Note: Descriptions are shown in the official language in which they were submitted.
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TITLE OF THE INVENTION
Tarpaulin retraction and extension device.
FIELD OF THE INVENTION
[0001] The present invention relates generally to the field of transportation,
and,
more particularly, to a tarpaulin retraction and extension device usable with
open
top vehicle mounted containers.
BACKGROUND
[0002] There are many systems for covering top apertures of truck-movable
containers, such as open top truck trailers and the bin of dump trucks. Many
such
systems conveniently roll a tarpaulin covering the top aperture around a rod
when
the top aperture is uncovered.
[0003] A disadvantage of many such systems is that they require relatively
complex and/or heavy components to operate the rod, which adds costs to the
systems. For example, many such systems have their rod, which is located on
top
of the container, rotated by an actuator that is located closer to the ground,
for
example adjacent the bottom part of the container.
[0004] Against this background, there exists a need for an improved tarpaulin
extension and retraction device. An object of the present invention is to
provide
such a device.
SUMMARY OF THE INVENTION
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[0005] In a broad aspect the invention provides a device for manipulating a
tarpaulin so as to selectively cover and uncover a top aperture of a
container, the
top aperture defining substantially opposed aperture first and second end
edges
and substantially opposed aperture first and second side edges extending
therebetween, the tarpaulin being configurable between an extended
configuration
and a retracted configuration, wherein, in the extended configuration, the
tarpaulin
substantially covers the top aperture, and in the retracted configuration, the
tarpaulin is substantially retracted from the top aperture and substantially
adjacent
the aperture first end edge. The device includes a guide mountable to the
container so as to extend along the aperture first side edge, the guide
defining
substantially opposed guide first and second ends located respectively
substantially adjacent the aperture first and second end edges when the guide
is
operatively mounted to the container; a stopper positioned at a stopping
location
along the guide; a caddie mounted to the guide and movable therealong between
the guide second end and the stopping location, the stopper being configured
and
sized for preventing movements of the caddie away from the guide second end
beyond the stopping location; a tarpaulin rod support defining a pivot section
and a
tarpaulin rod supporting section spaced apart therefrom, the tarpaulin rod
support
being pivotally mounted to the caddie in the pivot section; a tarpaulin rod
for rolling
the tarpaulin therearound when configuring the tarpaulin from the extended
configuration to the retracted configuration and for unrolling the tarpaulin
therefrom
when configuring the tarpaulin from the retracted configuration to the
extended
configuration, the tarpaulin rod defining a rod longitudinal axis, the
tarpaulin rod
being rotatably mounted to the tarpaulin rod support in the tarpaulin rod
supporting
section so as to be rotatable about the rod longitudinal axis, the rod
longitudinal
axis being substantially parallel to the aperture first end edge when the
device is
operatively mounted to the container; and an actuator operatively coupled to
the
tarpaulin rod for selectively rotating the tarpaulin rod about the rod
longitudinal axis
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to selectively roll the tarpaulin therearound and unroll the tarpaulin
therefrom to
respectively move the tarpaulin to the retracted and extended configurations.
[0006] Typically, the device further comprises a tensioner biasing the
tarpaulin
rod toward the guide second end.
[0007] Typically, the tensioner includes a cable rollable around the tarpaulin
rod,
a tensioner body mountable to the container and a tensioner biasing element
extending therebetween, the tensioner biasing element exerting a tension in
the
cable so that the cable pulls on the tarpaulin rod in a direction leading from
the
guide first end towards the guide second end, the cable being rolled around
the
tarpaulin rod when the tarpaulin is unrolled therefrom, and the cable being
unrolled
from the tarpaulin rod when the tarpaulin is rolled therearound. Typically, a
pulley
is mountable to the container for receiving the cable and redirecting the
cable
while allowing maintenance of the tension in the cable.
[0008] Typically, the tarpaulin rod includes a winch drum rotatable jointly
therewith defining a drum external surface for receiving the cable thereonto
and
provided substantially adjacent the tarpaulin rod support, the winch drum
having a
generally frustro-conical configuration and being provided with an
helicoidally-
shaped winding groove formed on the drum external surface for substantially
fittingly receiving the cable thereonto. In a specific embodiment of the
invention, a
sum of an unrolled tarpaulin length of the tarpaulin unrolled from the
tarpaulin rod
and an unrolled cable length of the cable unrolled from the tarpaulin rod
remains
substantially constant as the tarpaulin is moved between the extended and
retracted configurations.
