Releasable device and method

Information

  • Patent Grant
  • 6382583
  • Patent Number
    6,382,583
  • Date Filed
    Tuesday, April 18, 2000
    24 years ago
  • Date Issued
    Tuesday, May 7, 2002
    22 years ago
Abstract
A safety device may be used to provide separation in the event of a side impact collision. The device may be used in a utility pole guy wire system, interposed between the guy wire and the ground anchor. The device operates in bending. A lateral force of sufficient magnitude applied to the device by the errant vehicle causes a rod within the device to break in tension, even though the tensile strength of the rod may be greater than that of the guy wire. In operation, certain massive portions of the device are tied safely to the ground, while other portions are pulled over the moving vehicle by the tension of the guy wire. The invention may be designed to tolerate axial loads, but to fail reliably when a side force exceeds a desired threshold. When installed in series with a utility pole guy wire, the invention will withstand all normal tensile and incidental loads, and will release when subjected to a high side force as from an automobile impact.
Description




FIELD OF THE INVENTION




The present invention relates generally to releasable connectors. More particularly, the present invention relates to a releasable connector for a guy wire system. In addition, the present invention relates to a system for releasing a guy wire from an anchor device in the event of a collision.




BACKGROUND OF THE INVENTION




The United States has between eighty million and one hundred million wooden utility poles along approximately four million miles of public roads. Approximately fifteen hundred to two thousand fatalities and about one hundred thousand injuries occur each year as a result of automotive collisions with utility poles. In an automobile crash with a utility pole guy wire, the car may roll over or it may be thrown into oncoming traffic with disastrous consequences.




Known techniques for reducing the number and/or severity of collisions include: providing lateral separation from the road; placing utility lines underground; shielding poles with guard rails; and providing advanced warning signs, wider shoulders, better lighting, skid resistant pavement, and better roadway alignment. The known techniques are generally too costly and/or too inconvenient for wide-scale implementation, however. Another approach has been to construct the poles in such a way as to reduce the likelihood of injury in the event of a collision. The Federal Highway Administration, for example, has developed a slip base upgrade for utility poles which reduces the likelihood of severe injury in an accident. The problems caused by guy wires, however, have not been satisfactorily resolved in the prior art.




A frangible guy wire device was referred to in “Safer Timber Utility Poles,” Volume I, Summary Report, Texas Transportation Institute (“TTI”) (September 1986). The device tested by TTI consisted of a six foot length of three-quarters inch galvanized steel pipe. The device relied on stress concentration as the failure mechanism. The stress concentration was formed by a rigid section connecting two pipes. Failure occurs at the pipe threads adjacent to the rigid section. There are several problems associated with the device referred to in the TTI report. One such problem is that stress concentration is not a reliable release mechanism in a guy wire system. It is difficult to control the critical dimensions at the stress concentration point, and corrosion affects the performance characteristics of the device. In addition, the device tested by TTI was unduly sensitive to the bumper height of the colliding vehicle. In particular, the device might fail to release when a car approached from “underneath” the guy wire. In addition, the long pipe itself could create a hazard during a collision, and the device could not be easily rebuilt afterward.




Another known device for a guy wire system is described in U.S. Pat. No. 5,529,276 (Szablya). The Szablya device relies on stress concentration and shock bending stress. As such, it is not sufficiently reliable. The release characteristics of the Szablya device would be dependent on parameters such as surface finish, corrosion, wear and manufacturing tolerances, which may be difficult to control. In general, corrosion is a problem with any outdoor system that relies on stress concentration as a release mechanism. In addition, the parts of the Szablya device that remain with the guy wire after a break could become dangerous moving objects, since they are not tied to the ground. In addition, the Szablya device would be difficult to manufacture, and it would be difficult to rebuild the device after a collision.




