James & Wells ref: 32743/60 HCS
A LOADING MECHANISM
TECHNICAL FIELD
The present invention relates to a loading mechanism.
BACKGROUND ART
Trailers are used to store and transport boats.
The loading and unloading of a boat onto the trailer is facilitated by rollers mounted on the
trailer. The boat is moved over the rollers to move it onto or off from (load/unload) the trailer.
The simplest mechanical way to load or unload a boat is to push it. However, significant
strength is required to move a heavy boat over rollers. This means that many boat users may
struggle to push a boat so as to load and unload it from a trailer.
Winches are often used to drag boats out of the water, over rollers, and thereby onto the trailer.
However, these can be fiddly to use. It is necessary to align the boat with the trailer and secure
the winch rope to the front of the boat. This can be difficult to achieve. In addition, a boat user
often gets wet which many people wish to avoid.
Furthermore, manual winches still require strength or effort to load the boat. Again, not all boat
users possess sufficient strength to load the boat.
A further problem of many boat trailers is that these must be submerged in water in order for a
boat to be loaded onto the trailer. Exposure of the trailer to water, and in particular salt water,
can accelerate the rate of rusting of the trailer and its components.
Automatic boat trailers are known and an example is described in PCT Application No.
2004/000667. The device disclosed by this patent includes a plurality of rollers spaced apart
along a boat trailer’s length, and located approximately in line with the centre line of the trailer.
Those rollers are aligned along the centre of the trailer. The rollers are connected by a chain
drive mechanism so that a motor can rotate all of the rollers. However, this arrangement
requires that a person accurately aligns a boat with the rollers. This often can be logistically
difficult to achieve. It can also result in the person getting wet – again something which may
wish to be avoided.
A further issue with the boat trailer disclosed by PCT Application No. 2004/000667 is that the
chain drive mechanism has exposed moving parts such as the drive chain. Those parts may be
susceptible to rusting, which can be accelerated due to exposure to salt water or other damage.
That chain drive mechanism may also pose a safety risk due to the exposed/moving parts.
James & Wells ref: 32743/60 HCS
Yet a further problem of the boat trailer disclosed in this patent is that the rollers struggle to
transfer sufficient force to the boat to efficiently move that onto and off from a trailer. This is a
result of the position of the rollers, and that they are fixed with respect to the trailer.
A further type of boat trailer is disclosed by New Zealand Patent No. 547569. This includes a Y
shaped frame with a draw bar to engage a corresponding coupling on a vehicle. A ‘U’ shaped
frame sits inside and is pivotably mounted to the Y shaped frame. A pair of swivel arms is
configured to move the U shaped frame so as to raise and lower a boat with respect to the Y
shaped frame.
The device of New Zealand Patent No. 547569 was designed to facilitate launching of boats in
shallow water. However, this type of boat trailer cannot easily be used with launching boats on
inclined launching areas such as boat ramps.
Furthermore, the boat trailer of Patent No. 547569 requires submersion of the trailer in water.
As discussed above, such submersion can lead to wear and tear or rusting of the components.
It is therefore an objective of the present invention to address the foregoing problems or at least
to provide the public with a useful choice.
All references, including any patents or patent applications cited in this specification are hereby
incorporated by reference. No admission is made that any reference constitutes prior art. The
discussion of the references states what their authors assert, and the applicants reserve the
right to challenge the accuracy and pertinency of the cited documents. It will be clearly
understood that, although a number of prior art publications are referred to herein, this
reference does not constitute an admission that any of these documents form part of the
common general knowledge in the art, in New Zealand or in any other country.
Throughout this specification, the word "comprise", or variations thereof such as "comprises" or
"comprising", will be understood to imply the inclusion of a stated element, integer or step, or
group of elements integers or steps, but not the exclusion of any other element, integer or step,
or group of elements, integers or steps.
It is an object of the present invention to address the foregoing problems or at least to provide
the public with a useful choice.
Further aspects and advantages of the present invention will become apparent from the
ensuing description which is given by way of example only.
DISCLOSURE OF THE INVENTION
According to one aspect of the present invention there is provided a loading mechanism,
including
James & Wells ref: 32743/60 HCS
at least two roller assemblies,
at least one mounting for the at least two roller assemblies,
a drive mechanism configured to rotate the at least two roller assemblies,
characterised in that
in use the drive assembly rotates the at least two roller assemblies so as to move an object,
and wherein
that as the weight of the object applies pressure to the at least two rollers assemblies the
mounting allows the roller assemblies to move so as to change the orientation of at least two of
the roller assemblies relative to each other.
