Note: Descriptions are shown in the official language in which they were submitted.
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METHOD FOR FORMING A SLAT PIECE FOR VENETIAN BLIND AND
THE SLAT PIECE THUS FORMED
BACKGROUND OF THE INVENTION
The present invention generally related to a slat piece for a Venetian blind.
More
specifically, the present invention relates to a method of forming a slat
piece for
Venetian blinds.
Blinds for covering windows and other light transparent surfaces are available
in
a variety of different forms and materials depending on the particular visual
appearance desired. U.S. Patent No. 6,105,657 discloses a fabric blind slat 10
for
Venetian blinds as shown in FIG 1. The fabric blind slat 10 is made of a
flexible
woven piece 11 having a tubular engaging passage 12 disposed at both
longitudinal
sides thereon respectively for a stiff supporting rod 16 to be joined therein
to expand
the blind slat 10 horizontally.
There are some drawbacks to such conventional slat structure for a Venetian
blind. First, the fabric blind slat 10 is formed by the weaving operation
before the
supporting rods 16 are sequentially mounted and located into the tubular
engaging
passages 12 disposed at both longitudinal sides of the blind slat 10 thereof,
which is
both complicated and time-consuming in assembly as well as production. Second,
the
slat 10 itself is formed of a textile material, the need arises not only to
stiffen the
fabric sufficiently for it to retain a substantially planar form, but also to
bond the
fibers of the warps to an extent sufficient to prevent fraying out at the
longitudinal
edges of the slat, and to prevent unraveling of the threads. Third, slats made
from
textile material generally suffer a lower impermeability to light.
SUMMARY OF THE INVENTION
The present invention provides a method for forming a slat piece for Venetian
blinds and a slat piece thus formed. The slat piece includes a substrate
having a front
and a back surface. The front surface includes a first longitudinal edge, a
second
opposite longitudinal edge, and three areas of adhesive. Each of the adhesive
areas
extends in a longitudinal direction of the slat piece.
In an embodiment of the present invention, the first, second, and third
adhesive
areas define two empty areas that do not include adhesive on the front surface
for
forming tubular engaging passage(s).
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In another embodiment of the present invention, a method for forming a slat
piece is provided. The method comprises the steps of: providing a substrate
including
a front surface having a first longitudinal edge, a second opposite
longitudinal edge, a
first, a second and a third elongated adhesive areas sequentially extending on
the front
surface from the first longitudinal edge to the second longitudinal edge and
forming a
first and a second empty areas that do not include adhesive; folding the first
longitudinal edge of the front surface toward the second longitudinal edge of
the front
surface along a central axis of the first empty area so that the first
adhesive area
overlaps the second adhesive area and forms a first elongated passage with the
first
empty area; and folding the second longitudinal edge of the front surface
toward the
first longitudinal edge of the front surface along a central axis of the
second empty
area so that the third adhesive area contacts the first longitudinal edge
folded upward
and forms a second elongated passage with the second empty area.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG 1 illustrates a perspective view of a conventional slat structure for
Venetian
blind;
FIG 2 illustrates a perspective view of a slat piece according to a first
embodiment of the present invention;
FIG 3 illustrates a perspective view of a substrate for forming the slat piece
in
FIG. 2;
FIG. 4 illustrates a perspective view of a substrate in FIG. 3 in a step of
forming
the slat piece in Fig. 2;
Fig. 5 illustrates a perspective view of a slat piece according to a second
embodiment of the present invention;
Fig. 6 illustrates a perspective view of a substrate in Fig. 3 in a step of
forming
the slat piece of Fig. 5; and
Fig. 7 illustrates a schematic view of a method and apparatus for
manufacturing
the slat piece of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention provides an improved method for forming a slat piece 50
in Fig. 2 for Venetian blinds and slat pieces thus formed. The slat piece 50
according
to the present invention facilitates an easy and fast assembly of the slat
structure to
achieve economical efficiency and competitive power thereof.
In an embodiment, a substrate 20 for forming a slat piece according to the
present invention is shown in Fig. 3. The substrate 20 is prepared by
thermally
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forming a slat base from a felt batt, and optionally securing a layer of
fabric to the slat
base. The fabric may be natural (e.g. silk, cotton, wool, linen and the like),
or
synthetic, and the fabric may be treated with known fire retardants, stain or
water
repellants, dust repellants, UV light stabilizers, etc. In one embodiment, the
substrate
is a blind fabric utilizing natural or synthetic fibers of fabric as base
materials to form
an inexpensive fabric used in conjunction with conventional Venetian blinds
and
formed by a method comprising dipping, compressing, tentering, slitting into
desired
widths, heating, and forming as disclosed by U.S. Patent No. 5,273,781.