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[0009] Typically, the tarpaulin rod support is pivotable between a rod support
first
position and a rod support second position, the tarpaulin rod support being
between the caddie and respectively the guide first and second ends when
respectively in the rod support first and second positions.
[0010] Typically, a rod support biasing element extends between the caddie and
the tarpaulin rod support and biases the tarpaulin rod support toward the rod
support second position when the tarpaulin rod support is away from the rod
support second position.
[0011] In a variant, the rod support biasing element exerts substantially no
biasing
force between the caddie and the tarpaulin rod support when the tarpaulin rod
support is in the rod support second position.
[0012] Typically, the caddie includes a caddie body and two wheels each
rotatably mounted to the caddie body and rollable along the guide, the guide
being
received between the wheels so as to substantially prevent movements of the
caddie perpendicular to the guide.
[0013] In a variant, the caddie includes a caddie body and at least two wheels
each rotatably mounted to the caddie body and rollable along the guide, the
guide
being received between the wheels so as to substantially prevent movements of
the caddie perpendicular to the guide.
[0014] Typically, the wheels are grooved wheels each defining a
circumferential
groove and the guide defines opposed edges received in the circumferential
grooves.
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[0015] Typically, the guide is substantially rectilinear.
[0016] Typically, the device further comprises an anchoring block mountable to
the container substantially adjacent the aperture second end edge for
receiving
the tarpaulin rod when the tarpaulin is in the extended configuration.
[0017] Typically, the actuator includes a motor mounted to the tarpaulin rod
support.
[0018] Typically, the stopping location is closer to the guide first end than
to the
guide second end.
[0019] In another broad aspect, the invention provides an assembly,
comprising:
a container defining a top aperture, the top aperture defining substantially
opposed
aperture first and second end edges and substantially opposed aperture first
and
second side edges extending therebetween; a tarpaulin configurable between an
extended configuration and a retracted configuration, wherein, in the extended
configuration, the tarpaulin substantially covers the top aperture, and in the
retracted configuration, the tarpaulin is substantially retracted from the top
aperture and substantially adjacent the aperture first end edge; and a device
for
manipulating the tarpaulin so as to selectively cover and uncover the top
aperture.
The device comprises: a guide mounted to the container so as to extend along
the
aperture first side edge, the guide defining substantially opposed guide first
and
second ends located respectively substantially adjacent the aperture first and
second end edges; a stopper positioned at a stopping location along the guide;
a
caddie mounted to the guide and movable therealong between the guide second
end and the stopping location, the stopper being configured and sized for
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preventing movements of the caddie away from the guide second end beyond the
stopping location; a tarpaulin rod support defining a pivot section and a
tarpaulin
rod supporting section spaced apart therefrom, the tarpaulin rod support being
pivotally mounted to the caddie in the pivot section; a tarpaulin rod for
rolling the
tarpaulin therearound when configuring the tarpaulin from the extended
configuration to the retracted configuration and for unrolling the tarpaulin
therefrom
when configuring the tarpaulin from the retracted configuration to the
extended
configuration, the tarpaulin rod defining a rod longitudinal axis, the
tarpaulin rod
being rotatably mounted to the tarpaulin rod support in the tarpaulin rod
supporting
section so as to be rotatable about the rod longitudinal axis, the rod
longitudinal
axis being substantially parallel to the aperture first end edge; and an
actuator
operatively coupled to the tarpaulin rod for selectively rotating the
tarpaulin rod
about the rod longitudinal axis to selectively roll the tarpaulin therearound
and
unroll the tarpaulin therefrom to respectively move the tarpaulin to the
retracted
and extended configurations.
[0020] In some embodiments of the invention, the container is a vehicle
container
part of a road vehicle. The device mentioned in the above paragraph may also
include all the particularities of the device mentioned hereinabove in the
present
summary of the invention.