According to another aspect of the present invention there is provided a kitset of parts,
including
at least two roller assemblies,
at least one mounting for the at least two roller assemblies,
a drive mechanism,
characterised in that
when assembled and in use, the drive mechanism rotates the at least two roller assemblies so
as to move an object, and wherein as the weight of the object applies pressure to the at least
two roller assemblies the mounting allows the roller assemblies to move so as to change the
orientation of at least two of the roller assemblies relative to each other.
According to another aspect of the present invention, there is provided a loading method,
wherein the method uses a loading mechanism including at least two roller assemblies, a drive
mechanism, and at least one mounting for the roller assemblies,
the method including the steps of:
(a) using the drive mechanism to rotate the at least two roller assemblies so as to move the
object, and wherein the weight of the object applies pressure to the roller assemblies so
as to cause the roller assemblies to move and thereby change the orientation of at least
two of the roller assemblies relative to each other.
Throughout the present specification, reference to the term “loading mechanism” should be
understood as meaning an assembly to move an object on to or off from a cradle.
The term “cradle” refers to a plurality of components that can support an object.
James & Wells ref: 32743/60 HCS
The cradle has a front end, a back end, and a center line extending along its length.
Reference to the terms “front end” and “backward end” are arbitrary, and made with reference
to the normal direction of loading an object onto the cradle of a preferred embedment to the
present invention. These references should not be seen as anyway limiting on the scope of the
present invention.
The cradle may also include supplementary rollers. In-use these assist moving the object onto
or off from the cradle. The supplementary rollers may also define the cradle.
In a preferred embodiment the present invention relates to a loading mechanism for objects
with a width and/or shape which varies along its length.
In a particularly preferred embodiment the present invention relates to a loading mechanism for
use in loading and unloading boats onto a cradle on a trailer. Accordingly, reference herein will
be made to use of the loading mechanism with boats and trailers.
However, the foregoing should not be seen as limiting on the scope of the present invention. It
is also envisaged that the loading mechanisms can be used with loading boats onto objects
other than trailers such as a dry dock berth or non-trailer cradles.
It is also envisaged that the loading mechanisms according to the present invention may be
utilised in applications such as loading and unloading of jet skis, or loading and unloading of
heavy objects such as containers.
Preferably, the boats with which the present invention is used have a centre line. The boat is
symmetrical (a mirror image) about the centre line. However, the boat’s width and therefore its
shape varies along the length of the boat. This is a common design feature of boats and is as
should be understood by one skilled in the art.
Throughout the present specification reference to the term “roller assembly” should be
understood as meaning rotatable components. In use, a roller assembly rotates so as to move
a boat in a direction corresponding to the direction of rotation.
In a particularly preferred embodiment, the present invention includes at least two roller
assemblies spaced apart across the width of a trailer so as to be on either side of the centre
James & Wells ref: 32743/60 HCS
line of the cradle. Therefore, in-use the two roller assemblies are on either side of the centre
line of a boat with which the loading mechanism is to be used.
The inventors have discovered that having roller assemblies which in use are on either side of
the boat’s centre line provides a number of advantages. For instance, the roller assemblies are
better positioned to engage the boat's hull as the boat approaches the trailer. This enables the
roller assemblies to act as an aligning mechanism, which moves the boat towards, or into, an
optimum position. When the boat is in the optimum position the roller assemblies can better
apply force to the boat to load that onto the trailer.
It is also envisaged that the present invention may include a plurality of roller assemblies
spaced apart along the length of the trailer. Therefore the foregoing should not be seen as
limiting on the scope of the present invention.
In a preferred embodiment a roller assembly may be a plurality of individual rollers. The rollers
may be mounted on a common axle or otherwise coaxial with each other.
However, it is also envisaged that a roller assembly could be a single (integral) roller. Therefore
the foregoing should not be seen as limiting on the scope of the present invention.
Throughout the present specification reference to the term “drive mechanism” should be
understood as meaning a component that is configured to rotate a roller assembly.
In a preferred embodiment a drive mechanism includes at least one motor connected to a roller
assembly.
In a particularly preferred embodiment the drive mechanism includes a hydraulic drive system
comprising a hydraulic pump configured to drive rotation of a hydraulic motor.
However, the forgoing should not be seen as limiting on the scope of the present invention and
alternatives are envisaged, including one electric motor per roller assembly or a pneumatic
drive system includes a primary drive that powers a plurality of motors.