SUMMARY OF THE INVENTION




The disadvantages of the prior art are overcome to a great extent by the present invention. The present invention relates to a releasable connector device for providing a separation mechanism in a collision. The device may be formed of at least two elongated rigid elements and a tension member located between the rigid elements. During a side impact collision, the rigid elements pivot to amplify the axial stress applied to the tension member, such that the tension member breaks to provide the desired separation. If desired, a flexible connector or tether may be used to prevent the upper rigid element from separating from the lower element.




In a preferred embodiment of the invention, the rigid elements are steel pipes, and the tension element is a threaded steel rod located within the pipes. The present invention should not be limited, however, to the preferred embodiments shown and described in detail herein.




According to one aspect of the invention, a threaded unit is used to hold the upper pipe to the tension member. The threaded unit may be located within the upper pipe, if desired. The threaded unit may be arranged to slide out of the upper pipe along with the threaded rod during a collision.




According to another aspect of the invention, a threaded fixture is located within the lower pipe for connecting the tension member to the lower pipe.




The present invention also relates to a release system that has a connector device interposed between a guy wire and an anchor device. The connector device may be formed of elongated rigid elements in contact with each other at a break point (or at a separation plane). A flexible element may be used to secure the rigid elements together during a collision. The flexible element, which may be a cable, chain or the like, may be used to tie or tether the upper portion of the connector device to the lower portion of the device, to prevent the upper portion from causing damage and/or injury to the vehicle and/or its occupants.




In a preferred embodiment of the invention, a threaded rod is used as the breakable element in the connector device. When a bending stress is applied to the device, for example during a side impact collision, the threaded rod breaks in tension at a preselected break point. The tension in the guy wire causes the broken portion of the rod to be pulled out of the connector with sufficient force to minimize the possibility that the rod will come into contact with the moving vehicle or its occupants.




According to yet another aspect of the invention, the rigid elements are placed in an end to end relationship and a fulcrum bending point is formed between the rigid elements. During a collision, the device bends or pivots at the fulcrum point. The rigid elements themselves do not bend to the extent that any permanent deformation occurs. As a result, the pipe elements may be used in a rebuilt device, after the collision.




The present invention also relates to a method of operating a guy wire system, particularly during a vehicle collision. In operation, the impact force of the vehicle and tensile force in the guy wire create a bending moment in a connector device. The connector device may be interposed between the guy wire and an anchor device at approximately the height of the oncoming vehicle (i.e., the height of the bumper or other impact point of the vehicle). The bending moment causes a breakable element to break in tension. The tensile strength of the breakable element may be greater than that of the guy wire, if desired. The breakable element is broken because of the mechanical advantage applied by placing the connector device in bending.




As the vehicle (a car, truck, etc.) moves through the original location of the connector device, the guy wire tension causes at least a portion of the breakable element to be pulled through an upper pipe. A flexible connection keeps the upper pipe tied to a lower pipe, to reduce the amount of damage that might otherwise be done by the upper pipe. The tension of the guy wire causes the breakable rod to be cast up and over the moving vehicle. The remainder of the connector device remains anchored to the ground, where the vehicle can run over it.




An object of the invention is to provide a device that fails or releases reliably when subjected to a side force above a design threshold.




Another object of the invention is to provide a system that is actuated by automobiles, trucks and other vehicles, and that operates as intended over a wide range of vehicle speeds.




Another object of the invention is to provide a device that releases upon impact regardless of the direction of travel of the errant vehicle.




Yet another object of the invention is to provide a device that can be used in a wide variety of different size guy wire systems and in a variety of environmental conditions.




Another object of the invention is to provide a connector device that reliably performs a breakaway operation in bending at lateral loads smaller than those that would tend to tip a car over or allow it to ride up a guy wire.




Yet another object of the invention is to provide a low cost connector device that can be easily installed and repaired by utility crews.




