The disclosure of the present patent application relates to roadway and speed bump reflector design, and particularly to a low maintenance speed bump having reflective markers disposed within angled grooves, as well as a method and device for making the speed bump.
Speed bumps, as known in the art, are typically raised structures extending across a portion of a roadway. The bumps define an abrupt change in road elevation to keep vehicle speeds low. These types of elevation changes in the road may also be defined longitudinally along a roadway, raising the traffic level to the level of the sidewalk for a certain distance, and then lowered back to the usual traffic level. Such bump and ramp structures are optical speed limiters, or structures which are visible to drivers from a distance and allow drivers an opportunity to slow down prior to reaching the structure.
Speed bump structures can also be used at various points of possible conflict between motorized traffic and pedestrians, for example, in areas near schools, churches, hospitals, pedestrian crossings, and bicycle paths. It is also possible to integrate bicycle paths and pedestrian crossings into raised speed bumps to improve the safety of persons at crossings and junction areas, which are subject to accidents. Examples are entrances to residential areas, pedestrian crossings, and the like. These structures can also be used around construction sites, as traffic islands, and as dividers for separating or narrowing traffic lanes by extending longitudinally with the direction of traffic.
Conventional speed bumps require frequent maintenance, as the reflectors or markers of conventional speed bumps quickly deteriorate. When the reflectors or markers deteriorate, drivers cannot see the bump soon enough to slow down before reaching the bump. When drivers approach the bump at full speed, stability of the vehicle is impaired, and damage to the vehicle can result, e.g., front end components may be damaged or parts of the exhaust system may be torn off.
Markers on roadways similarly require frequent maintenance due to deterioration from their constant interaction with the tires of vehicles driving overtop. Deterioration of the markers can result in vehicle operators, which may be a human or a computer, to make errors when the information conveyed by the markers is not properly received.
Thus, a low maintenance speed bump solving the aforementioned problems is desired.
A low maintenance speed bump includes an elongated, rigid, solid body having an arcuate top surface and a flat base, a plurality of angled grooves defined within the top surface, and a reflective material disposed within the grooves. The reflective material is disposed lower than the top surface of the speed bump to prevent contact between vehicles passing over the speed bump and the reflective material. In this manner, the reflective material is protected from damage by vehicle tires, and the life of the reflective material is extended. Further, the angled grooves provide greater visibility of the reflective material to drivers approaching the speed bump. Accordingly, the low maintenance speed bump for use on roadways provides for added safety while requiring less maintenance.
A flexible inlay may be used for creating the angled grooves in the speed bumps. The flexible inlay includes multiple grooving plates disposed between guide blocks on opposing ends of the inlay. Multiple flexible guide wires extend though the grooving plates and a pair of guide blocks to maintain an aligned relationship between each of the guide blocks and the grooving plates. The size of the flexible inlay may be adjusted by adding or removing grooving plates. Grooves may be created in a speed bump or roadway by inverting the flexible inlay, laying the flexible inlay in a desired position before the final layer of material is laid down, and removing the inlay, thus resulting in a groove where the inlay was placed.
These and other features of the present disclosure will become readily apparent upon further review of the following specification and drawings.
Similar reference characters denote corresponding features consistently throughout the attached drawings.
Preferably, the grooves 112 are arranged in a plurality of rows 113. A plurality of groove rows 113 that are parallel to and equally spaced from each other can form a groove array. Although
As described above, the reflective material 114 is lower than the top surface of the speed bump 100. This prevents contact between the reflective material 114 and vehicles traversing the speed bump 100, and thereby extends the life of the reflective material 114. Accordingly, the speed bump 100 may require less maintenance than conventional speed bumps.
The arrays 110a, 110b preferably have a width W that is narrower than a width of a vehicle tire. The narrower width W will allow tires to pass over the arrays 110a, 110b while maintaining contact with the non-grooved portion of the bump 100 on opposing sides of the arrays 110a, 110b. This will result in a larger contact surface area between the tire and the surface of the bump 100 to produce more friction, and thereby increase control over and safety of the vehicle. The narrow width W of the arrays 110a, 110b may also increase longevity of the reflective material 114, as the weight of the car can be largely distributed to areas on the sides of the arrays 110a, 110b, reducing wear of the reflective material 114.
As described above, the angular offset of the grooves 112 may increase visibility of the reflective material 114. For example, the angular offset α of arrays 110a, 110b may be in opposite directions, as seen in
Although the grooves 112 can have any suitable dimension, the width μ of the individual grooves 112 may range from about one to three and one-half inches. The spacing ν between the individual grooves 112 may range from about one quarter to one and one-half inches. The number of groove rows in an array can range from about two to about eight. Width ω of an array preferably ranges from three to twelve inches. It is also contemplated that the arrays 110a, 110b be evenly spaced from each other across the entire speed bump 100, with larger spaces in between the arrays 110a, 110b than between groove rows within each array. The speed bump 100 may include three or more arrays. The embodiments shown in the drawings are exemplary and are not intended to be limiting.
A method of preparing the low maintenance speed bump 100 includes defining grooves 112 within paving material by placing an inverted flexible groove inlay 200 in a partially paved speed bump 100, paving around the flexible groove inlay 200 to create grooves 112 in the paving material, removing the flexible groove inlay 200, and adding reflective material 114 to the grooves 112 created by the inlay 200. Alternatively, the flexible inlay 200 may be pressed into soft paving material to create the grooves 112.
