Note: Descriptions are shown in the official language in which they were submitted.
CA 02234302 1998-04-07
1
'TRACTOR TRAILER COVER ASSEMBLY'
TECHNICAL FIELD
The present invention relates to semi-trailer vehicles
and more particularly to methods of covering cargo on semi-
trailers, such as 'flat deck' trailers.
BACKGROUND ART
Most durable goods and raw materials are shipped by semi-
trailer vehicles on the public highways of the developed
world. These vehicles are known to have a tractor unit and a
semi-trailer unit, the trailer coming in a variety of
arrangements depending on its intended cargo. The trailer,
for example, may be a van type with a substantially weather
proof interior cargo hold, or a flat bed or flat deck trailer.
In the latter case, the cargo must be covered in some fashion
to protect the cargo from the elements. Conventionally this
is done by flexible tarps wrapped around the cargo and
fastened in place with rope or elastic fastener materials.
Other covers for the cargo on a flat deck trailer are
sold under the tradenames "ROLL BACK" or "ROLL TITE". These
covers are individually installed and permanently fitted to
each individual flat deck trailer. This is done by modifying
the trailer by removing the 'rub rail' from the periphery of
the trailer. Other tarping arrangements include rack and tarp
arrangements which have modified posts placed along the
periphery of the flat deck trailer to position plywood sheets
in an upright position. The tarp is then stretched over the
cargo or, in the case of the rack and tarp arrangements,
stretched over the space between the sheets to provide a
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measure of weather protection for the cargo.
Though tarps arrangements such as this are generally
satisfactory, they do have some inherent weaknesses. For
example, the tarps are relatively heavy and difficult to
handle when manually stretched over the cargo. They tend to
rip or simply become unfastened due to the buffeting wind
forces exerted on the tarp during use. In either case, the
cargo can become exposed to the elements and therefore be
damaged. Tarped flat deck trailers also do not have important
clearance lighting, thus increasing the risk of traffic
accidents.
It is an object of the present invention to provide
obviate these disadvantages.
DISCLOSURE OF THE INVENTION
Briefly stated, the invention involves a cover for a
semi-trailer vehicle having a cargo support surface bordered
by a pair of longitudinal edge regions, the cover comprising
a roof and a pair of side walls forming a cargo receiving
passage therebetween; each of the pair of side walls
terminating at a longitudinal free edge region to expose the
cargo receiving passage to the cargo support surface, lifting
means for lifting the cover between a first position above the
cargo support surface and a second position in abutment with
the cargo support surface, and coupling means for removably
coupling each of the longitudinal free edge regions to a
corresponding longitudinal edge region.
In another aspect of the present invention, there is
provided a method of covering cargo on a semi-trailer vehicle
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having a cargo support surface bordered by a pair of
longitudinal edge regions, comprising the steps of:
providing a cover with a roof and a pair of side walls
forming a cargo receiving passage therebetween;
providing each of the pair of side walls with a
longitudinal free edge region in order to expose the cargo
receiving passage to the cargo support surface,
lifting the cover to a first position above the cargo
support surf ace ;
lowering the cover to a second position in abutment with
the cargo support surface, and
removably coupling each of the longitudinal free edge
regions to a corresponding longitudinal edge region.
In another aspect of the present invention, there is
provided a cover for a semi-trailer vehicle having a cargo
support surface bordered by a pair of longitudinal edge
regions, the cover comprising a unitary structure having a
roof, a pair of side walls forming a cargo receiving passage
therebetween; each of the edge regions including an upwardly
directed longitudinal rail member, each of the side walls
including a lower edge region with a transverse gap formed
therein for receiving the rail member, and releasable locking
means for locking each of the lower edge regions relative to
the cargo support surface, with each of the rails engaged the
corresponding gap.
In another aspect of the present invention, there is a
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method for covering cargo on a semi-trailer vehicle having a
cargo support surface bordered by a pair of longitudinal edge
regions, each of the edge regions including an upwardly
directed longitudinal rail member the method comprising the
steps of:
providing a roof and a pair of side walls forming a cargo
receiving passage therebetween;
forming in each of the side walls a lower edge region
with a transverse gap therein for receiving the rail member,
and
releasably locking each of the lower edge regions
relative to the cargo support surface, with each of the rails
engaged the corresponding gap.
