GB2552141A

GB2552141A - A vehicle obstruction assembly

Info

Publication number: GB2552141A
Application number: GB1611765.7A
Authority: GB
Inventors: Mellors Christopher
Original assignee: Ian Rivlin
Current assignee: Ian Rivlin
Priority date: 2016-07-06
Filing date: 2016-07-06
Publication date: 2018-01-17
Also published as: GB201611765D0

Abstract

A vehicle obstruction assembly 10 includes a trigger device 12, a control mechanism 14 for determining when a vehicle is travelling above a predetermined speed, an obstruction element 16 that is positioned after the trigger device. The obstruction element is moveable between a first retracted position and a second deployed position. The obstruction element is connected to the trigger device via a mechanical linkage arrangement 50. The control mechanism is configured such that when an approaching vehicle is travelling above a predetermined speed upon contact with the trigger device, the trigger device moves the obstruction element from the retracted position to the deployed position via the control mechanism and the mechanical linkage arrangement. The control mechanism may be a piston damper arrangement 40 with first and second fluid filled chambers (70 72 figure 6). The obstruction element may comprise a curved surface 62 that is uppermost when the obstruction element is in the deployed position. The trigger device may be a trigger plate 22. The obstruction element may be a speed bump and may comprise a spike strip

Description

A Vehicle Obstruction Assembly

FIELD OF THE INVENTION

The present invention relates to a vehicle obstruction assembly, particularly but not exclusively to speed bumps or ramps.

BACKGROUND OF THE INVENTION

It is common for speed bumps (also referred to as road humps or speed ramps) to be installed into roads in built-up areas and car parks as a so-called "traffic calming measure" to act as a deterrent to motorists travelling at excess speeds. The speed bumps are provided to encourage drivers to keep their vehicle speeds to a safe level. Traditionally, such speed bumps are often provided in the form of elongate mounded areas of road, e.g. formed from asphalt or concrete that extend across the width or part of the width of the road to ensure that each vehicle encounters the speed bump. Unfortunately, speed bumps of this type are an inconvenience as they do not fully discriminate between vehicles that are travelling too fast and vehicles that are travelling at a safe speed (i.e. they are still uncomfortable for vehicle occupants to drive over even below the speed limit). In addition, they contribute to vehicle wear and tear even at permissible speeds and in some circumstances can increase pollution by causing drivers to brake and accelerate violently when passing over bumps. Various examples of the design of such speed bumps can be found in "Local Transport Note 1/07" published by the UK Department for Transport.

More recently, speed bumps have been produced that retract or collapse when an approaching vehicle is travelling below a predetermined speed. However, providing a speed bump that is in the deployed position at rest, which is then lowered when a vehicle is travelling at a safe speed subjects the speed bump components to excess wear and tear due to the recurrent movement. This can result in the speed bumps needing to be repaved or replaced more regularly. Further, the collapsing mechanism may be noisy and therefore unpleasant for residents in the vicinity of the speed bump.

The present invention seeks to overcome or at least mitigate one or more of the problems associated with the prior art.

SUMMARY OF THE INVENTION

According to a first aspect of the invention there is provided a vehicle obstruction assembly comprising: a trigger device; a control mechanism for determining when a vehicle is travelling above a predetermined speed; and an obstruction element positioned downstream of the trigger device in a path of a vehicle, the obstruction element moveable between a retracted position in which no obstruction to a vehicle is caused and a deployed position in which progress of a vehicle is obstructed, wherein the trigger device and the obstruction element are connected via a mechanical linkage arrangement, further wherein the control mechanism is configured such that when an approaching vehicle is travelling above a predetermined speed upon contact with the trigger device, the trigger element moves the obstruction element from the retracted position to the deployed position via the control mechanism and the mechanical linkage arrangement.

Advantageously, providing an obstruction assembly that is lowered in its rest state and is only deployed when a vehicle is determined to be traveling above a predetermined speed (i.e. above the speed limit) results in an assembly that is subjected to less wear and tear as it is not deployed by every passing vehicle unnecessarily. Further, by not disrupting the passage of law-abiding drivers, it may reduce pollution and noise caused by vehicles braking and accelerating in the vicinity of the assembly.