The method may include adding multiple layers of asphalt on top of each other to build up the structure of the speed bump 100. Before laying the last layer, the flexible groove inlay 200 is inverted and placed on the bump 100 to form the grooves 112. As shown in
After the flexible groove inlays 200 are placed in their intended positions, the final layer of pavement is laid around the inlays 200. The inlay 200 may be positioned lower than the final pavement layer to allow compacting with the inlay 200 left in place. Alternatively, once the final layer of pavement is laid, the flexible groove inlay 200 can be pressed into the soft pavement before it is compacted or hardened.
Once the paving process is complete, the flexible groove inlays 200 are removed from the bump 100 to expose the grooves formed by the grooving plates. Removal can be performed by hand or by a small, portable hoist or crane.
Finally, the reflective material 114 can be placed within the grooves 112 formed by the inlay 200. The reflective material 114 may be in the form of paint or a precut polymer strip, which is applied to the bottom of the groove 112. Depending on the type of reflective material 114 chosen, a clear polymer sealer may be applied on top for added longevity. The reflective material 114, or the combination of reflective material 114 and sealer, may fill up a portion of the groove 112 or the entire groove 112. In the case of the polymer strip, a thermoplastic may be used, which can be heated to an adhesive state and then placed in the groove 112. Any type of reflective material may be used. For example, a retroreflective material (a material that reflects light to the original light source) may be used, for example, 3M Scotchlite™. It is also contemplated that the reflective material 114 may include first portions that are retroflective, second portions that reflect light, and third portions that scatter the light.
A semi-spherical protrusion 224 is located at a center of the grooving plate 210. The semi-spherical protrusion 224 keeps adjacent guide plates uniformly separated so the grooves are equally spaced. Other shapes and locations can be used for the protrusion to promote certain types of bending. For example, a rectangular protrusion would permit lateral bending and resist vertical bending.
The length of the flexible groove inlay 200 may be adjusted by adding or removing grooving plates 210. Decreasing the length of the inlay 200 can be accomplished by loosening the screws 218a,b,c on one of the guide blocks 216 and separating the guide block 216 from the guide wires 212. Once the guide block 216 is removed, a desired number of grooving plates 210 can be slid off the guide wires 212a, 212b, and 212c, and the guide wires 212a, 212b, 212c can be re-inserted into their respective guides 214a, 214b, and 214c in the previously removed guide block 216. Once all of the grooving plates 210 and the guide block 216 are slid together, the guide screws 218a, 218b, 218c can be tightened to lock the guide block 216 in place at a new location. Finally, the portions of the guide wires 212a, 212b, 212c extending past the guide block 216 may be cut flush with the guide block 216 to prevent them from interfering during the construction process. Lengthening the inlay 200 requires obtaining longer guide wires 212a, 212b, 212c and assembling the grooving plates 210 using the steps outlined above.
In some cases, the flexible groove inlays 200 may be used to surround and draw attention to a marking in the road.
The guide wires 212a, 212b, 212c may be made out of a flexible material, allowing the inlay 200 to conform to the shape of the speed bump 100 and/or create arcuate grooves. Examples of flexible materials include polyethylene and polypropylene. The guide blocks 216 and grooving plates 210 may be made out of rigid material. Examples include steel and aluminum.
To ensure easy and clean removal of the flexible groove inlay 200 from the bump 100, a flexible sleeve may be disposed around the inlay 200 prior to the groove forming process. The sleeve can be a flexible, high endurance, abrasion resistance material, such as Kevlar® Cut-Tex® PRO.
The flexible groove inlays 200 may be used to create roadway grooves 300 in areas other than speed bumps 100, as seen in
For example, roads may be designed to provide information to self-driving cars. This information may be critical to the stability of the auto-pilot and the safety of the passenger. Accordingly, it may not be acceptable to create in-road marks that can fade over time. The presently disclosed flexible groove inlay 200 may be used to create markings in the roadways that will not fade over time.
The marking may be used as lane dividers and guides, as well as to provide driving information, such as speed limit. For example, the speed limit may be coded into the road using different length lines that can be translated into numbers by the vehicle. The shortest line may indicate a zero, and the line may incrementally increase in size until the line length indicates a nine. The lines should be sharp and not subject to wear so they can be properly interpreted by the auto-pilot. By using a flexible groove inlay 200 to create a groove in the roadway, and then filling that groove with a thermoplastic or similar material, indicators will be produced that will not vary in size due to wear and will provide consistently accurate information to auto-pilots and human drivers of cars.
It is contemplated that the flexible groove inlay 200 may be used to create grooves in concrete. Once the concrete is distributed and screened or flattened, the inlay 200 can be pressed into the concrete. After pressing in the inlay 200, a final flattening may be performed. Once the concrete has partially cured, the inlays 200 can be removed leaving grooves in the concrete.
It is to be understood that the low maintenance speed bump is not limited to the specific embodiments described above, but encompasses any and all embodiments within the scope of the generic language of the following claims enabled by the embodiments described herein, or otherwise shown in the drawings or described above in terms sufficient to enable one of ordinary skill in the art to make and use the claimed subject matter.
This application claim claims the benefit of U.S. Provisional Patent Application No. 62/733,266, filed Sep. 19, 2018.
Number | Date | Country | |
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62733266 | Sep 2018 | US |