In still another aspect of the present invention, there
is provided a cover for a semi-trailer vehicle having a cargo
support surface bordered by a pair of longitudinal edge
regions, the cover comprising a unitary structure having a
roof, a pair of side walls forming a cargo receiving passage
therebetween; each of the edge regions having a rub rail
member forming an outermost periphery thereof, each of the
side walls including a lower edge region with an inner face
formed thereon, releasable locking means for locking each of
the lower edge regions relative to the cargo support surface,
to engage the rub rail with the inner face, substantially
along the entire length thereof.
In yet another aspect of the present invention, there is
provided a method for covering cargo on a semi-trailer vehicle
having a cargo support surface bordered by a pair of
CA 02234302 2007-02-16
longitudinal edge regions, each of the edge.regions
including a rub rail member forming an outermost
periphery thereof; the method comprising the steps of:
=
5 forming.on-each of the side walls, a lower edge
region with an inner face formed thereon, and
releasably locking each of the lower edge regions
relative to the cargo support surface, to form a.
substantially continuous engagement of-the rub rail'
with the inner face. .
In still another aspect, the present invention
provides a caster wheel comprising a wheel, axle means
for mounting.the wheel for rotation about a rolling
axis,.swivel frame means for supporting the wheel for
rotation about a swivel axis, ground engaging means
for inhibiting displ=acement of the caster wheel,.
In yet another alternative embodiment'a cover for
a semi-trailer vehicle having a'cargo support surface
bordered by a pair of longitudinal edg"e regions, said
cover having a roof and a pair of side walls forming a
cargo receiving passage therebetween; each of said
pair of side walls terminating at a longitudinal free
edge region to expose said cargo receiving passage_to
said cargo support surface, lifting means for lifting
said cover between a first position above said cargo
support surface and a second position in abutment with
said.cargo support surface, and coupling means for
removably coupling each of said longitudinal free edge
regions to a corresponding.longitudinal edge 'region,
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5a
the longitudinal edge regions including a longitudinal
rail member and a.plurality of passages adjacent said
rail member, said coupling means including a plurality
of coupling members, each of which is dimensioned to
extend through a corresponding passage, and adjustment
means for adjusting said coupling members relative to
said lower edge region.
BRIEF DESCRIPTION OF THE DRAWINGS
Several preferred embodiments of the present
invention will now be described, by way of example
only, with reference to the appended drawings in
which:
Figure 1 is a perspective view of a cover for a
flat deck semi-trailer vehicle;
Figure la magnified fragmentary perspective of a
20. portion of the cover illustrated in figure 1 in an
operative position;
Figurelb is a sectional view taken on line lb--lb.
of figure la;
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Figure 1c is a schematic end view of the cover of figure
1 in a storage position.
Figure 2 is an end view of the cover illustrated in
figure 1 in one operative position;
Figure 2a is a sectional view taken on line 2a-2a of
figure 2;
Figure 3 is a magnified view of the cover according to
figure 2 in another operable position;
Figure 3a is a sectional view taken on line 3a-3a of
figure 3;
Figure 4 is a schematic view of another portion of the
cover illustrated in figure 1;
Figure 4a is a more detailed schematic view of one
component of the portion illustrated in figure 4;
Figure 5 is a side view of the cover illustrated in
figure 1;
Figure 5a is a plan view of the cover illustrated in
figure 1;
Figure 6 is a perspective schematic view of an interior
portion of the cover illustrated in figure 1;
Figure 7 is a sectional view taken on line 7-7 of figure
6;
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Figure 8 is a fragmentary assembly view taken arrow 8 of
figure 6;
Figure 8a is a view taken on arrow 8a of figure 8;
Figure 8b is a view taken on arrow 8b of figure 8;
Figure 9 is a fragmentary assembly view taken arrow 9 of
figure 6;
Figure 10 is a fragmentary assembly view taken arrow 10
of figure 6;
Figure 10a is a view taken on arrow 10a of figure 10;
Figure 11 is a fragmentary assembly view taken arrow 11
of figure 6;
Figure 12 is a sectional view taken on line 12-12 of
figure 5;
Figure 13 is a side view of one component of the portion
illustrated in figure la;
Figure 14 is a front view of the portion illustrated in
figure 13;
Figure 15 is a magnified view of the region encircled at
15 in figure 5;
Figure 16 is a side view of a portion of another cover;
Figure 17 is a front view and a top view of one segment
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of the portion shown in figure 16;
Figure 18 is a front view of another segment of the
portion shown in figure 16;
Figure 19 is a side view of the portion shown in figure
16;
Figure 20 is a side view of a portion of still another
cover; and
Figure 21 is a front view of the portion shown in figure
20.