Preferably, the control mechanism may comprise a selectable lost motion connection between an input and an output thereof. The control mechanism may comprise a piston damper arrangement, the piston comprising an input end and an output end.

Advantageously, the piston damper provides an arrangement where a force is not transmitted to move the obstruction element when a vehicle is travelling below a predetermined speed, reduces the wear on the system. Additionally, the piston arrangement provides a reliable means for deploying the obstruction element above a predetermined speed.

Preferably, the input end of the piston may be connected to the trigger device. The output end of the piston may be connected to the obstruction element via the mechanical linkage.

Preferably, the piston comprises a piston head comprising a restriction therethrough. The piston may comprise first and second fluid filled chambers separated by the piston head. The restriction may be configured such that when the input end of the piston is moved above a predetermined speed, the fluid is prevented from flowing between the first and second chambers.

The fluid may be a magneto-rheological fluid or an electro-rheological fluid

Preferably, the mechanism may further comprise an arrangement, such as a generator, to selectively cause the fluid to have an increased viscosity.

Preferably, the obstruction element is pivotally connected to the assembly. The obstruction element comprises a stop arrangement for preventing over rotation of the obstruction element.

Advantageously, this provides an easy arrangement for preventing over extension of the obstmction element, thus preventing damage.

Preferably, the obstmction element comprises a curved surface that is uppermost when the obstmction element is in the deployed position.

The trigger device may be pivotally connected to the assembly and is configured to be depressed from a raised position by an approaching vehicle.

Advantageously, this ensures that an approaching vehicle will contact the trigger device to determine whether to deploy the obstmction element.

Preferably, a biasing element may be provided to bias the trigger device into the raised position. The biasing element may be a spring.

Preferably, the trigger device comprises a trigger plate.

Preferably, the obstmction element is biased into the retracted position.

The obstruction element may be configured with respect to the trigger device such that the obstmction element is in the deployed position when an approaching vehicle travels over the obstruction element above the predetermined speed.

Preferably, the control mechanism is configured such that, when an approaching vehicle is travelling above a predetermined speed, the obstruction element moves to the retracted position before a subsequent vehicle travelling below a predetermined speed travels over the obstruction element.

The assembly may be provided with an adjustment mechanism to adjust the position of the obstruction element in the deployed position.

Preferably, the assembly includes a frame, wherein the trigger device and obstruction element are connected to the frame.

Advantageously, this provides a compact arrangement of the obstruction element and trigger device in a single unit.

Preferably, the obstruction element is a speed bump.

The obstruction element may comprise a spike strip.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

Figure 1 is a side view of an obstruction assembly in a retracted position according to an embodiment of the present invention;

Figure 2 is an opposing side view of the obstruction assembly of Figure 1;

Figure 3 is an isometric view of the obstruction assembly of Figure 1 viewed from the underside;

Figure 4 is an alternative isometric view of the obstruction assembly of Figure 1 viewed from the underside;

Figure 5 is a side view of the obstruction assembly of Figure 1 in a partially deployed position;

Figure 6 is a schematic cross sectional view of the piston damper arrangement according to an embodiment of the present invention; and

Figure 7 is an enlarged schematic cross sectional view of the piston damper arrangement of Figure 4. DETAILED DESCRIPTION OF EMBODIMENT(S)

Referring firstly to Figures 1 to 5, an obstruction assembly is indicated generally at 10. The obstruction assembly 10 includes a trigger device 12, a control mechanism 14 for determining when an approaching vehicle is travelling above a predetermined speed and an obstruction element 16. The obstruction element 16 is positioned downstream of the trigger device 12 in the normal direction of travel of vehicles on a section of road where it is to be installed. The obstruction element 16 is moveable between a retracted position, in which no obstruction to a vehicle is caused (as is illustrated in Figure 1 to 4), and a deployed position, in which the progress of a vehicle is obstructed (as is illustrated in Figure 5).

