U.S. patent application number 10/128799 was filed with the patent office on 2003-10-30 for apparatus for preparing a fabric for seaming.
This patent application is currently assigned to AstenJohnson, Inc.. Invention is credited to Kuster, Heinz, Kuster, Stephan.
Application Number | 20030200635 10/128799 |
Document ID | / |
Family ID | 28790962 |
Filed Date | 2003-10-30 |
United States Patent
Application |
20030200635 |
Kind Code |
A1 |
Kuster, Heinz ; et
al. |
October 30, 2003 |
APPARATUS FOR PREPARING A FABRIC FOR SEAMING
Abstract
An integrated cutter for preparing the edges of a fabric for
seaming includes a hooked needle which oscillates vertically in a
guide bushing located close to the plane of the fabric between a
retracted position where the head of the needle is not exposed and
an extended position in which the needle penetrates the fabric. The
needle head is shaped so that when it moves upwardly it pushes
between a pair of yarns in one direction until the hook is above a
yarn in the other direction. The needle hook includes a transverse
groove shaped so that when it moves downwardly it captures this
yarn. The needle is a close fit within the guide bushing, to ensure
cooperation between cutting edges at the lateral ends of the
transverse groove and at the periphery of the hole at the top end
of the guide bushing around the needle, so that a short length of
the trapped yarn is severed cleanly as the cooperating cutting
edges at each side of the hook and at the top end of the guide
bushing pass each other when the needle moves downwardly. A carrier
moves the device laterally a preset distance, and the cycle is
repeated to cut another section of yarn. Since the integrated
cutter of this invention does not rely on friction within the
fabric to hold the yarn as it is cut, distortion of the adjacent
area of the fabric is minimised.
Inventors: |
Kuster, Heinz; (Sandpoint,
ID) ; Kuster, Stephan; (Sagle, ID) |
Correspondence
Address: |
VOLPE AND KOENIG, P.C.
DEPT AJ
UNITED PLAZA, SUITE 1600
30 SOUTH 17TH STREET
PHILADELPHIA
PA
19103
US
|
Assignee: |
AstenJohnson, Inc.
Charleston
SC
|
Family ID: |
28790962 |
Appl. No.: |
10/128799 |
Filed: |
April 24, 2002 |
Current U.S.
Class: |
26/10.4 |
Current CPC
Class: |
D03D 49/70 20130101 |
Class at
Publication: |
26/10.4 |
International
Class: |
D06C 013/00 |
Claims
We claim:
1. An integrated cutter device, for an apparatus for preparing for
seaming a selected area of a woven fabric, which fabric has a lower
surface adjacent the apparatus and an upper surface remote from the
apparatus, and which includes longitudinal and transverse yarns in
the weave pattern, the integrated cutter device comprising in
combination: a needle including a shank, a head and a hook located
adjacent to the head; a guide bushing having an axial aperture
which is constructed and arranged to be a close fit on the needle
shank and which has a first end face; a shuttle means located on
the upper surface of the fabric including a space to receive the
head of the needle; a first carrier means to support the needle and
the guide bushing with the first end face of the guide bushing
close to the lower surface of the preselected area of fabric; a
second carrier means to locate the shuttle with the space over the
guide bushing aperture; a means to oscillate the needle in the
guide bushing between a preselected retracted position and a
preselected extended position; and means to move both of the first
and the second carrier means together a preselected distance
relative to the selected area of fabric, wherein: (a) the head of
the needle is constructed and arranged to be pushed between a pair
of yarns in a first direction with minimal damage to either of
them; (b) the hook comprises a shaped groove across the shank of
the needle constructed and arranged to trap within the groove one
yarn in a second direction in the fabric; (c) the first and second
directions are substantially orthogonal to each other, and one of
them corresponds to the direction of the longitudinal yarns; (d)
the shaped groove is formed with a pair of first cutting edges at
each of its ends; (e) the guide bushing first end face is formed
with a pair of second cutting edges which cooperate with the pair
of first cutting edges; (f) the needle retracted position is
preselected to locate the head of the needle within the guide
bushing axial aperture close to the first end face of the guide
bushing; (g) the needle extended position is preselected to locate
the needle hook above the upper surface of the fabric; and (h) the
preselected distance through which the carrier means are moved
together corresponds to a distance NX, in which N is an integral
number and X is chosen from the group consisting of the linear
spacing between adjacent longitudinal yarns and the linear spacing
between adjacent transverse yarns.