BEST MODE FOR CARRYING OUT THE INVENTION
Referring to the figures, there is provided a cover 10
for a flat deck semi-trailer vehicle 12 having a deck 13 with
a cargo support surface 13a. As will be described in more
detail below, the cover has a unitary structure having a roof
14, a pair of side walls 16 forming a cargo receiving passage
therebetween. Each of the side walls should be sufficiently
long to accommodate standard flat-deck trailers such as those
having the typical length of 45', and a height of about 8' 7".
The roof may have similar length of about 45' and a width of
about 8' 6". Dimensions such as these should allow the cover
to conform to trailer manufacturers' specifications, and to
the Roads and Transport Association of Canada, as well as to
the applicable Canadian and U.S. department of transportation
specifications. Other dimensions may also be used. For
example, a cover that is 45' long may be used, if desired, to
cover a cargo having a length of 45' or less on a trailer
which is 45' or longer. Alternatively, the cover may only
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be a portion of the length of the trailer.
A pair of end wall portions are joined to the side wall
and roof portions so as to close the cargo-receiving passage.
At least one of the end wall portions includes an retractable
access door, known as an overhead door 20. In this case, each
end wall portion has an overhead door as shown.
The deck 13 includes a longitudinal periphery 22
including a pair of longitudinal edge regions and means is
provided for engaging the cover with the trailer adjacent the
longitudinal periphery. As is typical with flat deck trailers
of this type, the trailer has an upwardly directed
longitudinal rail member in the form of a rub rail 24 which is
positioned on the deck adjacent the periphery and is supported
by a number of spaced support flanges 26, which together with
the rub rail form a plurality of pockets, known as stake
pockets and a plurality of passages each between a pair of
stake pockets. As can be seen by figure la, the rub rail may
also be positioned by way of pipe supports shown in phantom at
28.
As will be described, each of the side walls terminates
at a longitudinal free edge region to expose the cargo
receiving passage to the cargo support surface. In addition,
coupling means is provided for removably coupling each of the
longitudinal free edge regions to a corresponding longitudinal
edge region.
The coupling means are in the form of coupling members 32
for projecting through the passages. In this case, the
coupling members are spaced along the skirt portion and each
includes an upper section 32a for attachment to the skirt
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portion and a lower section 32b laterally spaced from the
skirt portion so as to form a gap 34 therebetween to receive
the rub rail in the engaged position as shown in figure lb.
Each coupling member is independently adjustably mounted to
5 the lower skirt portion.
Each of the coupling members also includes an
intermediate section 32c with an inner surface being inclined
relative to and facing the gap so as to draw the rub rail into
10 abutment with the lower edge region. In this manner, the
lower edge region is arranged to extend below the cargo
support surface and the coupling members are arranged to draw
the inner face of the skirt portion tight to the outer face of
the rub rail to provide a tight fit so as not to exceed
approved widths of trailers.
For example, the coupling members may be about 2" thick
x 4" wide x 12" high with a pattern of coupling member
mounting holes 32e to allow for independent vertical
adjustment each of the coupling members relative to mating
holes 30a formed in the lower skirt portion. In this example,
there may not only be 92 inches of effective width of coupling
member applied along the length of the side wall but there may
also be 540 square inches of effective width of the lower
skirt portion bearing against the rub rail, that is by being
held tight against the rub rail with an exemplified skirt
overhang of 1 inch.
A plurality of removable pin members, for example swivel
lock steel pins 40, are provided for releasably and adjustably
mounting the upper section of each of the coupling members to
the lower skirt portion by way of mating holes 32e, 30a
respectively formed in each. A plurality of removable pin
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members, such as tension lock steel pins 42, are also provided
for inhibiting removal of the coupling member from the passage
and extend through the holes 32d in the lower section 32b.
