GB1574061A - Breakaway coupling assembly with fracture-initiating washer - Google Patents
Breakaway coupling assembly with fracture-initiating washer Download PDFInfo
- Publication number
- GB1574061A GB1574061A GB35324/77A GB3532477A GB1574061A GB 1574061 A GB1574061 A GB 1574061A GB 35324/77 A GB35324/77 A GB 35324/77A GB 3532477 A GB3532477 A GB 3532477A GB 1574061 A GB1574061 A GB 1574061A
- Authority
- GB
- United Kingdom
- Prior art keywords
- coupling
- connection member
- washer
- grooves
- connection
- 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
- 230000008878 coupling Effects 0.000 title claims description 102
- 238000010168 coupling process Methods 0.000 title claims description 102
- 238000005859 coupling reaction Methods 0.000 title claims description 102
- 239000000463 material Substances 0.000 claims description 9
- 229910000831 Steel Inorganic materials 0.000 claims description 5
- 229910052782 aluminium Inorganic materials 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- 239000010959 steel Substances 0.000 claims description 5
- 230000004044 response Effects 0.000 claims description 3
- 230000004075 alteration Effects 0.000 claims description 2
- 239000004411 aluminium Substances 0.000 claims description 2
- 230000000977 initiatory effect Effects 0.000 claims description 2
- 238000012986 modification Methods 0.000 claims description 2
- 230000004048 modification Effects 0.000 claims description 2
- 230000000712 assembly Effects 0.000 description 2
- 238000000429 assembly Methods 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 229910001369 Brass Inorganic materials 0.000 description 1
- 229910000906 Bronze Inorganic materials 0.000 description 1
- 235000003332 Ilex aquifolium Nutrition 0.000 description 1
- 241000209027 Ilex aquifolium Species 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 229910001297 Zn alloy Inorganic materials 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 239000010974 bronze Substances 0.000 description 1
- 229910010293 ceramic material Inorganic materials 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 description 1
- SLGWESQGEUXWJQ-UHFFFAOYSA-N formaldehyde;phenol Chemical compound O=C.OC1=CC=CC=C1 SLGWESQGEUXWJQ-UHFFFAOYSA-N 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 229920001568 phenolic resin Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 230000008569 process Effects 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01F—ADDITIONAL WORK, SUCH AS EQUIPPING ROADS OR THE CONSTRUCTION OF PLATFORMS, HELICOPTER LANDING STAGES, SIGNS, SNOW FENCES, OR THE LIKE
- E01F9/00—Arrangement of road signs or traffic signals; Arrangements for enforcing caution
- E01F9/60—Upright bodies, e.g. marker posts or bollards; Supports for road signs
- E01F9/623—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection
- E01F9/631—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection specially adapted for breaking, disengaging, collapsing or permanently deforming when deflected or displaced, e.g. by vehicle impact
- E01F9/635—Upright bodies, e.g. marker posts or bollards; Supports for road signs characterised by form or by structural features, e.g. for enabling displacement or deflection specially adapted for breaking, disengaging, collapsing or permanently deforming when deflected or displaced, e.g. by vehicle impact by shearing or tearing, e.g. having weakened zones
Landscapes
- Engineering & Computer Science (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Connection Of Plates (AREA)
Description
(54) BREAKAWAY COUPLING ASSEMBLY WITH
FRACTURE-INITIATING WASHER
(71) I, DOUGLAS BLANCHARD CHIS- HOLM, a citizen of the United States of
America, of 1906 Memory Court, Vienna,
Commonwealth of Virginia, United States of
America, do hereby declare the invention for which I pray that a patent may be granted to me, and the method by which it is to be performed to be particularly described in and by the following statement:- This invention relates to upright standard assemblies, in particular such assemblies having a frangible or break-away coupling.
Several varieties of breakaway couplings are known for the support of light standards, signs, parking meters, and the like.
