Technical Field of the Invention
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The present invention relates to an improved road blocker for controlling or selectively impeding access of vehicles to high security areas. In particular, the present invention relates to a road blocker having an improved impact surface which is ideal for eliminating upward movement of a colliding vehicle's front during impact and thereby eliminating the possibility of colliding vehicle's unwanted and at least partial entry in a protected area. Security areas may include government buildings, military bases, embassies, airports etc. where vehicles are selectively allowed and precautions need be taken against attacks implemented by using vehicles, such as trucks loaded with explosive materials.
Background of the Invention
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Devices which have movable pivotal blocking elements for selectively allowing and preventing the passage of vehicles along a roadway are known in the prior art. These devices are usually hidden, buried or embedded in the ground at the entrance of the security gateway of a protected site and are erected automatically under alarm conditions, such as when entrance of a suspected vehicle is to be prevented. Under normal conditions, road blockers remain buried under the ground allowing vehicular traffic flow to the site. Erection and retraction of road blockers are usually made by hydraulic or pneumatic actuating elements.
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A road barrier as disclosed in
EP 0 306 595 , comprises a frame with which a barrier plate is pivotally associated in order to be pivoted between a first position overlying the top and a second position angularly upwardly disposed relative to the top. Furthermore, mentioned road barrier comprises an L-shaped contact portion which engages with a stopping means in order to dissipate the impact energy throughout the barricade structure.
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EP 1 900 878 also discloses a road blocker inserted into a cavity under the ground level. This road blocker has a transportable container comprising a blocking unit component (blocking surface) with a cylindrical surface, a drive in order to change the position of the blocking element around a horizontal axis and stabilization bars.
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A plurality of patents/patent applications are present in the field in relation to hidden road blockers and to their inner configurations. As an example, blocking elements of the known road blockers have flat or generally convex (cylindrical) impact surfaces. However, these configurations cause the vehicle's front driving over the blocking element, since the impact results in forces being upwardly exerted on the colliding vehicle's chassis. In the present invention; by the use of a concave impact surface, the colliding vehicle's front is prevented from taking an upward movement and tires of a colliding vehicle's are localized. The geometry of the impact surface of the road blocker is designed to impede upward movement of the colliding vehicle's front, thus preventing the vehicle's at least partial entry in the protected site in a cheap, safe and easily accessible way without any need of an additional element.
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According to another aspect of the invention, damage assessments relating to the present hidden road blocker systems reveal that problems encountered after an impact are generally determined at the actuating systems of the blockers. Main reason of this general problem is the vulnerability of the actuating systems against large forces occurring during an impact. The present invention intends to solve this problem by applying flexibility to the operation of the actuating means.
Objects of the Invention
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One of the objects of the present invention is to provide an improved road blocker having a concave impact surface in order to localize the tires of a colliding vehicle thereby preventing the vehicle's front from taking upward movement and riding over the road blocker.
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Another object of the present invention is to provide a road blocker wherein the actuating systems are improved and remain flexible when large forces occur during an impact.
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A further object of the present invention is to provide a road blocker which has an improved hinge element for resisting to large forces.
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Yet another object of the invention is to provide a road blocker which comprises at least one stabilization bar in order to dissipate the impact energy throughout the barricade structure.
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These and other objects and advantages of the invention will be readily apparent in view of the following description and drawings of the above described invention.
Summary of the Invention
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The road blocker according to the present invention controls and selectively impedes passage of vehicles on a roadway. It comprises a framework for burying and integrating in a trench on a roadway, a blocking element which is rotatably attached on said framework and at least one actuating means for erecting and retracting said blocking element pivotably around an upper rear profile of said framework. The blocking element according to the present invention has an impact surface which is concave in shape for encompassing and localizing tires of a colliding vehicle during use. The blocking element comprises a plurality of support members whose lateral surface are concave arc shaped for receiving and transmitting impact forces occurring on the impact surface to the framework during use.
Brief Description of the Figures
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Accompanying drawings are given solely for the purpose of exemplifying a road blocker whose advantages over prior art were outlined above and will be explained in detail hereinafter:
- Fig. 1 is a perspective view of a road blocker according to the present invention in extended position.
- Fig. 2 is a perspective view of a road blocker without an impact surface according to the present invention in extended position.
- Fig. 3 is a perspective view of a prior art road blocker without an impact surface in extended position.
- Fig. 4 is a perspective view of stabilization bars according to the present invention in extended position.
- Fig. 5 is a perspective view of support members and gate according to the present invention in extended position.
- Fig. 6 is a perspective view of hinge and pinhole according to the present invention in extended position.
- Fig. 7 is a perspective view of a prior art hinge and pinhole in extended position.
- Fig. 8 is a schematic view of a blocking element according to the present invention in extended position ready for an impact.
- Fig. 9 is a cross-sectional view of a prior art blocking element in extended position ready for an impact.
Detailed Description of the Invention
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Referring now to the figures outlined above, the present invention relates to an improved road blocker (1) comprising a framework (3), at least one retractable and extendible blocking element (2) that is pivotally mounted on the framework (3) and actuating means (7) which controls the pivotal movement of the blocking element (2).
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As seen in Fig. 2, the framework (3) is configured to be placed into a trench within the ground along a roadway and comprises an upper front profile (31), an upper rear profile (32), upper lateral profiles (33), a plurality of lower profiles (34) and a plurality of vertical profiles (35). Thus, said framework (3) defines a substantially box-like enclosure integrally connected to said trench by concrete and it is used as a housing for the blocking element (2). The road blocker (1) may be embedded in a trench and made integral to the trench with for instance concrete.