The lower skirt portion 30 also has a conduit 31 for a motor
control circuit as will be described. The conduit 31 is held
in place by a molded polymer material at the inside face of
the lower skirt portion and at the junction with the lower
edge of the side wall.
Referring to figure 1, lifting means is provided for
lifting the cover between a first position above the cargo
support surface and a second position in abutment with the
cargo support surface, In this case, the lifting means
includes a plurality of spaced leg arrangements extending
below the cover, one of which is shown at 50. The leg
arrangements are length extensible and each includes a jack
portion 52, such as a casterjack. A particular feature of the
leg arrangement is the use of a weather protected motor and a
reduction gearbox, collectively shown at 54.
Each jack portion 52 has a lower leg segment 52a movable
relative to an upper leg segment 52b by way of a rotatable
crank member shown at 52c. In this case, the rotatable crank
member is connected to the output shaft of the reduction
gearbox 54a which in turn is coupled to the output shaft of
the motor unit 54b.
Each leg arrangement is movable between a storage or
secured position shown in solid lines at 'A' in figures 1 and
2 and an operative, or swung out, position 'B' in figures 1
and 3 and a mounting means is provided in the form of a hinge
assembly, such as three butt-type hinges, shown at 56, for
mounting each of the leg arrangements to a corresponding wall
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portion. Referring to figures 2a, 3a, each hinge 56 has a
first hinge element 56a which is secured to the rear edge 16a
of the wall portion 16 and a second hinge element 56b fixed to
the leg arrangement with a pivot member 56c providing a
vertical swing axis. Thus hinge assembly is arranged to
pivotally mount each leg arrangement for movement between the
storage and operable position about the vertical swing axis
and to releasably lock the leg arrangements in place, such as
in the storage and operative positions as shown. Each of the
leg arrangements also has a lower end for engaging a ground
surface, including a caster wheel 58.
The cover is provided with a lighting circuit which
includes a number of clearance lights surface mounted on the
front, rear and sides of the roof as shown at 59 in figures 1
and 3a, in walls 16 in complementary recess formed therein for
marker clearance lighting 59a and lower marker lighting shown
at 59b in figure 1.
Referring to figure 4, each motor unit is actuated by a
controller 60 which receives power from the tractor by way of
a plug 62 which fits an electrical outlet in the utility area
behind the vehicle cab and is provided with a multiple strand
cable as shown at 62a, each strand conveying a particular
circuit. The controller also has an outlet plug 61 to be
coupled with the trailer electrical hook-up plug, to continue
the electrical circuitry from the tractor to the trailer.
Referring to figure 4a, the controller 60 has a switching
means in the form of four switch units 64a to 64d to convey
the power to each of the motors, depending on the particular
movement required, that is to raise or lower the specific leg
arrangements. The switch units allow for the position of any
corner of the cover to be adjusted individually depending on
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irregularities of the ground surface. The controller also
includes a key switch 66 which serves as the main switching
arrangement to simultaneously power all four motors, by way of
two relays 66a, 66b, one for upward movement and the other
downward movement. In this case, the key switch has a number
of predetermined positions including a 'raise' position when
the switch engages contact 'A', a 'lower' position when the
switch engages contact 'B' and a manual override position when
the switch is intermediate contacts 'A' and 'B' (wherein the
motors may be actuated simultaneously to adjust the position
of the cover). The switch 66 and its associated relays 66a,
66b are also provided with a thermal breaker shown at 66c.
The controller is also provided with a self retractable cord
shown schematically at 68 with a sufficient length from the
controller to a designated electrical junction 69 on the
cover, to join with a motor control circuit and a lighting
circuit on the cover, shown generally at 69a. The control
circuit extends through the conduit 31 in the lower skirt
portion and includes individual lengths of coiled wire 70 to
join each motor thereto. It will be understood that the cover
will be provided with sufficient conduit to carry the
electrical circuitry for the cover and this will also include
lateral conduit through the roof and vertically through the
walls (the latter of which is shown in figure 15).
The controller may be permanently mounted to the cab of
the tractor unit or alternatively may be portable, that is
with its own power supply to enable the cover to be adjusted
in the absence of the tractor unit. An additional controller
junction 69 may be located at the rear of the trailer for the
portable controller or for attachment of another cover for
multi-trailer configurations known as 'B trains'.
