END TERMINAL FOR A CABLE BARRIER

Description

This application claims the benefit of U.S. Provisional Application No. 63/719,525, filed Nov. 11, 2024 and entitled “End Terminal for a Crash Cushion,” the entire disclosures of which are hereby incorporated herein by reference.

BACKGROUND

It is well known to install cable barrier systems along the side of roadways to redirect vehicles engaging the systems by way of a lateral impact. Such systems are typically non-gating, meaning the cables are non-releasably anchored at the ends of the barrier system. Such systems are therefore not well suited for dissipating the energy of a vehicle impacting the system in a head-on and/or reverse direction impact.

SUMMARY

In one aspect, one embodiment of an end terminal includes a lower anchor assembly configured to be anchored to the ground and an upper anchor assembly moveably coupled to the lower anchor assembly. The upper anchor assembly is moveable between an engaged position, wherein the upper and lower anchor assemblies are configured to engage at least one cable, and a disengaged position, wherein the upper and lower anchor assemblies are configured to release the at least one cable from engagement with the upper and lower anchor assemblies. The upper anchor assembly remains coupled to the lower anchor assembly when moved between the engaged and disengaged positions, but may be separated from the lower anchor assembly after the at least one cable is released.

In another aspect, one embodiment of a cable barrier system includes the end terminal, at least one cable having an end engaged by the upper and lower anchor assemblies in the engaged position; and at least one post longitudinally spaced from the end terminal and supporting the at least one cable.

In yet another aspect, one embodiment of a method of absorbing an impact from a vehicle includes impacting an impact plate forming at least a portion of an upper anchor assembly, moving the upper anchor assembly relative to a lower anchor assembly, releasing at least one cable engaged by the upper and lower anchor assemblies, and maintaining a connection between the upper and lower anchor assemblies while moving the upper anchor assembly relative to the lower anchor assembly.

The upper anchor assembly provides an impact surface that may be impacted by a vehicle in a head-on, or reverse direction, impact. The impact moves the upper anchor assembly and releases the cables, such that the vehicle may pass over the cables. At the same time, the upper anchor assembly, in the disengaged position, may be predictably laid down such that it does not present a hazard to the impacting vehicle.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a cable barrier system.

FIG. 2 is a plan view of the cable barrier system shown in FIG. 1.

FIG. 3 is an enlarged partial side view of the end terminal in an installed configuration.

FIG. 4A is an isometric view of the end terminal shown in FIG. 3.

FIG. 4B is an isometric view of an alternative embodiment of an end terminal.

FIGS. 5-7 show the side view of the range of allowable motion between the upper and lower anchor assemblies during an end-on impact.

FIGS. 8-10 show the side view of the range of allowable motion between the upper and lower anchor assemblies during a reverse direction impact.

FIG. 11 is a side view of one embodiment of a link.

FIG. 12 is an exploded isometric view of one embodiment of an end terminal.

FIG. 13 is an exploded isometric view of one embodiment of an end terminal with a plurality of cables disposed on the lower anchor assembly.

DESCRIPTION

It should be understood that the term “plurality,” as used herein, means two or more. As shown in FIGS. 1 and 2, the term “longitudinal,” as used herein, means of or relating to a length or lengthwise direction 2, for example a direction running the length of the barrier system parallel to a roadway. The term “lateral,” as used herein, means or relates to a sideways direction, for example orthogonal to the longitudinal direction 2. The term “coupled” means connected to or engaged with whether directly or indirectly, for example with an intervening member, and does not require the engagement to be fixed or permanent, although it may be fixed or permanent. The term “fixed” means not moveable. The terms “first,” “second,” and so on, as used herein, are not meant to be assigned to a particular component or feature so designated, but rather are simply referring to such components and features in the numerical order as addressed, meaning that a component or feature designated as “first” may later be a “second” such component or feature, depending on the order in which it is referred. It should also be understood that designation of “first” and “second” does not necessarily mean that the two components, features or values so designated are different, meaning for example a first direction may be the same as a second direction, with each simply being applicable to different components or features. The terms “upstream,” “downstream,” “upper,” “lower,” “top,” “bottom,” “front,” “rear” and variations or derivatives thereof, refer to the orientations of the cable barrier system and end terminal as shown in FIGS. 1 and 2.

