Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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AUTOMATIC RECOVERY SWING SIGN STRUCTURE
This invention relates to yieldab]e structures. ~ore
particularly, this invention relates to yieldable swing
sign structures which recover automatically.
On vehicle roadways r particularly in areas where
roadways are covered with snow for a part of the year/ a
continuing problem is the damage and destruction of
highway signs and delineators situated at the side of the
road for the guidance and warning of passing motorists.
Of necessity such signs and delineators must be in close
proximity to the roadway so that they can be readily
observed by passing motorists. Because of their proximity
to the edge of the road they are subject to damage by weed
mowers, snow plows and occasionally by automobiles.
A specific example is where signs are located by
narrow one-lane bridges along rural roads that have
concrete railings or abutments on both sides. Highway
department standards in some states require that one foot
by three foot reflective markers be installed directly
above these concrete abutments. Because various farm
equipment is wider than the space between these markers,
the markers many times are knocked down whenever the
equipment goes over the bridges. Also, snow plows blast
heavy snow against these markers causing the markers to
become so bent or twisted that they are no longer readable
by approaching motorists. In some areas as many as 15
percent o~ all rural signs require repair each spring
because of the damage inflicted during the winter.
These problems have been around for many years and
because of the expense of procuring, installing and
replacing roadway markers, the need to solve these
problems is great. The prior art teaches various
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solutions to these problems but because of various
reasons, i.e., too costly, poor maintenance and
impracticality, they have not been widely accepted.
Accordingly, the present invention provides a yield-
able structure comprising a yieldable member;support
member for supporting said yieldable member, said
yieldable member being substantially parallel to said
support member; pivoting means coacting with said support
member and said yieldable member for pivoting said yield-
able member, said pivoting means having a pivotal axis
about which said yieldable member pivots; positioning
means for positioning said yieldable member in a selected
position in relationship to said support member; limiting
means for limiting the displacement of said yieldable
member from the selected position in relationship to said
support member; and torsion means coacting with said
support member and said yieldable member for resisting a
radial displacement of said yieldable member from said
selected position, said torsion means coacting axially
through said pivotal axis of said pivoting means providing
a c~nter of rotation for said pivoting means, a first
portion of said torsion means being substantially parallel
to said yieldable means and said support member.
One embodiment of the invention will now be
described, by way of example, with reference to the
accompanying drawings in which:
FIG. 1 is an illustration o~ a highway sign in
accordance with the present invention.
FIG.2 is a detail of the highway sign illustrated in
FIG. 1.
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FIG. 3 is a cross section representation of the
pivoting mechanism showin~ the torsion bar in accordance
with the present invention.
FIGS. 4a, 4b, 4c and 4d are representations of the
pivoting mechanism illustrated in Figs. 1, 2 and 3 in
accordance with the present invention.
FIG. 5 is a planar view of the yieldable member and
the support member in the selected position in accordance
with the present invention.
FIG. 6 is a planar view of the yieldable member
displaced to the limit of its rotation about the pivoting
mechanism in accordance with the present invention,
FIG. 7 i5 an illustration of a second embodiment of a
highway sign in accordance with the present invention.
FIG. ~ is an illustration of a third embodi.ment of a
highway sign in accordance with the present invention.
FIG. 9 is an illustration of a horizontal sign in
accordance with the present invention.
FIG. 10 is an illustration of a swing gate in
2Q accordance with the present invention.
For a better understanding of the present invention,
together with other and further objects, advantages and
capabilities thereof, reference is made to the ~ollowing
disclosure and appended claims in connection with the
above-described drawing.
As shown in Fig. 1 is an illustration of a yieldable
structure 10 employed for supporting a highway sign. The
structure 10 comprises a yieldable member 20 and a support
member 30 for supporting the yieldable member 20. The
yieldable member 20 is a frame with a highway sign 40
attached. The support member 30 is substantially vertical
and elongated and the yieldable member 20 is substantially
parallel to the support member 30. The structure 10 has
two pivoting mechanisms 50. The pivoting mechanism 50 has
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two parts, a first "L" shaped portion 51 having a first
opening 84 and a second "L" shaped portion 52 havin~ a
second opening 85 shown in Figs. 2, 3, 4c and 4d. The
first "L" shaped portion 51 is fixed to the yieldable
member 20 and coacts with the second "Ll' shaped portion
52. The second "L" shaped portion 52 is fixed to the
support member 30 and coacts with the first "L" shaped
portion 51 as shown in Figs. 2 and 3. The combination of
the first "L" shaped pivot member 51 coacting with the
second "L" shaped pivot member 52 comprise the pivoting
mechanism 50. The pivoting mechanism 50 has a pi~otal
axis 60 shown in Fig. 3. The first "L" shaped pivot
member 51 and the second "L" shaped portion 52 shown in
Fig. 3 have the same pivotal axis 60 as the pivoting
mechanism 50.
The first "L" shaped pivot member 51 and the second
"L" shaped pivot memher 52 have bearings 63 and 64 through
which a torsion bar 70 passes as illustrated in Fig. 3.