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As shown schematically in figure 6, the roof 14 and the
side walls 16 are formed in a unibodied construction and
includes a frame subassembly 80, the side wall and roof
portions being integrally formed therewith. The subassembly
should have standard dimensions such as 45' x 7' 10" x 8' 6"
and is formed by a number of frame members such as square
sectioned aluminium members 82 fixed to complementary bracket
unions 84 to 87. These unions are provided in a number of
configurations each of which includes a body member with a
number of square sectioned legs extending outwardly therefrom.
As shown in the case of union 85 in figure 8, each body 85a
has a number of outer surfaces 85b to be coextensive with
those of the frame members, while the legs each have a reduced
rectangular cross section to fit the inner cross section of
the frame members and are formed from a molded solid fibre
reinforced phenolic composition.
Referring to figure 7, each of the roof and side walls
includes an interior expanded polymeric layer 90a, 92a and an
exterior skin 93 bonded thereto. The frame members of the
subassembly includes a plurality of intermediate vertical
members and a plurality of intermediate horizontal members,
one of which is shown at 82, each of the vertical and
horizontal members having one dimension 'a' which is equal to
the thickness 'A' of one adjacent layer and another dimension
'b' which is equal to ~the thickness 'B' of another adjacent
layer. Each of the interior layers has a pair of edges in
abutment with a corresponding pair of the vertical and
horizontal members.
Each of the interior layers has an exterior face 90d, 92d
and each of the vertical and horizontal members has an
exterior face 82b which is coextensive with the exterior face
CA 02234302 1998-04-07
of a corresponding interior layer and the exterior skin 93 is
bonded to the coextensive exterior faces. The interior
expanded polymeric layer is selected from expanded
polyethylene, polyurethane or polyvinylchloride resin
5 materials and has a relatively high density for rigidity and
strength. The interior layers may also, if desired, be formed
from materials such as plastic or aluminum honeycomb-type
panel, or carbon fibre composite materials and the like.
10 The roof and side wall panels meet at a corner region,
further comprising a conduit for receiving electrical wiring,
for example a 1/4 ID conduit 96 carrying the lighting circuit
wiring which is held in position by a molded polymer material
98. An interior skin 100, similar to the exterior skin,
15 extends across the entire inner surface area of the structure
and is a laminated material, preferably a laminated phenolic
material. However, the interior and exterior skins may also
be formed from materials such as sheet aluminum, plastic
materials such as polyethylene and polyvinylchloride, fibre
reinforced plastic sheeting and the like and, if desired, may
be provided with UV protective coatings.
To attach the cover to the flat deck semi-trailer, the
vehicle operator first positions the rear end of the flat deck
trailer in front of the cover and connects the controller with
the electrical junction in the tractor's utility area to
supply power to the cover. The self retractable cord 68 is
then withdrawn from the controller and joined to the
designated electrical junction on the cover.
The operator then manually opens both overhead doors to
expose the cargo receiving passage, and moves the leg
arrangements from their storage position to their operable
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position. The operator then activates the key switch to
deliver power simultaneously to the four motors thereby to
raise the cover to an elevated position with predetermined
clearance above the cargo support surface of the flat deck
trailer. The operator then backs the trailer through the
front overhead door opening of the adjacent end wall portion
to locate the cover above the cargo support surface.
The operator lowers the cover to a position nearer to the
cargo support surface but still sufficiently spaced therefrom
so that the operator can install the individual coupling
members on the bearing skirt with the swivel lock steel pins
by penetrating the mating holes in the bearing skirt and the
coupling members thereby to tightly position the coupling
member with the locking portion of the pin on inside face of
coupling member (as shown in figure lb.
The operator can then make subsequent adjustments as
needed if any of the c:oupling members are interfering with
load binders or existing rub rail supports for the cargo by
simply selecting alternate passages. In this manner, each
coupling member is arranged so that each is capable of
penetrating a corresponding passage before lowering the cover
in its final position with the rub rail in the gap as shown in
figure lb.