[0021] In another broad aspect, the invention provides a device for
manipulating a
tarpaulin so as to selectively cover and uncover a top aperture of a
container, the
top aperture defining substantially opposed aperture first and second end
edges
and substantially opposed aperture first and second side edges extending
therebetween, the tarpaulin being configurable between an extended
configuration
and a retracted configuration, wherein, in the extended configuration, the
tarpaulin
substantially covers the top aperture, and in the retracted configuration, the
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tarpaulin is substantially retracted from the top aperture and substantially
adjacent
the aperture first end edge, the device comprising: a guide mountable to the
container so as to extend along the aperture first side edge, the guide
defining
substantially opposed guide first and second ends located respectively
substantially adjacent the aperture first and second end edges when the guide
is
operatively mounted to the container; a caddie mounted to the guide and
movable
therealong between the guide first and second ends; a tarpaulin rod for
rolling the
tarpaulin therearound when configuring the tarpaulin from the extended
configuration to the retracted configuration and for unrolling the tarpaulin
therefrom
when configuring the tarpaulin from the retracted configuration to the
extended
configuration, the tarpaulin rod defining a rod longitudinal axis, the
tarpaulin rod
being rotatably mounted to the caddie so as to be rotatable about the rod
longitudinal axis, the rod longitudinal axis being substantially parallel to
the
aperture first end edge when the device is operatively mounted to the
container;
and an actuator operatively coupled to the tarpaulin rod for selectively
rotating the
tarpaulin rod about the rod longitudinal axis to selectively roll the
tarpaulin
therearound and unroll the tarpaulin therefrom to respectively move the
tarpaulin
to the retracted and extended configurations.
[0022] The device mentioned in the above paragraph may also include all the
particularities of the device mentioned hereinabove in the present summary of
the
invention.
[0023] Advantageously, the proposed device can be manufactured using a
relatively small quantity of materials as all the components thereof are
provided
adjacent the container aperture. Also, the actuator may be represented in some
embodiments by a relatively small, and therefore relatively inexpensive,
electric
motor.
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[0024] Other objects, advantages and features of the present invention will
become more apparent upon reading of the following non-restrictive description
of
some embodiments thereof, given by way of example only with reference to the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1, in a perspective view, illustrates a container and a device
for
manipulating a tarpaulin in accordance with an embodiment of the present
invention, the device being used to selectively cover and uncover a top
aperture of
the container, the tarpaulin being shown in an extended configuration;
[0026] Figure 2, in a partial perspective view, illustrates the container and
device
shown in Fig. 1, the tarpaulin being shown in a partially retracted
configuration;
[0027] Figure 3, in a first side elevation view, illustrates a guide
(partially), a
caddie and a tarpaulin rod support all part of the device shown in Figs. 1 and
2, the
tarpaulin rod support being shown in both rod support first and second
positions
alternatively achievable by the tarpaulin rod support;
[0028] Figure 4, in a second side elevation view, illustrates the guide,
caddie and
tarpaulin rod support of Fig. 3;
[0029] Figure 5, in a front elevation view, illustrates the guide, caddie and
tarpaulin rod support of Figs. 3 and 4;
[0030] Figure 6, in a side elevation view, illustrates a winch drum part of a
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tarpaulin rod, the tarpaulin rod being part of the device shown in Figs. 1 and
2;
[0031] Figure 7, in a side elevation view, illustrates a guide, caddie and
tarpaulin
rod support that may replace the guide, caddie and tarpaulin rod support shown
in
Fig. 4 in alternative embodiments of the invention; and
[0032] Figure 8, in a front elevation view, illustrates the guide, caddie and
tarpaulin rod support of Fig. 7.
DETAILED DESCRIPTION
[0033] Referring to Fig. 1, there is shown a device 10 for manipulating a
tarpaulin
11. The device 10 is mountable to a container 12 so as to selectively cover
and
uncover a top aperture 14 thereof, as better seen in Fig. 2. Still referring
to Fig. 2,
the top aperture 14 defines substantially opposed aperture first and second
end
edges 16 and 18, which are typically parallel to each other, and substantially
opposed aperture first and second side edges 20 and 22 extending therebetween,
which are also typically parallel to each other. The tarpaulin 11 is
configurable
between an extended configuration (shown in Fig. 1) and a retracted
configuration.