The torsion bar 70 acts like a hinge pin for the pivot
mechanism 50 as well as resisting a radial displacement of
the yieldable member 20 and resisting an axial displace-
ment of the yieldable member 20 in relation to the support
member 30. The first "L" shaped pivot member 51 and the
second "L" shaped member 52 have positioning notches 54,
55, 56 and 57 shown in Fig. 3. Figs. 4a, 4b and 4c
illustrate the positioning notches 54 and 56 of the first
"~" shaped pivot member 51. The first "L'l shaped pivot
member 51 shown in Fig. 4c is the same as the second "L"
shaped pivot member 52 illustrated in Fig. 4d. The
notches 54, 55, 56 and 57 all are made to impose an angle
of 40 from the horizontal plane of the pivot members 51
and 52. Shown in Fig. 4b are the notches 54 and 56
illustrating the 40 angle. The coacting of notches 54
and 56 with notches 55 and 57 respectively determine a
selected position which the yieldable member 20 has with
respect to the support member 30, illustrated in Fig. 5.
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Whenever a force, ha~ing a horizontal vector great enough,
is applied to the yieldable member 20, the notches 54 and
56 lift out of notches 55 and 57 respectively shown in
Fig. 3 by sliding along an inclined plane having the 40
angle shown in Fig. ~b. Once the notches 54 and 56 are
lifted out of notches 55 and 57 the yieldable member 20 is
free to be displaced carrying the highway sign ~0 attached
thereto in an arc pivoting about the torsion bar 70 which
passes through the pivotal axis 60 of the pivot mechanism
50 shown in Fig~ 3. The toxsion bar 70 resists the
displacement orce with a torsion force of its own. The
torsion force increases the greater the displacement
distance from the original selected position. The
yieldable member 20 can be displaced thxough an arc up to
but not exceedin~ a pre-determined position, such as 90,
from the selected position if sufficient force is applied.
Rotation limiting mechanism 58 and 59, shown in Fig. 5 and
6, limit the displacement of the yieldable member 20. One
of the rotation limiting mechanisms 58 located on one side
of the first "L" shaped pivot member 51 coacts with one of
the rotation limiting mechanisms 59 located on the inside
face of the second "L" shaped pivot member 52 when the
yieldable member 20 traverses an arc of 90 from the
selection position; thereby, preventing the yieldable
member 20 from proceeding past the 90 position in respect
to its original selected position. Once the force which
displaced the yieldable member 20 has been removed or
reduced sufficiently for the resisting torsion force of
the torsion bar 70 to overcome the displacement force the
yieldable member 20 will be returned to its original
selected position by the resisting torsion force of the
torsion bar 70. The resisting torsion force decreases as
the yieldable member 20 comes closer to its original
selected position and reduces to zero once the yi~ldable
member 20 reaches the selected position.
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The pivoting mechanism 50 may have shear pin
apertures 80 and 81 located in the first "L'l shaped pivot
member 51 and shear pin apertures 82 and 83 located in the
second "L" shaped pivot member 52 to provide an
alternative means for increasing the resistance to initial
displacement of the yieldable member 20. This is
accomplished by placing shear pins in the apertures 80 and
81 aligned with apertures 82 and 83. Shear pins of
different shear forces can be utilized to permit design
lQ variations.
The torsion bar 70 has a first portion 71 which is
substantially parallel to the support member 30 and the
yieldable member 20 as illustrated in Fig. 2. The torsion
bar 70 has a second portion 72 and a third portion 73,
shown in Fig. 2, which are substantially perpendicular to
the first portion 71, the yieldable mem~er 20 and the
support member 30. ~rhis configuration imparts a general
"S" shape to the tor.sion bar 70. The second portion 7~
coacts with the support member 30 and the third portion 73
coacts with the yieldable member 20 shown in Fig. 2 so
whenever t~le yieldable member 20 is displaced from the
selected position a torque is created in the torsion bar
70 which provides the torsion force to resist the
displacement of the yieldable member 20. The general "S"
shape of the torsion bar 70 also resists any axial
displacement of the yieldable member 20 ~rom the support
member 30 by the coacting of the second portion 72 with
the support member 30 and the coacting of the third
portion 73 with the yieldable member 20. The resistance
to an axial displacement helps maintain the engagement of
notches 54 and 56 with corresponding notches 55 and 57.
The length of torsion bar 70 can be changed to increase or
decrease the torque required depend.ing upon -the design,
the size, and weight of the yieldable member. As shown in
Fig. 7 and 8, different highway signs may require more
than one torsion bar~ Shown in Fig. 7 is a second
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embodiment of a yieldable structure 12 having a support
member 32, a yieldable member 2~, two torsion mechanisms
72, two pivoting mechanisms 10~ and a highway sign 42.
Shown in Fig. 8 is a third embodiment o~ a yieldable
structure 11, having a support member 31, a yieldable
member 21, three torsion mechanisms 71, three pivoting
mechanisms 101 and a highway sign 41. By changing the
number of torsion bars and, or the length of the bars, a
great variety of designs and variables may be incorporated
into the same basic support member, yieldable m~mber and
pivoting mechanisms.
In accordance with the invention the yieldable
structure can also be used to make horizontally supported
signs as shown in Fig. 9. Illustrated in Fig. 9 is a
horizontal structure 13 having a horizontal support member
33, a horizontal yieldable member 23, two torsion
mechanisms 73, two pivoting mechanisms 103 and a sign 43.
It can also be used to make yieldable mail bo~ supports,
yieldable display signs, swing gates, or any application
where a supported frame is displaced in an arc about a
vertical or horizontal support member by a force having a
horizontal vector. Fig. 10 illustrates an example of how
the instant invention can be used to make a swing gate 14
having a support member 34, a yieldable member 24, a
torsion mechanism 74 and a pivoting mechanism 104.
While there has been shown and described what is at
present considered the preferred embodiment of the
invention, it will be obvious to those skilled in the art
that various changes and modifications may be made therein
without departing from the scope of the invention as
defined by the appended claims.
