Note: Descriptions are shown in the official language in which they were submitted.
~ 1~ 2034~07
~ APPARATUS FOR COVERING AN O~:N1NG
D~lN~ IN A STRUCTURE
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a cover
apparatus for covering an opening and a fastener
apparatus for detachably stretching and fastening the
cover apparatus to a frame structure which defines that
opening.
2. Description of the Prior Art
Numerous protective covers for preventing rain,
debris and wind from disrupting the contents of such
places as a pickup truck bed are currently available.
Generally, the covers are made of some sort of fabric
which is detachably fastenable to a rigid frame so as to
enclose and protect a given area. The covering
materials used are generally stretchable to the extent
that once they are in a position, they are pulled taut
and then attached to the frame by numerous methods such
as snaps, y o..~..cts and anchoring elements, or hook-and-
loop fasteners.
The use of hook-and-loop type fasteners to
detachably fasten a cover to a rigid frame forms the
subject matter of U.S. Patent No. 4,272,119 issued to
one Robert M. Adams. U.S. Patent No. 4,757,854 issued
to Gary R. Rippberger, and the unpatented prior art
described in that patent, relate to fastener apparatus.
In the Rippberger patent, the end of the covering fabric
is attached to a tongue. In engaging the cover, the
tongue is slipped into a groove in the rigid frame. The
unpatented prior art described in the Rippberger patent
also utilizes a tongue-and-groove means of attachment.
The Rippberger patent differs from the unpatented prior
art in two respects. First, in the Rippberger patent,
the width of the tongue is greater than the depth of the
groove, which thereby purportedly eases the process of
~`
2 2034907
insertion and removal of the tongue from the groove;
whereas, in the unpatented prior art, the tongue is
completely enclosed by the groove. Second, in the
Rippberger patent, the cloth covering only partially
covers the tongue surface, which permits the cloth
covering to maintain some of its force directed parallel
to the tongue; whereas in the unpatented prior art, the
tongue is completely encased by the fabric covering and
thus the force against that covering tends to loosen the
tongue from the groove.
Although the Rippberger patent is seen as an
improvement over the unpatented prior art, there still
remains several problems with Rippberger which this
invention solves. Because of the tongue-and-groove
method of attachment utilized in the Rippberger patent,
the fabric has to be stretched in order to insert the
tongue into the groove. Once the tongue is completely
inserted into the groove, the tension on the cover
fabric is lessened. Not only does this appear to be
somewhat cumbersome to use, but after repeated use, the
reduced tension in the cover fabric might allow the
cover to rattle and come loose. Apparently, because of
this problem, the Rippberger patent employs a relatively
narrow and deep groove in order to aid in the prevention
of inadvertent detachment of the cover.
The present invention solves these and other
problems associated with the prior art.
SUMMARY OF THE INVENTION
The present invention relates to a versatile
apparatus for covering various openings. It involves
relatively simple, yet non-obvious, improvements over
the prior art wherein a generally L-shaped end plate is
attached to a flexible, stretchable cover and in
covering the opening, a base of the end plate pivots
about a lip portion. By so doing, the cover material
need not be stretched in order for the end plate to
- 3 2034907
initially engage the lip portion. Of even greater
significance is the fact that when the opening is fully
covered, most of the force resulting from the stretching
of the cover is directed toward maintaining the cover in
the covered position.
It is, therefore, a benefit of the present
invention that it provides a novel and improved method
and apparatus for covering an opening such as the bed of
a pickup.
A second benefit is the provision for a more
secure engagement of the frame by the cover and end
plate.
An additional benefit of the invention is the
ease of engagement and security for continuing
engagement of the lip portion with the end plate by use
of an angle between the leg and base portions of the end
plate which is greater than that of a right angle.
Another benefit of the invention is that by
folding over the vinyl coated cover material at the end
opposite the end plate, the cover provides its own
protective covering for itself when it is in the
uncovered state.
Still another benefit of the invention is that
the use of cross bars prevent the cover from sagging
into the opening.
Still another benefit of the invention is the
use of stiffening means such as a fabric stiffener along
the side edges of the cover to keep the hook-and-loop
fastener strips on the cover and the support structure
from engaging until after the end plate has engaged the
lip portion.
Still another benefit of the invention is the
use of a lock arrangement which automatically locks the
cover in the covered position and which can be released
by pressing on the top of the cover.