In a preferred embodiment, the drive mechanism is configured to rotate the rollers at a rate of
between 6 – 15 revolutions per minute, and more preferably 10 revolutions per minute.
James & Wells ref: 32743/60 HCS
The inventor has identified that this range of rotating rates for the rollers is particularly
advantageous in ensuring that the present invention works successfully. Without being limited
the inventors believes that these rates of rotation help to ensure that the rollers are better able
to engage the boat hull surface to transfer force to the boat hull (which is necessary to move
the boat). If the rollers rotate too quickly then they slip over the boat hull. If the rollers rotate to
slowly then the time taken to load and unload the boat onto the trailer is too long.
It should also be appreciated that the roller diameter has an effect on the rate of rotation
required to move a boat onto and off from the trailer within a useful timeframe. Accordingly, the
forgoing should not be seen as limiting on the scope of the present invention.
In a preferred embodiment the drive mechanism includes a square drive.
Throughout the present specification reference to the term “square drive” should be understood
as meaning a non-circular axle. In use, the axle is disposed in a correspondingly shaped
aperture in a roller.
The inventor's have found that the square drive provides a particularly efficient way to transfer
force from motors to the rollers. This is beneficial in helping to reduce the complexity of parts
used in the drive assemblies and minimising the weight of the present invention. Further, the
square drive may reduce slippage of the rollers on the axle which might occur using other
configurations and arrangements.
The square drive system also helps the rollers to be held in spaced apart positions along the
axle. This is beneficial in compensating for problems due to planing lines on a boat hull. As the
rollers are spaced apart they may be better able to flex. This means that the roller can maintain
contact with the hull which may help to transfer sufficient force to the hull to move the boat.
However, the foregoing should not be seen as limiting on the scope of the present invention
and alternatives are envisaged.
Throughout the present specification reference to the term “mounting” should be understood as
meaning a component to which one or more roller assembly is secured.
James & Wells ref: 32743/60 HCS
In a particularly preferred embodiment the present invention includes one mounting for each
roller assembly.
The mounting assembly is configured to facilitate, or otherwise allow, the roller assemblies to
move with respect to each other so as to change the orientation of the roller assemblies with
respect to each other.
In a particularly preferred embodiment a mounting facilitates one or more roller assemblies
pivoting by providing a pivot point between the roller assembly and the trailer.
However, this should not be seen as limiting as alternatives are envisaged. Those include a
mounting formed by a track and guide assembly, in which a roller assembly slides through an
arcuate path so as to change the orientation of the roller assemblies. This aspect of the present
invention should become clearer from the following description.
Throughout the present specification reference to the term “orientation of at least two roller
assemblies relative to each other” should be understood as meaning changing an internal axle
of two axis, wherein each of the axis extend along the length of an axle of a roller assembly.
However, the foregoing should not be seen as limiting on the scope of the present invention.
Alternatives for assessing the orientation of the roller assemblies are envisaged.
In a particularly preferred embodiment, the mountings are configured to move the roller
assemblies to a default position.
Throughout the present specification reference to the term “default position” should be
understood as meaning a position for the roller assemblies at a given angle without any weight
or pressure applied to them.
In a particularly preferred embodiment in the default position the roller assemblies form a “V”
when viewed along the length of the trailer. That shape helps the roller assemblies to engage
the forward part (bow) of a boat hull, and thereby may improve the present invention’s
effectiveness at loading a boat onto a trailer.
In a preferred embodiment, in the default position the internal angle of the “V” between the
James & Wells ref: 32743/60 HCS
o o o
rollers is in the range of substantially 40 – 50 , and more preferably substantially 45 .
In a preferred embodiment the mountings are configured to allow the roller assemblies to pivot
so that the angle between the roller assemblies is substantially 180 e.g. the rollers/axles are
substantially parallel. This range of motion helps the roller assemblies to maintain contact with
the boat hull as it moves onto or off from the trailer. Therefore the range of motion helps to
account for changes in the shape or width of the boat, and thereby may improve the present
invention's efficiency.
In addition, the roller assemblies may be better able to transfer force to the boat hull e.g. there
is a greater contact between the surface of the roller assembly and the boat hull than would
have occurred were the roller assemblies held in a fixed position with respect to each other.
The inventors have also found that the preferred range of angles is useful to facilitate use of the
present invention with a range of different boats differing in the shape and configuration of their
respective hulls.
However, the foregoing should not be seen as limiting on the scope of the present invention.