In the illustrated embodiment, the obstruction assembly 10 includes a frame assembly 18 that includes an upper frame panel 20. The trigger device 12 and the obstruction element 16 are secured to the upper frame panel 20. Such an arrangement provides the obstruction assembly 10 as a single, compact unit to be installed in a suitable recess in a road surface. In this embodiment, the frame assembly 18 is fabricated from multiple lengths of angle section to provide strength, whereas the frame panel 20 provides a substantially flat surface that is intended to be installed in alignment with the road surface. However, it will be appreciated that the obstruction assembly may not include a frame (or may include separate frames for the trigger device and the obstruction element), and the trigger device and the obstruction element may be provided as separate components that are then connected together via a linkage.

In the illustrated embodiment, the trigger device 12 includes a trigger plate 22 that is pivotally secured to the underside of the frame panel 20 at trigger plate pivot point 28. The frame panel 20 is provided with an elongate slot 24, through which the trigger plate 20 extends, so as to be able to contact the wheels of an approaching vehicle. It will be appreciated that the trigger plate may be provided as two separate plates, or as a series of teeth, for example, and that any suitable arrangement may be used so as to be deflected by an approaching vehicle. The trigger plate 24 is moveable between a raised position (as illustrated in Figures 1 to 4) and a depressed position (as illustrated in Figure 5). In the raised position, the trigger plate 22 is angled upwardly with respect to the frame panel 20, and is able to be depressed by the wheels of an approaching vehicle. In the depressed position, the trigger plate 22 is substantially coplanar with the upper surface of the frame panel 20.

The trigger device 12 is also provided with a trigger lever 26 which extends away from the pivot point 28. The lever 26 is configured such that, when the trigger plate 20 is in the raised position, an upper surface of the lever 26 abuts against the underside of the frame panel 20. Movement of the trigger plate 22 to the depressed position causes rotation of the trigger device 12 about the pivot point 28 and causes the lever 26 to be pivoted away from the underside of the frame panel 20.

The trigger device lever 26 is provided with a first mounting formation 30 at a distal end thereof. The first mounting formation 30 is provided in the form of a substantially circular recess in the underside of the lever 26. The obstruction assembly 10 also includes a second mounting formation 32 that is arranged to substantially oppose the first formation 30, when the trigger plate 20 is in the raised position. The second mounting formation 32 is arranged to be substantially coplanar with the frame panel 26 and spaced apart therefrom. The second mounting formation 32 is secured to the frame panel 20 by two opposing struts 34. The second mounting formation 32 is provided in the form a substantially circular recessed region.

Although not illustrated for clarity, a biasing element is positioned between the first and second mounting formations 30, 32. The biasing element is configured to bias the trigger plate 22 into the raised position so that it can be depressed by an approaching vehicle. The biasing element 36 may be provided in the form of a compression spring. However, it will be appreciated that any suitable biasing arrangement may be used. It will further be appreciated that the configuration of the first and second mounting formations 30, 32 may vary depending on the biasing arrangement that is used.

The lever 26 of the trigger device 12 also includes a mounting boss 38. The mounting boss 38 extends substantially parallel to the frame panel 20. In the illustrated embodiment, the control mechanism 14 includes a piston damper arrangement 40. The piston 40 has an input end 42 and an output end 44. The input end 42 of the piston 40 is pivotally mounted to the mounting boss 38 via a drive pin. Specifically, the input end 42 is provided with a cylindrical aperture 46, and the drive pin is inserted therethrough to pivotally mount the piston 40 to the trigger device 12.

The output end 44 of the piston 40 is connected to the obstruction element 16 via a mechanical linkage. The mechanical linkage is provided in the form of a pivot lever 48 and link rod 50. The frame assembly 18 is provided with a support bracket 52. The support bracket 52 extends downwardly from the underside of the frame panel 20. A first end of the pivot lever 48 is pivotally secured to the frame assembly 18 at the distal end of the support bracket 52 at fixed pivot point 54.