These and various other advantages and features
of novelty which characterize the invention are pointed
4 2034907
out with particularity in the claims annexed hereto and
forming a part hereof. However, for a better
understanding of the invention, its advantages and
objects obtained by its use, reference should be made to
the drawings which form a further part hereof, and to
the accompanying descriptive matter, in which there is
illustrated and described a preferred embodiment of the
invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE 1 is a perspective view of an embodiment
of a flexible cover in accordance with the principles of
the present invention attached to a pickup with the
cover being disposed in the covered position;
FIGURE 2 is a fragmentary perspective view of
the embodiment shown in Figure l illustrating operator
movement of the end plate toward a lip portion of the
frame, and also showing cross bars and semi-flexible
plastic members which extend transversely of the pickup
bed and aid in supporting the flexible cover;
FIGURE 3 is a bottom plan from underneath the
cover which shows the support frame and flexible cover
in the covered position;
FIGURE 4 is an enlarged fragmentary sectional
view as seen generally along line 4-4 of Figure 3 which
illustrates the end plate in a fastened position and
illustrates in phantom line the end plate in an
unfastened position where it first engages the lip
portion of the frame;
FIGURE 5 is an enlarged fragmentary sectional
view as seen generally along line 5-5 of Figure 3 which
shows the cover in the covered position and shows the
lock in the latched position where it engages the end
plate and shows in phantom line the lock in the stored
position;
FIGURE 6 is a fragmentary perspective view of
the cover in the uncovered position illustrating the
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cover rolled up proximate the front end of the pickup
bed;
FIGURE 7 is a fragmentary sectional view
similar to Figure 4 but depicting a second embodiment of
the invention, wherein the apparatus is shown in a first
operative position;
FIGURE 8 is a fragmentary sectional view
similar to Figure 7, wherein the apparatus is shown in a
second operative position;
10FIGURE 9 is a fragmentary perspective view
showing a flexible cover constructed according to the
embodiment of Figures 7 and 8 being removed from a
pickup bed;
FIGURE 10 is a fragmentary perspective view of
a cover constructed according to the embodiment of
Figures 7-9, illustrating the cover rolled up proximate
the front end of the pickup bed;
FIGURE 11 is a first cross-sectional view
depicting how a cover constructed according to the
second embodiment of the invention is mounted to a frame
of a pickup bed;
FIGURE 12 is a second cross-sectional view
depicting an improved mounting arrangement for a front
end of the cover, which is provided in the second
embodiment of the invention;
FIGURE 13 is an enlarged partial view
illustrating an embodiment of a hook and loop fastener
arrangement used to attaching crossbars to the cover;
and
30FIGURE 14 is a partial sectional view of the
front end plate.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
Referring now to the drawings, there is
illustrated a preferred embodiment of the present
invention, wherein reference numeral 10 designates the
cover. Figure 1 illustrates the cover 10 in use on the
6 2034907
bed of a pickup truck. Figure 2 shows the flexible,
stretchable fabric cover 10 attached to a substantially
rigid/ extruded aluminum, end plate 20 which comprises a
base portion 22 and a leg portion 24 interconnected so
as to form an end plate having a generally L-shaped
cross section. Although, in the preferred embodiment
shown, the end plate is a continuously extruded L-shaped
plate, it will be appreciated that only selected
portions of the end plate 20 might include a leg portion
24 and a base portion 22. Furthermore, the end plate 20
might have other configurations; e.g., the end plate 20
might have a somewhat T-shape where the base portion 22
is the top of the T and the leg portion 24 is the
vertical stem of the T. In the embodiment shown, the
cover 10 includes a hem 11 including a cord member 13
which is inserted in the hem 11, the hem 11 being
inserted and retained in a channel 21 at the distal end
of the end plate 20 facing away from the tailgate 39.
In alternate embodiments, the cover 10 might be attached
to the leg portion 24 intermediate the base portion 22
and the distal end of the leg portion 24.