2. An integrated cutter according to claim 1 wherein the guide
bushing first end face comprises a replaceable cutter section of
harder material to provide the pair of second cutting edges.
3. An integrated cutter according to claim 1 wherein the needle
head has a tapering pointed shape.
4. An integrated cutter according to claim 1 wherein the needle
shank and head have a triangular cross section, the hook groove is
located substantially parallel to one of the faces of the triangle
and the hook opening is toward the opposite apex of the
triangle.
5. An integrated cutter according to claim 1 wherein the needle
shank and head have an isosceles triangular cross section, the hook
groove is located substantially parallel to the shortest face of
the triangle and the hook opening is toward the opposite apex of
the triangle.
6. An integrated cutter according to claim 1 wherein the needle
shank and head have an isosceles triangular cross section, the hook
groove is located substantially parallel to a face of the triangle,
the hook opening is toward the opposite apex of the triangle and
the needle head has a tetrahedral shape.
7. An integrated cutter according to claim 1 wherein the means to
oscillate the needle between the retracted and extended positions
comprises a linear motion device.
8. An integrated cutter according to claim 7 wherein the linear
motion device is chosen from the group consisting of a solenoid
device, a cam device, and an air cylinder.
9. An integrated cutter according to claim 8 wherein the linear
motion device comprises an air cylinder.
10. An integrated cutter according to claim 9 wherein the linear
motion device comprises a double acting air cylinder.
11. An integrated cutter according to claim 1 wherein the means to
move both of the first and the second carrier means together a
preselected distance relative to the selected area of fabric
comprises at least one intermittently actuated lead screw device.
Description
FIELD OF THE INVENTION
[0001] This invention relates to an apparatus for preparing a woven
fabric for seaming. More particularly, the present invention
relates to a cutter for the cutting and removal of transverse yarns
from a portion of a fabric to provide an area which is used in
forming a seam. In most fabrics, the transverse yarns are weft
yarns.
BACKGROUND OF THE INVENTION
[0002] Many industrial devices require what is effectively a
continuous length of woven fabric, for example the fabrics used in
a papermaking machine to carry the paper web that is being made; in
sequence these are a forming fabric, a press felt fabric and a
dryer fabric. Each of these fabrics comprises at least one
continuous fabric loop which circulates within each of the forming,
press, and dryer sections of the papermaking machine. Although it
is possible to weave a fabric for a small machine as a continuous
loop, in many applications this is not necessary. Generally, the
fabric is woven as a continuous run, cut to a desired length, and
the thus formed ends seamed to provide the required loop of
fabric.
[0003] A woven seam is preferred in forming fabrics, because it can
provide a smooth, flat, join which does not alter significantly the
drainage properties of the fabric. To create a woven seam, the
transverse threads near to the edge of the two ends of the fabric
are removed, to provide a fringe consisting of exposed longitudinal
yarn ends. The two fringes are then overlayed, and the longitudinal
yarns from one end are rewoven into the other end, as far as
possible into the same yarn path thus preserving the fabric weave
pattern. Alternatively, the exposed yarn ends are woven back into
the same fabric end to provide loops, which are joined to each
other by a pintle or by a spiral coil.
[0004] For some applications, a relatively narrow strip of woven
fabric is converted into a loop using the spiral winding technique
described by Best, in U.S. Pat. No. 5,268,076, by Rexfelt, in U.S.
Pat. No. 5,360,656, and by Fekete, in U.S. Pat. No. 5,785,818. The
spirally wound loop of fabric is flattened, and the two ends formed
by the folding step are seamed together. A woven seam is not used,
instead a length of warp is exposed at the fold line to provide
pintle loops; the two ends are joined by interdigitating the pintle
loops and inserting a pintle or a plastic spiral.
