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Claims  |
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I claim:
1. An apparatus for anchoring and selectively tensioning and relaxing a
sheet material on a planar surface structure, said apparatus comprising:
an elongated base member having a generally U-shaped lateral cross-section,
said base member including a base plate portion and a pair of laterally
spaced-apart leg portions protruding from said base plate portion, each of
said leg portions having a slot formed therein, said slots facing
generally toward one another, said base member further having a number of
ratchet teeth serially spaced longitudinally therealong;
means for fixedly securing said elongated base member to the planar surface
structure;
a clip member having a clip plate portion received within said slots for
selective slidable longitudinal movement along said base member, an
attachment portion for releasably engaging a portion of the sheet
material, and a pawl portion protruding from said clip plate portion and
resiliently biased toward releasable engagement with any one of said
ratchet teeth on said base member in order to substantially prevent
longitudinal movement of said clip member relative to said base member in
a first longitudinal direction when said pawl portion engages one of said
ratchet teeth;
first means in said clip plate portion to allow a lever member to be
inserted for selectively moving said clip member in a second, opposite
longitudinal direction relative to said base member in order to serially
advance said pawl portion from engagement with one of said ratchet teeth
to engagement with an adjacent ratchet tooth and to tension the sheet
material; and
second means in said clip plate portion to allow a lever member to be
inserted for selectively disengaging said pawl portion from said ratchet
teeth in order to allow movement of said clip member relative to said base
member in said first longitudinal direction and to relax said sheet
material.
2. An apparatus according to claim 1, wherein said attachment portion of
said clip member includes a generally hook-shaped end adapted for
releasable engagement with the sheet material.
3. An apparatus according to claim 2, wherein the sheet material includes
an anchor member secured thereto, said anchor member having a groove
formed therein for releasably receiving said hook-shaped end in a
interlocking engagement with said anchor member.
4. An apparatus according to claim 3, wherein said attachment portion of
said clip member further includes an offset portion offset away from said
base member and disposed adjacent said hook-shaped end, said anchor member
on the sheet material being disposed between said offset portion and said
base member when said hook-shaped end is received within said groove in
said anchor member.
5. An apparatus according to claim 4, wherein said offset portion of said
clip member is resiliently biased into said offset relationship with said
base member.
6. An apparatus according to claim 1, wherein said first means includes an
opening formed in said clip plate portion and is positioned to allow a
lever member to be selectively inserted therethrough into engagement with
said ratchet teeth in order to forcibly urge said clip member in said
second longitudinal direction relative to said base member.
7. An apparatus according to claim 1, wherein there is a discontinuity on
said pawl portion of said clip member, and said second means includes an
opening formed in said clip plate portion and is positioned to allow a
lever member to be selectively inserted through said opening into
engagement with said discontinuity on said pawl portion in order to
forcibly disengage said pawl portion from said ratchet teeth and allow
said clip member to be moved relative to said base member in said first
longitudinal direction.
8. An apparatus according to claim 7, wherein said first means includes a
second opening formed in said clip plate portion and is positioned to
allow a lever member to be selectively inserted therethrough into
engagement with said ratchet teeth in order to forcibly urge said clip
member in said second longitudinal direction relative to said base member.
