AU705297B2 - Anchor for cables - Google Patents
Anchor for cables Download PDFInfo
- Publication number
- AU705297B2 AU705297B2 AU74061/96A AU7406196A AU705297B2 AU 705297 B2 AU705297 B2 AU 705297B2 AU 74061/96 A AU74061/96 A AU 74061/96A AU 7406196 A AU7406196 A AU 7406196A AU 705297 B2 AU705297 B2 AU 705297B2
- Authority
- AU
- Australia
- Prior art keywords
- cable
- safety barrier
- anchoring
- anchoring body
- fitting
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000004873 anchoring Methods 0.000 claims description 67
- 230000004888 barrier function Effects 0.000 claims description 34
- 239000002184 metal Substances 0.000 claims description 6
- 238000006073 displacement reaction Methods 0.000 claims description 3
- 239000004809 Teflon Substances 0.000 claims description 2
- 229920006362 Teflon® Polymers 0.000 claims description 2
- 239000000758 substrate Substances 0.000 claims description 2
- 239000000463 material Substances 0.000 claims 2
- 239000004033 plastic Substances 0.000 claims 2
- 229920003023 plastic Polymers 0.000 claims 2
- 239000004677 Nylon Substances 0.000 claims 1
- 239000004698 Polyethylene Substances 0.000 claims 1
- 229920006351 engineering plastic Polymers 0.000 claims 1
- 229920001778 nylon Polymers 0.000 claims 1
- -1 polyethylene Polymers 0.000 claims 1
- 229920000573 polyethylene Polymers 0.000 claims 1
- 229910000831 Steel Inorganic materials 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 239000010959 steel Substances 0.000 description 5
- 230000006378 damage Effects 0.000 description 4
- 238000010276 construction Methods 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000010008 shearing Methods 0.000 description 3
- 208000027418 Wounds and injury Diseases 0.000 description 2
- 238000013459 approach Methods 0.000 description 2
- 229920001903 high density polyethylene Polymers 0.000 description 2
- 239000004700 high-density polyethylene Substances 0.000 description 2
- 208000014674 injury Diseases 0.000 description 2
- 229920000642 polymer Polymers 0.000 description 2
- 238000005299 abrasion Methods 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000008901 benefit Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 230000008439 repair process Effects 0.000 description 1
Landscapes
- Refuge Islands, Traffic Blockers, Or Guard Fence (AREA)
Description
AUSTRALIA
Patents Act COMPLETE SPECIFICATION
(ORIGINAL)
Class Int. Class Application Number: Lodged: Complete Specification Lodged: Accepted: Published: Priority Related Art: a
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Name of Applicant: Bridon New Zealand Limited Actual Inventor(s): Philip Pearce Timothy John Heldt Address for Service: PHILLIPS ORMONDE FITZPATRICK Patent and Trade Mark Attorneys 367 Collins Street Melbourne 3000 AUSTRALIA Invention Title: ANCHOR FOR CABLES Our Ref 474253 POF Code: 1607/296728 The following statement is a full description of this invention, including the best method of performing it known to applicant(s):
I
FIELD OF THE INVENTION This invention relates to anchors for cables and has particular application with respect to safety fences designed to redirect or prevent passage of vehicles over prohibited ground and is particularly, but not exclusively, applicable to safety fences used on the sides of roads or central reservations of high-speed carriageways, roads or motorways, or embankments.
BACKGROUND
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Many different road safety barriers are available and in use throughout the world. One type of barriers are wire cable safety barriers which generally consist of tensioned horizontal cables attached to a number of upright posts spaced a certain distance apart.
Wire cable safety barriers have the ability to significantly reduce vehicle damage and occupant injury upon impact when compared to other available types of road barriers.
However, there is still a small risk of serious vehicle damage and occupant injury if a vehicle happens to impact the barrier under certain conditions. This danger arises on impact close to an anchorage portion (where the cables terminate) of such fences and/or where part of a vehicle may get jammed under the cable. Under these conditions the vehicle may be brought abruptly to a halt.
U. U U 25 OBJECT It is an object of the present invention to provide an improved anchorage method for wire cable safety barriers or at least one that provides the public with a useful choice.
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r-I STATEMENT OF INVENTION In one aspect the invention comprises a means for anchoring a cable, the means comprising an anchoring body adapted to be secured to a substrate and including a means for attaching a portion of the cable to the anchoring body and characterised by having disengaging means whereby in use a predetermined deflection of the cable results in the disengagement of the cable from the anchoring means.