Fig. 2 illustrates a partially retracted configuration in which the tarpaulin
11 is
almost completely retracted to the retraced configuration. In the extended
configuration, the tarpaulin 11 substantially covers the top aperture 14. In
the
retracted configuration, the tarpaulin 11 is substantially retracted from the
top
aperture 14 and substantially adjacent the aperture first end edge 16. The
device
includes a guide 24, a stopper 26, a caddie 28, a tarpaulin rod support 30, a
tarpaulin rod 32 and an actuator 34. In a typical embodiment, the device 10
also
includes a tensioner 36.
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[0034] The term "substantially" is used throughout this document to indicate
variations in the thus qualifies terms. These variations are variations that
do not
materially affect the manner in which the invention works and can be due, for
example, to uncertainty in manufacturing processes or to small deviations from
a
nominal value that do not cause significant changes to the invention. These
variations are to be interpreted from the point of view of the person skilled
in the
art. Also, directional terminology such as below and horizontal, among others,
is
used in this document and refer to the device 10 and container 12 in a typical
operational configuration. This terminology is used for clarity reasons and
should
not be used to restrict the scope of the appended claims unless explicitly
mentioned in the claims.
[0035] It should be noted that Fig. 1 illustrates the device 10 mounted to a
container 12 that is typically a vehicle mounted container, such as a
container 12
mountable on a platform truck, an open top truck trailer or the bin of a dump
truck.
However, the device 10 is usable with other suitable containers 12. Also, in
the
context of a movable container 12, Fig. 1 illustrates a case in which the
container
is moved in a direction parallel to the container first and second end edges
16 and
18. The tarpaulin 11 is therefore retracted laterally relative to the
direction of
motion. However, it is within the scope of the invention to have tarpaulins 11
retractable along the direction of motion.
[0036] Referring to Fig. 2, the guide 24 is mountable to the container 12 so
as to
extend along the aperture first side edge 20, typically slightly below the
aperture
first side edge 20. The guide 24 defines substantially opposed guide first and
second ends 38 and 40 located respectively substantially adjacent the aperture
first and second end edges 16 and 18 when the guide 24 is operatively mounted
to
the container 12. The guide 24 is typically substantially rectilinear. For
example, as
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better seen in Fig. 5, the guide 24 is an elongated tubular element of
substantially
square transversal cross-sectional configuration mounted obliquely so as to
form a
diamond shape when seen by an upstanding observer looking at the device 10
mounted in an operative configuration to the container 12. In this example,
the
guide 24 defines lower and upper edges 42 and 44, the purpose of which is
better
described hereinbelow. In alternative embodiments of the invention, the guide
24
may have any alternative shape. For example, and non-limitingly, as seen in
Fig.
8, a guide 124 having a substantially circular transversal cross-sectional
configuration may be used instead. The guide 24 is mounted to the container 12
in
any suitable manner, for example using mounting brackets 25 provided adjacent
the guide first and second ends 38 and 40 that mounted to the container 12 in
any
suitable manner, for example by being welded thereto or by using screws or nut
and bolt combinations. The mounting brackets 25 each define a guide receiving
recess snugly receiving a respective portion of the guide 24 thereinto.
[0037] Returning to Fig. 2, the stopper 26 is positioned at a stopping
location 46
along the guide 24, the stopping location 46 being typically closer to the
guide first
end 38 than to the guide second end 40. For example, the stopper 26 includes a
pair of plates 48 (only one of which is clearly seen in the drawings) provided
on
opposite sides of the guide 24 and secured to each other using for example nut
and bolt combinations 49 extending each through both plates 48, with the
plates
48 being compressed toward each other by the conventional bolt heads and the
nuts. Tightening the nut and bolt combinations 49 secure the stopper 26 to the
guide 24 as the guide 24 is then frictionally held fixed between the plates
48. It
should be noted that loosening the nut and bolt combinations 49 allows moving
the
stopper 26 along the guide 24 during installation of the device 10 to provide
an
adjustment on the range of motion of the caddie 28.
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[0038] The caddie 28 is mounted to the guide 24 and movable therealong
between the guide second end 40 and the stopping location 46. The stopper 26
is
configured and sized for preventing movements of the caddie 28 away from the
guide second end 40 beyond the stopping location 46.