9. An apparatus for anchoring and selectively tensioning and relaxing a
sheet material display on a billboard structure, the sheet material
display being disposed on a front face of the billboard structure with at
least one end portion extending over an edge of the billboard and along a
portion of a rear face of the billboard structure, said apparatus
comprising:
an elongated base member having a generally U-shaped lateral cross-section,
said base member including a base plate portion and a pair of laterally
spaced-apart leg portions protruding from said base plate portion, each of
said leg portions having a slot formed therein, said slots facing
generally toward one another, said base member further having a number of
ratchet teeth serially spaced longitudinally therealong;
means for fixedly securing said elongated base member to the rear face of
the billboard structure;
a clip member having a clip plate portion received within said slots for
selective slidable longitudinal movement along said base member, an
attachment portion having an attachment end adapted for releasably
engaging a portion of the sheet material display, and a pawl portion
having a discontinuity thereon and protruding from said clip plate portion
and resiliently biased toward releasable engagement with any one of said
ratchet teeth on said base member in order to substantially prevent
longitudinal movement of said clip member relative to said base member in
a first longitudinal direction generally toward the edge of the billboard
structure when said pawl portion engages one of said ratchet teeth, said
clip plate portion having a first opening formed therethrough for allowing
a lever member to be selectively inserted therethrough into engagement
with said ratchet teeth in order to forcibly urge said clip member in a
second, opposite longitudinal direction relative to said base member in
order to serially advance said pawl portion from engagement with one of
said ratchet teeth to engagement with an adjacent ratchet tooth and to
tension the sheet material display in said second longitudinal direction,
said clip plate portion also having a second opening formed therethrough
for allowing the lever member to be selectively inserted therethrough into
engagement with said discontinuity on said pawl portion in order to
forcibly disengage said pawl portion from said ratchet teeth and to allow
movement of said clip member relative to said base member in said first
longitudinal direction to relax said sheet material display.
10. An apparatus according to claim 9, wherein said attachment end of said
attachment portion is generally hook-shaped, the sheet material display
including an anchor member secured to the portion of the sheet material
display extending along a portion of the rear face of the billboard
structure, the anchor member having a groove formed therein for releasably
receiving said hook-shaped attachment end in an interlocking engagement
with the anchor member.
11. An apparatus according to claim 10, wherein said attachment portion of
said clip member further includes an offset portion offset away from said
base member and disposed adjacent said hook-shaped end, said anchor member
on the sheet material display being disposed between said offset portion
and said base member when said hook-shaped end is received within said
groove in said anchor member.
12. An apparatus according to claim 11, wherein said offset portion of said
clip member is resiliently biased into said offset relationship with said
base member. |
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Claims |
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Description |
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BACKGROUND AND SUMMARY OF THE INVENTION
The invention relates generally to an apparatus for anchoring and
selectively tensioning or relaxing a sheet material on a panel structure,
and more particularly for such apparatuses used for anchoring and
selectively tensioning and relaxing or releasing a sheet material display
on a billboard structure.
Large billboards displaying advertising or public service messages are a
common sight along roadways and other areas for communicating messages to
the public. One common type of billboard has a front display face that is
fourteen feet high and forty-eight feet wide. Although other sizes of
billboards are also used, this fourteen foot by forty-eight foot size is
especially advantageous for high visibility along roadways and from
relatively great distances.
Although effective for communicating advertising or public service
messages, the process of positioning a display message on such billboards,
and replacing one display message with another, has been found to be
expensive, time-consuming, and cumbersome. In the past, such display
messages were painted or printed on a paper-like sheet of material, which
was then cut into strips or sections that could be pasted or otherwise
adhered to the front face of the billboard. More recently, large
relatively flexible sheets of synthetic materials were developed,
typically composed of a reinforced nylon material, onto which the display
message was painted or otherwise printed, typically with the use of
computer-aided processes. These large sheet material displays, commonly
referred to as "superflex" material, are then rolled onto a large roll,
which was then lifted into position using a crane or other suitable
lifting apparatuses. The sheet material display is then unrolled onto the
front face of the billboard, with the vertical and horizontal edge
portions of the sheet material display extending around the edges of the
billboard. The edges are then typically anchored and tensioned by way of a
number of separate of flexible strip-and-hook mechanisms, which include a
wheel-type ratchet mechanism for tightening the strap and thereby
tensioning the sheet material display.
The above-described method for anchoring and tensioning the sheet material
display on the billboard, using the strap and ratchet wheel mechanisms
described above, has been found to present a number of significant
disadvantages. First, the personnel involved in anchoring and tensioning
the display sheet are required to carry a large number of the strap and
ratchet wheel mechanisms when climbing onto the rear face of the
billboard, frequently at great heights. Secondly, because of variations in
the supporting structure for the billboard, there is frequently no
conveniently-located portion of the support structure to which the straps
can be anchored. Accordingly, in the case of the large billboards
mentioned above, the erection, anchoring, and tensioning of sheet material
billboard display frequently takes several hours to accomplish and
presents great danger and difficulty to persons performing the task. Also,
because one end of the strap and ratchet wheel mechanisms includes a hook
that must be inserted through an opening in a bar that is in turn hemmed
into the edges of the sheet material, anchoring difficulties are
frequently encountered if the holes in the anchoring bar are not located
near a support member of the billboard supporting structure. As a result,
in such an instance, the opposite end of the strap and ratchet wheel
mechanisms must be secured to the supporting structure by way of ropes,
cables, wire, additional straps, or the like, which is cumbersome,
time-consuming and frequently unsuitable.
