U.S. patent application number 10/354547 was filed with the patent office on 2004-08-05 for blind stitch sewing mechanism for a sewing machine.
Invention is credited to Block, Paul, Lydick, Michael.
Application Number | 20040149191 10/354547 |
Document ID | / |
Family ID | 32770384 |
Filed Date | 2004-08-05 |
United States Patent
Application |
20040149191 |
Kind Code |
A1 |
Block, Paul ; et
al. |
August 5, 2004 |
Blind stitch sewing mechanism for a sewing machine
Abstract
A blind stitch sewing mechanism for a sewing machine includes a
curved, oscillating needle, and a looper, having only one degree of
freedom, for cooperatively forming a blind stitch with the curved
oscillating needle.
Inventors: |
Block, Paul; (Nesconset,
NY) ; Lydick, Michael; (Medford, NY) |
Correspondence
Address: |
KEUSEY, TUTUNJIAN & BITETTO, P.C.
14 VANDERVENTER AVENUE, SUITE 128
PORT WASHINGTON
NY
11050
US
|
Family ID: |
32770384 |
Appl. No.: |
10/354547 |
Filed: |
January 31, 2003 |
Current U.S.
Class: |
112/176 |
Current CPC
Class: |
D05B 1/24 20130101 |
Class at
Publication: |
112/176 |
International
Class: |
D05B 001/24 |
Claims
What is claimed is:
1. A blind stitch sewing mechanism for a sewing machine,
comprising: a curved, oscillating needle; and a looper, having only
one degree of freedom, for cooperatively forming a blind stitch
with said curved oscillating needle.
2. The blind stitch sewing mechanism according to claim 1, wherein
said looper has an aperture for allowing said curved, oscillating
needle to pass there through.
3. The blind stitch sewing mechanism according to claim 1, wherein
said looper has a hook for lifting a thread off of said curved,
oscillating needle and wrapping the thread around said looper.
4. The blind stitch sewing mechanism according to claim 3, wherein
the hook wraps the thread around said looper to form a knot.
5. The blind stitch sewing mechanism according to claim 3, further
comprising a looper holder and a set screw for collectively
maintaining a position of the looper holder, and wherein said set
screw further allows for angular adjustment of the hook.
6. The blind stitch sewing mechanism of claim 1, wherein said
looper has a central axis, and the only one degree of freedom
corresponds to rotation of the looper around the central axis.
7. The blind stitch sewing mechanism of claim 1, wherein said
looper is a butterfly looper.
8. The blind stitch sewing mechanism of claim 1, wherein the only
one degree of freedom corresponds to movement of the looper along
an arc.
9. A blind stitch sewing mechanism for a sewing machine,
comprising: a curved needle for oscillating back and forth between
an ascended position and a descended position; and a butterfly
looper having a main body portion, a hook, and a central axis of
rotation, said butterfly looper for lifting a thread off of said
curved needle using the hook and wrapping the thread around the
main body portion by rotating along the central axis, when the
curved needle is oscillating to the descended position, and wherein
a knot is formed when the curved needle is oscillating to the
ascended position.
10. The blind stitch sewing mechanism of claim 9, wherein said
butterfly looper has an aperture for allowing said curved needle to
pass there through when said curved needle is oscillating.
11. The blind stitch sewing mechanism of claim 9, further
comprising a butterfly looper holder and a set screw for
collectively maintaining a position of the butterfly loop holder,
and wherein said set screw further allows for angular adjustment of
the hook.
12. A method for sewing a blind stitch on a sewing machine,
comprising the steps of: providing a curved needle; providing a
butterfly looper having a central axis, a hook, and a main body
portion; oscillating the curved needle back and forth between an
ascended position and a descended position; rotating the butterfly
looper along the central axis so as to lift a thread off of the
curved needle using the hook and wrap the thread around the main
body portion, when the curved needle is oscillating to the
descended position, and wherein a knot is formed when the curved
needle is oscillating to the ascended position.
13. The method of claim 12, wherein the butterfly looper has an
aperture, and said oscillating step comprises the step of passing
the curved needle through the aperture.
14. The method of claim 12, further comprising the step of
providing a capability to adjust an angular position of the
butterfly looper.
15. The method of claim 12, further comprising the step of
providing a capability to adjust an angular position of the
butterfly looper via a single set screw.
16. A method for sewing a blind stitch on a sewing machine,
comprising the steps of: providing a curved needle; providing a
looper having only one degree of freedom; oscillating the curved
needle back and forth to form a blind stitch by lifting a thread
off of the needle and forming a knot.
17. The method of claim 16, further comprising the step of
providing a capability to adjust an angular position of the
looper.
18. The method of claim 16, further comprising the step of
providing a capability to adjust an angular position of the
butterfly looper via a single set screw.
Description
FIELD OF THE INVENTION
[0001] The present invention generally relates to sewing machines
and, more particularly, to a blind stitch sewing mechanism for a
sewing machine.