In a preferred embodiment of the invention, the connector device resembles a slender rod, several feet long. The device is connected in series with the utility pole guy wire. The lower end of the device is hinged to the ground anchor. The upper end of the device is securely attached to the taught guy wire. When struck by an errant vehicle, the device is pushed out of line with the anchor and utility pole attachment points. The tension in the guy wire increases. A component of the tensile force is applied at a right angle to the axis of the device. The transverse force component creates bending moments which operate to break the device in bending, such that the guy wire is released. The tension in the guy wire causes it to snap away from the vehicle to avoid further damage to the vehicle or its occupants. Following an impact event, a utility crew only needs to replace the failed link to place the guy wire back in service. In a preferred embodiment of the invention, the guy wire system may be rebuilt or repaired with hand tools.




The present invention is superior to prior art designs based on stress concentrations at threads, notches or scored areas. Stress concentration devices are highly dependent on device geometry, surface finish and corrosion. Consequently, stress concentration is an unreliable failure mechanism for use in roadside environments.




Another object of the invention is to provide a failure mechanism that functions only in the event of a side impact. In a preferred embodiment of the invention, failure is caused by mechanical amplification of tensile force on a preloaded rod. The mechanical amplification is a function of component geometry specifically, the device diameter, and overall length. The side impact release mechanism and the ultimate tensile strength of the system are mechanically decoupled, and they can be separately engineered.




In a preferred embodiment of the invention, the releasable device has a higher axial tensile strength than the strongest guy wire in common use, yet the device fails reliably in a side impact with the lightest vehicle under consideration, and is not released by an impact from a slowly moving bicycle or by vandalism. Breakaway devices that rely on weaknesses caused by stress concentration, in contrast, can be separated by tension loading and by side impact loading, and therefore require a separate design for every guy wire strength.




These and other advantages and features of the invention will become apparent from the following detailed description which is provided in conjunction with the accompanying drawings.











BRIEF DESCRIPTION OF THE DRAWINGS





FIG. 1

is a side view of a connector device constructed in accordance with a preferred embodiment of the present invention.





FIG. 2

is a partially broken away side view of the connector device of FIG.


1


.





FIG. 3

is an enlarged view of the portion of the connector device designated by circle


3


in FIG.


2


.





FIG. 4

is a partially broken away side view of the connector device located within a guy wire system.





FIG. 5

shows the guy wire system of

FIG. 4

at a subsequent stage of operation.





FIGS. 6-9

illustrate the guy wire system of

FIGS. 4 and 5

at sequential stages of operation.





FIG. 10

is a partially broken away side view of a device constructed in accordance with another preferred embodiment of the present invention.





FIG. 11

cross sectional view of the device of

FIG. 10

, taken along the line


11





11


.











DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS




Referring now to the drawings, where like reference numerals designate like elements, there is shown in

FIG. 1

a connector device


10


constructed in accordance with a preferred embodiment of the present invention. The connector device


10


has a top eye


12


for connection to a guy wire and a bottom eye


14


for connection to an anchor device. The guy wire and the anchor device are not shown in FIG.


1


. The connector device


10


includes a top tube


16


, a bottom tube


18


, and a threaded steel rod


20


(FIG.


2


). The rod


20


is used to secure the guy wire to the bottom tube


18


. In operation, the rod


20


is broken at a break point


22


when the connector device


10


is bent sideways by an impact force


24


(FIGS.


4


and


5


).




Referring again to

FIG. 2

, the top tube


16


may be in the form of a sturdy steel cylinder with opposite ends


26


,


28


and a cylindrical interior space


30


. A fixture


32


is welded, bolted or otherwise rigidly secured in the top tube


16


near the second end


28


. The fixture


32


has a narrow opening


34


(

FIG. 3

) for receiving the rod


20


. The inner diameter of the opening


34


may be slightly greater than the outer diameter of the threaded rod


20


. The rod


20


is not threadedly connected to the fixture


32


.