In another aspect the invention provides a safety barrier comprising a plurality of cables and means for anchoring each cable as just described. The anchoring body has one or more apertures each adapted to receive one or more cables.
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-3- Preferably the anchoring body has one or more apertures and/or slots adapted to receive the cable and has suitable fasteners to retain part of the cable within the body.
More preferably the anchoring body has one or more apertures and/or slots adapted to receive the cable at an angle and has suitable fasteners to retain part of the cable within the body.
In one version the cable can be held in an open ended slot or cavity and allowed to escape from the slot or cavity if the cable is deflected by more than a predetermined amount. In another version the cable or cable attachment is designed to fail if the cable is deflected by more than a predetermined amount.
Preferably the cable is held in the anchoring body at an angle of 3' 160 relative to the ground.
More preferably the cable is held in the anchoring body at an angle of 40 100 relative to the ground.
Preferably the cable or cable fitting will escape or fail if the angle of the cable exceeds a .4 predetermined angle in the range of 10' More preferably the cable or cable fitting will escape or fail if the angle of the cable exceeds a predetermined angle in the range of 120 24'.
Preferably there is a cable fitting attached to the cable and adapted to be attached to the anchoring body.
More preferably the means for attaching the cable to the anchoring body is a threaded fitting attached to the cable, the diameter of which matches the diameter of an aperture 30 and/or width of a slot in the anchoring body.
It could be a mechanical connection or a swaged connection.
In another version the threaded fitting has a narrowed portion adapted to be sheared by the disengaging means.
9274BAU5.N96/SY iV I r II T -4- In one version, the disengaging means is part of the anchoring means but in some applications the disengaging means may be placed apart from the anchoring means.
The disengaging means may be adapted to shear the cable fitting and can have a fixed spatial relationship to the cable in use so that the cable is spaced apart from the disengaging means in normal use but a predetermined displacement of the tensioned cable results in it causing the cable fitting to shear or fracture.
In this version, the disengaging means adapted to shear the cable fitting comprises a shearing edge.
The disengaging means may comprise one or more sharp edges attached to the anchoring body and forming an angle with the line of the cable.
Preferably the anchoring body is adapted to be set into a concrete foundation.
More preferably the anchoring body is adapted to be located substantially below ground level.
Optionally, the shearing edge and the threaded fitting are both made of steel.
eoo Optionally, the threaded fitting is made of a grade of steel with suitable flow characteristics for the swaging process, and has high tensile strength but is adapted to fracture locally at a predetermined position when subjected to sideways or vertical displacement.
e,.ooi o In another aspect the invention provides a cable safety barrier having a plurality of posts, one or more cables tensioned between said posts wherein each cable is anchored at least one end and having a disengaging means on or adjacent to the anchor and adapted to disengage the cable if the cable is displaced sideways/vertically by more than a predetermined amount.
Preferably the anchoring means is as described above.
9274BAU5.N96/SY/iv Throughout the description and claims of this specification the word "comprise" and variations of that word such as "comprises" and "comprising" are not intended to exclude other additives, components, integers or steps.
**e **ae a s ee a99 a* a C W A"\VOR P V; CLETJ" DE£E't .6 D
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PREFERRED EMBODIMENT The following is a description of a preferred form of the invention given by way of example only, with reference to the accompanying drawings, in which: Figure 1: shows a first preferred embodiment of the invention in side view with respect to a vehicle wheel.
Figure 2: shows the embodiment of figure 1 in greater detail.
Figure 3: shows a second preferred embodiment in side view.
Figure 4: shows the anchoring body of the second preferred embodiment in end view.
Figure 5: shows one possible arrangement of tensioned cables forming part of a wire cable safety barrier of the type with which the anchoring means of this invention could be used.
Figure 6: shows a third preferred embodiment of the invention in side view.
Figure 7: shows the anchoring body, fastener and member of the third preferred embodiment in more detail.
r r FIRST PREFERRED EMBODIMENT (Figures 1,2 and A cable safety barrier 300 consists of one or more upright posts 301 spaced apart and adapted to fold downwards on impact by a vehicle. Tensioned between the posts 301 is one or more cables 302 adapted to absorb a collision load of a vehicle and leading from the last post to an anchoring means 100 comprising an anchoring body 105 which is set 25 in a concrete foundation 104, below ground level.
