Note: Descriptions are shown in the official language in which they were submitted.
105477'~
BACKGROUND AN~ 5ARY ~OE ~7~N~T10N
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 United States Patent Nos. 3,630,474;
3,572,223; 3,349,531 and 3,521,413. 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 propaga-
tion; i.e., one surface of the ruptured coupling slides over ano~her surface
of the coupling during the impact failure process.
It would be desirable if there was avail~ble an improved breakl~way
coupling for support poles, standards and the like.
It would also be desirable if there was available an improved break-
away support assembly of high tensile and compressive strength but which
ruptures when rapidly loaded in a direction normal to its direction of maxi-
mum strength.
It would also be desirable to have an improved method for the sup-
port of standards which provides structures of adequate strength and which
fails readily under impact normal to the longitudinal axis of the standard.
It would further be desirable if there were available an improved
support assembly employing at least one generally vertically disposed support
which, on being impacted by a body such as an automobile, would readily fail
from a horizontally directed impact yet have adequate tensile and compressive
strength in the vertical direction.
According to the present invention there is provided an upright
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1054~77;~
standard assembly comprising the combination of a generally vertical standard,
a base member, a connection member, and 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 any plane containing
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 end defining
a connection member receiving opening therein, said connection member extend-
ing 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, a~d 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 means for
initiating the radial fracture of said coupling body member.
1()54~7'~
A fracture-initiating washer may also be provided in combination
with the connection member, standard, and coupling means, the fracture-
initiating washer being formed of relatively hard material having one or
more teeth formed thereon for cooperation with corresponding slots formed
in the coupling means and
. ~- - 4 -
~oS477~
( exten~ing along the lenyth of the grooves therein from the con-
nection member receiving opening thereof. Preferably the frac-
ture-initiating washer is formed of steel, or other material
harder than the material forming the coupling means, and the
connection member receiving bore extendin~ 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 being threaded.
It is the primary object o the present invention to
provide an assembly for mounting an upright standard including
an inexpensive coupling body that is strong in tension and com-
pression, but will radially fracture easily when the standard is
subjected to a horizontal force. This and other objects of the
present invention will become apparent from an inspection of the
detailed description of the invention, and from the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGVRE 1 is a schematic partially cutaway view of an
assembly in accordance with the present i,nvention;
FIGU~E 2 is a schematic ~iew of a coupling of the pre-
sent invention after rupture by lateral impact;
FIGURE 3 is a schematic isometric representation of
one embodiment of a coupling in accordance with the present in-
O vention;
FIGUl~ 4 is an isometric view of an alternate embodiment
o~ the invention;
~OS477'~
FIGURE 5 is an isometric view of still another embodi-
ment of the invention, as are FIGURES 6 and 8;
FIG~RE 7 is an end view of a further embodiment of
the invention;
FIGURE 9 is a perspective view of an embodiment of
a coupling body according to the present invention like that in
FIGURE 7;
FIG-J~E 10 is a perspective view of another modification
of the coupling body of FIGURE 9;
FIGU~E 11 is a side view of an embodiment according
to the present invention utilizing a toothed washer to facili-
tate the initiati~n of fracture in the coupling;
~IGURE 12 is a perspective view of the coupling of
FIGURE 11; and
FIGURE 13 is a perspective, upside-down view of the
exemplary fracture-initiating washer of FIGURE 11.
DETAILED DESCRIPTION OF THE DRAWINGS
In FIGURE 1 there is a schematic isometric fractional
view of an assembly in accordance with the invention generally
designated by the reference numeral 10. ~he assembly 10 com-
prises in cooperative combination a base or fixed support mem-
ber 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
O 25 13, 13a and 13b and a fourth coupling (now sho~n). A support
1054'77;~
.
member or platc 15 is disposed adjacent the couplings 13, 13a
and 13b 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, 13b and a fourth coupling ~not shown) by means of con-
nection members or bolts 16, 16a, 16b and one not shown. Each
of the couplings, or coupling bodies, 13, 13a, 13b, is symmetri-
cally disposed about any plane containing the generally vertical
axis of connection A extending through connection members 16, 16a
and 16b. An upright member or fixture support 18 is rigidly af-
fixed to the plate 15. The fixture support 18 has affixed
thereto the item desired to be supported, such as street or road-
way lamps, signs, parking meters, warehouse roof supports, traf-
lS fic signals, power or communication lines, pipe lines and thelike. It is understood that such items may be supported by one
or more of such supports, depending on the require~ents of the
particular item to be supported. The couplings 13, 13a, 13b and
a fourth coupling (not shown) haYe relati~ely high tensile and
2~ 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.