In a preferred embodiment, the fixture


32


also has a cylindrical receiving space


36


, and a bevel portion


38


that connects the receiving space


36


to the narrow opening


34


. Providing the bevel portion


38


adjacent the narrow opening


34


avoids the formation of stress concentrations at the proximal end of the fixture


32


.




A threaded cylinder unit


40


is sidably received in the receiving space


36


. The unit


40


has a cylindrical exterior surface


50


and a conical surface


51


. The outer diameter of the cylindrical surface


50


is slightly less than the inner diameter of the cylindrical receiving space


36


. In a preferred embodiment of the invention, the unit


40


has interior threads along its entire length, and those threads are threadedly connected to the threaded rod


20


. The threaded cylinder unit


40


may be provided with hexagonal wrench flats


54


for rotating the unit


40


relative to the threaded rod


20


, as shown in FIG.


2


.




If desired, the entire unit


40


may be machined from a single piece of metal. In the illustrated embodiment, the unit


40


is made of steel. For certain applications, however, the unit


40


may be made of a different material.




The purpose of the cylinder unit


40


is to pull the top and bottom tubes


16


,


18


together such that the device


10


operates as a single integral unit. The prestress applied by the unit


40


protects the rod


20


from fatigue stress in the vicinity of the break point


22


.




Prior to assembly, the conical surface


55


(

FIG. 3

) of the bevel portion


38


may diverge outwardly slightly less than the conical surface


51


of the threaded unit


40


. This ensures the contact between threaded unit


40


and bevel portion


38


occurs in a region where there is sufficient material to eliminate excessive bending in bevel portion


38


of fixture


32


. In addition, it helps minimize the gap


59


between the proximal face


61


of the threaded unit and a bottom fixture


56


, such that the rod


20


snaps at the break point


22


in tension and does not undergo excessive elongation before breaking during a side impact collision. The length of the gap


59


may be kept to a minimum to reduce the amount of elongation that occurs in the rod


20


before it breaks. In addition, the bevel portion


38


provides a gradual transition from the thick cylindrical portion of the fixture


32


to the thin edge surrounding the narrow opening


34


.




The bottom fixture


56


is rigidly secured within an opening of the bottom tube


18


. The bottom fixture


56


may be secured to the bottom tube


18


by a weld (not shown), a bolt or by another suitable connecting structure. The bottom fixture


56


has interior threads


60


that are aligned with the narrow opening


34


of the top fixture


32


. The threaded rod


20


is threadedly secured in the bottom fixture


56


. In operation, rotation of the threaded cylinder unit


40


causes the conical surface


51


to be forced into the bevel portion


38


of the first fixture


32


, such that the rod


20


is placed in tension at the break point


22


.




A tool (not shown) may be provided for tightening the threaded unit


40


. The tool may have a socket that engages the wrench flats


54


, and a head that is driven by hand or by a power tool. An extension may be located between the socket and the head. In operation, the extension extends through the top tube


16


such that the head can be rotated from outside of the tube


16


while the socket is engaged on the wrench flats


54


. The tool may be used to tighten the unit


40


to a predetermined torque. Alternatively, the tool may be used to turn the unit


40


a predetermined number of times after it has been hand-tightened on the rod


20


.




The tension in the rod


20


is counteracted by compression between the two tubes


16


,


18


(or compression between the two fixtures


32


,


56


depending on the alignment of the tube ends


28


,


58


and the fixtures


32


,


56


). Thus, the rod


20


is prestressed in tension at the break point


22


before the connector device


10


is installed between the guy wire


62


(

FIG. 4

) and the anchor device


64


. Sufficient prestress tension should be applied to maintain the two tubes


16


,


18


pressed together in end to end contact during installation and throughout the life of the device


10


prior to a collision.




In a preferred embodiment of the invention, the threaded components


20


,


40


,


56


of the connector device


10


are all made of steel. Making all of the connected components of the same metal material reduces the potential for galvanic corrosion. The present invention should not be limited, however, to the preferred embodiments shown and described herein in detail. Corrosion may also be prevented, for example, by providing plastic coatings or others of known art on various components and/or employing a molybdenum disulfide grease as is known in the art.