Some of these couplings or connectors are shown in U.S. Patent Nos. 3,630,474; 3,572,223; 3,349,531 and 3,521,413, the teachings of which are herewith incorporated by reference thereto. Such breakaway connectors or couplings desirably fail readily when the supported structure is subjected to lateral impact such as may be applied by a colliding automobile. However, the coupling must have substantial tensile and compressive strength. Yet such couplings desirably fail under the impact force in such a manner as to substantially reduce accident severity to motorists who are sufficiently unfortunate to be closely involved with the failure of such a coupling
Many breakaway coupling devices employ a shear or sliding mode of crack propagation, i.e. one surface of the ruptured coupling slides over another surface of the coupling during the impact failure process.
According to the present invention there is provided an upright standard assembly comprising the combination of
(a) a generally vertical standard,
(b) a base member,
(c) a connection member,
(d) means affixed to one of said base member or said standard for receiving said connection member to releasably attach said standard to said base member, and having a generally vertical axis of connection extending through said connection member, said means comprising coupling means for receiving said connection member and for fracturing radially with respect to said axis of connection in response to an impact force applied to said standard in a generally horizontal direction generally normal to said axis of connection, said coupling means comprising a coupling body generally symmetrically disposed about said axis of connection, said body having a first end in operative association with said base member, and a second end in operative association with said upright standard, at least one of said first and second ends defining a connection member receiving opening therein, said connection member extending into said body a predetermined length along said axis of connection, said body having a plurality of grooves which define regions of minimum strength, said grooves surrounding said connection member receiving opening of said coupling body and extending from said connection member receiving end of said body parallel to said axis of connection and extending at least the length of said predetermined length of said connection member received by said body, and extending so that upon an impact force in a generally horizontal direction acting upon said standard, said coupling means will radially fracture to thereby release said connection member and thereby provide detachment of said standard from said base member, and
(e) means for initiating the radial fracture of said coupling body member, said means comprising (i) at least one fractureinitiating slot formed in at least one of said grooves and extending from the end of said coupling body defining said connection member receiving opening parallel to said axis of connection, said at least one slot extending a distance less than said predeter mined length of said connection member received by said body, and (ii) a radial fracture-initiating washer having at least one radially extending tooth formed thereon for receipt by said at least one fractureinitiating slot, said washer disposed between one of said generally vertical standard and said base member, and said coupling body, and said connection member extending through said washer. In this arrangement, upon an impact force in a generally horizontal direction acting upon the standard, the coupling will radially fracture to thereby release the connection member and provide detachment of the standard from the base member.
The grooves in the coupling body may extend the entire length of the body, and the body may be formed of aluminum, and either cast or extruded. Preferably the fracture-initiating washer is formed of steel, or other material harder than the material forming the coupling means, and the connection member receiving bore extending through the washer is not threaded.
Similarly, the top portion of the coupling means extending below the bottom termination of the fracture-initiating slots therein preferably is threaded.
By the present invention it is possible to provide an assembly for mounting an upright standard, including an inexpensive coupling body, that is strong in tension and compression in the vertical direction, but will radially fracture easily and rapidly when the standard is subjected to a horizontal force.
Embodiments of the present invention are described below with reference to the appended drawings:- Figure 1 is a schematic partially cutaway view of an assembly embodying the present inventionS
Figure 2 is a side view of part of the assembly shown in Fig. 1, slightly modified:
Figure 3 is a perspective view of the coupling member shown in Figure 2; and
Figure 4 is a perspective, upside-down view of the fracture-initiating washer shown in Figure 2.
Referring to Figure 1, the assembly 10 comprises in coperative combination a base or fixed support member 12 having disposed therein four anchor means 14, 14a, 14b and one not shown, such as anchor bolts.
Affixed to each of the anchor means or bolts are frangible or breakaway couplings 13, 1 3a and 1 3b and a fourth coupling (not shown). A support member or plate 15 is disposed adjacent the couplings 13, 13a and 1 3b and the fourth coupling (not shown) and remote from the base 12. The base 12 and plate 15 are maintained in fixed spaced relationship by the couplings 13, 13a, 13b and the fourth coupling (not shown). The plate 15 is affixed to the couplings 13, 13a and 1 3b and a fourth coupling (not shown) by means of connection members, in this case bolts 16, 16a, 16b and one not shown.