Figure 2 also illustrates a support frame
structure 30 fastened by fasteners 31 to an inside upper
edge of the pickup bed and comprising an L-shaped
horizontally extending longitudinal base portion 32, and
a raised longitudinal portion 34 extending above and
inclined toward the pickup bed. The portion 34 forms a
bottom shelf portion 15 which rests on top of the pickup
bed side walls, a foam padding 17 being adhesively
attached to the shelf portion 15. Members 36 having an
inclined portion 35 and a lip portion 37 are suitably
fastened to the support frame structure 32 by fasteners
33 proximate the back end of the pickup bed. As
illustrated in Figures 2 and 4, when covering the pickup
bed, the base portion 22 of the end plate 20 is placed
by the operator to engage the lip portion 37 of the
member 36. The lip portion 37 functions as a pivot
7 2~)349~7
about which the end plate 20 pivots. The inclined
portion 35 provides a cavity/recess for the base portion
22 to pivot into. It will be appreciated that numerous
frame structures might be used in accordance with the
principles of the present invention. Indeed, in some
applications, a separate frame structure might not be
present. For example, the pickup bed itself might serve
as the frame.
The cover 10 is suitably attached to a front
end of the pickup bed by a frame member 11 such that the
cover 10 can be rolled up and secured proximate the
front end of the pickup bed in an uncovered state when
not in use.
Figure 3 is a view of the cover 10 shown in
Figures 1 and 2 from underneath.
Figure 4 illustrates the act of completing the
covering of the pickup bed opening. In that figure, the
end plate 20 and the cover 10 have been unrolled and the
base portion 22 of the end plate 20 is shown in phantom
line engaging the lip portion 37 in an unfastened
position. In the unfastened position, the cover 10 is
not stretched tight and is loose. The leg portion 24 of
the end plate 20 is then depressed by the user and
pivoted downward, until as shown in Figure 4, the leg
portion 24 comes to rest on a stop 38 in the fully
fastened position. When going from the unfastened to
the fastened position, the end plate 20 stretches the
cover 10 tight and fastens the cover 10 in the covered
position. In that position, the base portion 22 is
securely seated in the cavity/recess under the inclined
portion 35. The act of depressing the leg portion 24
against the stop 38 also stretches the cover 10 which
creates a force along the length of the cover 10 and
which thereby facilitates maintaining the base portion
22 under the inclined portion 35 in the fastened
position. In the fastened position, the stretched cover
10 also forces down on the end plate 20 proximate the
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intersection of the leg and base portions which forms a
peak/crest 9 along the end plate 20 which is the highest
point of the end plate 20. As illustrated in Figure 4,
the base portion 22 includes an enlarged ridge 23 which
comes into contact with a plastic wear surface 29 of the
frame 30 as the end plate 20 is pivoted into the
fastened position. In some embodiments, the base
portion 22 may actually be made to deflect somewhat as
the ridge 23 comes into contact with the wear surface
29. In the preferred embodiment, the end plate 20 is
deflected upward slightly as the ridge 23 swipes across
the surface 29. After the ridge 23 swipes across the
surface 29, the downward force exerted by the cover lO
forces the base portion 22 down onto the surface 29.
This is facilitated by the inclined surface of the base
portion 22 intersecting with the lip portion 37. The
ridge 23 cooperates with the surface 29 to assist in
maintaining the end plate 20 in the fastened position by
providing resistance to upward pivoting of the end
plate. Also, in the preferred embodiment shown, the end
plate 20 includes a wear plate 27 attached by fastener
28 to the base portion 22 so as to make contact with the
lip portion 37 during the pivotal motion. When the end
plate 20 is fully depressed into the fastened position,
it generates an audible feedback as it hits the stops 38
which lets the user know the cover is securely closed.
In the preferred embodiment shown, the end plate 20,
assisted by the tension force of the cover 10, literally
snaps into place.
As illustrated in Figure 4, the angle A between
the leg portion 24 and the base portion 22 of the end
plate 20 is greater than 90 degrees. From an
operational standpoint, this particular configuration
has several advantages. Because of the angle A, when
the base portion 22 cooperatively engages the lip
portion 37, the cover 10 is not stretched at that point
in time, thereby reducing wear on the cover 10 and
9 2034907
permitting ease of cooperative engagement. In addition,
when the leg portion 24 abuts the stop 38, then because
of the angle A, the base portion 22 is inserted further
under the inclined portion 35. This permits additional
safety, in that more force is required in order for the
base portion 22 to be removed from the fully fastened
position. As illustrated in Figure 4, when in the
closed or latched position, the leg portion 24 of the
end plate 20 is inclined dGwnwardly and substantially
covers th~ tailgate 39 of the pickup. The stops 38
provide sufficient clearance for the tailgate 39 to be
open without having to open the cover 10. In alternate
embodiments of the invention, the stops 38 need not be
present. By being inclined downwardly, the end plate 20
resists forces due to wind or jarring of the pickup
which might tend to pivot the leg portion 24 upward and
thus unfasten the cover. This is accomplished at least
in part, by the design of the end plate 20 which
converts any such forces to a generally downward force
on the crest 9 of the end plate 20, thereby increasing
resistance between the ridge 23 and the surface 29. As
noted above, the ridge 23 engages the surface 29 to
resist opening or pivoting of the end plate 20. In
alternate embodiments, the wear surface 29 might be
replaced by other surfaces such as the sides of the
pickup bed.