Referring again to

FIG. 1

, the rigid steel members


16


,


18


may be connected to each other by one or more flexible chains, ropes or cables


66


. The ends of the illustrated cable


66


may be attached to the elongated pipes


16


,


18


by welds


68


,


70


or the like. When the connector device


10


is in its assembled pre-collision configuration (with the ends


28


,


58


of the tubes


16


,


18


contacting each other as shown in FIG.


1


), the length of the cable


66


may be greater than the distance between the welds


68


,


70


. As shown in

FIG. 1

, the cable


66


contains slack when the connector device


10


is in its assembled configuration. The slack may be taken up when the rod


20


is broken at the break point


22


. The cable


66


operates as an extendable tether to keep the top tube


16


attached to the bottom tube


18


when the rod


20


is broken, as discussed in more detail below.




The anchor device


64


(

FIG. 4

) may be any suitable device for securing a utility pole guy wire to the ground


72


. A shackde


73


may be connected to the anchor device


64


to permit rotation (with at least two degrees of freedom) about mutually orthogonal axes, each perpendicular to the longitudinal axis of the device


10


. The shackle


73


may be connected through the bottom eye


14


. In operation, the bottom tube


18


may remain firmly connected to the anchor device


64


, which remains connected to the ground


72


, even in the event of a high speed automotive collision. Thus, according to a preferred mode of operation, the bottom tube


18


remains connected to the ground


72


during a side impact collision.




The distal end of the threaded rod


20


is threaded or welded into an end socket


74


. The top eye


12


is located in the distal portion of the end socket


74


. The end socket


74


may be used to rigidly connect the threaded rod


20


to the guy wire


62


. The guy wire


62


may be a conventional steel wire for securing a utility pole against lateral forces. The tensile strength of the threaded rod


20


at the break point


22


may be greater than the tensile strength of the guy wire


62


.




In an alternative embodiment of the invention (not shown in the drawings), the rod


20


is threaded only in the vicinity of the bottom fixture


56


, the threaded unit


40


and the end socket


74


. The smoother the rod


20


, the easier it will slide out of the upper tube


16


, and the easier it will be snapped away from the errant automobile by the tension in the guy wire


62


.




In a preferred embodiment of the invention, an end cap


76


is located between the proximal end


78


of the end socket


74


and the first end


26


of the top tube


16


. The end cap


76


has a cylindrical body portion


77


that slidably overlaps the top tube


16


. The end cap


76


may be connected to the end socket


74


and/or the rod


20


. The end cap


76


is not connected to the top tube


16


. Consequently, when the end socket


74


is pulled away from the top tube


16


(by the guy wire


62


), the end cap


76


and the upper portion of the rod


20


remain integrally connected to the end socket


74


and the guy wire


62


. As noted above, the distal end of the rod


20


is rigidly secured in the end socket


74


.




As shown in

FIG. 2

, the cylindrical portion


77


of the end cap


76


laps over the outside of the tube


16


. The overlapping construction provides superior environmental control over the interior of the tube


16


. When the tension in the guy wire


62


is applied, it tends to move the cap


76


slightly away from the distal end


26


of the top tube


16


. The movement is caused by the elongation of the rod


20


caused by the tension of the guy wire


62


. In the illustrated embodiment, the end cap


76


can move slightly away from the tube


16


and still the body portion


77


overlaps the distal portion


26


of the tube


16


.




In addition, the end cap


76


may be used to centralize the rod


20


within the top tube


16


. This way, the distal end


26


of the top tube


16


does not have to be moved into side contact with the rod


20


before the desired breaking action occurs at the separation plane (


22


). In other words, it is helpful to keep the rod


20


stationary with respect to the tube


16


during the initial moments of a collision so that there is no sideways slack in the system


10


,


62


.