The pivot lever 48 is provided with four connection points 56 proximate a second end thereof for connecting a first end of the link rod 50 to the pivot lever 48. The different connection points are provided so as to adjust the speed of deployment of the obstruction element 16 in conjunction with the length of the link rod 50. In other embodiments, only a single connecting point and a fixed length link rod 50 may be used. The pivot lever 48 is also provided with a mounting formation 56 for mounting the output end 44 of the piston 40 to the pivot lever 48. The mounting formation 56 is located proximate to, but offset from, the fixed pivot point 54 such that movement of the output end 44 of the piston 40 causes the pivot lever 48 to pivot about the pivot point 54. A second end of the link rod 50 is in turn pivotally connected to the obstruction element 16 at moveable pivot point 58.The obstruction element 16 is pivotally connected to the frame panel 20 at fixed pivot point 60, which is offset from the moveable pivot point 58. The obstruction element 16 is provided with a curved outer surface 62, which is uppermost when the obstruction element is in the deployed position (as illustrated in Figure 5)The obstruction element 16 is hollow to reduce the weight and inertia thereof.. The obstruction element 16 is also provided with a stop element 64. The stop arrangement 64 works to prevent over rotation of the obstruction element when being moved into the deployed position by abutting against the underside of the of the frame panel 20. The obstruction element also includes a substantially planar surface 63 that is positioned to be uppermost when the obstruction element 16 is in the retracted position, in substantial alignment with the upper surface of frame panel 20.

Referring now to Figures 6 and 7, the piston damping arrangement 40 is illustrated in more detail. The piston damping arrangement 40 includes a piston rod 66 and a cylinder housing 68. The cylinder housing 68 includes a first chamber 70 and a second chamber 72. The first and second chambers are filed with a fluid. Any suitable fluid may be used, for example the fluid may be a low viscosity fluid such as air or a higher viscosity fluid such as hydraulic oil.

The first and second chambers 70, 72 are separated by a piston head assembly 74. The piston head assembly 74 includes a first head portion 76 that is fixed with respect to the piston rod 66 and a second head portion 78 that is moveable with respect to the piston rod 66, and hence is moveable with respect to the fixed portion 76. The fixed head portion 76 and the moveable head portion 78 are biased apart by two compression springs 80. However, it will be appreciated that any suitable number of springs 80 may be used.

The fixed portion 76 includes a port (not shown) to allow fluid to flow therethrough. It will be appreciated that any suitable number of ports may be used. There is a small annular channel 82 provided between the moveable portion 78 and the inside wall of the cylinder housing 68. This annular channel 82 and the port in the fixed portion 76 provides a flow path for the fluid between the first and second chambers 70, 72 when the fixed and moveable portions 76, 78 are separated (as illustrated in Figures 6 and 7. However, when the moveable portion 78 is in contact with the fixed portion 76, the moveable portion 78 substantially covers the port(s) in the fixed portion 76 and prevents fluid from flowing between the first and second chambers 70, 72.

In Figure 6, the piston 40 is illustrated in its rest position. When the piston rod 66 is moved at a slow speed, i.e. below a predetermined speed, the rod 66 and the fixed portion 76 move in a direction towards the second chamber 72. Due to this movement, the fluid in the second chamber 72 applies a force to the underside 86 of the moveable portion to urge the moveable portion 78 towards the fixed portion 76. Due to the slow speed of movement, the force applied to the moveable portion 78 is insufficient to overcome the biasing force of the springs 80. Accordingly, the fixed and movable portions 76, 78 remain spaced apart and the fluid is able to flow from the second chamber 72 into the first chamber 70 and limited or no force is transferred from the input end 42 to the output end 44 of the piston 40.

When the piston rod 66 is moved at a higher speed, i.e. above a predetermined speed, the force applied to the moveable portion 78 by the fluid in the second chamber 72 is increased. Due to the viscosity of the fluid in the second chamber 72, when the rod 50 moves about a predetermined speed, the fluid is unable to flow around the moveable portion 78. This causes the force applied by the fluid to the underside 86 of the moveable portion 78 to be increased such that the force is sufficient to overcome the biasing force of the springs 80. This causes the moveable portion 78 to contact the fixed portion 76 and substantially cover the ports in said fixed portion. This prevents fluid from flowing from the second chamber 72 to the first chamber 70 and results in a force being transmitted from the input end 42 to the output end 44 of the piston 40. Movement of the output end results in movement of the mechanical linkage so as to pivot the obstruction element 16 into the deployed position. It will be appreciated that in alternative embodiments, the annular channel may not be present and the moveable portion 78 may be provided with one or more ports that are offset from the port(s) in the fixed portion 76, so as to provide a flow path between the first and second chambers 70, 72.