Each of the couplings, or coupling bodies 13, 13a, 13b is symmetrically disposed about a generally vertical axis of connection extending through connection members 16, 16a and 16b. An upright member or fixture support 18 is rigidly affixed to the plate 15. The fixture support 18 has affixed thereto the item desired to be supported, such as street or roadway lamps, signs, parking meters, warehouse roof supports, traffic signals, power or communication lines, pipe lines and the like. It is understood that such items may be supported by one or more of such supports, depending on the requirements of the particular item to be supported. The couplings 13, 13a, 13b and a fourth coupling (not shown) have relatively high tensile and compressive strength, but rupture readily when impact force is applied in a direction normal to the axis of the coupling, that is, in a horizontal plane.
Couplings in accordance with the present invention can be prepared from a wide variety of materials. The property that is most important is that the material be subject to fracture under conditions of use. A wide variety of metals can be employed, including aluminum, either cast or machined, steel, brass, bronze, stainless steels, zinc alloys and the like. Various plastic materials are also useful including phenol-formaldehyde resinous compositions, polystyrene, nylon and the like. Ceramic materials are also suitable. The coupling bodies can be either cast or extruded.
The coupling means 13 is shown in more detail in Figure 2, though here it is shown as a generally cylindrical non-tapering body with grooves (described below) over its whole length; this is merely an alternative to the partly tapered partly grooved shape shown in Fig. 1.
The coupling means 13 has longitudinal grooves 58 extending its whole length and fracture-initiating slots 87' extending along the line of these grooves a distance D' from the end of the coupling. The portion 90 of the internal bore 57 of the coupling 13 which extends a distance D' from the end of the coupling is not threaded. The portion T (Fig. 2) extending from the bottom of the slots 87' downwardly is threaded and receives the connection member 16. The distances D' + T is equal to the length L of the connection member 16 received in the opening 57 of the coupling 13.
As shown in Fig. 4 the fracture-initiating washer 93 has teeth 94. The end portions 96 of each of the teeth 94 are flat and the the bore 95 has smooth walls so that when the washer is in position as shown in Fig.
2 there is no positive frictional engagement between the washer and the connection member 16.
As shown in Fig. 2 in the completed assembly the teeth 94 of the washer 93 cooperate with the slots 87' in the coupling member 13.
When the coupling is subjected to a horizontal force arising from an impact on the standard 18, the teeth 94 localise the entire impact load on the coupling member 13 resulting in an efficient splitting of the coupling member 13 generally along the longitudinal grooves 58.
The washer 93 is preferably made of a harder material than that of the coupling 13; for example when the coupling member 13 is of aluminium (as is preferred) the washer 93 may be of steel. Any suitable number of teeth 94 may be provided on the washer 93 for example one tooth 94 for each slot 87' or one tooth for every other slot, (similarly the coupling member 13 may have any suitable number of grooves or slots).
Generally, in the preparation of couplings in accordance with the present invention it is desirable to use from 2 to 20 longitudinally extending regions of weakness that is, grooves formed in the outer wall of the coupling and surrounding the connectorreceiving cavity. For most applications, the depth of the groove ranges from about 10 to about 90 percent of the thickness of the wall (discounting any threads which may be present), and beneficially from about 15 to 50 percent of the wall thickness. Beneficially such grooves should terminate in a relatively sharp V configuration, preferably having a radius not greater than about 0.002 inch. However, in some instances a radius of up to 0.2 inch may be tolerated. A minimum of two grooves or regions of weakness should be present, and generally not more than 20 of such grooves are employed.Beneficially for most applications, between three and six grooves are adequate.
Generally for most purposes the grooves are symmetrically disposed about the longitudinal axis of the coupling, permitting the coupling to be installed with disregard to orientation about the axis. However, in certain instances the appropriate longitudinal regions of weakness may be applied only on a side which is remote from the direction of impact. Couplings in accordance with the present invention generally fail because of tensile rupture initiated at the bottom of the longitudinally extending grooves and do not in general rely upon shear failure. Thus, the couplings in accordance with the present invention provide a relatively high tensile and compressive strength relative to the impact force required to cause failure applied in the direction normal to the axis of coupling.
Employing couplings in accordance with the present invention, the impact required for failure in any given design is quite uniform from specimen to specimen.