The cover is then secured to the flat deck semi-trailer
.in such a manner that the rub rail abuts the inclined face of
the intermediate section thereby drawing the rub rail outer
face in into tight engagement with the inner face of the lower
skirt portion. The tension lock steel pins are then inserted
through the coupling members below the rub rail. With the
cover now in place, the operator retracts the leg arrangements
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to a position above the flat deck and thereafter pivots the
leg arrangements to their storage position as shown in figure
1. The leg arrangements are then secured in place against the
closed overhead doors, thereby completing the installation.
To remove the cover, the above procedure is reversed.
Referring to figure 1c, the cover 10 may be placed in a
storage position by fastening the cover to a support member,
such as an I-beam shown at 110, positioned transversely
relative to the cover. Furthermore, the cover 10 may be
restrained to a nearby anchoring object, such as a pole shown
at 112 by some form of restraint such as a cable (which may
retractable if desired) shown at 114. This enables the cover
10 to be stored on the ground or other suitable surface in a
manner that affords some resistance to wind, in cases where
the cover is not otherwise fastened to the surface, by way of
the coupling members 32. Alternatively, the cable may be
attached to the vehicle itself, such as to a designated anchor
point on the flat deck, to guard against the wind lifting the
cover when being installed thereon.
Referring to figures 16 to 19, there is provided another
coupling member shown at 150 for attachment along the skirt
portion. In this case, the coupling member includes a first
segment 152 with an upper region 152a which is arranged for
anchoring to the cover, by way of passages 152b, and a
corresponding number of removable fasteners 153 to extend
there through.
A second segment is provided at 154 which has a number of
passages 154a for anchoring relative to the longitudinal rail
member, by way of fasteners shown at 155, such as removable
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pin members, for example the tension lock steel pins 42, as
discussed herein above. Furthermore, the first segment 152 is
provided with a number of slots 152c which overly the passages
154a in order for the same removable pin members 42 to pass
there through.
The second segment 154 is movably mounted relative to the
first segment by way of sliding coupling means shown at 156,
which is preferably in the form of a projection 156a slidably
mounted in a complementary shaped recess 156b. Biasing means,
such as spring means, in the form of a compression spring 158,
is also provided between the first and second segments for
cushioning movement therebetween as well as for biasing the
first and second segments toward an extended position as shown
in figure 17.
Thus, the first segment is slidable engaged with the
second segment. The aligned passages 154a and the slots 152c
together with the fastener forms a first limit of relative
travel between the first and second segments, while the spring
means positioned between the first and second segments forms
a second limit of relative travel between the first and second
segments.
In use, the coupling member 150 is assembled with the
cover 10 by fastening the first segment to the lower skirt
portion and the second segment to the rub rail in the manner
shown in figure 19. In this case, forces being exerted on the
cover 10 may cause the first segment to move relative to the
second segment, thereby causing the removable pins to move
along the corresponding slots and the spring to be compressed,
the greater the forces, the greater the relative movement
between the first and second segments.
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Thus, the independently self adjusting individual
coupling members 150 have two interlocking mating portions and
a spring captured therein. The coupling members allow the
cover a range of vertical movement, limited upwardly by the
tension lock steel pin 42, that is as it engages the lower
boundary of the slot 152c, and downwardly by the compressing
of the spring.
The coupling membe:rs are particularly beneficial because
they are independently self adjusting and, as such, are able
to accommodate the iriherent resiliency of the cover by
allowing some limited movement between the cover and the flat
deck. These self adjusting coupling members may be used to
couple the cover to the flat deck along two opposed regions of
the cover, that is for example, a region bounded by one end of
the cover and a distance of, say, one third of the length of
the cover inwardly toward its central region. Two such
regions are shown by A and B in figure 1.
The self adjusting coupling members offer a counter
effect to off axis motion and movement typically seen in the
structure of a trailer under load, to accommodate, among other
things, lateral flexure or twisting along the longitudinal
axis or the lateral axis of the flat deck as it moves along a
road surface or over such obstacles as curbs, speed bumps and
rail road tracks, or for that matter as can occur under some
'no load' conditions.