[0005] It is difficult and time consuming to prepare these fabrics
for seaming. In the past, the longitudinal and transverse yarns,
which are most often the warps and wefts, at the two ends of a
length of fabric have been unravelled manually. This is a slow,
labour intensive process which must be carried out with
considerable care if the fabric adjoining the unravelled portions
is not to be damaged. This is particularly true for the fabrics
used in modern wide high speed papermaking machines, which can be
over 10 meters wide.
[0006] It has been proposed to automate this process.
[0007] Kopcke, in U.S. Pat. No. 4,736,499 describes a device in
which vertically reciprocating needles pull sections of weft thread
out of the plane of the fabric which are then cut out by a cutter,
to provide a strip across the fabric in which a predetermined
length of weft has been removed. A difficulty with the Kopcke
machine is that in one pass it can only remove as many weft threads
as there are needles provided to pull them out of the plane of the
fabric. If a longer length of warp has to be exposed to make the
seam, then the machine has to traverse the width of the fabric more
than once.
[0008] Kuster et al., in U.S. Pat. No. 6,014,797 describe s similar
device in which a needle including a hook is used to pull a weft
out of the plane of the fabric to be cut by a separate cutter. The
machine then moves a preset distance to cut the next weft. A
difficulty with the Kuster et al. machine is that it cannot move
across the fabric to capture successive wefts which are not
parallel to the line of the edge of the fabric. This creates
problems when a Kuster et al. machine is used to prepare a spirally
wound fabric for seaming, because the wefts in such fabrics are not
parallel to the fabric edges.
[0009] A further problem common to both the Kopcke and Kuster et
al. machines is that a two part cutter unit is used. The wefts are
physically pulled out of the plane of the fabric by a hooked needle
and a separate cutter severs the deflected length of weft. This
complicates the cutting process, because the friction inherent in a
heat set weave may not be sufficient to resist the lateral force
applied to the fabric by the needle, so that the fabric adjoining
the area in which the seam is to be made can become distorted. This
is not desirable.
SUMMARY OF THE INVENTION
[0010] This invention seeks to overcome these difficulties, and to
provide an apparatus for preparing a fabric for seaming in which
the methods disclosed by Kopcke and Kuster et al. to move the
cutter unit relative to the fabric are utilised, but a different
integrated cutter is used. In the following description it is
assumed that, as described by both Kopcke and Kuster et al., the
fabric area which is being prepared for seaming is carried on
suitable surface in a substantially horizontal plane with the
cutter unit located beneath the fabric; other orientations could be
used if desired.
[0011] The integrated cutter of this invention includes a hooked
needle which moves in a guide bushing, with the guide bushing top
end located very close to the plane defined by the lower surface of
the fabric. This integrated cutter can be used both to form an edge
fringe for a woven seam in a conventional fabric as described by
Kuster et al., to form an area of exposed warp yarns to provide
pintle loops to be joined by a pintle or a plastic spiral as
described by Kopcke, and to prepare the ends of a flattened loop of
spiral wound fabric for seaming.
[0012] In the integrated cutter of this invention, a hooked needle
oscillates vertically into and out of the fabric in a guide bushing
supported by a carrier beneath the fabric. The needle oscillates
between a retracted position where the head of the needle is not
exposed and an extended position in which the needle penetrates the
fabric. The upper end of the guide bushing is more or less in
contact with the lower surface of the fabric. The needle head is
shaped so that when it moves upwardly it pushes between a pair of
yarns in one direction, for example warp yarns, with minimal, if
any, damage to either of them, until the hook is above a yarn in
the other direction, for example a weft yarn. The needle hook
includes a transverse groove shaped so that when it moves
downwardly it captures this yarn. The needle is a close fit within
the guide bushing, to ensure cooperation between cutting edges at
the lateral ends of the transverse groove and at the periphery of
the hole at the top end of the guide bushing around the needle.