BACKGROUND OF THE INVENTION
[0002] In the mattress industry, there is a manufacturing operation
that requires a unique sewing process to achieve what could only be
formerly produced with hazardous and volatile adhesives. The
operation requires the attachment of a first piece of material to
the underside of a second piece of material, without any indication
of the attachment from the finished side. A conventional sewing
machine would pierce both sides of the second piece of material,
forming a stitch visible from either side of the second piece of
material.
[0003] The most apparent solution was to use what is referred to as
a "blind stitch" sewing machine, which was previously developed for
the garment and light textile industries. The blind stitch sewing
machine was primarily used to sew the hems of pants, skirts,
curtains, and other light goods such that the stitch could not be
seen on the outside. The needle depth was regulated with a fine
depth control, allowing operators to just pierce the first few
threads of the outer layer, preserving the finished look of the
material on the outside.
[0004] Manufacturers in the mattress industry soon saw the
advantages of this type of approach, and created a demand for a
"mattress panel" grade sewing workstation to assist their
operations. Most iterations of this workstation closely resembled
the original apparel unit, with various feed-assist devices
attached to help pull the material through a machine that was
incapable of manipulating the ten or more pound panels being forced
through them.
[0005] An awareness of the original blind stitch sewing machine's
complexity also began to develop, as units were run to the brink of
their mechanical abilities. The original blind stitch sewing
machine (described further herein below) required an inherently
complex and often times counter-intuitive mechanism to develop the
motion necessary to form the blind stitch. Adjustments made to
these machines sometimes affected the machines in such a way that
entire machines needed to be sent back to the original manufacturer
for re-timing and set up.
[0006] FIG. 1 is a diagram illustrating a portion of a blind stitch
sewing machine, according to the prior art. In the conventional
blind stitch sewing machine, there is a curved needle 105 that
travels in an arc 101, stopping at two points (A, B). There is a
forked "looper" 110 that meets up with the needle 105 at its two
different stop locations. The forked looper 110, while moving on
the arc 101, also "flip flops" on an axis best described as "in and
out" of the page. Thus, if the horizontal axis is considered the
"x-axis" and the vertical axis is considered the "y-axis", then the
forked looper 110 can be considered to move along the "z-axis"
while also moving along the arc 101 (which is parallel to the
horizontal or x-axis). Accordingly, the forked looper 110 can be
considered to have two degrees of freedom, one along the x-axis and
the other along the z-axis. While the forked looper 110 is at point
A, the looper 110 is "bottom up". At point B, the forked looper 110
is "bottom down". Thus, while the forked looper 110 is moving along
the arc 101, the forked looper 110 also moves in and out of the
page as well (i.e., along the z-axis). When the needle 105 is
sitting at point B, the forked looper 110 actually slides forward
out of the page and "shovels" the thread 170 off of a flat spot on
the needle 105, grabbing the thread 170 and carrying the thread 170
back over the material as the needle 105 travels along its arc 101
to point A. At point A, the needle 105 then travels between the two
tines of the forked portion of the forked looper 110, and forms a
"knot" through the loop of the thread 170 that was picked up during
the "shovel" process at point B previously.
[0007] The material is forced up through a groove in a throat plate
115 by a smooth polished rib 120 from below, that is spring
pressured upwards. The objective is to connect a first piece 191 of
material (e.g., border material) to a second piece 191 of material
(e.g., quilted panel material) without showing the stitch from the
other side; in this case, the bottom (i.e., finished) side 199. The
polished rib 120 is designed so as to not leave a mark or dent in
the finished side 199 of the material.
[0008] There are numerous eccentric drivers (not shown) required to
develop the astoundingly complex, timed motion of the forked looper
110, any one of which if misadjusted could have an extremely
adverse affect on the timing of the sewing machine.
[0009] Accordingly, it would be desirable and highly advantageous
to have a blind stitch sewing mechanism for a sewing machine that
overcomes the above-described problems of the prior art.
SUMMARY OF THE INVENTION
[0010] The problems stated above, as well as other related problems
of the prior art, are solved by the present invention, a blind
stitch sewing mechanism for a sewing machine.
[0011] According to an aspect of the present invention, there is
provided a blind stitch sewing mechanism for a sewing machine. The
blind stitch sewing mechanism includes a curved, oscillating
needle, and a looper, having only one degree of freedom, for
cooperatively forming a blind stitch with the curved oscillating
needle.
[0012] According to another aspect of the present invention, there
is provided a blind stitch sewing mechanism for a sewing machine.
The blind stitch sewing mechanism includes a curved needle for
oscillating back and forth between an ascended position and a
descended position. The blind stitch sewing machine further
includes a butterfly looper having a main body portion, a hook, and
a central axis of rotation. The butterfly looper lifts a thread off
of the curved needle using the hook and wraps the thread around the
main body portion by rotating along the central axis, when the
curved needle is oscillating to the descended position. A knot is
formed when the curved needle is oscillating to the ascended
position.