The anchoring body 105 is adapted to receive a cable 102 at an angle. The angle the cable 102 forms in relation to the ground can be called the "normal cable angle".
A threaded fitting 103 is swaged to the cable 102 and attached to the anchoring body 105 through an aperture in the anchoring body 105. The anchoring body 105 is a substantially rectangular structure angled and set in a concrete foundation 104. The threaded fitting 103 is held within the anchoring body 105 by one or more fasteners on the inner side of said body 105.
9274BAU5.N96/SY/iV I 11 -6- The threaded fitting 103 at its upper end is an unthreaded metal collar 108 which has a neck 106 that is substantially narrower than the collar part.
The threaded fitting 103 is made of steel having suitable flow characteristics for tilhe swaging process and high tensile strength combined with a section adapted to fracture at a predetermined position when subjected to a shearing force. High tensile strength is required to ensure the threaded fitting can withstand the high tensile load to which it is subjected under normal impact conditions. The reduced section helps to ensure that the threaded fitting shears off at a predetermined position if certain impact conditions are met.
There is a shear blade 107 joined to and rigidly supported by the anchoring body 105 and angled downwards towards the neck 106 of the metal collar 108. If the cable is lifted upwards the shear blade will contact the neck 106 and cause the threaded fitting 103 to shear off.
~If the cable gets jammed over a wheel or other part of a vehicle 101, as the vehicle approaches the anchoring body the cable will be lifted upwards, increasing the gradient 20 of the cable and increasing the angle between the cable and the ground. The upward lifting of the cable causes contact between the shear blade and thile cable. As the angle continues to increase the cable is pressed with increasing force against the shear blade and at the "critical cable angle" the threaded fitting will be severed through the "neck" portion. The normal cable angle is in the range of 3 -16* and thile critical cable angle is in the range of 10*-35 SECOND PREFERRED EMBODIMENT (Figures 3,4 and A cable safety barrier 300 consists of one or more upright posts 301 spaced apart and adapted to fold downwards on impact by a vehicle. Tensioned between the posts 301 are one or more cables 302 adapted to absorb a collision load of a vehicle and leading from the last post to an anchoring means 200 comprising an anchoring body 201 which is set in a concrete foundation 205, below ground level.
A threaded fitting 204 is swaged to the cable 202 and attached to the anchoring body 201 through a slot 206 in the anchoring body 201. The anchoring body 201 is adapted 9274BAU5.N96SY/Iv -7to receive the cable at an angle and is a substantially thick plate structure angled and set in a concrete foundation 205. The threaded fitting 204 is held within the anchoring body 201 by one or more fasteners 203 on the far side of said body 201.
The slot 206 is elongate and located on the upper edge of the anchoring body 201. The slot 206 has one open side on the uppermost end of the anchoring body 201.
The axis of the slot may be vertical (as illustrated in Figure 4) or angled obliquely sideways and upwards, in a direction away from the carriage way.
The tension of the cable 202 holds the threaded fitting firmly in place against the anchoring body 201. The fasteners 203 prevent the threaded fitting being pulled free through the slot 206 except when certain impact conditions are met.
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Preferably the anchoring body 201 is angled approximately 0-16' from a vertical line and away from the cable 202 entering the anchoring body 201, and more preferably is angled from 30 to If the cable gets jammed over a wheel or other part of a vehicle as shown in figure 1, as the vehicle approaches the anchorage the cable will be lifted upwards, increasing the gradient of the cable and increasing the angle between the cable and the ground. With the upward lifting of the cable the threaded fitting will slide upwards in the slot and will eventually disengage completely from the anchoring means.
One advantage of this embodiment of the invention is the ease of repair when the cable is so disengaged. It is likely that neither the cable nor the anchoring body are damaged during the process of disengagement and the cable can simply be reattached to the anchoring body by reinserting it in the slot of the anchoring body and retensioning the cable.
C e THIRD PREFERRED EMBODIMENT (Figures 6 and 7) A variation of the preferred embodiment (shown in Figure 3) can be seen in Figures 6 and 7. This variation may incorporate a member 207 between the anchoring body 201 and a metal bearing plate 208 of the fastener.
9274BAU5 .N96/SY/iV Preferably this member provides a means of consistent release, enabling the cable 202 to become dislodged from the anchoring body 201 after a predetermined amount of deflection is applied to the cable 202.