In FIGURE 2 there is schematically depicted failure
b~ lateral impact of a coupling 13c such as the couplings 13,
~5 13a and 13b of FIGU~E 1. The body 13c has broken away from the
portion 13c thereby releasing the bolt 16c from the coupling 13c
C ~nd permitting lateral movement of a plate or support 15a through
~hich the bolt 16c passes.
~o5477'~
. In FIGURE 3 there is schematically depicted an iso-
metric view of a coupling in accordance with the present inven-
tion generally designated by the reference numeral 20 and suit-
able for use as couplings 13, 13a, 13b and the fourth coupling
(not shown) of FIGURE 1. The coupling 20 has an elongate body
or portion 21 of a generally cylindrical configuration having a
first end 22, a second end 23 and an axis of coupling, or axis
of connection, a generally coaxial with the body 21. The body
21 defines a generally axially extending connection receiving ca-
vity 25 extending toward the second end 23. The body portiondefining the cavity also defines internal bolt or threaded con-
nected engaging threads 26. In the region of the connection re-
ceiving cavity 25, the body 21 defines a plurality of longi-
tudinally extending regions of weakness, channels or grooves 27.
lS A circumferential external grooves 28 defined by the body 21
intersects the axially extending slots or grooves 27 generally
adjacent the centralmost portion of the threads 26. A second
internally threaded connection-receiving cavity 29 is defined
in the body 21. The cavity 29 is generally coaxially disposed
with the cavity 25. A radially extending circumferentially dis-
posed wrench-recieving opening 30 is defined by the body 20.
The opening 30 is disposed to permit installation by means of
a hook spanner wrench.
The coupling 20 in FIGURE 3 is readily employed in
an assembly such as the assembly of FIGURE 1 to replace the coup-
lings 13, 13a, 13b and the fourth coupling (not shown). When
C; , . ,
.
~o~4'77'~
- the couplings, such as the couplings 20 are subjected to lateral
impact, rupture of the couplings occurs generally at a location
of the circular groo~e 28 which serves to prevent propagation
of a crack or cracks to the end 23 of the coupling and opposit-
ly disposed to the direction of impact permitting ready release
of the connecting bolts such as the bolts 16, 16a, 16b and 16c.
Under normal, i.e., non-impact conditions, the coupling pro-
vides ample tensile and compressive strength, but is relatively
weak when subjected to impact in a plane normal to the axis A
of the coupling 20.
In FIGURE 4 there is depicted a side view of an
alternate embodiment of a coupling of the invention generally
designated by the reference numeral 35. The coupling 35 has a
body 36 of generally elongate cylindrical configuration gener-
ally similar to the body of ~IGURE 2. The body 36 defines aninternal passageway 37 extending therethrough having an internal
surface 38. The surface 38 defines a thread adapted to receive
a fastener such as a mating threaded bolt. A plurality of slots
or channels 39 interrupt the surface 38 and are generally equi-
angularly dispoed about the axis B of the body 36. The body36 has an external surface 41 which is also interrupted by the
slots 39, the slots 39 define longitudinally extending regions
of weakness or minimum strength of the coupling 35. A spanner
hole 42 is defined by the body 36 generally in a like manner to
the opening 30 of FIGURE 3.
_ g ~
105477Z
The embodiment of FIGURE 4 is particularly desirable
~ when ~olt release from the cavity 25 is desired with minimum
lateral impact. The embodiment of FIGURE 4 is employed in ap-
plications similar to that of FIGURE 3 but provides an increased
resistance to rupture when subjected to lateral impact.