In a preferred embodiment, rollers according to the present invention have a tread on their
contact surface.
The tread may improve the roller’s ability to grip a boat hull and therefore transfer force to the
boat hull to move this on to or off from the cradle.
In addition, the tread provides channels to facilitate moving of water. This feature may also
assist in the rollers maintaining contact with and transferring force to the boat hull. The function
of the tread is similar to the function of a tread in vehicle tires as should be known to one skilled
in the art.
However, the inventors have surprisingly found that use of rollers having a tread is particularly
beneficial to function of the loading mechanism according to the present invention. This is
surprising as existing industry wisdom is that rollers should preferably be smooth.
However, the foregoing should not be seen as limiting on the scope of the present invention,
James & Wells ref: 32743/60 HCS
and it is also envisaged that rollers according to the present invention preferably have a
substantially cylindrical shape. The rollers therefore have a long and round contact surface.
That surface can help in smoothly loading a boat onto or off from a trailer by providing a large
contact surface which can abut a boat hull.
In a particularly preferred embodiment the rollers may have an overhang.
Reference through the present specification to the term “overhang” should be understood as
meaning that the contact surface of the roller is wider than the main body of the roller. This
enables the rollers to flex or deform when under pressure in use. Therefore the roller may be
able to wrap around, or deform to account for, features of shape in the boat hull. For instance,
many boats have planning lines, being ridges extending along the boat's length. That the roller
can flex enables it to maximise the surface area of the roller in contact with boat hull. This helps
to maximise the transfer of rotational force to the boat hull and may improve the present
invention's efficiency.
However, the foregoing should not be seen as limiting on the scope of the present invention
and alternatives are envisaged including rollers that have a uniform cross section, are solid, or
where the main body is wider than the contact surface.
In a preferred embodiment where the rollers have a tread they are formed from a material
having a shore hardness in the range of substantially 40 to 80.
In a particularly preferred embodiment where the rollers have a tread are made from a material
having a shore hardness of substantially 45.
The inventors have identified that the hardness of the materials from which the rollers are made
can have a significant effect on the invention's effectiveness. It is believed that this is because
the rollers need to be resilient enough to transfer the force of rotation to the boat hull.
However, the rollers must also be able to deform to the shape of the boat hull and therefore
cannot be too hard.
Alternatively, if the roller is too soft then it is likely to be ripped or damaged through contact with
the boat hull.
James & Wells ref: 32743/60 HCS
It is also envisaged that in embodiments where the rollers have a smooth cylindrical contact
surface that they made be made from a material having a shore hardness in the range of
substantially 50 to 80, or more preferably substantially 70.
However the foregoing should not be seen as limiting on the scope to the present invention as
the rollers can be made from materials having a hardness outside of the preferred range.
It is also envisaged that the rollers could be made from a composite of two or more materials.
In such an embodiment the contact surface may have a hardness in the range described
herein, whereas the main body of the roller may be outside of that range.
It should be appreciated from the foregoing that the present invention provides a number of
advantages over the prior art. These may include any or all of the following:
The kit set may be easily retrofitted to an existing trailer.
The movement of the rollers relative to each other as they rotate so as to move a boat
helps to keep the rollers in contact with the boat's hull. Therefore the present invention
is better able to transfer force to the boat and is better able to move them.
Is better able to automatically load and unload a boat, and can handle the increase in
weight as the boat leaves the water.
Provides a self aligning mechanism to maneuver a boat into a position in which it can be
loaded onto the trailer.
Is cost effective to manufacture.
Reliable.
Easily accounts for different boat hull shapes and can therefore be used with a variety of
different boats.
BRIEF DESCRIPTION OF DRAWINGS
Further aspects of the present invention will become apparent from the following description
which is given by way of example only and with reference to the accompanying drawings in
James & Wells ref: 32743/60 HCS
which:
Figure 1A is a front perspective view of a trailer incorporating a loading mechanism
according to the present invention in the default position;
Figure 1B is a rear perspective view of Figure 1A;
Figure 2A is a perspective view of a loading mechanism according to the present
invention;
Figure 2B is a view of Figure 2A with the roller assemblies in a different position to
Figure 2A;
Figures 3A – 3D are schematics showing loading of a boat onto a trailer using a
loading mechanism according to the present invention;
Figure 4A – 4C are end on views of schematics showing Figure 3;
Figure 5A is an end perspective view of a roller according to the present invention;
Figure 5B is an end on view of Figure 5A;
Figure 6A is a first close up perspective view of a section of loading mechanism;
Figure 6B is a second close up perspective view of the section of a loading
mechanism shown in Figure 6A.