Referring to FIGS. 1 and 2, the cable barrier system 10 includes a redirective, gating cable end terminal 12, which anchors a plurality of cables 14 (shown as four). The system may include less than four cables, e.g., at least one cable, or more than four cables. In the disclosed embodiment, two pairs of vertically spaced cables are coupled to opposite sides of a plurality of longitudinally spaced and vertically extending posts 16. The posts 16 are configured to absorb energy of a vehicle in a head-on impact from a vehicle 58 travelling in the longitudinal direction 2, for example by being breakable.

An anchor for the end terminal 12 includes a lower anchor assembly 18 configured for being anchored to the ground and an upper anchor assembly 20 moveably coupled to the lower anchor assembly. The term “assembly” may include a single component, or a combination of components. In one embodiment, the lower anchor assembly 18 is anchored to the ground with a plurality of anchor rods 22 and/or adhesive, such as epoxy. The upper anchor assembly 20 is moveable (i.e., rotatable and/or translatable) between an engaged position, wherein the upper and lower anchor assemblies 18, 20 engage at least one cable 14, and a disengaged position, wherein the at least one cable 14 is released from engagement with the upper and lower anchor assemblies 18, 20. In the engaged position, the upper and lower anchors 20, 18 engage and hold the at least one cable 14 in tension. In one embodiment, the upper anchor assembly 20 remains coupled to the lower anchor assembly 18 when moved between the engaged and disengaged positions.

In one embodiment, the anchor includes at least one link 30, 130 coupling the upper and lower anchor assemblies 20, 18. The link 30, 130 may be pivotally connected to one or both of the upper and/or lower anchor assemblies, for example with a shaft 34 defining a pivot axis 32. A slide member 36 is connected to the other of the upper and lower anchor assemblies, and is slidably and pivotally engaged with the link 30, 130. In one embodiment, the link 30, 130 includes a track 38, 138, wherein the slide member 36 is moveable along the track 38, 138 as the upper anchor assembly 20 moves between the engaged and disengaged positions. The slide member 36 may include a shaft 42 and the track 38, 138 may include a slot 40, 140 formed in the link 30, 130, wherein the shaft 42 is slidable in the track 38, 138, or slot 40, 140, with the link thereby translating and pivoting relative to the shaft 42 as the upper anchor assembly 20 is moved from the engaged position to the disengaged position. As shown in the embodiments of FIGS. 3, 4A and 5-10, the slot 40 may extend along more than ½ of the length of the link 30. As shown in the embodiment of FIGS. 4B, 11. 12 and 13, the slot 140 may be formed along only an end portion of the link 130, or along less than ½ the length thereof. The length of the slot 40, 140 defines and limits the amount of travel of the upper anchor assembly when the link 30, or creates a stop for the link 130 that may initiate deformation thereof. The slide member 36 engages an end 44 of the slot 40, 140 at the maximum amount of travel, or at the start of deformation, for example when the upper anchor assembly 20 has moved past the disengaged position such that the cables 14 have been released. In one embodiment, the link 30, 130 is pivotally connected to the lower anchor assembly 18 with the shaft 34, and the slide member 36 is connected to the upper anchor assembly 20. It should be understood that the shaft and slide members may be reversed, or secured to the opposite of the upper and lower anchor assemblies.