[0039] For example, as seen for example in Fig. 4, the caddie 28 includes a
caddie body 47, which may be substantially plate-shaped and substantially
parallel
to the plates 48 of the stopper 26, and wheels 50 rollable along the guide 24
and
rotatably mounted to the caddie body 47. The guide 24 is received between the
wheels 50 so as to substantially prevent movements of the caddie 28
perpendicular to the guide 24.
[0040] More specifically, the caddie 28 includes at least two wheels 50
rollable
along the guide 24, and in a specific embodiment of the invention, as shown in
Fig. 4, exactly three wheels 50. For example, two wheels 50 are provided above
the guide 24 and one wheel 50 is provided below the guide 24. The wheels 50
typically receive the guide 24 substantially snugly therebetween. For example,
the
wheels 50 are grooved, such as grooved pulleys, and each define a
circumferential groove 52, seen in Fig. 5. The circumferential grooves 52
receive
one of the lower and upper edges 42 and 44, which prevents horizontal
movements of the caddie 28 perpendicular to the guide 24 and rotation of the
caddie 28 about the longitudinal axis of the guide 24. In other embodiments,
as
seen in Fig. 8, only two wheels 50 are mounted to an alternative caddie 128.
Also,
in some embodiments, small lateral movements between the wheels 50 and the
guide 24 are allowed. Preferably, these movements are smaller than the depth
of
the grooves 52. In yet other embodiments (not shown in the drawings), more
than
three wheels 50 are provided.
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[0041] However, in alternative embodiments of the invention, the caddie body
47
has any other alternative shapes. In some alternative embodiments, the caddie
28
is slidable along the guide 24 instead of including wheels. In yet other
embodiments, bearings are provided between the caddie 28 and the guide 24 to
allow relative movements therebetween.
[0042] With reference to Fig. 3, the tarpaulin rod support 30 defines a pivot
section 54 and a tarpaulin rod supporting section 56 spaced apart therefrom.
The
tarpaulin rod support 30 is pivotally mounted to the caddie 28 in the pivot
section
54, for example using a pin 57. The tarpaulin rod support 30 is pivotable
between
a rod support first position, indicated by arrow A in Fig. 3, and a rod
support
second position, indicated by arrow B in Fig. 3. Therefore Fig. 3 does not
illustrate
a pair of tarpaulin rod supports 30, but the single tarpaulin rod support 30
positioned at two alternative positions. The tarpaulin rod support 30 is
between the
caddie 28 and respectively the guide first and second ends 38 and 40 when
respectively in the rod support first and second positions.
[0043] Typically, a rod support biasing element 59, for example a spiral
torsion
spring rolled around the pin 57, extends between the caddie 28 and the
tarpaulin
rod support 30. The rod support biasing element 59 biases the tarpaulin rod
support 30 toward the rod support second position when the tarpaulin rod
support
30 is away from the rod support second position. Typically, the rod support
biasing
element 59 is configured so as to exert substantially no biasing force between
the
caddie 28 and the tarpaulin rod support 30 when the tarpaulin rod support 30
is in
the rod support second position, and the biasing force tending to rotate the
tarpaulin rod support 30 toward the rod support second position increases as
the
tarpaulin rod support 30 moves towards the rod support first position.
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[0044] The tarpaulin rod 32 is provided for rolling the tarpaulin 11
therearound
when configuring the tarpaulin 11 from the extended configuration to the
retracted
configuration and for unrolling the tarpaulin 11 therefrom when configuring
the
tarpaulin 11 from the retracted configuration to the extended configuration.
The
tarpaulin rod 32 defines a rod longitudinal axis 58 (seen in Fig. 2) and the
tarpaulin
rod 32 is rotatably mounted to the tarpaulin rod support 30 in the tarpaulin
rod
supporting section 56 so as to be rotatable about the rod longitudinal axis 58
in a
conventional manner. The rod longitudinal axis 58 is substantially parallel to
the
aperture first and second end edges 16 and 18 when the device 10 is
operatively
mounted to the container 12.
[0045] The actuator 34 is operatively coupled to the tarpaulin rod 32 for
selectively rotating the tarpaulin rod 32 about the rod longitudinal axis 58
to
selectively roll the tarpaulin 11 therearound and unroll the tarpaulin 11
therefrom to
respectively move the tarpaulin 11 to the retracted and extended
configurations.