In use, the obstruction assembly 10 will be fitted into a recess in a road surface such that the frame panel 20 is substantially coplanar with said road surface. When an approaching vehicle, or more specifically the front wheel(s) of an approaching vehicle, impacts upon the trigger plate 22, the trigger plate 22 is depressed from its raised position. Depression of the trigger plate 22 causes the trigger device 12 to rotate, thus pivoting the trigger lever 26 away from the underside of the frame panel 20. Movement of the lever 26 transmits the force from the impact of the vehicle to move the input end 42 of the piston 40. It will be appreciated that the trigger plate 22 itself causes little resistance to a vehicle passing over it, and so will not appreciably affect the comfort of vehicle occupants.

If the approaching vehicle is travelling below a predetermined speed, for example below 30 mph (48 kph), movement of the piston rod 66 occurs at a sufficiently slow speed such that the biasing force of the springs 80 are not overcome and fluid is able to flow between the first and second chambers 70, 72. In this situation, the impact force is not transferred to the output end 44 of the piston 40 and the output end does not move. Accordingly, there is lost motion between the trigger device 12 and the obstruction element 16 and so the obstruction element 16 remains in the retracted position.

If the approaching vehicle is travelling above a predetermined speed, movement of the piston rod 66 occurs at a faster speed. Due to this higher speed, the force applied to the moveable portion 78 is sufficient to overcome the biasing force of the springs 80 and the flow path between the first and second chambers 70, 72 is blocked.

Prevention of fluid flow between the first and second chambers 70, 72 enables the input motion to be transmitted to the output end 44 of the piston 40, which causes the output end 44 to move (i.e. there is little or no lost motion). This movement of the output end of the piston causes the pivot lever 48 to pivot about pivot point 54, in a direction away from the frame panel 20. This in turn moves the lever 50 so as to pivot the obstmction member 16 about pivot point 60 into the deployed (raised) position.

When the trigger plate 22 is in the depressed position, the biasing element (not shown) urges the lever 26 and hence the trigger device 12 into the raised position. The direction of this biasing force is such that the fluid flow path between the first and second chambers 70, 72 will not become blocked, and so little or no force is transmitted through the piston 40.

Following deployment of the obstruction element 16, an approaching vehicle will drive thereover to act as a speed deterrent. The obstruction element 16 will be urged back into the retracted position under the force of gravity, i.e. it is not stable in the deployed position. The configuration of the obstruction element 16 determines the amount of time that the obstruction element 16 will take to move to the retracted position under the force of gravity. This length of time is configured to be greater that the time taken for a vehicle to travel between the trigger device and the obstruction element when travelling at the predetermined speed. This arrangement ensures that when a car is travelling above a predetermined speed at the trigger device, the obstruction element is in the deployed position when the vehicle travels thereover.

Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.

In alternative arrangements, it will be appreciated that a different damping arrangement may be used, for example it may include a non-newtonian shearthickening fluid, a thixotropic liquid, a magnetorheological damper or an electrorheological fluid damping arrangement. In embodiments where an electro rheological damper is employed, a generator (not shown), such as a linear or rotary generator attached to a moving part of the mechanism upstream of the damper, may be employed to selectively provide the electrical energy to solidify the damper above a predetermined vehicle speed. Where a magneto rheological fluid is used, a generator may be employed to generate a magnetic field. Further or alternatively, a generator may be used to power ancillary equipment associated with the assembly 10, such as a data logger to track the number of vehicles passing over the assembly, their speeds etc., a display to provide messages to drivers such as their speed or other messages, or even to feed power to the power grid or into other uses in the vicinity of the assemble.

The piston may also be configured to "lock" at a different vehicle speed, e.g. 5 mph (8 kph) or 20 mph (32 kph).

It will be appreciated that the obstruction element may be varied to suit the application, and that the size may be varied to change the amount of protrusion of the obstruction element when in the deployed position.

Alternative forms of trigger plates may be used, for example the trigger may be provided in the form of a sliding component that is depressed downward by an approaching vehicle.

It will be appreciated that alternative forms of mechanical linkage arrangement may be used. For example, a cable or any other suitable linkage may be provided between the trigger device and the obstruction element.

