Note: Descriptions are shown in the official language in which they were submitted.
CA 02746178 2011-07-13
TITLE: EXPANDER FOR MOUNTING AN IDLE END OF A ROLLER BLIND TO A
ROLLER TUBE
FIELD OF THE INVENTION
The invention relates generally to roller blinds and in particular idle ends
for mounting an
end of a roller blind tube to a mounting bracket
BACKGROUND OF THE INVENTION
Roller blinds always include an elongated roller tube having opposite ends
which is
mounted between support brackets. The support brackets are generally suspended
at the top of a
window frame so that the roller blind drapes over the window. The roller blind
generally has a
clutch end positioned at one end of the roller tube and an idle end positioned
at the opposite end
of the roller tube. The roller tube is suspended to the support brackets at
the clutch end and idle
end.
Installing a roller blind often starts by measuring the width of the window
and cutting the
roller tube to match the width of the window. The roller tube is generally an
elongated
aluminum tube which can be easily cut at the installation site. It will be
appreciated that given
the long length of the desired roller tube, it is quite possible to make a
small error in the
measuring or cutting of the roller tube. Generally, measuring and cutting
errors range between a
few millimeters to a few centimeters. If the roller tube is accidentally cut
two centimeters too
long, it is a trivial matter to shorten the roller tube. However, if the
roller tube is cut two
centimeters too short, then the wrongly cut piece of roller tube will have to
be discarded. In
addition to wasting the material cost of the discarded section of roller tube,
cutting the roller tube
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too short can seriously decrease the efficiency of the installation because
time will be wasted in
mounting a wrongly sized roller tube. A system which would correct cutting
errors in roller
tubes would therefore decrease costs and increase efficiency.
SUMMARY OF THE INVENTION
In accordance with one aspect of the present invention, there is provided a
system for
correcting errors in cutting the length of a roller tube by effectively
expanding the length of a
roller tube which is to be mounted to an idle end to form a roller blind. The
system includes at
least one flat disk coaxially mounted between the idle end and one end of the
roller tube. The
flat disk has a thickness equal to a desired length of expansion of the roller
tube. The flat disk
has a central opening dimensioned to receive the idle end.
With the foregoing in view, and other advantages as will become apparent to
those
skilled in the art to which this invention relates as this specification
proceeds, the invention is
herein described by reference to the accompanying drawings forming a part
hereof, which
includes a description of the preferred typical embodiment of the principles
of the present
invention.
DESCRIPTION OF THE DRAWINGS
Figure 1 is a perspective view of an idle end expander made in accordance with
the present
invention for use with an idle end and a roller tube.
Figure 2 is a perspective view of two idle end expanders made in accordance
with the present
invention for use with an idle end and a roller tube.
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Figure 3 is a side view of an idle end coupled to a roller tube without the
spacer portion of the
present invention.
Figure 4 is a side view of two idle end expanders made in accordance with the
present invention
and mounted between an idle end and a roller tube.
Figure 5 is a side view of an idle end expander made in accordance with the
present invention for
use with an idle end and a roller tube.
Figure 6 is a side view of two idle end expanders made in accordance with the
present invention
for use with an idle end and a roller tube.
In the drawings like characters of reference indicate corresponding parts in
the different
figures.
DETAILED DESCRIPTION OF THE INVENTION
Referring firstly to figures 1 and 2, an expander system for use with a roller
tube and idle
end is shown generally as item 10 and consists of a flat circular member 12
which is configured
to mount coaxially between idle end 16 and roller tube 14 so as to compensate
for the roller tube
being too short. Roller tube 14 is generally an elongated extruded aluminum
tube having an
interior 18 and an outside surface 34. Grooves 30 are formed on the outside
surface 34 of roller
tube 14 and channels 32 project into interior 18. The length of roller tube 14
is generally several
feet and is cut to suite the length of the desired roller blind (not shown)
which is to be made
using the roller tube. Idle end 16 is dimensioned to fit within end 15 of
roller tube 14. Idle end
16 has barrel portion 20, flange portion 24 and a plurality of fins 22
radiating from barrel portion
20. Fins 22 are dimensioned to permit idle end 16 to fit snuggly within
interior 18 of roller tube
14. Fins 22 are spaced apart such that channels 32 fit between adjacent fins
to permit the idle
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end to fit all the way in roller tube 14 such that flange 24 lies flush
against end 15. Spacer 12 is a
disc shaped plastic member having an external diameter equal to the external
diameters of roller
tube 14 and flange portion 24 of idle end 16. Spacer 12 has central opening 26
which is
dimensioned and configured to fit over and receive barrel portion 20 of idle
end 16. Slots 28 are
formed in spacer 12 and configured such that they can be aligned with and
receive fins 22 of idle
end 16. When idle end 16, spacer 12 and roller tube 18 are coaxially aligned,
spacer 12 can be
snuggly fitted between flange 24 and end 15, thereby effectively lengthening
roller tube 14 by
the thickness of spacer 12. As best seen in figure 2, it is possible to
further increase the effective
length of roller tube 14 by using a plurality of identical spacers. The length
by which roller tube
14 is increased is a sum of the thicknesses of the spacers used.
Referring now to figure 3, without spacer 12, idle end 16 can be mounted to
end 15 of
roller tube 14 such that flange portion 24 of the idle end snuggly abuts end
15. This is the
configuration which is likely to be used in the event that roller tube 14 is
cut to the correct size
and need not be expanded. As best seen in figure 4, each spacer 12 has a
thickness 36. As shall
be discussed below, preferably, thickness 36 is selected to be between 2 mm to
6 mm. Adding
one spacer 12 increases the effective length of roller tube 14 by the amount
of thickness 36.
Adding several spacers increases the effective length of roller tube 14 by the
cumulative total
thicknesses of all the spacers. Hence, in the example shown in figure 4, if
each spacer 12 has a
thickness of 5mm, then the effective length of roller tube 14 will be
increased by 1 cm.
Spacers 12 are intended to be used in order to correct measuring errors when
roller tube
14 is cut. It has been discovered that a majority of cutting/measuring errors
are in the range of
only one or two centimeters. Since the actual cutting error is essentially
random, each spacer is
preferably in the range of between 2 to 6 mm in thickness to enable one or two
standardized
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spacer sizes to be used. This eliminates the need for carrying a plurality of
different sized
spacers. As seen in figures 5 and 6, fins 22 of idle end 16 have a length 38
of over 4 centimeters,
which is significantly longer than similar fins on standard idle end used with
roller blinds. The
increased length of fins 22 is to accommodate a larger number of spacers 12
and therefore enable
several spacers to be mounted to the idle end. It will be appreciated that
spacers 12 do not help
secure end 15 of roller tube 14. Roller tube 14 is supported on fins 22, so
adding several spacers
12 between flange 24 and end 15 actually decreases the amount of contact
between fins 22 and
the roller tube. To compensate for this decreased contact between fins 22 and
roller tube 14, fins
22 are made several centimeters longer to ensure that sufficient contact
between the roller tube
and the idle end is maintained even when several spacers 12 are used.
A specific embodiment of the present invention has been disclosed; however,
several
variations of the disclosed embodiment could be envisioned as within the scope
of this invention.
It is to be understood that the present invention is not limited to the
embodiments described
above, but encompasses any and all embodiments within the scope of the
following claims
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