In the preferred embodiment, the cover 10 is
attached to the end plate 20 by straps 19 attached at
one end to the bottom of the cover 10 and at the other
end to the base portion 22 of the end plate 20 proximate
the front end of the end plate 20 by suitable fasteners
25. By having the cover 10 strapped to the front end of
the end plate 20 and attached to the back end of the end
plate 20, as the end plate 20 is rolled with the cover,
the straps eliminate an additional fold. If the cover
were attached only to the back end of the end plate 20,
on the very first fold there would be no cover 10 being
2034907
folded since in typical use the end plate 20 will be
rolled over the top of the cover 10. However, in the
embodiment shown, on the very first fold, the cover 10
is folded with the end plate 20 so as to thereby reduce
the total number of folds required by one.
Additionally, when unrolling the cover 10 into the
covered position, this arrangement prevents the end
plate 20 from hitting the tail gate 39. It will be
appreciated that in alternate embodiments this feature
need not be present.
Also illustrated in Figures 2 and 3 are cross
bars 40 and semi-flexible plastic members 42. The cross
bars 40 extend transversely of the pickup bed and
prevent the cover from sagging into the opening by
resting on the frame 32 and aid in covering and
uncovering the opening. The cross bars 40 are retained
in sleeves 43 sewed onto the bottom of the cover 10.
When the cover 10 is initially placed over the frame 30,
the semi-flexible plastic members 42 extend beyond the
ends of the sleeves 43 and hold up the edges of the
cover so as to help prevent hook-and-loop fastener 44,
disposed along the side edges of the cover, from
engaging with cooperating hook-and-loop fastener 46
disposed along the sides of the frame 34. Hook-and-loop
fasteners 44 and 46 might be VELCRO~. It will be
appreciated that in alternate embodiments, the fasteners
might be any suitable type such as hook and hook
material, other self-adhesive material, magnetic tape on
steel, tongue and groove, etc. In yet other
embodiments, fasteners might not be used.
In the embodiment shown, the semi-flexible
plastic members 42 are an integral part of the sleeves
43 and extend beyond the end of the sleeves. By holding
up the outer edges of the cover 10, the sleeves 43 and
semi-flexible plastic members 42 permit the cover to be
stretched and fastened before the hook-and-loop
fasteners 44 and 46 are engaged to one another. To
2034907
11
securely engage the hook-and-loop fasteners 44 and 46,
the user simply walks along the sides of the pickup and
forces the side edges of the cover 10 down onto the
frame 34 such that the hook-and-loop fasteners 44 and 46
S engage. This eliminates the necessity of continually
having to adjust the engagement of the hook-and-loop
fasteners 44 and 46 when covering the opening and allows
uniform stretching of the cover 10 since the end plate
20 can be pivoted into the fastened position without the
hook-and-loop fasteners 44 and 46 being yet engaged.
In the particular embodiment illustrated in
Figures 4 and 5, a lock element is illustrated. Figure
4 shows the lock 50 in the storage position. The L-
shaped lock 50 is comprised of a base portion 52 and a
leg portion 54. The leg portion 54 is pivotally
attached by member 51 beneath the base of the frame 30.
The lock 50 is under tension in its stored position such
that when pivoted away from the frame 30, the lock 50
springs upward and engages the base portion 22 of the
end plate 20. When the lock 50 is in its locked
position, the base portion 52 does cooperatively engage
the base portion 22 of the end plate 20. In the
embodiment shown, the ridge 23 facilitates retention of
the lock 50 with the end plate 20. The use of the lock
50 prevents the accidental or deliberate unauthorized
uncovering of the cover 10 by a person. By engaging the
base portion 22, the base portion 52 of the lock 50
prevents the leg portion 24 of the end plate 20 from
pivoting upwardly and releasing the cover 10.