As is apparent from the foregoing specification, the present invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. For this reason, it is to be fully understood that all of the foregoing is intended to be merely illustrative and is not be construed or interpreted as being restrictive or otherwise limiting of the present invention, excepting as it is set forth and defined in the hereto-appended claims.
WHAT I CLAIM IS:
1. An upright standard assembly comprising the combination of
(a) a generally vertical standard,
(b) a base member,
(c) a connection member,
(d) means affixed to one of said base member or said standard for receiving said connection member to releasably attach said standard to said base member, and having a generally vertical axis of connection extending through said connection member, said means comprising
coupling means for receiving said connection member and for fracturing radially with respect to said axis of connection in response to an impact force applied to said standard in a generally horizontal direction generally normal to said axis of connection, said coupling means comprising a coupling body generally symmetrically disposed about said axis of connection, said body having a first end in operative association with said base member, and a second end in operative association with said upright standard, at least one of said first and second ends defining a connection member receiving opening therein, said connection member extending into said body a predetermined length along said axis of connectlon, said body having a plurality of grooves which define regions of minimum strength, said grooves surrounding said connection member receiving opening of said coupling body and extending from said connection member receiving end of said body parallel to said axis of connection and extending at least the length of said predetermined length of said connection member received by said body, and extending so that upon an impact force in a generally horizontal direction acting upon said standard, said coupling means will radially fracture to thereby release said connection member and thereby provide detachment of said
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (11)
- **WARNING** start of CLMS field may overlap end of DESC **.the bore 95 has smooth walls so that when the washer is in position as shown in Fig.2 there is no positive frictional engagement between the washer and the connection member 16.As shown in Fig. 2 in the completed assembly the teeth 94 of the washer 93 cooperate with the slots 87' in the coupling member 13.When the coupling is subjected to a horizontal force arising from an impact on the standard 18, the teeth 94 localise the entire impact load on the coupling member 13 resulting in an efficient splitting of the coupling member 13 generally along the longitudinal grooves 58.The washer 93 is preferably made of a harder material than that of the coupling 13; for example when the coupling member 13 is of aluminium (as is preferred) the washer 93 may be of steel. Any suitable number of teeth 94 may be provided on the washer 93 for example one tooth 94 for each slot 87' or one tooth for every other slot, (similarly the coupling member 13 may have any suitable number of grooves or slots).Generally, in the preparation of couplings in accordance with the present invention it is desirable to use from 2 to 20 longitudinally extending regions of weakness that is, grooves formed in the outer wall of the coupling and surrounding the connectorreceiving cavity. For most applications, the depth of the groove ranges from about 10 to about 90 percent of the thickness of the wall (discounting any threads which may be present), and beneficially from about 15 to 50 percent of the wall thickness. Beneficially such grooves should terminate in a relatively sharp V configuration, preferably having a radius not greater than about 0.002 inch. However, in some instances a radius of up to 0.2 inch may be tolerated. A minimum of two grooves or regions of weakness should be present, and generally not more than 20 of such grooves are employed.Beneficially for most applications, between three and six grooves are adequate.Generally for most purposes the grooves are symmetrically disposed about the longitudinal axis of the coupling, permitting the coupling to be installed with disregard to orientation about the axis. However, in certain instances the appropriate longitudinal regions of weakness may be applied only on a side which is remote from the direction of impact. Couplings in accordance with the present invention generally fail because of tensile rupture initiated at the bottom of the longitudinally extending grooves and do not in general rely upon shear failure. Thus, the couplings in accordance with the present invention provide a relatively high tensile and compressive strength relative to the impact force required to cause failure applied in the direction normal to the axis of coupling.Employing couplings in accordance with the present invention, the impact required for failure in any given design is quite uniform from specimen to specimen.As is apparent from the foregoing specification, the present invention is susceptible of being embodied with various alterations and modifications which may differ particularly from those that have been described in the preceding specification and description. For this reason, it is to be fully understood that all of the foregoing is intended to be merely illustrative and is not be construed or interpreted as being restrictive or otherwise limiting of the present invention, excepting as it is set forth and defined in the hereto-appended claims.WHAT I CLAIM IS: 1. An upright standard assembly comprising the combination of (a) a