The end cap


76


may be used to seal off the end


26


of the top tube


16


. The end cap


76


may prevent ice, water, salt and the like from reaching the interior operative components


40


,


22


of the device


10


. The end cap


76


may also be used to discourage vandalism and the like by providing a neat, closed construction.




As shown in

FIG. 4

, the connector device


10


may be sized to receive the impact force


24


of an oncoming automotive vehicle (not shown in FIG.


4


). Although

FIG. 4

shows the impact force


24


being applied at a location above the separation plane between the two tubes


16


,


18


, the impact force


24


may be applied at other locations on the connector device


10


. The impact force


24


causes the connector device


10


to bend or pivot at a fulcrum point


80


. That is, the rigid elements


16


,


18


rotate relative to each other about the fulcrum point


80


. The fulcrum point


80


is located within the plane between the two tubes


16


,


18


. During a collision, the applied bending moment stretches the rod


20


(

FIG. 4

) and eventually breaks the rod


20


at the break point


22


(FIG.


5


). The device


10


employs mechanical advantage to amplify the tension in the tension member


20


until it breaks at the break point


22


. During the collision, the tension applied to the rod


20


at the break point


22


is greater than the tension in the guy wire


62


.




After the break occurs at the break point


22


, the tension in the guy wire


62


causes the upper portion of the rod


20


to be snapped upwardly to a location where it is less likely to impact the automobile. That is, when the break occurs, the upper portion of the rod


20


stays with the guy wire


62


, and the top tube


16


stays with the bottom tube


18


. The cable


66


(

FIG. 1

) keeps the tubes


16


,


18


flexibly connected to each other, which provides advantages as discussed in more detail below in connection with

FIGS. 6-9

. The guy wire


62


tends to snap upwardly and stay near the utility pole where it is less likely to damage the vehicle or injure its occupants or swing into the normal flow of traffic.





FIG. 6

shows the guy wire system


10


,


62


in a pre-collision assembled configuration. The guy wire


62


is attached to a utility pole (not illustrated) in a known manner. The anchor device


64


is likewise secured to the ground


72


in a manner known in the art. The guy wire


62


should preferably be installed tight so that no slack needs to be taken up before a release occurs in a collision. In other words, the illustrated connector


10


is preferably installed in a taught guy wire system. The connector device


10


is interposed between the guy wire


62


and the ground attachment device


64


. The utility pole may be, for example, a forty foot long wooden telephone pole, and the guy wire


62


may be anchored at a desired angle (for example, sixty degrees) with respect to the ground


72


. The present invention should not be limited, however, to the specific structures and instrumentalities shown and described herein.




Referring now to

FIG. 7

, the bumper


82


of an oncoming vehicle


84


applies an impact force to the connector device


10


. The vehicle


84


may be an automobile, truck or the like. The impact force


24


causes the two pieces


16


,


18


of the connector device


10


to pivot at the fulcrum point


80


, such that the rod


20


is broken at the break point


22


(FIG.


8


). As the vehicle


84


continues to move through the guy wire system, the top tube


16


may be run over by the vehicle


84


. The cable


66


operates as a flexible hinge that extends between the top and bottom tubes


16


,


18


. The top tube


16


remains attached to the ground


72


via the cable


66


, the bottom tube


18


, and the anchor device


64


(FIG.


9


).




The illustrated arrangement causes the relatively massive top tube


16


to remain near the ground


72


, such that the vehicle


84


tends to run over it. The top tube


16


is prevented from flying upward where it could potentially injure the vehicle occupants. The present invention also males it easier to locate the top tube


16


after the collision so that the connector device


10


can be rebuilt with a minimum number of replacement parts. During a collision, the end socket


74


and the end cap


76


remain attached to the guy wire


62


. As a result, the end socket


74


and the end cap


76


may be reused in a rebuilt connector device


10


. In many cases, the only part that will need to be replaced to rebuild the connector device


10


will be the threaded rod


20


.