Consequently, a short length of the trapped yarn corresponding
approximately to the width of the groove in the needle is severed
cleanly as the cooperating cutting edges at each side of the hook
and at the top end of the guide bushing pass each other. When the
needle has moved downwardly to be within the guide bushing, so that
the needle head is not exposed, the carrier moves the device
laterally a preset distance, and the cycle is repeated to cut
another section of yarn. During the cutting process, the fabric is
held more or less flat on the supporting surface by a relatively
light shuttle, which moves with the carrier supporting the guide
bushing. It can thus be seen that the yarns are cut into quite
short pieces which fall away beneath the fabric and are trapped,
for example by a vacuum system. Further, since the integrated
cutter of this invention does not rely on friction within the
fabric to hold the wefts as they are cut, distortion of the
adjacent area of the fabric is minimised. Additionally, the
integrated cutter of this invention can be moved either parallel
to, or orthogonal to, the edge of the fabric.
[0013] Thus in a broad embodiment this invention seeks to provide
an integrated cutter device, for an apparatus for preparing for
seaming a selected area of a woven fabric, which fabric has a lower
surface adjacent the apparatus and an upper surface remote from the
apparatus, and which includes longitudinal and transverse yarns in
the weave pattern, the integrated cutter device comprising in
combination:
[0014] a needle including a shank, a head and a hook located
adjacent to the head;
[0015] a guide bushing having an axial aperture which is
constructed and arranged to be a close fit on the needle shank and
which has a first end face;
[0016] a shuttle means located on the upper surface of the fabric
including a space to receive the head of the needle;
[0017] a first carrier means to support the needle and the guide
bushing with the first end face of the guide bushing close to the
lower surface of the preselected area of fabric;
[0018] a second carrier means to locate the shuttle with the space
over the guide bushing aperture;
[0019] a means to oscillate the needle in the guide bushing between
a preselected retracted position and a preselected extended
position; and
[0020] means to move both of the first and the second carrier means
together a preselected distance relative to the selected area of
fabric, wherein:
[0021] (a) the head of the needle is constructed and arranged to be
pushed between a pair of yarns in a first direction with minimal
damage to either of them;
[0022] (b) the hook comprises a shaped groove across the shank of
the needle constructed and arranged to trap within the groove one
yarn in a second direction in the fabric;
[0023] (c) the first and second directions are substantially
orthogonal to each other, and one of them corresponds to the
direction of the longitudinal yarns;
[0024] (d) the shaped groove is formed with a pair of first cutting
edges at each of its ends;
[0025] (e) the guide bushing first end face is formed with a pair
of second cutting edges which cooperate with the pair of first
cutting edges;
[0026] (f) the needle retracted position is preselected to locate
the head of the needle within the guide bushing axial aperture
close to the first end face of the guide bushing;
[0027] (g) the needle extended position is preselected to locate
the needle hook above the upper surface of the fabric; and
[0028] (h) the preselected distance through which the carrier means
are moved together corresponds to a distance NX, in which N is an
integral number and X is chosen from the group consisting of the
linear spacing between adjacent longitudinal yarns and the linear
spacing between adjacent transverse yarns.
[0029] Preferably, the guide bushing first end face comprises a
replaceable section of harder material to provide the pair of
second cutting edges.
[0030] Preferably, the needle head has a tapering pointed
shape.
[0031] Preferably, the needle shank and head have a triangular
cross section, the hook groove is located substantially parallel to
one of the faces of the triangle and the hook opening is toward the
opposite apex of the triangle. More preferably, the needle shank
and head have an isosceles triangular cross section, the hook
groove is located substantially parallel to the shortest face of
the triangle, and the hook opening is toward the opposite apex of
the triangle. Most preferably, the needle shank and head have an
isosceles triangular cross section, the hook groove is located
substantially parallel to a face of the triangle, the hook opening
is toward the opposite apex of the triangle and the needle head has
a tetrahedral shape.
[0032] Preferably, the means to oscillate the needle between the
retracted and extended positions comprises a linear motion device.