The self adjusting coupling members thus provide for
confined movement of the lower skirt portion relative to the
rub rail in the regions near the ends of the lower skirt. If
desired, the self adjusting coupling members may be used with
more rigidly fixed coupling members, such as those discussed
CA 02234302 1998-04-07
herein above, which are positioned in the central area of the
cover. Alternatively the self adjusting coupling members may
be used exclusively instead of the coupling members above
described. This will depend, on the extent of relative
5 movement desired between the cover and the flat deck.
The first and second segments can be cushioned by a
number of different components such as compression springs as
mentioned above, as well as other compression members such as
10 foams, hydraulic and pneumatic cylinders, gels and other
materials which are capable with being resiliently deformed.
Thus, the present invention provides a cover which can be
:installed on a wide variety of semi-trailer vehicles such as
15 flat deck trailers, including those with a preformed arch.
The use of the coupling members allows the cover to adapt to
specific dimensional variations between the trailers,
including those with a preformed arch. In the latter case,
the coupling members can be independently adjusted so that
20 those in the central area of the cover extend to a lesser
extent from the lower skirt portions than those in front and
rear regions of the lower skirt portions.
Thus, one embodiment of the present invention provides a
cover with a unitary structure that should fit a wide range of
standard flat deck trailer configurations, including those
referred to in the trucking industry as "high boy" and "low
boy", without the neeci for alternations to the flat deck
trailer itself.
Another caster wheel assembly is shown at 200 in figures
20 and 21. In this case, the assembly 200 has a wheel 202,
axle means such as an axle pin (not shown) for mounting the
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wheel for rotation about a rolling axis, swivel frame means
204 for supporting the wheel for rotation about a swivel axis
shown at 206 and ground engaging means shown generally at 208
for inhibiting displacement of the caster wheel assembly.
The ground engaging means 208 includes a first anchor
member 210 pivotally coupled to the swivel frame means, a
second anchor member 212 pivotally coupled to the swivel frame
means and spring means 214 for biasing the first anchor member
toward the second ancho:r member. The first and second anchor
members each further include a remote end region 216, 218 for
engaging a ground surface. Preferably, the remote end region
has a gripping formation such as a saw toothed surface.
Preferably, the first and second anchor members extend
outwardly of the wheel and in opposite directions. Each of the
first and second anchor members are arranged to pivot relative
to the rolling axis.
Further provided is a displacement means 220 for
displacing the first and second anchor members between
operative and inoperative positions. In this case, the first
anchor member has an outer support portion 210a and the
displacement means further includes a first displacement
member 222 pivotally mounted to the outer support portion, and
a second displacement member 224 joined between the first
displacement member and the second anchor member, wherein
travel of the first displacement member causes the first and
second anchor members to be moved toward either the
inoperative position or the operative position.
The caster wheel assembly 200 is positioned on the lower
end of a leg arrangement such as that shown at 50 in an
CA 02234302 1998-04-07
22
earlier embodiment. When the leg arrangement is in its
storage position, the caster wheel assembly is thus in its
inoperative position, that is not in contact with the ground
surface. In this case, the spring 214 draws the first and
second anchor members towards one another.
The caster wheel assembly 200 is thus displaced toward
the ground surface when the caster jack motor is actuated,
thereby lengthening the leg extension, finally bringing the
wheel caster wheel assembly into contact with the ground
surface. The first point of contact with the ground surface
:is the remote end regions of both the first and second anchor
portions, which causes the remote end portions to penetrate
the ground, the depth of the penetration depending on the
hardness of the ground surface and the spring rate of the
:3pring.
As weight is applied to the caster wheel, the anchor
portions are spread apart to the position as shown in figures
20 and 21, that is in their operative positions. It can be
seen that in this position, the anchor portions, with their
ground griping formations, provide a solid engagement with the
ground surface and act to inhibit any rolling displacement of
the wheel 202 relative thereto.
The first and second anchor portions can be moved to
their inoperative positions (as shown by the dashed lines at
'A') by the user downwardly displacing the first displacement
member 222 which in turn causes both the first and second
anchor members to be upwardly displaced, the latter by way of
the second displacement member 224. If the user wishes to
reapply the anchor portions, he need merely return the first
displacement member 222 to its position as shown in figure 20.