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According to the present invention, the blocking element (2) has an upper surface (24) which normally forms part of the roadway when the road blocker (1) is in its retracted position (not erected position) for enabling safe passage of vehicles. At this retracted position, said upper surface (24) which has a flat surface lies parallel to the roadway. The blocking element (2) also comprises an impact surface (21) which reveals only when the road blocker is erected in result of an alarm. The impact surface (21) faces the direction from which a vehicle to be prevented arrives. Additionally, said impact surface (21) has a unique concave shape for encompassing and localizing the tires of a colliding vehicle during operation.
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Road blockers that have convex blocking surfaces are disclosed in the prior art. Referring now to Figure 9, a prior art impact surface which has a convex configuration results in the upward movement of the colliding vehicle's front and directs the vehicle driving over the blocking element due to convex configuration of the impact surface. Bearing in mind that the aft of the impact surface refers to a location within the protected area, a convex geometry, which refers that the center of radii of the impact surface is in the aft of the impact surface, behaves as a lever for tires of the colliding vehicle, hence resulting in the upward movement of the tires upon impact. In conclusion, the present invention solves this problem by using a concave impact surface (21) in a cheap, safe and easily accessible way without any need of an additional element as shown in figure 8. With reference to the concave geometry of the impact surface, we refer that the center of radii of the impact surface is in the front of the blocker, i.e. in a position from where the impact is expected. The center of radii of the impact surface corresponds to a position on the right part of the impact surface (21) of the road blocker in Figs. 8 or 9, i.e. at a location from which the vehicle arrives.
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Figures 4 and 5 show the details of the inner part of the blocking element (2) in which a plurality of support members (22) are arranged next to each other and in support to the concave impact surface (21). Each support member (22) is preferably figured similar to the A-shape without a hole when viewed from the side. One side of the each support member is fixed to the inner side of the upper surface (24) and the second side is fixed to the inner side of the impact surface (21). Mentioned fixation may be realized by welding, riveting or other similar means. Furthermore, mentioned second side of the support members shall reflect a concave arc, as shown in figure 4, in order to fit flush with the geometry of the concave impact surface (21). Preferably, the support means (22) are made of a single piece metal sheet of more than 5 mm thickness.
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The blocking element (2) is pivotally assembled to the framework (3), especially to the upper rear profile (32) of the framework (3). According to the present invention one end of the each support member which is fixed to the upper surface (24) incorporates a hinge pin (41) that engages to the hinge body (42) which is embedded to the upper rear profile (32) of the framework (3). This improved structure increases the resistance of the hinge (4) against to instantaneous huge pressures occurring during an impact. For further information, figure 7 shows the prior art hinge mechanism which is not as resistive against an equally instantaneous and huge pressure.
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Second end of each support member (22) which is fixed to the impact surface (21) takes the shape of a stabilization protrusion (23) as shown in figure 4. Said stabilization protrusions (23) are intended to engage with the lower part of the upper front profile (31) of the framework (3) at the extended position. At the time of a collision, the impact on the impact surface (21) is transmitted to the hinge and the stabilization bar (23) through the support member. Afterwards, the hinges transmit the impact force to the framework (3) and the stabilization protrusions (23) transmit the impact force to the upper front profile (31) and hence to the entirety of the framework (3).
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According to a preferred embodiment of the present invention, the upper surface (24) also incorporates a service hatch (6) as shown in figures 2 and 5. This hatch enables access to the inner parts of the road blocker (1) for maintenance or repair purposes after the fixation of the framework (3) into the trench. In a preferred embodiment, each of said support means (22) has an arc shaped cavity (36) for allowing a living space to a serviceman in case said blocking element (2) is accidentally retracted during maintenance.
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One or more actuating means (7) are established into the framework (3) to control the pivotal movement of the blocking element (2). According to a preferred embodiment of the present invention, said actuating means is a cylinder and piston assembly and actuated hydraulically or pneumatically. Said assembly is rotatably connected with one of the lower profiles (34) and one of the support members (22). Figure 6 shows details of the piston-support member (22) connection. Accordingly, the connection area of the piston-support member (22) is a joint (5) that is composed of a joint body (51) fixed on the piston connection area, a joint pin (52) and a joint slot (53) which is formed on the connection area of the support member (22). In brief, the actuating means is attached to said blocking element (2) with a rotating joint which is provided with an I shaped slot (53) enabling travelling of joint pin (52) so as to compensate for material extensions occurring during an impact.
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At the time of a collision any impact that was applied on the impact surface (21) is transmitted to the support member (22) and also to the actuating means (7). This impact is substantially absorbed by the framework, however instantaneous forces occurring at the moment of the collision might change the position of the actuating means slightly. However, actuating means such as a cylinder and piston assembly are vulnerable to instantaneous tensile forces and are not able to extend in their length, resulting in residual damage on their structure and hence malfunction after an impact. According to a preferred embodiment of the present invention, the joint slot (53) is formed preferably as an I-shaped hole so as to allow the some flexibility to the joint so as to compensate any extensions in length resulting from impacts. The pistons joint pin (52) has the freedom to move freely in the joint slot (53) to some extent for eliminating structural damage to the actuating element.
