Note: Descriptions are shown in the official language in which they were submitted.
I41.;
CA 02387818 2002-05-29
1
TITLE OF INVENTION
PANEL JOINT FOR KITCHEN RANGE HOOD
FIELD OF THE INVENTION
This invention relates to kitchen range hoods. In particular, this invention
relates
to the fabrication of joints between the panels of the body of a kitchen range
io hood.
BACKGROUND OF THE INVENTION
The body of a kitchen range hood typically comprises a top panel, two side
is panels, a rear panel and a bottom panel to accommodate one or more air
intakes
and fan grills. The panels are generally joined at their edges by welding.
Welds in range hoods may be visible or invisible. An example of a visible weld
on a panel joint in a range hood is provided in Fig. 2. The lap joint
construction is
2o more clearly illustrated in Fig. 5. The edge of a side panel 12 is made to
extend
inwardly to provide a horizontal portion to overlay the edge of the top panel
14.
The overlapping edges are then welded together, typically resulting in visible
welds 13 as illustrated in Fig. 2. The lap joint also results in an exposed,
sharp
edge 28 which can result in injury to workmen or users.
One approach that avoids sharp edges is illustrated in Fig. 3. The edge of
side
panel 12 is provided with a downward extension 16. The edge of top panel 14 is
similarly provided with a downward extension 18. Extension 18 is made longer
than extension 16. Extension 18 is then folded over and back onto extension
16.
~. i,r,~. 1~.1
CA 02387818 2002-05-29
2
The extension assembly is then folded onto itself against the underside of the
top
surface. This approach provides a flush joint without sharp edges, but is
mechanically difficult to achieve.
s Fig. 4 illustrates a prior art form of flange-butt joint (sometimes called
an edge
flange joint) wherein an edge of side panel 12 is bent inward and includes a
downward extension or flange 20. An edge of top panel 14 is bent downward to
provide a corresponding extension or flange 22. Extensions 20 and 22 are then
welded together, one side of the welding tool being accommodated by the gap 21
io between the main vertical surface of side panel 12 and extension 20. This
approach provides a relatively flush seam without sharp edges. However, the
gap 21 between the main surface of side panel 12 and extension 20 tends to be
small, making it difficult to clean splatter or debris from the weld area. In
addition, the cleaning process is made hazardous by the sharp edges of
is extensions 20 and 22, particularly when such cleaning is done by hand.
Yet another prior art approach is illustrated in Fig. 6. This is a modified
lap joint
wherein one of the overlapping edges is doglegged to provide a flusher seam.
The depth of the dogleg is chosen to match the thickness of top panel 14 which
ao is then seated in a step formed by the dogleg. The two surfaces are then
welded
together. This arrangement usually results in a visible weld on the top outer
surface 31 of the joint. There also remains an undesirable sharp edge 30.
It is therefore an object of this invention to provide a construction and
method of
Zs fabricating a joint for the panels of a kitchen range hood that allows the
weld to
be substantially hidden whole also avoiding the sharp edges on the outer
surface
of the joint.
i-to, , ~ I
CA 02387818 2002-05-29
3
It is a further object of the invention to minimize the protrusion of sharp
edges on
the inside of such a joint.
It is yet a further object of the invention to provide such a joint which is
relatively
s easy to access with a welding tool.
These and other objects of the invention will be better understood by
reference to
the detailed description of the preferred embodiment which follows.
to SUMMARY OF THE INVENTION
In one aspect, the invention comprises a body for a kitchen range hood
comprising a top panel comprising a main panel portion having an underside and
a top panel edge. The top panel edge has a flange that is folded under the
main
is panel portion so as to abut and be flush with the underside. A side panel
has a
side panel edge that comprises a downwardly extending portion and a horizontal
portion extending from an end of the downwardly extending portion. The flange
is in face to face abutment with the horizontal portion and is secured to it.
Securement may be by welding.
In another aspect, the invention is a method of welding a joint between a side
panel and a top panel in a kitchen range hood comprising steps of:
providing a body of a kitchen range hood as described above;
2s
bringing a flat electrode into contact with a section of the main panel
portion that overlies the flange;
bringing a point electrode into contact with the horizontal portion;
r:m~ ~' I .
CA 02387818 2002-05-29
4
spot welding between the flat and point electrodes.