CA 02234302 1998-04-07
23
Thus, when the caster wheel assembly is not in contact
with the ground surface, the anchor portions may be arranged
so that they are in a 'relaxed' position below the contact
point of the wheel and relatively nearer to one another (as
shown in chain dotted lines at 'b') in comparison with the
position shown in solid lines when the wheel is in contact
with the ground surface. The benefit of this 'relaxed'
position is that the spring can be relaxed, thereby increasing
the life of the spring. In effect, this means that the
anchor portions may 'float' with little or no tension on the
spring. Alternatively, the anchor portions may be arranged to
limit to travel between the inoperative position shown in
dashed lines and the operative position as shown in solid
lines. Thus, the caster assembly 200 will enhance the leg
arrangements, by improving their grip of the ground surface as
well as to increase the surface area on which the force of the
each leg arrangement will be applied, which should, in some
cases, lower the pressure being exerted on a ground surface.
While the caster wheel assembly 200 is discussed in the
context of a leg arrangement making use of a caster jack as
shown herein above, it should be recognized that the caster
wheel assembly may be equally applicable to other uses outside
that of a cover as used herein above.
While the above described cover is used in connection
with a flat deck trailer, it should be recognized that the
cover may be used for other trailer configurations including
drop deck trailers, and multiple trailer configurations
referred to in the trucking industry as 'A Trains, B Trains
and C Trains'. In this case of drop deck trailers, the cover
should have a length that would be equal to the length of the
:intermediate cargo supporting area of the trailer, that is
CA 02234302 1998-04-07
24
between the rear wheel assembly area and the front fifth wheel
interconnection area. Some of these trailers may not have a
rub rail in place, in which case, other forms of coupling
means may be used for removably coupling each of the
longitudinal free edge regions of the side walls of the cover
to a corresponding longitudinal edge region of the trailer.
While the above cover makes use of independently
adjustable coupling members, it will be understood that the
coupling members need not necessarily be independently
adjustable but rather can be collectively mounted directly to
one or more lower skirt portions. In this case, the skirt
portion may, if desired, be adjustably mounted to the side
wall portion.
It will be understood that a number of materials may be
utilized in the fabrication of the various components of the
covers described hereinabove, for example, the materials
discussed in connection with the frame sub-assembly, the
interior and exterior skins and the like in connection with
the roof and side walls,, as well as the skirt and the coupling
inembers used therewith. These components may also be
assembled using a number of well known techniques such as for
example, welding, bonding or mechanical fastening, depending
of course on the materials selected.
The frame sub-assembly, for example, can be made from one
or a number of materials such as aluminum, steel, or a range
of appropriate polymeric materials, as outlined above,
including the higher molecular weight engineering plastics
such as those referred to as UHMW (ultra high molecular
weight) plastics, as well as composite materials including
fibre composites including glass and carbon fibre composites.
CA 02234302 1998-04-07
The interior and exterior faces of each of the roof and
side walls may be from, either alone or in combination,
aluminum, steel, or various polymeric materials as outlined
above, including the higher molecular weight engineering
5 plastics such as those referred to as UHMW (ultra high
molecular weight) plastics, as well as composite materials
:including fibre composites including glass and carbon fibre
composites.
10 The skirt and the coupling members, for example, can
also be made from, either alone or in combination, aluminum
materials such as aluminum or steel, in extrusion or plate
form, polymeric materials such as polyethylene and phenolic
resins which may be avai-lable in a range of molecular weights,
15 such as the higher molecular weight engineering plastics such
as those referred to as UHMW (ultra high molecular weight)
plastics, as well as composite materials including fibre
composites including glass and carbon fibre composites.
20 The materials selected for these component may depend,
to a large extent, on the manufacturing facilities available
as well as the operating specifications of the cover itself.
For example, the polymeric materials have the advantage of
being relatively light. and durable, which makes polymeric
25 material especially useful for the coupling members, allowing
the coupling members to provide a point of flexure between the
flat deck and the cover.
While the above cover provides for tight engagement of
the lower skirt portior- with the outer face of the rub rail,
the cover may if desired be coupled to the flat deck trailer
by other forms of rails or other means to couple the
longitudinal free edge region of each side wall to a
CA 02234302 1998-04-07
26
corresponding longitudinal edge region on the flat deck. In
addition shock absorbing members or similar components may be
:incorporated into the coupling means to minimize vibrations
between the cover and the flat deck.
