity value.

16. A temperature warning device according to any preceding claim in which the at least one reflector unit comprises an array of reflectors and an array of lenses.

17. A temperature warning device according to any preceding claim in which the at least one reflector comprises a corner cube reflector.

18. A temperature warning device according to any preceding claim in which the first material in the first part of the first chamber comprises a liquid that undergoes a liquid to solid phase change and increases in volume below the trigger temperature.

19. A temperature warning device according to claim 18 in which the first material comprises any of water, deuterium, water I deuterium mix.

20. A temperature warning device according to any preceding claim in which the third material in the second chamber is a gas.

21. A temperature warning device according to any preceding claim in which the housing is shaped to fit with a housing of an existing road stud.

22. A temperature warning device according to any preceding claim further comprising at least one wireless communication module which is placed in a communication state when the device is in the temperature warning state.

23. A temperature warning device according to claim 22 in which the at least one wireless communication module is placed in a communication state by extension of the flexible membrane.

24. A road stud comprising a temperature warning device according to any of claims 1 to 23.Application No: GB2319709.8Examiner:Contract Unit ExaminerClaims searched: 1-24Date of search: 12 November 2024Patents Act 1977: Search Report under Section 17Documents considered to be relevant:Category Relevant to claims Identity of document and passage or figure of particular relevance A - NL7307978 A (DE VRIES PETRUS D C) the whole document A - GB 1432564 A (ASS ENG LTD) page 2, lines 14-91; figures 5, 6 A - DE2634579 Al (FUELLER FERDINAND) pages 3, 4; figures A - DE2010851 Al (MAHLO HANS P) page 4, line 13 - page 6, line 4; figures 1-3Categories:X Document indicating lack of novelty or inventive A Document indicating technological background and / or state step of the art. Y Document indicating lack of inventive step if P Document published on or after the declared priority date but combined with one or more other documents of same category'. before the filing date of this invention. & Member of the same patent family E Patent document published on or after, but with priority date earlier than, the filing date of this application.Field of Search:Search of GB, EP, WO &US patent documents classified in the following areas of the UKCX :Worldwide search of patent documents classified in the following areas of the IPC____________EQ IF; GO IK; G02B; G08B__________________________________________The following online and other databases have been used in the preparation of this search reportInternational Classification:Subclass Subgroup Valid From GO IK 0011 / 06 01 / 01 / 2006 EOIF 0009 / 40 01 / 01 / 2016 EOIF 0009 / 553 01 / 01 / 2016 EOIF 0009 / 571 01 / 01 / 2016 GO IK 0011 / 12 01 / 01 / 2021 G02B 0005 / 24 01 / 01 / 2006 G08B 0019 / 02 01 / 01 / 2006

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