Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
Wheelbarrow Insert 2 1 2 9 3 0 9
This invention relates to a removable insert for enlarging
the carrying capacity of a wheelbarrow.
Wheelbarrow inserts or attachments for enlarging carrying
capacity are known in the art. For example see U.S. Patent
Nos.4,645,225 and 2,805,885, published PCT International
Application No.PCT/GB90/01673 (Publication No.W0 91/06460), and
U.S. Design Patent No. 269,335. However, each of these is for a
device which requires fastener attachment to the wheelbarrow
and/or is bulky for storage. The former means that the device
is not quickly and easily installed or removed. The latter
means that the device is not conveniently stored when not in
use. None of the prior art devices is therefore considered to
be so suitable for use in a setting where there is a variety of
tasks for the wheelbarrow, some benefitting from an enlarged
carrying capacity, eg. when collecting leaves in the fall, or
cleaning debris from a construction area. Unless an enlargement
device can be quickly and easily installed and removed, and
conveniently stored, such is likely not to be used, especially
if the task is not overly time consuming or if storage space is
at a premium.
There is therefore a need for a wheelbarrow carrying
capacity enlargement device which is light weight, easy to set-
up and remove from the wheelbarrow and which can be easily
stored without taking up very much space.
Summary of the Invention
The invention therefore provides a wheelbarrow enlargement
insert comprising front, back and two side panels for mating
insertion into a bucket of the wheelbarrow, whereby volumetric
capacity of the wheelbarrow is increased. The insert preferably
is made of self-supporting semi-rigid creaseable sheet material,
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such as corrugated cardboard or corrugated plastic, which does
not require a supporting frame. Either each of the front and
back panels, or each of the two side panels, includes a crease
between side edges of each panel adapted cooperatively to enable
selective opening of the insert for the mating insertion, as
well as folding of the insert to a substantially flat storage
form. There is thus at least one pair of opposed creases, but
preferably there are two pairs. One pair of opposed creases if
present, ie. the pair formed from the crease on the front panel
and the crease on the back panel, allows the opening or folding
to occur along a substantially longitudinal, vertical plane.
The other pair of opposed creases if present, ie. the pair
formed from the creases respectively on the side panels, allows
for the opening and folding along a substantially transverse,
vertical plane. Preferably, each crease extends along a mid-
line from a top edge to a bottom edge of a given panel.
In another embodiment, the insert further comprises a
bottom panel having one crease adapted to cooperate, with one of
the above discussed pairs of creases, during the opening and
folding. This crease is in-line with this pair of creases.
In another aspect, there is provided a method of
manufacturing a wheelbarrow enlargement insert made of semi-
rigid creaseable material in front, back and side panels. The
method comprises fabricating the panels with dimensions in
accordance with dimensions of a bucket of the wheelbarrow and a
desired height of the panels above the base of the bucket, and
provides either a crease between respective side edges of each
of the front and back panels, or a crease between respective
side edges of each of the side panels, such that there is
thereby provided at least one pair of creases adapted
cooperatively to enable selective opening of the insert for
mating insertion into the bucket and folding of the insert to a
substantially flat storage form.
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Brief Description of the Drawings
Preferred embodiments of the present invention are shown in
the accompanying Figures, in which:
FIG. 1 is a perspective view of a wheelbarrow including an
enlargement insert according to the present invention;
FIG. 2 is an overhead view of an unfolded enlargement
insert according to the present invention;
FIG. 3 is a perspective view of an enlargement insert
according to the present invention which is being folded flat;
FIG. 4 is an overhead view of one method of assembly of an
enlargement insert according to the present invention;
FIG. 5 is a side view of an enlargement insert according to
the present invention which has been folded flat using creases
on front and back panels of the insert;
FIG. 6 is a top view of unassembled pieces of an
enlargement insert according to the present invention which
includes an optional bottom panel;
FIG. 7 is a side view of an enlargement insert according to
the present invention which has a bottom panel, and which has
been folded flat using creases on front, back and the bottom
panels; and,
FIGS. 8a and 8b respectively show end (front or back) and
side views of an unfolded enlargement insert according to the
present invention with references for use in construction, and
FIG. 8c is a view of a side panel of an alternate enlargement
insert according to the present invention, in which the slopes
of the front and back of said insert differ substantially, with
reference for use in calculating the position of the side
creases as part of construction.
Description of Preferred Embodiments
3c~
The enlargement insert 1 preferably sits in the bucket 2 of
a wheelbarrow without fasteners or other security aids. The
insert gains its stability and tightness of fit as it is filled,
as the weight of the filling material 3 pushes the sides of the
insert outward and downward against the sides of the bucket.
Optionally, the insert may be tied in with string (not shown)
wrapped around the wheelbarrow handles and through holes in the
insert provided for that purpose, eg. to help prevent the insert
from falling out when dumping off ledges.
The insert has substantially the same base dimensions as
the base of the wheelbarrow's bucket, and has substantially the
same slope to its side, front and back panels as corresponding
panels of the bucket. However, the insert has higher side,
front and back panels than the corresponding panels of the
bucket. It is the case that the insert of the present invention
fits most conventional wheelbarrows, regardless of bucket size:
in larger buckets the insert wedges more deeply, and vice versa in
smaller buckets. The insert is not intended to create a
precision fit, thereby facilitating easy placement in the bucket
and avoiding the complications that can arise with precision
assemblies. A bottom panel 9 is optional to the insert. Flaps
8 are preferably provided for adhesive attachment of the bottom
panel to the side panels.