The upper anchor assembly 20 may include an impact plate 50 configured to be impacted by the vehicle 58, whether on a front, upstream face/surface 52 during a head-on impact, or rear, downstream face/surface 54 during a reverse direction impact. The impact plate 50 has a vertical orientation in the engaged position (FIGS. 3 and 4A) and a non-vertical orientation in the disengaged position (FIG. 5). The phrase “vertical orientation” refers to the impact plate, and the impact surface on either side thereof, having an orientation within ±20 degrees of a vertical plane. The phrase “non-vertical orientation” refers to the impact plate lying flat or forming an acute angle (α (head on rotation) or β (reverse direction rotation)) relative to a horizontal plane 56, defined by the ground surface in one embodiment, and wherein the impact plate is also offset an angular amount from the orientation of the impact plate in the engaged position/vertical orientation. This means, for example and without limitation, that if the impact plate, or impact surface thereof, is at ±20 degrees in a vertical orientation, the impact plate is at an orientation of 0 -70 degrees in a non-vertical orientation. The impact plate 50 may be rotated in a clockwise (FIGS. 5-7) or counterclockwise direction (FIGS. 8-10) relative to the lower anchor assembly 18, when viewed from a left hand side, in response to an end-on or reverse direction impact respectively. The upper anchor assembly 20 includes an engaging portion 60, for example a downwardly extending flange 62 or plate with slots 64 (or teeth), angled forwardly relative to the vertical plane 66 when in the engaged position, wherein the engaging portion 60 is configured to engage the at least one cable 14, for example an end 70 of the cable.

The lower anchor assembly 18 also includes an engaging portion 80, configured in one embodiment as an upwardly extending flange 82 or plate with slots 84, which forms a plurality of teeth. The flange 82 may have the same angular orientation as the flange 62, such that the flanges are parallel in an “as installed” configuration, or engaged position of the upper and lower anchor assemblies. The flanges 62, 82 overlap, with the upper anchor assembly flange 62 positioned in front of, or upstream of, the flange 82 of the lower anchor assembly 18 in one embodiment. The slots 64, 84 of the upper and lower anchor assemblies are aligned to form an opening through which the cables 14 are disposed. In one embodiment, each cable 14 may include a washer and nut, or similar enlarged catch member 88, having a greater circumference than the cable 14, such that the catch member 88 engages an upstream face 90 of the upper anchor assembly 20, with the cable extending through the respective opening defined by the aligned slots 64, 84. The interface between the catch member 88 and face 90 allows the cables 14 to be put in tension against the anchor, with the tension applied against the flanges 62, 82. Since the flanges 62, 82 are angled and abutted, and the cables 14 angle upwardly, the cables 14 apply a substantially normal force to the flanges 62, 82 under tension such that there is no force vector attempting to separate the upper and lower anchor assemblies 20, 18, or if any such force vector is applied, the force vector does not overcome the friction force between the abutting flanges 62, 82. A pair of fasteners 100, e.g., bolts and nuts, extend longitudinally through the respective flanges of the upper and lower anchor assemblies when configured in the engaged position. The fasteners may alternatively be configured as rivets or similar mechanical systems. The fasteners 100 define a pair of fuses, which may fail in tension or shear during the head-on and reverse direction impacts respectively, but maintain the positioning and connection between the upper and lower anchor assemblies 20, 18 during assembly and before tension is applied to the cables 14 during assembly. The fasteners 100 also remain intact during a lateral, redirective impact.

The link 30 may also be angled forwardly relative to the vertical plane 66 when the upper anchor assembly 20 is in the engaged position. In one embodiment, the link 30 forms a first, obtuse angle (θ) relative to a horizontal plane 56 in the engaged position and a second obtuse and/or acute angle (σ) relative to the horizontal plane 56 in the disengaged position, wherein the first obtuse angle (θ) is greater than the second obtuse and/or acute angle (σ).

In one embodiment, the slidable linkage, including the link 30, 130, connects or attaches the upper anchor assembly 20 to the lower anchor assembly 18 (generically for any end terminal system, specifically for a cable end terminal system). In one embodiment, the link 30, 130 retains/couples together the upper and lower anchor assemblies 20, 18 while allowing movement (e.g., rotation and a relative (fixed) translation/separation) between the upper and lower anchor assemblies 20, 18. As shown in the Figures, the slidable linkage includes the link 30. The range of motion (1) allows for the release of the system cables 14, which are constrained by, and/or between, the upper and lower anchor assemblies 20, 18 in the engaged position, and (2) prevents, in one embodiment, the upper anchor assembly 20 from becoming a hazard to an impacting vehicle by allowing it to predictably lay down during impact. The system cables 14 may be integrated into, and define in part, a crash cushion, or cable barrier system. The cables 14 are tensioned to provide re-directive capabilities to the crash cushion during lateral impacts but are configured to release from the anchor in head/end-on, or reverse, impacts. By keeping the upper anchor assembly 20 retained with, or coupled to, the lower anchor assembly 18 in one embodiment, for example with link 30, the upper anchor assembly 20 is prevented from completely detaching from the lower anchor assembly 18 and becoming a potential hazard to other traffic, pedestrians or workers in a construction zone.