For example, the actuator 34 is a motor mounted to the tarpaulin rod support
30
and coupled to the tarpaulin rod 32 using suitable transmission mechanisms,
such
as gears, to transmit the rotational motion of an output shaft of the motor to
the
tarpaulin rod 32. In some embodiments, the motor is an electric motor
controlled
using a controller (not shown in the drawings) connected therethrough through
electrical wires 35.
[0046] Referring to Fig. 2, the tensioner 36 is used to provide tension in the
device 10 so that when the tarpaulin 11 is unrolled from the tarpaulin rod 32,
the
tarpaulin rod 32 moves toward the aperture second end edge 18. Therefore, the
tensioner 36 biases the tarpaulin rod 32 toward the guide second end 40 so
that
the tarpaulin rod 32 moves toward the guide second end 40 when the tarpaulin
11
is unrolled therefrom. This functionality could be achieved in other manners,
for
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example by using the actuator 34, or another actuator, to move the caddie 28
in a
suitable direction along the guide 24. The tensioner 36 is similar to a device
having
the same purpose and described in US Patent Application Publication No
2002/0021018 by Royer published In February 2002.
[0047] The tensioner 36 includes a cable 60 rollable around the tarpaulin rod
32,
a tensioner body 62 (shown in cross-section in Fig. 2) mountable to the
container
12 using suitable mounting brackets 61 and a tensioner biasing element 64
extending therebetween and exerting a tension in the cable 60 so that the
cable 60
pulls on the tarpaulin rod 32 in a direction leading from the guide first end
38
towards the guide second end 40. The cable 60 is rolled around the tarpaulin
rod
32 when the tarpaulin 11 is unrolled therefrom, and the cable 60 is unrolled
from
the tarpaulin rod 32 when the tarpaulin 11 is rolled therearound.
[0048] In some embodiments of the invention, the cable 60 is simply wound
around the tarpaulin rod 32, which has then typically a substantially constant
diameter therealong. In other embodiments, the tarpaulin rod 32 includes a
winch
drum 66 rotatable jointly therewith defining a drum external surface 67 for
receiving the cable 60 thereonto, as seen in Fig. 6, and provided
substantially
adjacent the tarpaulin rod support 30. The winch drum 66 has a generally
frustro-
conical configuration and is provided with an helicoidally-shaped winding
groove
69 formed on the drum external surface 67 for substantially fittingly
receiving the
cable 60 thereonto. The cable 60 has one end thereof fixed to the winch drum
66.
In some embodiments, the tensioner 36 also includes another pulley 68
mountable
to the container 12 for receiving the cable 60 and redirecting the cable 60
while
allowing maintenance of the tension in the cable 60.
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[0049] The tensioner body 62 is for example substantially elongated and
defines
substantially opposed tensioner body first and second ends 70 and 72. The
tensioner body 62 may take for example the form of a substantially elongated
tube
receiving the tensioner biasing element 64 and part of the cable 60 thereinto.
The
tensioner body may for example be mountable to the container 12 along the
aperture first side edge 20.
[0050] The tensioner biasing element 64 is for example a coil spring having
one
end thereof secured to the tensioner body 62 substantially adjacent the
tensioner
body first end 70 and the other end thereof secured to the cable 60. The
pulley 68
is mounted to the tensioner body 62 substantially adjacent the tensioner body
second end 72 so as to be substantially freely rotatable relative thereto. The
tensioner body second end 72 is substantially adjacent the aperture second end
edge 18.
[0051] The cable 60 extends from the tensioner biasing element 64 toward the
tensioner body second end 72, loops around the pulley 68, and is partially
rolled
around the tarpaulin rod 32, either directly or around the winch drum 66. The
cable
60 is mounted to the tarpaulin rod 32 so that a tension is maintained in the
cable
60 by the tensioner biasing element 64. In some embodiments of the invention,
for
example through the use of a suitably configured winch drum 66, a sum of an
unrolled tarpaulin length of the tarpaulin 11 unrolled from the tarpaulin rod
32 and
an unrolled cable length of the cable 60 unrolled from the tarpaulin rod 32
remains
substantially constant as the tarpaulin 11 is moved between the extended and
retracted configurations. In turn, this ensures that the length of the
tensioner
biasing element 64 does not change as the tarpaulin is extended and retracted,
which maintains a substantially constant tension in the cable 60. This is
achieved
by having a drum external surface 67 that has a slope such that when a length
of
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tarpaulin 11 is unrolled from the tarpaulin rod 32, substantially the same
length of
cable 60 is rolled around the winch drum 67. The best match between the
lengths
of tarpaulin 11 and cable 60 rolled and unrolled is achieved when at any time,
the
outside diameter of the portion of the tarpaulin 11 that is rolled around the
tarpaulin rod 32 is equal to the diameter of the winch drum 66 at the location
at
which the cable 60 enters the winding groove 69. In embodiments in which the
winch drum 66 is not used, the tensioner biasing element 64 may change
slightly
in length to accommodate changes in the length of the cable 60 unrolled from
the
tarpaulin rod 32.