A pair of creases 6,7 may be provided upwardly along the
respective middles of the side panels. A pair of creases 4,5
may also be provided upwardly along the respective middles of
the front and back panels. One pair of creases must be
provided, but preferably, both of such pairs of creases are
provided. Both pairs of creases allow, if present, for
selective folding of the insert along a lateral (side to side)
or longitudinal (front to back) plane. The latter is
illustrated in FIG. 3. Such folding results in a substantially
flat storage form of the insert. The creases also allow for the
insert to flex outwardly and tightly against the bucket walls
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during filling. Furthermore, it has been found that partial
collapse of the insert may occur during dumping of a load, which
appears to assist in the dumping.
In manufacturing a preferred embodiment of the insert,
initial measurements are obtained of the base, and slopes of the
sides, front and back of a wheelbarrow bucket for which inserts
according to the invention are to be mass produced. In
referring to FIG. 2, both sides of the insert preferably are
identical, having a base length Lsb and top length Lst. The front
and back panels of the insert preferably have equal base lengths
and equal top lengths, denoted by LEb and LEt respectively. In
referring to FIG. 8a, which is an end (front or back) view of an
unfolded insert, it can be seen that both sides of the insert
preferably have an equal slope (measured as an angle in degrees
upward from the base horizontal), denoted by 0s~ The front and
back panels may have different slopes, 0F and 0B respectively, as
shown in FIG. 8b. The widths of the sides, front and back
panels of the insert are denoted by Ws~ WF and WB respectively.
To the extent that the base dimensions and the side, front
and back panel slopes are predetermined by the bucket, it is the
height, h, measured as the vertical component of the distance
between the top and bottom edges of the insert, which gives it
the increased carrying capacity. Therefore, to build the insert
the following figures should be supplied: Lsb, LEb, 05, 0F' 0B'
and h. The above figures may be used to determine the widths
and top lengths under the following formulae:
Widths:
Side, Ws = h/sin 0s
Front, WF = h/sin 0F
Back, WB = h/sin 0B
Lengths:
~ laq3~s
Side Panel Top,
LSt LSb + WFCOS0F + WBCOS0B
Front and Back Panel Tops,
LEt = LEb + 2(Wscos05)
The positions of the creases for use in folding the insert
for storage are preferably determined as follows (refer to Fig.
8c):
Side Panel creases:
Because the front and back slopes of the insert may not be
equal, the method of calculating the position of the side panel
creases is not straightforward. Two temporary angles, called ~SF
and ~SB~ must first be calculated. If an enlargement insert is
folded through the creases in its sides to its flat storage form
and then ~stood up" against a wall so that the top edges of the
front and back panels are horizontal, then ~SF represents the
inside angle between a vertical line and the top edge of the
side panel where it meets the front, and similarly ~SB represents
the inside angle between a vertical line and the top edge of the
side panel where it meets the back.
~SF = 90 - tan 1 [WSCOS05 / WF] ~ tan 1 [WFCOS0F / W5]
~SB = 90 - tan~1[Wscos05 / WB] ~ tan~1[WBcos0B / Ws]
Factor FB is a ratio, expressed as a fraction of 1. Here 1
represents the entire length of the top or bottom edge of the
side panel. Factor FB represents, in relative terms, how far
along the top or bottom edge of the side panel, as measured from
the back edge of the side panel, the crease intersects this top
or bottom edge.
FB = sin a5F / (sin ~SF + sin ~SB)
Therefore along the bottom edge of each side panel the crease is
dSBb units from the back, where:
dSBb = FB x LSb-
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Similarly, the crease intersects the top edge of each side dSBt
units from the back, where:
dSBt = FB x Lst
If the front and back slopes, 0F and 0B' are equal then factor FB
= 1/2 and the crease is up the middle of the side, equidistant
from the front and back.
Front and back panel creases:
Because both sides always have equal slopes, a crease may always
be up the middle of each of the end panels, equidistant from the
sides of the end panels. Therefore, at the base of the front
and back panels, the crease preferably is 1/2 ~b units from
either side. Similarly, at the top the crease preferably is 1/2
~t units from either side of the end panels.
When laying out a side panel for construction, the
following measurement sequence may be applied to a piece of
semi-rigid material of width equal to Ws the width of the side
panel. Decide which edge of the material represents the top,
then (see FIG. 8c):
1. Start at upper back corner of side:
2. Add WBCOS0B to obtain the point of the bottom back
corner;
3. Add Lsb to obtain the point of the bottom front corner;
4. Add WFCOS0F to arrive at the upper front corner of
side.
Similarly, the front and back panels' layouts may be achieved.
Each panel, if made separately, may be attached to an
adjacent panel by means of a two-inch side flap 8, using
adhesive. It is contemplated that the insert may be made in
combining individual panels for attachment in a sequence as
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shown in FIG. 4, or in combining sections of two or more panels,
or in one section from one piece of material.