The slidable linkage, including the link 30, 130, may be positioned on only one side of the anchor, or on both sides of the assemblies, as shown for example in FIGS. 4B, 12 and 13.

As shown in the images below, the slidable link 30, 130 is made of steel, although it should be understood that it may be made of other materials, including other metals and/or composites. The slidable link 30, 130 is attached to the upper and lower anchor assemblies 20, 18 with the shafts 34, 42, e.g., pins or shouldered bolts (to allow free rotation and translation without any resistance between these parts). However, it is feasible that non-shouldered bolts or any other connection method may also work for the functioning of such a slidable linkage device. In one embodiment, the link 30 may be a non-frangible component. However, the link 130 may be designed as a frangible component, meaning it may be deformed, which allows for separation between the upper and lower anchor assemblies 20, 18 at a pre-defined location/orientation, for example after the upper anchor assembly 20 has moved through the disengaged position wherein the cables 14 have been released.

In one embodiment, and referring to FIGS. 11-13, the link 130 may include a line of weakness 132, which allows the link to deform, such that the link 130 is deformable along the line of weakness 132 as the upper anchor assembly 20 is moved past the disengaged position. In one embodiment, the link 130 includes an opening 134 defining the pivot axis 32 of the link 130, with the pivot axis 32 running through one of the lower and upper anchor assemblies 20, 18. The pivot axis 32 is shown on the lower anchor assembly in FIG. 12, but it should be understood that the axis may be formed on the upper anchor assembly. In one embodiment, the line of weakness 132 is formed as a slit that extends between the opening 134 and a peripheral edge 136 of the link 130. Put another way, the line of weakness 132 forms or defines a hook 238 at the end of the link 130, with the hook 238 being pivotally connected to one of the upper and lower anchor assemblies about the pivot axis 32. The link 130, and the hook portion 238 in particular, may deform, such as by bending or fracture, during a head-on impact, with the link 130 thereby releasing from the lower/upper anchor assembly 20, 18, and with the upper anchor assembly 20 releasing from the lower anchor assembly 18 after the upper anchor assembly has moved to the disengaged position, or after the upper anchor assembly 20 has released the cables 14. In this way, the line of weakness 132, e.g., slit, releases the upper anchor assembly 20 at a predetermined force and creates the energy absorbing “hook” element 138 to reduce the kinetic energy of the upper anchor assembly 20 during an impact event. In essence, the line of weakness 132, e.g., slit, forms the hook 238 at the connection point of the link 130. When acted on by a force, the hook 238 deforms, e.g., bends, open to release the link 130 from the shaft. This deformation, or bending, requires energy, which comes from and reduces the kinetic energy of the upper anchor assembly 20, thereby decreasing the velocity of the upper anchor assembly. The amount of energy absorbed by the deformation of the link 130 may be controlled by adjusting the width of the slit, the width of the material of the hook and/or link, the location of the slit (i.e., the orientation relative to the longitudinal axis of the link), the thickness of the link, and/or the shape of the hook.

In other embodiments, the line of weakness 132 may be less visible than the slit, for example by thinning the width or distance between the hole edge and link edge on one or both sides, by reducing the thickness of the link at various locations, and/or by creating a frangible region with one or more openings, or voids/recesses, formed through or in the link at various locations, so as to modify the cross-sectional area that may be stretched or fractured. In some embodiments, the link 130 may be completely fractured into two separate components during an impact event.