In FI~URE 5 there is depicted an alternate em~odiment
of the invention generally designated by the reference numeral
45. The coupling 45 comprises a body portion 46 having a first
end 47 and a second end 48. The body 46 has an axis of connec-
tion generally designated as C. At the first end 47 of the body46 is defined an axially extending internal passageway 51 having
an internally threaded surface and adapted to receive a threaded
connection such as a bolt. A plurality of Y-shaped grooves 52
are disposed in the outer surface of the body 46 adjacent the
cavity 51 to provide longitudinally extending regions of weak-
ness or minim~m strength. A second axially extending threaded
cavity 54 is disposed within the second end of the body 46 and
is generally coaxially disposed with respect to the axis C and
is also provided with an internally threaded surface. The sec-
ond end 48 of the body 46 has a generally frustoconical configu-
ration which tapers toward the first end 46.
The en~odiment of FIGURE 5 is partiGularly advanta-
geous when the couplin~ is employed to connect a standard and
a base wherein the base has substantially less physical strength
than the material of the standard, such as when connecting a
steel standard to a concrete base.
O` ,.
.
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1054 77~
(' In FIG~RE 6 there is schematically illustrated an
~, ~
isometric view of an alternate coupling in accordance with the
invention generally designated by the reference numeral 65. The
coupling 65 comprises a bolt receiving portion 66 of generally
cylindrical configuration. The portion 66 defines an internally
threaded passageway 67 axially disposed within the body 66 and
a plurality of grooves 68 disposed about the cavity 67 and extend-
ing axially and parallel thereto to provide a plurality of longi-
tudinally extending regions of weakness or regions of minimum
strength. The portion 66 is rigidly affixed to a base or sup-
port end 71. The base portion 71 has a generally flat plate-
like configuration and defines a plurality of peripherally dis-
posed openings 72 passing entirely therethrough and adapted to
receive anchor bolts or like fastening means.
The embodiment of FIG~RE 6 is particularly useful when
a breakaway coupling supporting a metal standard must be affixed
to a low strength body such as a wooden deck.
In FIG~E 7 there is depicted an alternate em~odiment
of the invention generally designated by the reference numeral
55. The view as depicted in FIGURE 7 is an end view. The coup-
ling 55 has a body portion 56 having an internal passageway 57
extending entirely therethrough and having an internally threaded
surface to engage suitable attaching means such as bolts, studs
and the like. The body 56 is of a square configuration and in
each of the external faces thereof has a groove 58 generally
centrally disposed therein and extending toward the axis of the
passageway 57. The grooves have generally straight parallel sides
-- 11 ~ . ' .
. , ~. ,, ., . ,, _ _ ___ _ .. . .. . . ....
~054~77Z
and terminate adjacent the passageway 57 in a shaxp V inwardly
pointing configuration.
, The embodiment of FIGURE 7 is particularly desirable
when small quantities of couplings are to be made and can be
readily fabricated f rom square bar stock with a minimum of
machine operation.
In FIG~RE 8 there is depicted an alternate embodiment
of the invention designated by the reference numeral 75. The
coupling 75 has a body 76 having the general configuration of
the body 21 of FIGURE 3 and a connector-receiving cavity 77
having an unthreaded internal surface. The body 76 remote from
the,cavity 77 is affixed to a base plate 78 having a plurality
of mounting aperatures 79 defined therein. The body 76 is fur-
ther affixed to the base 78 by means of a plurality of fillet
plates or braces 81 of triangular configuration radially spaced
about the body 76. The coupling of FIGURE 8 is particularly
desirable for small signs requiring a single standard which are
affixed to a low strength deck and are attached to the coupling
75 by a pin, bolt, set screw or adhesive entering the cavity 77
to engage a standard or support, not shown.