[0052] In some variants, the device 10 includes a pair of guides 24, stoppers
26,
caddies 28 and tarpaulin rod supports 30, each provided on a respective side
of
the container 12. However, in other variants, the additional guide 24, stopper
26,
caddie 28 and rod support 30 is not required.
[0053] In some embodiments of the invention, as seen in Fig. 1, the device 10
also includes at least one anchoring block 73, and typically a plurality of
spaced
apart anchoring blocks 73, mountable substantially adjacent the aperture
second
end edge 18 for receiving the tarpaulin rod 32 when the tarpaulin 11 is in the
extended configuration. The anchoring blocks 73 are provided slightly below
the
aperture second end edge 18 and each define an inverted J-shaped recess 74,
better seen in Fig. 2.
[0054] Operation of the device 10 is as follows. Taking for example as an
initial
configuration the extended configuration, the tarpaulin 11 extends across the
top
aperture 14 of the container 12. The tarpaulin rod 32 and any portion of the
tarpaulin 11 that may remain rolled therearound are received in the recess 74
and
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tension in the tarpaulin 11 is maintained by the tensioner 36. The caddie 28
is at or
substantially adjacent the guide second end 40 and the tarpaulin rod support
30 is
in the rod support second position.
[0055] When an intended user wishes to retract the tarpaulin 11, the actuator
34
is used to rotate the tarpaulin rod 32 in a direction leading to the tarpaulin
11 being
rolled therearound and the cable 60 to be unrolled therefrom. In turn, this
rotational
motion moves the caddie toward the stopper 26 as the tarpaulin rod 32 is
pulled
along the tarpaulin 11. The tensioner 36 and the rod support biasing element
59
maintain the tarpaulin rod support 30 in the rod support second position.
[0056] When enough of the tarpaulin 11 has been rolled around the tarpaulin
rod
32, the caddie 28 reaches the stopper 26, which interferes with the movement
of
the caddie body 47 to stop the caddie 28 from moving when the caddie body 47
abuts against one of the plates 28. Further movement of the tarpaulin rod 32
to
further roll the tarpaulin 11 therearound are then only possible if the
tarpaulin rod
support 30 pivots about the pin 57 toward the rod support first position, as
seen in
Fig. 2. Typically, the tarpaulin rod support 30 is configured and sized so
that in the
rod support first position, with the caddie 28 abutting against the stopper
26, the
tarpaulin 11 is in the retracted configuration. This movement towards the rod
support first position is made against the tension provided by the tensioner
36 and
the rod support biasing element 59.
[0057] To extend the tarpaulin 11, the above operations are reversed,
movements
of the tarpaulin rod 32 toward the aperture second end edge 18 being
facilitated by
the rod support biasing element 59 and the tensioner 36 at first, and by the
tensioner 36 after the tarpaulin rod support 30 has been moved to the rod
support
CA 02853979 2014-06-11
19
second position.
[0058] In some embodiments of the invention, although not shown in the
drawings, the stopper 26 is omitted and the tarpaulin rod 32 is directly
mounted to
a caddie 28 movable along the guide 24. Therefore, in such embodiments, there
is
no pivoting tarpaulin rod support 30.
[0059] Although the present invention has been described hereinabove by way of
exemplary embodiments thereof, it will be readily appreciated that many
modifications are possible in the exemplary embodiments without materially
departing from the novel teachings and advantages of this invention.
Accordingly,
the scope of the claims should not be limited by the exemplary embodiments,
but
should be given the broadest interpretation consistent with the description as
a
whole.