The substrate 20 includes a front surface 22 and a back surface 24. The front
surface 22 includes a first longitudinal edge 23, a second longitudinal edge
25
opposite to the first longitudinal edge, a first, a second, and a third
elongated adhesive
areas 26, 27, and 28 sequentially positioned on the front surface 22 from the
first
longitudinal edge 23 to the second longitudinal edge 24 and forming a first
and a
second empty areas 30, 36 that do not include adhesive. Each of the empty
areas 30
and 36 has a respective central axis 32, 38 extending in a longitudinal
direction of the
substrate 20.
The application of adhesive onto the front surface 22 may be implemented in
any conventional manner, such as by means of roller and doctor blade
arrangement as
is well known in the art. Preferably, the adhesive may be a heat activated
adhesive,
such as Polyurethane Reactive (PUR) hot melt adhesive.
In the embodiment of the substrate 20 illustrated in Fig. 3, the three
adhesive
areas 26, 27, and 28 are oriented along, or in juxtaposition to the
longitudinal edges.
In the preferred embodiment illustrated, the first adhesive area 26 is applied
with
adhesive. It should be noted, however, that the adhesive area 26 do not need
to apply
the adhesive and the width of the adhesive area 26 is chosen so as to insure
that the
first longitudinal edge can be fixed onto the second adhesive area 27.
FIGS. 4 and 2 illustrates the method for forming the slat piece 50 in
according
with a first embodiment of this invention. As shown in FIG 4, the substrate 20
is
folded so by folding the first longitudinal edge 23 of the front surface
toward the
second longitudinal edge 25 of the front surface along the central axis 32 (in
Fig. 3) of
the first empty area 30 (in Fig. 3) so that the first adhesive area overlaps
the second
adhesive area 27 and forms a first elongated passage 40 with the folded first
empty
area 30 (in Fig. 3).
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In the preferred embodiment illustrated, the first longitudinal edge 23 folds
over
a minor extent of the width of the second adhesive area 27, for example
2millimeters.
However, of course, the first longitudinal edge 23 can fold over a greater or
less
extent of the width of the second adhesive area 27 as long as the first
longitudinal
edge 26 is fixedly secured onto the second adhesive area 27.
In the next step of the process, illustrated in FIG 2, the second longitudinal
edge
is folded over along the central axis 38 of the second empty area 36 so that
the third
adhesive area 28 contacts a portion 34 of the back surface 24 of the substrate
20. This
forms a second elongated passage 42 (depicted by a phantom line 44) and
completes
the slat piece 50 according to the first embodiment of the present invention.
Fig. 5 shows a slat piece 50' in accordance with the second embodiment of the
present invention, wherein only one elongated passage 52 (depicted by phantom
lines)
is formed in the slat piece 50'. In this embodiment, the slat piece 50' is
formed by
using the substrate 20 shown in Fig. 3.
As illustrated in Fig. 6, the first longitudinal edge 23 of the front surface
22 is
folded toward the second longitudinal edge 25 of the front surface 22 so as to
cause
the first empty area 30 and second empty area 36 (shown in Fig. 3) coincide
with each
other. This causes the first longitudinal edge 23 of the front surface to
contact the third
adhesive area 28 and forms a portion 34' of back surface 24 as shown.
In the next step of process, illustrated in Fig. 5, the second longitudinal
edge 25
is folded over so that the third adhesive area 28 contacts the portion 34' of
the back
surface 24 and the passage 52 is thus formed.
Fig. 7 illustrates schematically a manufacturing process in a production line.
A
roll of slat base 60 is fed to a gluing stage 61 where the adhesive is applied
at
predetermined spaced location as to form the substrate 20 shown in Fig. 3. A
folding
stage 62 is then used to fold the glued substrate 20 by using a suitable
means, such as
a standard plow folder or gate folder. After the folding stage 62, the folded
substrate
20 is then fed to a processing machine 64 which applies pressure and heat to
the
moving substrate after which the substrate becomes adhesively bonded thus
precluding movement of the pleats out of their assembly position. After
cooling, the
completed slat piece is reeled up and collected on a take-up roller 66.
Alternatively,
the completed slat piece may be transversely chopped into individual slat
pieces with
a cutter (not shown).
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While preferred embodiments of the present invention are shown and described,
it is envisioned that those skilled in the art may devise various
modifications of the
present invention without departing from the spirit and scope of the appended
claims.
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