Referring now to

FIGS. 4 and 5

, according to a preferred embodiment, the tubes


16


,


18


are sufficiently massive to ensure that they are not damaged during a high speed collision. The tubes


16


,


18


resist bending such that the connector device


10


separates and pivots at the fulcrum point


80


. The tubes


16


,


18


should be sufficiently strong and durable to resist degradation by vandalism, weather and the like.




Although the collision shown in

FIGS. 7-9

involves the vehicle


84


moving toward the utility pole, the invention should not be limited to that mode of operation. The safety device


10


operates as intended regardless of the direction of movement of the oncoming vehicle


84


. When the vehicle


84


is moving away from the pole, the side impact force


24


may be applied somewhat higher up the device


10


. In a preferred embodiment of the invention, all of the operative components, including the tubes


16


,


18


, are axially symmetrical with respect to the central axis of the threaded rod


20


. This way, the device


10


fails reliably as intended regardless of the direction of impact.




If desired, a plastic or metal guy wire cover (not shown), of a type known in the art, may be located over the connector device


10


.




Numerous structural and organizational changes may be made to the device


10


without departing from the spirit and scope of the present invention. For example, as shown in

FIGS. 10 and 11

, a relatively long steel cable


100


may be employed to flexibly secure the top tube


16


to the bottom tube


18


. The cable


100


may be employed instead of the cable


66


shown in FIG.


1


. The

FIG. 10

cable


100


may be inserted through openings


102


,


106


,


108


in the two fixtures


32


′,


56


′. The cable


100


may form a loop such that it is prevented from passing back through the openings


106


,


108


in the top fixture


32


′. The middle portion


114


of the cable


100


may be looped around the bottom eye


14


. The ends of the cable


100


may be connected to each other by a suitable connection mechanism to form a closed loop. The cable


100


need not be welded or otherwise attached to the bottom tube


18


.




The cable


100


is slack in the pre-collision assembled position shown in FIG.


10


. When the rod


20


is broken during a collision, the flexible cable


100


prevents the top tube


16


from moving away from the bottom tube


18


, although hinged movement between the two tubes


16


,


18


is permitted.




Furthermore, the present invention is not limited to use in utility pole guy wire systems. The invention may also be applicable, for example, to triple cable barrier systems. Thus, the invention may be used to prevent a car from becoming wedged under the downstream end of a triple cable barrier system where the cables extend from the last post to a buried anchor.




The invention may also be applicable to a wide variety of other systems. In general, the invention may be used wherever a releasable connector may be employed as part of a tension system that is released by a side impact. The invention may be used, for example, as a shunt for a patient's blood vessel, and for other surgical implants and/or other medical purposes. The invention may also be employed in the rigging of sail boats, such as offshore racing boats, rock climbing equipment, and tethers for space vehicles and other equipment. Under some design thresholds, a releasable connector may be actuated by hitting it on the side to release a sailboat rigging component in the event of an emergency, for example.




Reference has been made to preferred embodiments in describing the invention. However, additions, deletions, substitutions, or other modifications which would fall within the scope of the invention defined in the claims may be implemented by those skilled in the art without departing from the spirit or scope of the invention. Accordingly, the invention is not to be considered as limited by the foregoing description, but is only limited by the scope of the appended claims.