Figure 6 illustrates use of a storage strap 60
in an embodiment of the present invention. When the
cover is rolled up into the uncovered state, a first
hook-and-loop fastener attached to a storage strap 60 is
detachably fastened to a second hook-and-loop fastener
62 which maintains the cover 10 rolled up in the
uncovered state. In the particular embodiment shown is
Figure 3, the storage strap 60 is positioned closer to
203 4 907
12
one longitudinal slde of the cover 10. This permits the
engagement and release of the storage strap 60 to be
accomplished by the user from one side of the vehicle.
The top of the cover 10 in the preferred
embodiment has a vinyl coating 63 to keep out water. In
the embodiment shown, the cover 10 is folded
transversely back on itself proximate the front end of
the pickup bed such that the vinyl coating 63 extends
around the underside of the cover 10 as is illustrated
in Figure 3. When the cover 10 is rolled up, the vinyl
coating 63 on the underside of the cover 10 encircles
the rolled cover 10 so as to protect the cover 10 from
the elements.
Referring now to Figures 7-14, a second
preferred embodiment of the invention will now be
described. As is best shown in Figures 7 and 8, the
second embodiment 110 of the invention includes a cover
112 which is provided with a vinyl coating on each of
its two surfaces. The double coating provides for less
shrinkage during use, a higher tear strength than a
cover which has only a single surface coated, and will
withstand lower temperatures than a single coated cover.
As is also shown in Figures 7 and 8, a modified
end plate 114 includes a base portion 115 and a leg
portion 117. Leg portion 117 is provided with a flat
lower surface 116, which is constructed to engage a flat
upper surface 158 of the support frame structure 30 when
the cover apparatus is in its locked position. In this
way, the modified end plate 114 and its flat lower
surface 116 obviates the need for additional stop
members, such as the stop members 38 which are provided
in the embodiment of Figure 5. A sealing gasket 118 is
provided on a distal portion of the flat lower surface
116, for sealingly engaging an upper surface of the
tailgate 39.
As is further shown in Figures 7 and 8, an
improved locking arrangement 120 is provided for
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13
automatically locking the end plate 114 into a fixed,
stretching position with respect to the support frame
structure 30. Locking arrangement 120 preferably
includes a pawl element 122 which is constructed and
arranged to engage the enlarged ridge 23 on the base
portion 115 of the modified end plate 114. A flexible
leaf spring 124 is cantilevered with respect to the
support frame structure 30 by a connector 127, as is
shown in Figure 7. Pawl 122 is connected to the end of
leaf spring 124 which in turn is connected to support
frame structure 30. As a result, leaf spring 124 biases
pawl 122 toward the base portion 115 of the modified end
plate 114 so as to automatically engage the ridge 23 of
the end plate 114 upon pivoting the end plate 114
downward so as to close the cover such that the cover
114 is automatically locked in the closed position. The
locking arrangement 120 further includes an upright
member 134 attached to the leaf spring 124 by a bolt 136
for releasing the pawl element 122 from the ridge 23
upon being pressed downward as illustrated by the arrow
in Figure 8. Since an upper end of the upright member
134 is adjacent the cover 112, an operator can simply
push down on the cover 112 in an area vertically aligned
with the upright member 134 so as to release the locking
arrangement 120. This allows the cover 112 to be opened
without having to open the tailgate 39.
In the embodiment which is illustrated in
Figures 7 and 8, connector 127 includes an adjustment
bolt 126 having a head 128, a stud 130 and an adjustable
nut element 132. Adjusting the connector 127 allows the
pawl to be moved back and forth for proper alignment
with the ridge 23.
Referring now to Figures 9 and 13 of the
drawings, the second embodiment of the invention
includes a plurality of crossbars 40 that extend across
almost the entire width of the cover 112. The crossbars
40 are attached to the cover 112 proximate their ends by
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14
a hook and loop fàstener arrangement 138. The hook and
loop fastener arrangement 138 includes a loop material
138a adhesively attached to the crossbars 40 and a hook
material 138b sewn to the cover 112. The hook material
138b is sewn proximate its midsection so that its end
portions are free to wrap around the loop material 138a
on the crossbars 40. Each end portion will circumvent
roughly half the circumference of the loop material
138a. Thus the sewn portion of the hook material 138b
will be disposed intermediate the end of each of the
crossbars 40 and the cover 112 when the crossbars are
attached to the cover. This facilitates retaining the
crossbars 40 in place.