BEST MODES FOR CARRYING OUT THE INVENTION
Aspects of the present invention have been described by way of example only and it should be
appreciated that modifications and additions may be made thereto without departing from the
scope thereof.
There is provided a loading mechanism generally indicated as (1). The loading mechanism (1)
is secured to a boat trailer (1A).
The loading mechanism (1) may be sold as a kitset of parts including instructions on how to
assemble the loading mechanism (1) to the boat trailer (1A). The instructions (not shown in the
Figures) can include any or all of the steps discussed herein.
Referring first to Figures 1A, 1B, and Figures 2A, 2B.
The roller assemblies (2, 3) can pivot with respect to each other so as to change their
orientation with respect to each other. In the embodiment shown in the Figures, the roller
assemblies (2, 3) can pivot such that they are substantially parallel, with their axis (Y) aligned.
This is important to roller assemblies (2, 3) transferring sufficient force to the boat (18) to move
it onto or off from the trailer (1A).
James & Wells ref: 32743/60 HCS
The loading mechanism includes two roller assemblies (2, 3). Each of the roller assemblies (2,
3) are identical, and therefore only roller assembly (2) will be described. However, in the
drawings, like references refer to like components.
Roller assembly (2) includes a mounting arm (4) which pivotally secures the roller assembly (2)
to a trailer (5). The mounting arm (4) may be secured to a wobble roller mount as is known to
one skilled in the art.
Roller assembly (2) is free to pivot about pivot point (6). The mounting arm is configured so that
the weight of the roller assembly (2) causes it to pivot about pivot point (6) such that an inner
end (7) of roller assembly (2) is lower than an outer end (8). Pivoting of the roller assemblies
(2, 3) about pivot point (6) enables their orientation with respect to each other.
The orientation of the roller assemblies (2, 3) with respect to each other is best understood with
reference to an imaginary axis indicated as (Y) in Figures 2A and 2B. The imaginary axis (Y)
extends along the length of the axle (10).
The internal angle (X) between the axis (Y) of the roller assemblies (2, 3) changes as the roller
assemblies (2, 3) pivot about pivot point (6).
Roller assembly (2) has a plurality of rollers (9) that are each mounted on an axle (10). The
rollers (9) are spaced apart from each other along the length of axle (10).
Spacing the rollers (9) apart allows them to flex independently of each other. Therefore, the
rollers (9) may be better able to accommodate changes in shape of the boat hull (20), or
plaining lines (23) which the rollers (9) may touch when moving a boat onto or off from a trailer
(1A).
In addition, the rollers (9) are able to be easily cleaned. This can prevent damage to the rollers
(9) by particulate matter (grit) or rusting caused by salt water.
A drive motor (11) is secured to mounting arm (4) and operatively coupled to an axle (10). In
use, the drive motor (11) rotates and thereby causes the axle (10) to rotate. This in turn rotates
rollers (9) - as will be discussed below.
Drive motors (11) are connected to a hydraulic pump (12) which is mounted on the trailer (1A).
An electric motor (not shown) is mounted to the trailer and a battery (not shown). The battery
provides a power source to drive rotation of the electric motor.
The electric motor (not shown) drives hydraulic pump (12).
Hydraulic pump (12) is connected to drive motors (11) in parallel. Therefore, hydraulic pump
(12) applies equal driving force to drive motors (11).
James & Wells ref: 32743/60 HCS
The connection of hydraulic pump (12) to drive motors (11) is such that it can control rotation of
drive motors (11) in a clockwise or anticlockwise direction. This enables the drive motors (11)
to rotate the axles (10), and thereby the roller assemblies (2, 3), in either a clockwise or
anticlockwise direction.
A remote (not shown) is able to communicate with hydraulic pump (12) and send signals which
cause the pump (12) to engage and disengage. The remote can also tell hydraulic pump (12)
which direct in to rotate roller assemblies (2,3). This allows a user to control rotation of roller
assemblies (2, 3).
Referring now to Figures 5A and 5B which show features of one embodiment of the rollers (9).
The rollers (9) shown in Figures 5A and 5B have a substantially cylindrical shape. Each roller is
made from polyurethane has a shore hardness of substantially 70A.
Each roller (9) has a central main body (14) and a contact surface (15). The contact surface
(15) is longer than the main body (14). This provides an overhang indicated by (16) whereby
the contact surface (15) extends beyond the dimensions of the main body (14).