A minor modification of the coupling 55 of FI~URE 7
is shown at 55' in FIGURE 9. The coupling 55' is substantially
the same as the coupling 55 in FIGU~E 7, having a plurality of
grooves 58 extending along the length thereof, except that six
(6) groo,ves 58 are provided instead of just four, and radial
fracture initiating means, shown generally at 83, are provided
O ' . . ',
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lOS477'~
in order to reduce the impact forces necessary to radially
(. fracture the coupling 55' to release a connection member 16
therefrom. The fracture initiating means 83 may comprise shar-
pened bottom portions 84 of portions 85 of coupling 55' which
define the grooves 58, the grooves 58 thus having a slightly
greater cross-sectional area at the end of the coupling 55'
having the connection member receiving opening 57 therein, than
the cross-sectional area further down the coupling 55'. The
tapered portions 84 decrease the impact force necessary to radi-
ally fracture the coupling 55', while not significantly detract-
ing from the tension and compression forces that may be applied
to the coupling 55' without fear of failure thereof during normal
use. In FIGURE 10, another modification of the radial fracture
initiating means 83 is provided for the coupling 55', in the form
of slots 87 formed in the grooves and extending from the end of
the coupling body 55' having the connection member receiving open-
ing 57 therein, parallel to the axis of connection A, the slots
87 extending a distance D less than the length L of the connec-
tion member 16 received by the opening 57. The portions 85
which define the grooves 58 in the FIGU~E 10 embodiment have
rounded circumferential portions thereof instead of the pointed
circumferential portions shown in FIGU~ES 7 and 9.
FIGURE 11 shows an assembly according to the present
invention having further component parts associated therewith
for initiating the fracture in the coupling 55"'. The coupling
55"' is substantially the same as the coupling 55" of FIGURE 10
.
1()54'772
exccpt that the slots 87' formed therein preferably are sliyhtly
wider than the slots 87 in coupling 55", and preferably the
portion 90 thereof, e~tending the distance D' -between the top
of the coupling 55"' and the bottom of the slots 87', is not
5 threadecl, rather only the portion T extending from the bottom
- ' of the slots 87' downwardly, being threaded, the distances
' D' ~ T - the length L of the connection member 16 received
by the opening 57 in the coupling 55-'. Disposed between the
plate 15 of a generally vertical standard and the coupling 55"'
10 is a fracture-initiating washer 93 having one or more teeth'
94 formed thereon for cooperating with the slots 37' formed
. - in the coupling 55"', and having a bore 95 (see FIGURE 13)
formed therethrough for allowing passage of the connection
member 16 therethrough. Each of the teeth 94 preferably have -
15 terminal portions 96 thereof that are flat, and preferably thebore 95 therethrough has smooth walls 97 so that no positive,
holding engaqement between the connection member 16 and the
washer 93 is provided. The washer 93 is preferably made of
harder material than is the coupling 55"'; for instance, when
20 the coupling 55"' is made of aluminum (as is usual) the washer
93 niay be made of steel. While only three teeth have been
shown for the ~lasher 93 in FIGURE 13, it is to be understood
tilat any number of teeth 94 may be provided, such as one- tooth
94 for each slot 87' of the cbupling (the coupling also may
.` 25 have as many grooves or slots as deslred), one tooth 94 for
every other slot 81', etc. Teeth 94 localize the entire im-
C~ pact load, resulting in more efficient splitting of the
couplinq body.
,
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.
. . .
.. . . . ..
~054~77'~
~ (- 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 frac-
ture 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
lQ bodies can be either cast or extruded. For instance, the
coupling 45 in FIGURE 5 preferably could be cast from alumi-
num, while the coupling 55 shown in FIGURES 7, 9 and 10 may
readily be extruded from aluminum.
Generally in the preparation of couplings in accor-
dance with the present invention it is desirable to use from 2
to 20 longitudinally extending regions of weakness. Such longi-
tudinally extending regions of weakness most beneficially are
grooves formed in the outer wall of the coupling and surrounding
the connector-receiving cavity. For ~ost applications, the
depth of the groove ranges from about 10 to about 90 percent
o~ 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
~054~7'~
a radius of up to 0.2 inch may be tolerated. A minimum of
two grooves or regions of weakness should be present, and gen-
erally not more than 20 of such grooves are employed. Bene-
ficially 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 coup-
ling, 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
10 on a side which is remote from the direction of impact. Coup-
lings in accordance with the present invention generally fail
because of tensile rupture initiated at the bottom of the longi-
tudinally extending grooves and do not in general rely upon
shear failure. ~hus, the couplings in accordance with the pre-
15 sent invention provide a relatively high tensile and compressive
strength relative to the impact force required to cause failure
app~ied in the direction normal to the axis of coupling. Em-
ploying couplings in accordance with the present invention,
the impact required for failure-in any given design is quite
20 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
25 and description. For this reason, it is to be fully understood
that all of the foregoing is intended to be merely illustrative
O and is not to 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.
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