Preferably this member is non-metallic.
Preferably this member is resistant to corrosion or any major change over time in its frictional characteristics.
Preferably this member is a rectangular plate of polymer such as high density polyethylene, or teflon.
Preferably the dimensions of this member range fromn the following: 40 mm x 40 mm x 2 mm thick to 150 mm x 150 mm x 10 mm thick and may be rectangular or circular in shape.
•Although the preferred embodiment is not restricted to any specific dimensions (of the cable length, diameter etc) preferably these dimensions range from the following: Cable Diameter 16 mm 28 mm Fastener 40 mm x 40mm x 10mm 150 mm x 150 mm x 25 mm HDPE Member 40 mm x 40 mm x 2 mm 150 mm x 150 mm x 10 mm Anchoring Body angle to the vertical 30 The use of a polymer member 207 has been proved to give much more consistent and predictable cable release at a cable angle of 10-12° greater than the angle at which the anchor slot is tilted back from the vertical.
VARIATIONS
The anchoring means could be located above ground level, although it is preferable in terms of safety fence structure and space to locate the anchoring means firmly in the ground.
9274BAU5.N96/SYIiV I r Generally the cables used for barriers of the type described in this invention are steel of a 3 x 7 construction and heavily galvanised to prevent corrosion. This type of cable construction is used to give the cable a high modulus of elasticity. Large outer wires provide good abrasion resistance and good corrosion resistance. However it may be possible to use other grades of steel, other rope constructions and other metallic or non-metallic materials in various applications.
The disengaging means could be placed apart from the anchoring means, for example, attached to one of the posts forming part of the barrier. There may be a disengaging means attached to a post of the barrier as well as to an anchoring body of the barrier.
The shear edge need not be a blade or a sharpened edge. It may be sufficient it some embodiments for the cable to be forced against any rigid structure to provide the shear force.
Figure 5 shows the two lower cables interweaving between the support posts. This is exactly how the cable are orientated in the Brifen safety barrier design produced by the applicant. However other cable systems are possible. In one competing system all four 20 cables remain parallel and are positioned in the slots in the tops of the posts.
Alternatively, the two lower ropes could be positioned on the outside of the posts, but remain parallel rather than interweaving between the posts. The improved anchor design is equally applicable to any of the abovementioned configurations, as well as to other cable systems used for safety barriers.
Finally it will be appreciated that a variety of changes might be made to the above example without departing from the general scope of the invention, as set forth in the claims.
9274BAU5.N96/SY/iv I
Claims (13)
1. Means for anchoring a cable, the means comprising an anchoring body adapted to be secured to a substrate and including a means for attaching a portion of the cable to the anchoring body and characterised by having disengaging means whereby in use a predetermined deflection of the cable results in the disengagement of the cable from the anchoring means.
2. A safety barrier comprising a plurality of cables and means for anchoring each cable as claimed in claim 1, wherein the anchoring body has one or more apertures each adapted to receive one or more cables.
3. A safety barrier as claimed in claim 2, wherein each cable has a cable fitting 15 attached thereto and forming that portion of the cable which is adapted to be attached to the anchoring body.
4. A safety barrier as claimed in claim 2 or claim 3, wherein at least one of the 20 apertures in the body consists of an open ended slot. A safety barrier as claimed in any one of claims 2 to 4, wherein each cable can be held in an open ended slot in the anchoring body and allowed to escape from the slot if the cable is deflected by more than a predetermined amount.
6. A safety barrier as claimed in claim 5, wherein each cable is held in the anchoring body at an angle of 3" 16° relative to the ground.
7. A safety barrier as claimed in claim 5, wherein the open ended slot in the 30 anchoring body is angled from 16 from the vertical and away from the line of the cable entering the body.
8. A safety barrier as claimed in any one of claims 2 to 7, wherein each cable or cable fitting will escape or fail if the angle of the cable exceeds a predetermined angle in the range of 10° 35° relative to the ground. 9274BAU6.199/SY/Lv I-
11- 9. A safety barrier as claimed in claim 8, wherein each cable or cable fitting will escape or fail if the angle of the cable exceeds a predetermined angle in the range of 12° 24° relative to the ground. A safety barrier as claimed in any one of claims 2 to 9, wherein each cable fitting is a threaded fitting capable of attachment to the anchoring body by means of a threaded fastener. 11. A safety barrier as claimed in claim 10, wherein the threaded fitting has a narrowed portion adapted to be sheared by the disengaging means. 15 12. A safety barrier as claimed in claim 10 or 11, wherein the disengaging means is adapted to shear the cable fitting and has a fixed spatial relationship to the cable in use so that the cable is spaced apart from the disengaging means in normal use but a predetermined displacement of the cable results in it causing the cable fitting to shear or fracture. a
13. A safety barrier as claimed in any one of claims 4 to 10, wherein the cable or cable fitting is held in its slot by a fastener and a bearing plate.