It is also envisaged that each roller (9) can have a shape and configuration generally similar to
a type, having a tread on a contact surface of the roller (9).
In Use
Referring now to Figures 3 and 4.
A vehicle (not shown) is used to position trailer (1A) with respect to a body of water (17).
Remote (not shown) is used to engage drive mechanism so that hydraulic pump (12) rotates
drive motors (11). This in turn causes roller assemblies (2, 3) to rotate.
A boat (18) is moved so that bow (19) approaches loading mechanism (1).
One or both of roller assemblies (2, 3) abut boat hull (20) on the side of the boats centre line
(21).
If the boat hull (20) is not in line with the central axis (22) of boat trailer (1A) then the force
applied to boat hull (20) moves boat (18) so as to align its centre line (21) with the central axis
(22) of the trailer (1A).
The shape and/or width of boat hull (20) which varies along its length. As boat (18) moves onto
the trailer (1A) the boat hull (20) applies pressure to roller assemblies at different angles. This
causes roller assemblies (2, 3) to pivot around pivot points (6). Inner end (7) of roller
assemblies (2, 3) moves upwards while outer ends (8) pivot downwards.
This changes the orientation of the roller assemblies (2, 3) with respect to each other.
James & Wells ref: 32743/60 HCS
The change in orientation of the roller assemblies (2, 3) as the boat hull (20) moves onto trailer
(1A) and is best seen in Figures 4A – 4C.
The change in angle ensures that the roller assemblies (2, 3) are better able to engage the
surface of the boat hull (20) as that moves onto trailer (1A). Accordingly, the roller assemblies
(2, 3) are better able to transfer rotation of force to the boat. This may assist in loading and
unloading of the boat onto the trailer.
The roller assemblies (2, 3) continue rotating until the boat is moved entirely onto the trailer
(1A).
Boat hull (20) has plaining lines (23) which extend along its length. If the rollers (9) contact the
plaining lines then the rollers (9) can deform (bend) around the plaining lines (23). This is
achieved by the overhang (16) providing the roller (9) with a degree of flexibility.
The rollers (9) deforming helps to ensure that the roller assemblies (2, 3) can maintain contact
with the boat hull. This is important in ensuring that the loading mechanisms (1) can apply
sufficient force to the boat hull to move it onto the trailer (1A).
The inventors have found that one of the most difficult aspects of loading a boat onto a trailer is
moving the boat (18) when it is substantially out of the water e.g. getting the last 1 – 2 metres of
the boat (18) onto the trailer (1A). At this stage, all of the boat’s weight is bearing on the roller
assemblies (2, 3).
The hydraulic pump (12) is disengaged so that roller assemblies (2, 3) stop rotating.
To unload the boat from the trailer (1A) the remote sends a signal to the pump (12). The pump
forces hydraulic fluid through the drive motors (11) in a direction which causes the drive motor
(11) to rotate axle (10) in an appropriate direction. Rotation of axle (10) causes rollers (9) to
rotate in a corresponding manner. The rollers (9) apply force to boat hull (20) to move boat
(18) with respect to the trailer (1A) and into body of water (17).
It should be appreciated that the present invention has a number of advantages over the prior
art.
The roller assemblies being laterally spaced across the width of the boat trailer (1A) is
important. Due to this configuration, the roller assemblies (2, 3) are in-use on either side of the
boat’s centre line. Therefore, the roller assemblies (2, 3) are able to provide an aligning
mechanism to move a boat into an optimum position to be loaded onto the trailer.
In addition, this enables the roller assemblies to move effectively transfer force to the boat hull
so as to load and unload the boat onto the trailer (1A).
That the roller assemblies are able to move relative to each other also helps them to maintain
James & Wells ref: 32743/60 HCS
contact with the boat hull. Again, this is important in helping the roller assemblies (2, 3) to
transfer force to and thereby move the boat hull.
The configuration and properties of the rollers may also important in ensuring that the invention
is successful. The inventors have identified the particular ranges of hardness as providing
particular advantages.
Other advantages may include but are not limited to:
Being cost effective to manufacture;
Reliable and less prone to mechanical failure than existing boat trailer
mechanisms;
Can be easily retrofitted to existing boat trailers;
Can be easily adapted to work with boats of different sizes, shapes, and
dimensions.
Aspects of the present invention have been described by way of example only and it should be
appreciated that modifications and additions may be made thereto without departing from the
scope thereof as defined in the appended claims.
James & Wells ref: 32743/60 HCS