Claims
  • 1. A connector device for providing separation in a side impact collision, said device comprising:first and second elongated rigid elements; and a tension member located between said rigid elements; and wherein said elongated rigid elements are arranged to pivot relative to each other during said side impact collision, such that tension in said tension member is amplified until said tension member breaks; and wherein said device further comprises a flexible connector for preventing said first rigid element from separating from said second element during said collision.
  • 2. A connector device for providing separation in a side impact collision, said device comprising:first and second elongated rigid elements; and a tension member located between said rigid elements; and wherein said elongated rigid elements are arranged to pivot relative to each other during said side impact collision, such that tension in said tension member is amplified until said tension member breaks; wherein said rigid elements include steel pipes, and wherein said tension member is located within said first and second rigid elements; wherein said device further comprises a threaded unit for applying tension to said tension member, said threaded unit being located within said first rigid element; and wherein said device further comprises a threaded fixture for connection to said tension member, said threaded fixture being located in said second rigid element.
  • 3. The device of claim 2, wherein said threaded unit and at least a portion of said tension member are arranged to slide out of said first rigid element during said collision.
  • 4. A guy wire system, comprising:a guy wire; an anchor device for applying tension to said guy wire; and a releasable connector device interposed between said guy wire and said anchor device, and wherein said releasable connector device includes first and second elongated rigid elements in contact with each other at a break point, and a tether for securing said rigid elements together and for keeping said first and second elongated rigid elements together during a collision.
  • 5. The system of claim 4, further comprising a threaded rod for connecting said second rigid element to said guy wire.
  • 6. The system of claim 5, wherein said rod extends through said first rigid element.
  • 7. The system of claim 6, further comprising an end socket for connecting said rod to said guy wire, said end socket being located between said first rigid element and said guy wire.
  • 8. The system of claim 7, wherein said rigid elements define a fulcrum point at a peripheral location where said connector device bends during said collision.
  • 9. The system of claim 8, further comprising a threaded device for applying tension to said threaded rod, said threaded device being located in said first rigid element.
  • 10. A method of operating a guy wire system, wherein said guy wire system includes a connector device and a guy wire, and wherein said method includes the steps of:providing said connector device and said guy wire; applying a bending moment to said connector device, and thereby causing a breakable element to break within said connector device; subsequently, pulling a portion of said breakable element through a first rigid portion of said connector device; using said guy wire to pull said portion of said breakable element through said first rigid portion of said connector device; and providing an extendable connection between said first rigid portion of said connector device and a second rigid portion of said connector device.
  • 11. The method of claim 10, wherein said bending moment is applied by a moving vehicle.
  • 12. The method of claim 14, wherein said guy wire is attached to said connector device during said step of applying said bending moment.
  • 13. A method of operating a guy wire system, said method including the steps of:applying a bending moment to a connector device, and thereby causing a breakable element to break within said connector device; subsequently, using a guy wire to pull a portion of said breakable element through a first rigid portion of said connector device; and providing an extendable connection between said first rigid portion of said connector device and a second rigid portion of said connector device; and wherein said bending moment is applied by a moving vehicle; wherein said guy wire is attached to said connector device during said step of applying said bending moment; and wherein said method further comprises the step of threading a threaded unit on said breakable element to place said breakable element in tension.
  • 14. The method of claim 13, wherein said threaded unit remains attached to said guy wire during said step of using said guy wire to pull said breakable element through said connector device.
  • 15. The method of claim 10, further comprising the step of anchoring said connector device to the ground.
  • 16. The method of claim 15, further comprising the step of securing said guy wire to a utility pole.
  • 17. A method of making a guy wire system, said method comprising the steps of:assembling a side impact releasable connector by: locating a threaded rod within a rigid element; extending a tool through said rigid element; and subsequently, rotating said tool to tighten a threaded device on said rod; and connecting said side impact releasable connector to a guy wire.
  • 18. A method of assembling a side impact releasable connector, wherein said side impact releasable connector includes first and second rigid elements, and wherein said method comprises the steps of:providing a flexible tether between said first and second rigid elements; locating a threaded rod within said first rigid element; extending a tool through said first rigid element; and subsequently, rotating said tool to tighten a threaded device on said rod.
Government Interests

This invention was made with government support under Contract No. DTRS57-99-C-00011 awarded by the U.S. Department of Transportation. The government has certain rights in the invention.

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