In another aspect, the invention comprises a joint between a first and a
second
s panels of a kitchen range hood body. An edge of the first panel is folded
under
itself to provide a flange that is flush with the underside of the first
panel. An
edge of the second panel is provided with a step including an extension that
underlies the flange and is connected to it. The connection may be by welding.
io The foregoing was intended as a broad summary only and of only some of the
aspects of the invention. It was not intended to define the limits or
requirements
of the invention. Other aspects of the invention will be appreciated by
reference
to the detailed description of the preferred embodiment and to the claims.
is
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENT
A detailed description of the preferred embodiment will be provided by
reference
to the drawings thereof and of the prior art, in which:
Fig. 1 is a perspective view of the body of a prior art kitchen range hood;
Fig. 2 is a perspective view of a prior art joint between a side panel and a
top panel of a range hood;
Fig. 3 is a cross-sectional view of a second prior art panel joint;
Fig. 4 is a cross-sectional view of a third prior art panel joint;
~:i~L
CA 02387818 2002-05-29
s
Fig. 5 is a cross-sectional view of the prior art panel joint illustrated in
Fig.
2;
Fig. 6 is a cross-sectional view of a fourth prior art panel joint;
s
Fig. 7 is a cross-sectional view of the panel joint for the left and right
sides
of the body of a range hood, according to the preferred embodiment of the
invention; and,
io Fig. 8 is a cross-sectional view of the panel joint of the preferred
embodiment of the invention, also showing the welding tool as used
according to the method of the invention.
is DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring to Fig. 7, the body of a kitchen range hood includes a side panel
12.
Side panel 12 is provided with an inwardly extending portion 15, which may be
at
a 90 degree angle or, as illustrated in Fig. 7, in a gradual curve terminating
in a
ao horizontal portion 17.
A downwardly defined step or dogleg includes a downwardly extending portion
30 and a horizontal, inwardly extending portion 32 extending from the end of
downward extension 30 at a right angle. The depth of the step, i.e. the extent
of
Zs downwardly extending portion 30, is about twice the thickness of top panel
14.
Top panel 14 includes a main panel portion having a top surface 17 and an
underside 19. The edge of top panel 14 is bent under itself as at 34 to create
a
flange 36. The bent edge of top panel 14 is then seated in the step created by
i a,:
CA 02387818 2002-05-29
6
extensions 30 and 32. Flange 36 rests flush with extension 32 in face to face
abutment, and the bent edge also abuts extension 30.
The joint may be constructed by first providing the mating flange-butt
s arrangement of Fig. 4 but without welding the flanges together. They are
then
bent (preferably inwardly) to provide the structure of Fig. 7. The joint is
then
preferably pressed or crimped so as to ensure secure contact across the joint.
This consists of a simpler mechanical manipulation than that required for the
fabrication of the prior art joint of Fig. 3. The joint is then ready for
welding.
io
It will be appreciated that this structure results in the absence of any sharp
edges on the top surface of the joint. In the welding process, this
arrangement of
seam also provides an additional layer (flange 36) of thickness as compared to
the prior art lap joint of Fig. 5 or of Fig. 6. This extra layer 36 enhances
the ability
is to produce a hidden weld on the top surface of the joint, particularly when
also
using the method of welding the joint according to the invention.
The welding of the joint according to the invention is performed by a form of
spot
welding. Referring to Fig. 8, a broad, flat electrode 38 is used for the top
surface
ao 37 of the joint, namely the portion of the main panel surface that overlies
flange
36, while a point electrode 40 is used on the bottom (hidden) surface of the
joint.
The use of a broad flat electrode on the top surface acts to distribute the
current
across the surface of the joint. Conversely, the point electrode concentrates
the
current. As a result, the weld is concentrated near the point electrode,
between
Zs extension 32 and intermediate layer or flange 36, with minimal welding
between
the top surface 37 and extension 36.
The result is a relatively invisible weld mark on the outside or top portion
of the
joint and a solid but hidden weld between extensions 32 and 36. This
i.;r; ',
CA 02387818 2002-05-29
7
construction also allows easy access for the two components of the weld tool
while eliminating any sharp edges at the top of the joint and minimizing the
obstruction caused by any sharp edges on the inside of the joint.
s While the preferred embodiment of the invention contemplates folding over
the
edge of the top panel and seating it in a step formed by a side panel edge,
the
arrangement may be reversed wherein the edge of the side panel is folded over
and seated in a step formed by the edge of the top panel.
io The above description has been intended to illustrate the preferred and
alternative embodiments of the invention. It will be appreciated that
modifications
and adaptations to such embodiments may be practiced without departing from
the scope of the invention, such scope being most properly defined by
reference
to this specification as a whole and to the following claims.
is