generally vertical standard, (b) a base member, (c) a connection member, (d) means affixed to one of said base member or said standard for receiving said connection member to releasably attach said standard to said base member, and having a generally vertical axis of connection extending through said connection member, said means comprising coupling means for receiving said connection member and for fracturing radially with respect to said axis of connection in response to an impact force applied to said standard in a generally horizontal direction generally normal to said axis of connection, said coupling means comprising a coupling body generally symmetrically disposed about said axis of connection, said body having a first end in operative association with said base member, and a second end in operative association with said upright standard, at least one of said first and second ends defining a connection member receiving opening therein, said connection member extending into said body a predetermined length along said axis of connectlon, said body having a plurality of grooves which define regions of minimum strength, said grooves surrounding said connection member receiving opening of said coupling body and extending from said connection member receiving end of said body parallel to said axis of connection and extending at least the length of said predetermined length of said connection member received by said body, and extending so that upon an impact force in a generally horizontal direction acting upon said standard, said coupling means will radially fracture to thereby release said connection member and thereby provide detachment of saidstandard from said base member, and (e) means for initiating the radial fracture of said coupling body member, said means comprising (i) at least one fracture-initiating slot formed in at least one of said grooves and extending from the end of said coupling body defining said connection member receiving opening parallel to said axis of connection, said at least one slot extending a distance less than said predetermined length of said connection member received by said coupling body, and (ii) a radial fractureinitiating washer having at least one radially extending tooth formed thereon for receipt by said at least one fracture-initiating slot, said washer disposed between one of said generally vertical standard and said base member, and said coupling body, and said connection member extending through said washer.
- 2. An assembly as recited in Claim 1 wherein said grooves in said coupling body extend the entire length of said body.
- 3. An assembly as recited in claim 1 or claim 2 wherein said washer is made of a material harder than the material of which said coupling body is made.
- 4. An assembly as recited in claim 3 wherein said washer is made of steel and said coupling body is made of aluminum.
- 5. An assembly as recited in any one of claims 1 to 4 wherein said connection member is a threaded rod, and wherein said coupling body connection member receiving opening is threaded for receipt of said threaded rod connection member therein, and wherein no threads are provided in the portion of said connection member receiving opening of said coupling body from the end thereof to the termination of said at least one fracture-initiating slot.
- 6. An assembly as recited in any one of claims 1 to 5 wherein said washer has a bore therein for receipt of said connection member therethrough, and wherein said bore has relatively smooth surfaces, no threading being provided therein.
- 7. An assembly as recited in any one of claims 1 to 6 wherein a slot is provided in said coupling member associated with each groove therein.
- 8. An assembly as recited in claim 7 wherein said washer has one tooth corresponding to each of the slots formed in the coupling body with which it cooperates.
- 9. An assembly as recited in claim 7 wherein said washer has one tooth for every other slot formed in the coupling body with which it cooperates.
- 10. An assembly as recited in any one of claims 1 to 9 wherein both said first and second ends of said coupling body have connection receiving openings therein, and wherein one connection member extends from said base member to said coupling body, and another connection member extends from said standard through said washer to said coupling body.
- 11. An upright standard assembly substantially as herein described with reference to and as shown in the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB35324/77A GB1574061A (en) | 1977-08-23 | 1977-08-23 | Breakaway coupling assembly with fracture-initiating washer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB35324/77A GB1574061A (en) | 1977-08-23 | 1977-08-23 | Breakaway coupling assembly with fracture-initiating washer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1574061A true GB1574061A (en) | 1980-09-03 |
Family
ID=10376444
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB35324/77A Expired GB1574061A (en) | 1977-08-23 | 1977-08-23 | Breakaway coupling assembly with fracture-initiating washer |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB1574061A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0146401A3 (en) * | 1983-12-20 | 1986-04-16 | Geoffrey Lawson Norman Stratham | Improvements in or relating to methods and apparatus for supporting tubular posts |
-
1977
- 1977-08-23 GB GB35324/77A patent/GB1574061A/en not_active Expired
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0146401A3 (en) * | 1983-12-20 | 1986-04-16 | Geoffrey Lawson Norman Stratham | Improvements in or relating to methods and apparatus for supporting tubular posts |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PCNP | Patent ceased through non-payment of renewal fee |