Accordingly, the need has arisen for a simpler, more uniform, and more
convenient apparatus for anchoring, tensioning, and subsequently releasing
a sheet material display on a billboard structure. The present invention
seeks to meet this need by providing an apparatus that is associated and
attached to the billboard and that allows for easily and conveniently
tensioning and subsequently relaxing a sheet material display on a
billboard structure.
The apparatus according to the present invention includes an elongated base
member having a generally U-shaped lateral cross-section, with the base
member including a base plate portion and a pair of laterally spaced-apart
leg portions protruding from the base plate portion. Each of the leg
portions preferably includes a slot formed therein, with the slots on the
leg portions facing and opening generally toward one another. The
preferred base portion further includes a number of ratchet teeth serially
spaced longitudinally therealong, and openings formed therein for
receiving fasteners in order to fixedly secure the elongated base member
to the panel or billboard structure, or alternatively including other
known devices for fixedly securing the base member to the panel structure.
The anchoring apparatus of the invention also includes a clip member having
a clip plate portion received within the above-mentioned slots for
selective slidable longitudinal movement along the base member, an
attachment portion for releasably engaging a portion of the sheet material
or an anchoring bar hemmed into the sheet material, and a pawl portion
protruding from the clip plate portion and resiliently biased into
releasable ratcheting engagement with the ratchet teeth on the base
member. Such engagement with any one of the ratchet teeth substantially
prevent longitudinal movement of the clip member relative to the base
member in a first longitudinal direction (toward the edge of the
billboard) when the pawl portion engages one of the ratchet teeth, thus
anchoring the sheet material display in a desired, tensioned state. The
clip member is selectively movable in a second, opposite longitudinal
direction (away from the edge of the billboard) relative to the base
member in order to serially advance the pawl portion from engagement with
one of the ratchet teeth to engagement with an adjacent ratchet tooth,
thereby increasing the tensioning of the sheet material. The pawl portion
is also selectively releasable in order to disengage from the ratchet
teeth in order to then allow movement of the clip member relative to the
base member toward the edge of the billboard, thereby relaxing or
releasing the sheet material for removal.
Preferably, the above-mentioned tensioning of the sheet material is
accomplished by inserting a screwdriver or other lever-type member through
an opening formed in the clip plate portion and into engagement with the
ratchet teeth in order to forcibly pry or urge the clip member with a
pivoting motion of the lever so as to move the clip member relative to the
base member and away from the edge of the billboard. Releasing or
relaxation of the sheet material display is preferably accomplished by
inserting the screwdriver or other lever member through an opening in the
clip plate portion and into engagement with a discontinuity on the pawl
portion of the clip member, thus allowing the resilient pawl portion to be
forcibly disengaged from the ratchet teeth and allowing the clip member to
be moved relative to the base member in longitudinal direction toward the
edge of the billboard, thereby relaxing or releasing the tension on the
sheet material display.
Furthermore, in the preferred embodiment of the present invention, the
attachment portion of the clip member includes a generally hook-shaped end
adapted for releasable engagement with the sheet material or with an
anchoring member or bar secured to the sheet material. Preferably, the
anchoring bar or member includes a groove formed therein for releasably
and interlockingly receiving the hook-shaped end of the attachment portion
of the clip member. The preferred attachment portion of the clip member is
at least partially offset outwardly or rearwardly away from the base
member in an area adjacent the hook-shaped end, thus allowing the
anchoring bar or member on the sheet material to be disposed between the
offset portion and the base member when the hook-shaped end is received
within the groove in the anchoring bar or member. This provides clearance
for tensioning or relaxing movement of the anchored edge of the sheet
material relative to the base member of the apparatus, as well as allowing
for convenient engagement or disengagement of the attachment portion with
or from the sheet material.