Although the obstruction element has been described with reference to a speed bump. It will be appreciated that the system may be used to deploy other things if a vehicle is driving above a predetermined speed. For example, the assembly may be configured to deploy a spike strip, also known as a tyre shredder, should a vehicle be travelling above a predetermined speed.

It will be appreciated that if a vehicle drives over the obstruction assembly in reverse, the obstmction assembly will be in the retracted position. The angle of the trigger plate with respect to the frame panel is such that a wheel driving in reverse would depress the trigger plate in a similar manner to that described above without causing damage to the trigger plate. If the vehicle was travelling above a predetermined speed, the obstmction element would be moved to the deployed position, as described above.

Claims

Claim

1. A vehicle obstruction assembly comprising: a trigger device; a control mechanism for determining when a vehicle is travelling above a predetermined speed; and an obstruction element positioned downstream of the trigger device in a path of a vehicle, the obstruction element moveable between a retracted position in which no obstruction to a vehicle is caused and a deployed position in which progress of a vehicle is obstructed, wherein the trigger device and the obstruction element are connected via a mechanical linkage arrangement, further wherein the control mechanism is configured such that when an approaching vehicle is travelling above a predetermined speed upon contact with the trigger device, the trigger element moves the obstruction element from the retracted position to the deployed position via the control mechanism and the mechanical linkage arrangement.

2. An assembly according to claim 1, wherein the control mechanism comprises a selectable lost motion connection between an input and an output thereof.

3. An assembly according to claim 2, wherein the control mechanism comprises a piston damper arrangement, the piston comprising an input end and an output end.

4. An assembly according to claim 3, wherein the input end of the piston is connected to the trigger device.

5. An assembly according to claim 3 or claim 4, wherein the output end of the piston is connected to the obstruction element via the mechanical linkage.

6. An assembly according to any one of claims 3 to 5, wherein the piston comprises a piston head comprising a restriction therethrough.

7. An assembly according to claim 6, the piston comprising first and second fluid filled chambers separated by the piston head.

8. An assembly according to claim 7, wherein the restriction is configured such that when the input end of the piston is moved above a predetermined speed, the fluid is prevented from flowing between the first and second chambers.

9. An assembly according to any one of claims 3 to 8 wherein the fluid is a magneto-rheological fluid or an electro-rheological fluid

10. An assembly according to claim 9 wherein the mechanism further comprises an arrangement, such as a generator, to selectively cause the fluid to have an increased viscosity.

11. An assembly according to any preceding claim, wherein the obstruction element is pivotally connected to the assembly.

12. An assembly according to claim 11, wherein the obstruction element comprises a stop arrangement for preventing over rotation of the obstruction element.

13. An assembly according to any preceding claim, wherein the obstruction element comprises a curved surface that is uppermost when the obstruction element is in the deployed position.

14. An assembly according to any preceding claim, wherein the trigger device is pivotally connected to the assembly and is configured to be depressed from a raised position by an approaching vehicle.

15. An assembly according to claim 14, further comprising a biasing element to bias the trigger device into the raised position.

16. An assembly according to claim 15, wherein the biasing element is a spring.

17. An assembly according to any preceding claim, wherein the trigger device comprises a trigger plate.

18. An assembly according to any preceding claim, wherein the obstruction element is biased into the retracted position.

19. An assembly according to claim 18, wherein the obstruction element is configured with respect to the trigger device such that the obstruction element is in the deployed position when an approaching vehicle travels over the obstruction element above the predetermined speed.

20. An assembly according to any preceding claim, wherein the control mechanism is configured such that, when an approaching vehicle is travelling above a predetermined speed, the obstruction element moves to the retracted position before a subsequent vehicle travelling below a predetermined speed travels over the obstruction element.

21. An assembly according to any preceding claim, further comprising an adjustment mechanism to adjust the position of the obstruction element in the deployed position.

22. An assembly according to any preceding claim, further comprising a frame, wherein the trigger device and obstruction element are connected to the frame.

23. An assembly according to any preceding claim, wherein the obstruction element is a speed bump.

24. An assembly according to any one of claims 1 to 22, wherein the obstruction element comprises a spike strip.

25. A vehicle obstruction assembly as substantially described herein with reference to the accompanying figures.