More preferably, the means to oscillate the needle comprises a
linear motion device chosen from the group consisting of a solenoid
device, a cam device, and an air cylinder. Preferably, the linear
motion device comprises an air cylinder. More preferably, the
linear motion device comprises a double acting air cylinder.
[0033] Preferably, the means to move both of the first and the
second carrier means together a preselected distance relative to
the selected area of fabric comprises an intermittently actuated
lead screw device.
BRIEF DESCRIPTION OF THE DRAWINGS.
[0034] This invention will now be described with reference to the
attached drawings in which:
[0035] FIG. 1 shows the general arrangement of the integrated
cutter device;
[0036] FIGS. 2 and 3 show a top and side view of the integrated
cutter of FIG. 1 attached to the carrier means;
[0037] FIG. 4 shows the device used to hold down the fabric;
[0038] FIG. 5 shows the guide bushing used in the device of FIG.
1;
[0039] FIG. 6 shows a cylindrical section needle and its
cooperating guide bushing;
[0040] FIG. 7 shows a triangular section needle and its cooperating
guide bushing;
[0041] FIG. 8 shows a conventional hooked needle; and
[0042] FIGS. 9, 10 and 11 show the relationship between the needle
hook and weft yarn diameter.
DETAILED DESCRIPTION OF THE DRAWINGS.
[0043] Referring first to FIGS. 1, 2 and 3 the arrangement of an
integrated cutter unit according to this invention is shown. The
integrated cutter device 1 comprises a mounting bracket 2 which
carries the other components. At its top end, the bracket 2
supports the block 3 and at its lower end a linear motion device 4,
which in this instance is air cylinder. Other linear motion devices
are well known, such as a cam system or a solenoid system, and can
be used. The air cylinder piston rod 5 carries a needle holder 6
which is moved in the needle guide 7 by the piston rod 5. The
needle 8 is mounted into the holder 6 and through the guide bushing
9 in the block 3. As shown in FIG. 1, the needle is in its extended
position. The exact locations of both the extended and retracted
positions are adjusted to suit the fabric being prepared for
seaming; macro-adjustment is obtained by relocating the air
cylinder 4, and microadjustment is obtained by adjusting the
position of the holder 7 on the piston rod 5 using the locking nut
10.
[0044] The bracket 2 is located so that the top surface 11 of the
block 3 is substantially coplanar with the support plate 12 for the
fabric, shown in chain line as 13, which is being prepared for
seaming(see FIG. 3). The bracket 14 is attached to the support
plate 12, to which is attached the lead screw device shown
generally at 15. The lead screw unit moves the integrated cutter
device relative to the fabric 13 along the lead screw 16; such
devices are well known. A second lead screw unit(not shown) is used
to move the integrated cutter at a right angle to the unit 15 thus
allowing movement of the integrated cutter along the line of either
the longitudinal or transverse yarns, which will generally be the
warp yarns and the weft yarns respectively.
[0045] In order to keep the area of fabric 13 being treated
substantially flat, the device shown in FIG. 4 is placed on its
upper surface. The device comprises a shuttle 17 with a suitable
aperture in it, a hold down device 18, which can be for example a
magnet, and a transparent top cover 19. A space 20 is provided
within the shuttle, into which the head 21 of the needle 8
penetrates in its extended position.
[0046] The cross section of the guide bushing 9 within which the
needle 8 oscillates is shown in FIG. 5. The guide bushing 9 is
conveniently cylindrical, and conveniently is reversible. The
needle 8 oscillates in the aperture 22. As shown at 23 the edge of
the aperture is machined to be sharp, and provides the second
cutting edge. An alternative structure is shown at the other end of
the guide bushing. A thin cutter section 24 of a hard material,
such as steel, with a cutting edge 25 is used, which allows the
guide bushing 9 to be fabricated from brass or bronze. As the
cutting edges wear, the guide bushing or the cutter section, as
appropriate, can be reversed relatively easily.