Additional objects, advantages and features of the present invention will
become apparent from the following description and appended claims, taken
in conjunction with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 illustrates a typical billboard installation, exemplifying one of
the primary applications of the present invention.
FIG. 2 is a somewhat diagrammatic elevational view of the rear face of the
billboard of FIG. 1, generally illustrating the installation of a number
of anchoring apparatuses according to the present invention for anchoring
and selectively tensioning or relaxing a sheet material display on the
billboard.
FIG. 3 is an enlarged, perspective detail view of one of the anchoring
apparatuses according to the present invention installed on a typical
billboard structure.
FIG. 4 is an elevational view of the anchoring apparatus of FIG. 3.
FIG. 5 is a cross-sectional view taken generally along line 5--5 of FIG. 4.
FIG. 6 is a cross-sectional view taken generally along line 6--6 of FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
FIGS. 1 through 6 depict one preferred, exemplary embodiment of an
anchoring apparatus according to the present invention, which is
particularly adapted for anchoring and tensioning a sheet material display
on a large billboard structure. One skilled in the art will readily
recognize from the following description that the present invention is not
limited to billboard applications, but is also advantageous in other
structures wherein a sheet material is to be anchored and selectively
tensioned or relaxed on a panel structure.
FIGS. 1 and 2 depict a large billboard structure 10, which can be mounted
on the roof of a building 12 or supported from the ground in many typical
installations. In a common construction of such a billboard structure 10,
a relatively flexible sheet material display 14, bearing an advertising or
public service message, is disposed on a front face of the billboard
structure 10, with edge portions of the sheet material display extending
around the edge of the billboard structure and along a portion of the rear
face of the billboard structure 10.
As illustrated in FIGS. 2 and 3, the billboard structure 10 typically
includes a number of panel portions 16, with their associated panel frames
18. In the common fourteen-foot by forty-eight foot size billboard
mentioned above, such a construction would result in twelve four-foot by
fourteen-foot panel portions being secured together by fastening or
securing means, such as lag screws, tie rods, or other securing methods
known to those skilled in the art. As shown diagrammatically in FIG. 2, a
number of anchoring apparatuses 20, according to the present invention,
are secured to the panel frames 18 of the panel portion 16 and grippingly
engage the sheet material display 14, as is shown in more detail in FIG.
3.
Each of the preferred anchoring apparatus 20 for the exemplary billboard
application illustrated in the drawings includes a base member 24, which
has a generally U-shaped lateral cross-section, including a base plate
portion 26 and a pair of laterally spaced-apart leg portions 28 protruding
rearwardly or outwardly from the base plate portion 26, as shown in FIGS.
3 through 6. One or more fasteners 30 extend through openings 32 in the
leg portions 28 in order to fixedly secure the base member 24 to the panel
frames 18 of the panel portions 16. Optionally, however, if necessary or
desired in a particular application, openings 32' can be provided in the
base plate portion 26 in addition to, or in lieu of, the openings 32
extending through the leg portions 28.
Each of the leg portions 28 preferably includes a slot 34 extending
longitudinally therethrough, with the slots 34 preferably facing generally
toward one another and disposed generally at outer edges of the leg
portions 28. A plurality of ratchet teeth 36 are preferably included in
the base plate portion 26, although in certain applications of the present
invention, such ratchet teeth 36 could alternately be provided at
positions other than on the base plate portion 26, as will become apparent
to one skilled in the art.
A clip member 40 includes a clip plate portion 42, whose lateral edges are
preferably slidably received within the slots 34 in the leg portions 28
for selective slidable longitudinal movement relative to the base member
24. The clip member 40 also includes an attachment portion 44, which can
be formed integrally with the clip plate portion 42, as illustrated in the
drawings, or which can alternately be a separate piece secured to the clip
plate portion by fasteners, such as screws, rivets, or other means
suitable for the given application. The attachment portion 44 preferably
includes a generally hook-shaped end 46, which is adapted to grippingly
and anchoringly engage a preferred anchor member or bar 47 secured to the
sheet material display 14, such as the anchoring member 47 shown in the
drawings, which is received within a hem portion 48. The preferred
anchoring member 47 includes a groove 49 formed in one or more of its
edges for receiving the hook-shaped end 46 of the attachment portion 44 in
a generally interlocking, but releasable relationship, shown in FIGS. 3
and 5.