The crossbars 40 support the cover 112 during
use. Straps 140 connect the cover 112 to the end plate
114, as is also shown in Figure 9. Of course, the
straps might also be attached to the crossbars 40. The
straps 140 facilitate positioning of the end plate 114
relative to the lip portion 37 of the members 36. The
straps 140 facilitate folding of the cover 112 onto the
end plate 114.
Looking now to Figure 10, another feature of
the second embodiment of the invention is the provision
of a heavy fabric stiffener 142 which is sewn along each
side of the cover 112 adjacent to the hook and loop
fasteners 46. In the embodiment shown, the fabric
stiffener 142 is roughly four inches wide and extends
substantially the full length of the cover 112. The
fabric stiffener 142 stiffens the sides of the cover 112
so as to facilitate holding the loop material 46 along
the sides of the cover 112 away from the hook material
46 on the support structure so as to prevent inadvertent
engagement of the hook and loop fastener 46 prior to
stretching the cover 112 lengthwise of the truck bed
during the covering process. Once the cover 112 is
stretched and secured with the end plate 114, the user
then goes along the sides of the cover 112 and presses
2Q34907
. 15
the sides of the cover 112 onto the support structure so
as to engage the hook and loop fastener 46 and thus
secure the sides of the cover 112.
In the preferred embodiment of the invention,
the straps 140 are sewn onto the fabric stiffener 142 as
well. In addition, the hook material 138b is also sewn
onto the fabric stiffener 142.
Figure 11 illustrates the connection of a
modified support frame 144 to the box 146 of a pickup
truck or equivalent structure. As may be seen in Figure
11, the box 146 of a pickup truck commonly has an inside
wall 148. The modified support frame 144 includes a
side rail 150 having a lower vertical portion 152, a
horizontal inwardly extending portion 154, an inclined
portion 156 which supports the hook and loop fastener
strip 46, and a raised longitudinal portion 34, which
has a flat upper surface 158. According to the second
embodiment of the invention, a C-type clamp 160 is used
to secure the lower, vertical portion 152 of side rail
150 to the inside wall 148 of the pickup truck box 146.
C-type clamp 160 includes a C-shaped element 162 having
a first clamping end 164 and a second end 166 through
which a clamping bolt 168 is threaded. A resilient pad
170 may be positioned between the inside wall 148 of box
146 and the outer surface of vertical side rail portion
152, as is shown in Figure 11. By turning bolt 168 in a
first direction, side rail 150 may be clamped to box
146. Those two elements may be disconnected by turning
bolt 168 in a second, opposite direction. Several of
the C-type clamps may be provided along the length of
side rail 150 for a secure connection to the box 146 of
a pickup truck.
In the preferred embodiment the same plate
configuration is used for both the end plate and the
front plate to attach the cover 112 to the front of the
pickup truck box 146. Both of the plates 114 are made
of extruded aluminum in the preferred embodiment.
~- 16 2034907
Looking now to Figures 12 and 14, an improved connecting
arrangement 174 for connecting the front end plate of
the cover assembly to the side rail 150 of frame 144
will now be discussed. The end plate 114 includes a
channel 171 having vertical walls 172 and a two
horizontal walls 173 separated by a groove or opening.
According to the second embodiment of the invention, a
lower surface 176 of horizontal walls 173 act in
conjunction with an upper clamping surface 178 of a
cantilevered clamp element 180 to securely clamp the
raised longitudinal portion 34 of side rail 150. The
cantilevered clamp element 180 is secured to the lower
surface 176 by means of a mounting nut and bolt assembly
182. An adjustment nut and bolt assembly 184 passes
through the cantilevered clamp element 180 and is
inserted into the channel 171 for urging the
cantilevered clamp element 180 toward the surface 176
upon tightening of the bolt assembly, which causes the
raised longitudinal portion 34 of side rail 150 to be
securely clamped between surfaces 176, 178. A clamping
arrangement 174 is provided on each side of the front
end plate 114, so that the front end plate 114 may be
connected to each of the side rails 150 in an adjustable
manner which allows for transverse movement of the front
end plate 114 so as to facilitate alignment and which
allows for longitudinal movement along the frame 144 so
as to facilitate adjustment of the cover tension.
It is to be understood, however, that even
though numerous characteristics and advantages of the
present invention have been set forth in the foregoing
description, together with details of the structure and
function of the invention, the disclosure is
illustrative only, and changes may be made in detail,
especially in matters of shape, size and arrangement of
parts within the principles of the invention to the full
extent indicated by the broad general meaning of the
terms in which the appended claims are expressed.