14. A safety barrier as claimed in claim 13, wherein the anchoring body is formed °,25 of metal, and the bearing plate is formed of metal, and a layer of plastics material is sandwiched between the metal plate and the anchoring body. 4.io A safety barrier as claimed in claim 14, wherein the plastics material is chosen from the group of engineering plastics including nylon, Teflon and high density 30 polyethylene. *4o94*
16. A cable safety barrier having a plurality of posts, one or more cables tensioned between said posts wherein each cable is anchored at least one end and having a disengaging means on or adjacent to the anchor and adapted to disengage the cable if the cable is displaced sideways/vertically by more than a predetermined amount. 9274BAU6.199/SyI/ I I -12-
17. A means for anchoring a cable substantially as described herein with reference to any one of figures 1-4 or 6 or 7 of the accompanying drawings.
18. A cable safety barrier substantially as described herein with reference to any one or more of the accompanying drawings. DATED: 16 February, 1999 PHILLIPS ORMONDE FITZPATRICK Attorneys for: BRIDON NEW ZEALAND LIMITED S 2 5* 30 30 9274BAU6.199/SY/iv
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US08/865,454 US6065738A (en) | 1996-11-29 | 1997-05-29 | Anchor for cables |
| EP97303733A EP0845558A3 (en) | 1996-11-29 | 1997-06-02 | Anchor for cables |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NZ28058695 | 1995-12-01 | ||
| NZ280586 | 1995-12-01 |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| AU7406196A AU7406196A (en) | 1997-06-05 |
| AU705297B2 true AU705297B2 (en) | 1999-05-20 |
Family
ID=19925564
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU74061/96A Expired AU705297B2 (en) | 1995-12-01 | 1996-11-29 | Anchor for cables |
Country Status (1)
| Country | Link |
|---|---|
| AU (1) | AU705297B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1792016A1 (en) * | 2004-08-27 | 2007-06-06 | Hill & Smith limited | Safety barrier anchorage |
| US8596617B2 (en) | 2006-11-06 | 2013-12-03 | Axip Limited | Impact energy dissipation system |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| NZ546970A (en) * | 2006-05-04 | 2009-01-31 | Armorflex Ltd | Improvements in and relating to cable-barriers |
| NZ555598A (en) | 2007-06-01 | 2010-02-26 | Armorflex Ltd | Improved Barrier Section Connection System |
| NZ556782A (en) | 2007-07-27 | 2010-03-26 | Armorflex Ltd | Method of producing a frangible post |
| US8424849B2 (en) | 2008-06-04 | 2013-04-23 | Axip Limited | Guardrail |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3390865A (en) * | 1965-06-19 | 1968-07-02 | Nat Res Dev | Safety fences |
| EP0435441A2 (en) * | 1989-11-20 | 1991-07-03 | Energy Absorption Systems, Inc. | Vehicle crash barrier with friction brake |
| US5039066A (en) * | 1988-11-08 | 1991-08-13 | British Ropes Limited | Safety fences |
-
1996
- 1996-11-29 AU AU74061/96A patent/AU705297B2/en not_active Expired
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3390865A (en) * | 1965-06-19 | 1968-07-02 | Nat Res Dev | Safety fences |
| US5039066A (en) * | 1988-11-08 | 1991-08-13 | British Ropes Limited | Safety fences |
| EP0435441A2 (en) * | 1989-11-20 | 1991-07-03 | Energy Absorption Systems, Inc. | Vehicle crash barrier with friction brake |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1792016A1 (en) * | 2004-08-27 | 2007-06-06 | Hill & Smith limited | Safety barrier anchorage |
| US8596617B2 (en) | 2006-11-06 | 2013-12-03 | Axip Limited | Impact energy dissipation system |
Also Published As
| Publication number | Publication date |
|---|---|
| AU7406196A (en) | 1997-06-05 |
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