The clip member 40, which is preferably composed of spring steel, also
includes a pawl portion 50, which likewise may be integrally formed
therewith, or attached thereto as shown in the drawings, with the pawl
portion 50 preferably being resiliently biased into engagement with the
ratchet teeth 36, such that when the pawl portion 50 is in such engagement
with any one of the ratchet teeth 36, the clip member 40, and thus the
sheet material display 14 are substantially prevented from longitudinal
movement in a direction toward the edge of the billboard structure 10, as
shown in FIG. 3. In order to securely retain the sheet material display 14
in its desired position on the billboard structure 10, with a desired
amount of tension in order to substantially eliminate or minimize wrinkles
in the sheet material display, the clip member 40 is urged in a tensioning
direction, generally away from the edge of the billboard structure 10
shown in FIG. 3, with the pawl portion 50 resiliently engaging one of the
ratchet teeth 36.
In order to increase the tension on the sheet material display 14, a
tensioning opening 54 is provided in the clip plate portion 42 for
allowing the insertion of a screwdriver or other lever member 60
therethrough into engagement with one of the ratchet teeth 36. After
which, the lever member 60 can be manipulated in a generally prying or
pivoting manner in order to forcibly urge the clip plate portion, and thus
the edge of the sheet material display 14, in a tensioning direction away
from the edge of the billboard structure 10, as shown in FIGS. 3 and 5.
Because the preferred anchoring apparatus 20 is secured to, and thus
permanently associated with, each of the panel portions 16 in the
exemplary application shown in the drawings, such anchoring and selective
tensioning of the sheet material display 14 is accomplished with relative
ease and convenience, using only a common tool, such as a screwdriver, as
a lever member 60. In addition, no separate straps or ratchet wheels need
be provided at a billboard site or carried up onto a billboard structure.
When it is desired to remove or replace a particular sheet material display
14, in order to eliminate or change the message displayed on the billboard
structure 10, a screwdriver or lever member 60 can then be inserted
through a release or relaxation opening 56 in the clip plate portion 42,
into engagement with a hook or discontinuity 52 in the pawl portion 50 in
order to allow the resiliently-biased pawl portion 50 to be pried or
pivoted out of engagement with the ratchet teeth 36. This allows the clip
plate portion, and thus the attachment portion 44, the anchoring member
47, and the edge of the sheet material display 14, to be moved in a second
longitudinal direction, generally toward the edge of the billboard
structure 10, as shown in the detailed perspective view of FIG. 3. Such a
maneuver releases the tension on the sheet material display 14, thereby
allowing the anchoring member 47 to then be moved slightly in a downward
direction (as viewed in FIG. 3) to disengage the hook-shaped end 46 of the
attachment portion 44 from the groove 49 in the anchoring member 47. The
anchoring member 47 can be rotated slightly out of the space 58 between
the offset and preferably resilient attachment portion 44 and the base
member 24, thereby releasing the edge of the sheet material display 14
from the anchoring apparatus 20, and consequently allowing removal or
replacement of the sheet material display 14.
After the display sheet 14 has been removed, the anchoring apparatuses 20
remain secured to the panel frame members 18 and can be left with their
clip members 40 in a relaxed or "loosened" positions generally aligned
with one another to allow for ease of insertion of, and engagement with,
the anchoring member 47 on the display sheet 14 of a new display. This
aids greatly in the erection, anchoring and tensioning of the replacement
display.
The foregoing discussion discloses and describes exemplary embodiments of
the present invention. One skilled in the art will readily recognize from
such discussion, and from the accompanying drawings and claims, that
various changes, modification and variations may be made therein without
departing from the spirit and scope of the invention as defined in the
following claims.
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