[0013] These and other aspects, features and advantages of the
present invention will become apparent from the following detailed
description of preferred embodiments, which is to be read in
connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] FIG. 1 is a diagram illustrating a portion of a blind stitch
sewing machine, according to the prior art;
[0015] FIG. 2 is a diagram illustrating a portion of a blind stitch
sewing mechanism for a sewing machine, according to an illustrative
embodiment of the present invention;
[0016] FIGS. 3-6 illustrate a cycle of a needle relative to a
butterfly looper, according to an illustrative embodiment of the
present invention; and
[0017] FIGS. 7-11 are diagrams illustrating a cycle of a needle
relative to a looper other than a butterfly looper to which the
present invention may be applied, according to an illustrative
embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention is directed to a blind stitch sewing
mechanism for a sewing machine. The present invention is capable of
handling the heaviest workloads and speeds required in sewing,
e.g., border material to a quilted panel of a mattress without
puncturing the quilted panel or leaving a visible mark on the
finished side of the quilted panel. Moreover, the present invention
is significantly less complex than prior art blind stitch sewing
mechanisms.
[0019] A blind stitch operation is a "chain stitch" operation that
uses only one thread to form the stitch. A blind stitch is the type
of stitch that can be completely unraveled and pulled out, like a
thread in a sweater in a cartoon. A similar "one thread" operation
was used in the sewing of buttons to garments, and utilized a
unique looper called a "butterfly" looper, named in part due to its
unique shape. The butterfly looper was adapted for use in the
present invention, and is described in that regard with respect to
FIGS. 2-6. It is to be appreciated that while the present invention
is primarily described herein with respect to the butterfly looper,
any type of looper having only one degree of freedom may also be
readily employed in accordance with the present invention, while
maintaining the spirit and scope of the present invention. By
employing a looper having only one degree of freedom, many
significant advantages are gained over the forked looper of the
prior art that has two degrees of freedom. For example, the use of
a looper having only one degree of freedom results in a tremendous
reduction in complexity over the forked looper of the prior art.
For a looper other than a butterfly looper that also has only one
degree of freedom, such one degree of freedom may correspond, e.g.,
to movement of the looper along an arc for the purpose of sewing a
blind stitch. This differs from the butterfly looper described
below in that the butterfly looper moves rotably along an axis that
passes through the butterfly looper. FIGS. 7-11 are diagrams
illustrating a cycle of a needle relative to a looper other than a
butterfly looper to which the present invention may be applied,
according to an illustrative embodiment of the present invention.
It is to be appreciated that the looper 700 shown in FIGS. 7-11 has
only has one degree of freedom similar to a butterfly looper. The
looper 700 manipulates thread 170 with respect to a needle 105 to
form a blind stitch.
[0020] FIG. 2 is a diagram illustrating a blind stitch sewing
mechanism 200 for a sewing machine, according to an illustrative
embodiment of the present invention. The blind stitch sewing
mechanism 200 includes a butterfly looper 210. The butterfly looper
210 in FIG. 2 replaces the forked looper 110 used in the prior art
blind stitch sewing machine shown in FIG. 1. It is to be
appreciated that the use of the butterfly looper 210 provides a
significantly less complex but more robust approach to sewing blind
stitches than the prior art. For example, the butterfly looper 210
has only one degree of freedom, namely, rotation along its central
axis. In contrast, the forked looper 110 of FIG. 1 has two degrees
of freedom, namely "flip-flopping" along the z-axis and arcing
along the y-axis.
[0021] FIGS. 3-6 illustrate a cycle of the needle 105 relative to
the butterfly looper 210, according to an illustrative embodiment
of the present invention. FIG. 3 illustrates the needle 105
beginning its descent down into the material penetration area. The
butterfly looper 210 is turning its point to prepare to meet the
needle 105.
[0022] FIG. 4 illustrates the needle 105 "bottomed out" in the
penetration area, and rising up through the guide hole into the
butterfly looper area. The butterfly looper 210 has almost turned
to meet up its pointed hook with the needle 105.
[0023] FIG. 5 illustrates the needle 105 fully penetrated and at
the top of its stroke. Notice the center hole in the butterfly
looper 210. The center hole allows the needle 105 to reach its peak
without hitting the butterfly looper 210. This clearance is unique
to the butterfly looper 210.
[0024] FIG. 6 illustrates the hook of the butterfly looper 210 just
skimming the flat of the curved needle 105, lifting the thread off
of the back of the needle 105 and beginning to wrap it around the
body of the butterfly looper 210. When the needle 105 returns
again, this wrap will fall off of the butterfly looper 210 and form
the knot, similar to the forked looper 110 of the prior art.
[0025] Notice the simplicity of the timing. A mechanic needs only
loosen a set screw 265 in a butterfly looper holder 260, and adjust
the point of the hook angularly so as to catch the thread off of
the back of the butterfly looper 210. It is to be appreciated that
while the adjustments to the butterfly looper 210 are described
herein with respect to a set screw 265, other arrangements and/or
physical structures may be employed to provide angular adjustment
to the butterfly looper 210 as readily contemplated by one of
ordinary skill in the related art.
[0026] Although the illustrative embodiments have been described
herein with reference to the accompanying drawings, it is to be
understood that the present invention is not limited to those
precise embodiments, and that various other changes and
modifications may be affected therein by one of ordinary skill in
the related art without departing from the scope or spirit of the
invention. All such changes and modifications are intended to be
included within the scope of the invention as defined by the
appended claims.
* * * * *