[0047] The cross sectional shapes of two suitable needle shanks,
and of the required cooperating guide bushings, are shown in FIGS.
6 and 7. The main function of the needle cross sectional shape is
to ensure that the head of the needle penetrates between adjacent
yarns in the first direction, for example a pair of warp yarns, in
the fabric, with minimal, if any, damage to any yarns in the first
direction which are not to be cut. Additionally, since the first
cutting edges are formed in the needle, it is desirable that the
needle be shaped so that these adjacent yarns are moved away from
the cutting process. Two needle shapes which do this are shown.
[0048] In FIG. 6 a modified conventional needle is shown with its
guide bushing. The needle 8 has a shank 26, a hook 27 including a
shaped groove 28 and a head 29. In this needle, the shank is
cylindrical, and the aperture 26A in the guide bushing 9 is also
cylindrical. The head 29 is more or less conical, and tapers to a
blunt point 29A. In contrast to the conventional cylindrical needle
shown in FIG. 8 for comparison, the shaped groove 28 is more or
less straight across the body of the needle, with sharp edges at
28A, 28B on each side of the needle. The end edges 23 of the guide
bushing 9 are also cut sharp. In FIG. 8 the shaped groove 48 is
more or less rounded, without sharp edges at its ends.
[0049] In FIG. 7 a the needle 8 has a triangular shank 33 and the
guide bushing 9 has a triangular aperture 34. The three edges 35,
36 in the needle and 37 in the guide bushing 9 are all made sharp.
The groove in the needle 8 is substantially parallel to one side of
the triangular cross section of the needle and the hook opening is
toward the opposite apex of the triangle. This is the preferred
needle shape: the width of the face 38 of the needle spaces the
adjacent yarns (not shown) somewhat away from the cutting edges 35,
36 thus minimising damage to them. The triangular cross section of
the shank 33 should be one in which the three sides of the shank
provide a shaped groove that is sufficiently long to trap a short
length of yarn. It is thus preferred that the cross section is at
least an isosceles triangle, with the groove substantially parallel
to the short face, or more preferably the shape is an equilateral
triangle with the groove substantially parallel to one of the
faces; in both cases the hook opening faces toward the opposite
apex of the triangle.
[0050] In the modified needle of this invention it is necessary
that the hook will engage the yarn to be cut. This relationship is
shown in FIGS. 9, 10 and 11.
[0051] In FIG. 9 the shaped groove 28 is large enough to trap the
yarn 40, ensuring an essentially clean cut between the first and
second cutting edges of the needle 8 and guide bushing 9
respectively. When the needle 8 is extended again, the short cut
piece of the yarn 40 falls away.
[0052] In FIG. 10 the yarn 41 is larger than the shaped groove 28;
as can be seen in FIG. 11, although the yarn 41 has been caught by
the hook 25 it does not enter fully into the shaped groove 28. The
consequence is shown in FIG. 10: the yarn 41 is not cut cleanly,
and only a portion 42 of it at best is cut away. It can thus be
seen that the dimensions of the shaped groove 28 need to be matched
to the yarn 41 to ensure that it will enter the shaped groove 28
for cutting as shown in FIG. 9.
[0053] In use, the integrated cutter of this invention moves across
the fabric in short steps, which, as noted above, are conveniently
controlled by a lead screw device. The cutter can be moved more or
less parallel to a selected yarn with each step corresponding to
the distance X between successive yarns. Alternatively, the
integrated cutter can be moved more or less parallel to a selected
yarn with each step corresponding to the distance N times X where X
is the distance between successive yarns and N is an integral
number and corresponds to the number of yarns desired between each
cutting location.
[0054] Additionally, due to a combination of the shape of the
needle head allowing the needle to nudge apart a pair of adjacent
yarns, and the location of the cutting edges very close to the
lower surface of the fabric, the integrated cutter of this
invention can be used to prepare the folded ends of a spirally
wound fabric even though the longitudinal warp yarns and the
transverse weft yarns are both at an angle to the fold line
corresponding to the angle adopted in the spiral winding
process.
* * * * *