The line of weakness 132 is designed such that the link 130 absorbs kinetic energy of the upper anchor assembly 20 during release in a predetermined manner defined by the line of weakness. The kinetic energy of the upper anchor assembly 20 may also be absorbed by others features, including but not limited to friction between the various components including the flanges 60, 80 and link 30, 130, and/or deformation of the connection/coupling between the link and the upper anchor assembly and/or lower anchor assembly. In one embodiment, the link 130 slides, allowing for rotation and/or translation of the upper anchor assembly to the disengaged position, wherein the cables are released, before the link 130 is deformed and releases the upper anchor assembly 20 from the lower anchor assembly 18.

During assembly, the cables 14 are positioned in the slots 84 of the lower anchor assembly 18, with the ends 70 of the cables located upstream of the slots. The upper anchor assembly 20 is then installed in an “as-installed” configuration, with the cables 14 received in the slots 64 of the upper anchor assembly. The upper and lower anchor assembly may be coupled with the pair of fasteners 100. The cables 14 may thereafter be put in tension, for example with turn buckles, such that the ends 70, and catch member 88, apply a force to and abut the face 90 of the upper anchor assembly, forcing the upper anchor assembly 20 against the lower anchor assembly 18.

In operation, and during a head-on or reverse direction impact, the vehicle 58 impacts the upstream or downstream face 52, 54 of the impact plate 50 on the upper anchor assembly 20. The upper anchor assembly 20 is thereafter moved relative to the lower anchor assembly 18, for example by a combination of rotation about the pivot axis 32 and translation as the link 30, 130 slides and/or rotates relative to the slide member 36, or shaft 42. In one embodiment, the upper anchor assembly 20 is moved upwardly and also pivots rearwardly relative to the lower anchor assembly during a head-on impact. The forwardly angled link 30, 130 ensures that the upper anchor assembly 20 is lifted, or moved upwardly, as the link 30, 130 rotates past 90 degrees. The upper anchor assembly 20 moves relative to the lower anchor 18 assembly from the engaged position to a disengaged position, which is the position where the cables 14 are released from the lower and upper anchor assemblies 18, 20. The upper anchor assembly 20 may initially lift the cable ends 70 to release the cables 14 that are engaged by the upper and lower anchor assemblies. During this initial movement between the engaged and disengaged positions, a connection may be maintained between the upper and lower anchor assemblies 20, 18, e.g., with the link 30, 130, as the upper anchor assembly 20 is moved relative to the lower anchor assembly 18. In one embodiment, the connection is maintained for the entire travel path of the upper anchor assembly 20, which is laid over onto the ground as shown in FIG. 7. In another embodiment, the link 130 deforms and releases the connection between the upper and lower anchor assemblies 20, 18 after moving the upper anchor assembly to and/or past the disengaged position relative to the lower anchor assembly.

Referring to FIGS. 8-10, the upper anchor assembly 20 also is moved in response to a reverse direction impact, with the upper anchor assembly rotating and/or translating forwardly, or in the upstream direction, with the separation of the upper anchor assembly 20, or movement to the disengaged position, releasing the cables 14. Again, the link 30 may maintain a connection between the upper and lower anchor assemblies through the entire movement path of the upper anchor assembly, as shown for example in FIG. 10 where the upper anchor assembly is laid over onto the ground. Alternatively, the link 130 may deform so as to release the upper anchor assembly 20 from the lower anchor assembly 18 after the upper anchor assembly has moved through the disengaged position and released the cables 14.

During the head-on impact, the fastener 100 fails in tension. As the upper anchor assembly moves upwardly and rearwardly, the fastener 100 is loaded mostly in tension which ultimately causes the fastener to fail, thereby releasing the upper and lower anchor assemblies 20, 18 while also dissipating some energy. During a reverse direction impact, the fastener 100 fails in shear. During the reverse direction impact, the impacting vehicle 58 forces the cables 14 to move in an upward direction which causes the upper anchor assembly 20 to move vertically. This causes the fasteners 100 to be loaded mostly in shear which ultimately causes the fasteners 100 to fail.

Although the present invention has been described with reference to preferred embodiments, those skilled in the art will recognize that changes may be made in form and detail without departing from the spirit and scope of the invention. As such, it is intended that the foregoing detailed description be regarded as illustrative rather than limiting and that it is the appended claims, including all equivalents thereof, which are intended to define the scope of the invention.