U.S. patent application number 10/557119 was filed with the patent office on 2008-01-24 for multi-needle chain-stitch sewing machine.
This patent application is currently assigned to Nahmaschinenfabrik Emil Stutznacker GmbH & Co KG. Invention is credited to Klaus Stutznacker.
Application Number | 20080017089 10/557119 |
Document ID | / |
Family ID | 33479379 |
Filed Date | 2008-01-24 |
United States Patent
Application |
20080017089 |
Kind Code |
A1 |
Stutznacker; Klaus |
January 24, 2008 |
Multi-Needle Chain-Stitch Sewing Machine
Abstract
The invention relates to a multi-needle chain-stitch sewing
machine, for the production of mattress sheets, made from a sewed
material, comprising several, in particular at least three sewed
material layers, preferably with one sewed material layer made from
an elastic material, for example sponge, and a cover layer with a
sewing pattern, by means of a sewing machine and a supply device
for the sewed material layers to be sewn. According to the
invention, a multi-needle chain-stitch sewing machine may be
further developed which avoids the problems of conventional
solutions with which, in particular, a simple and economical feed
of the sewed material layers to the sewing machine is possible
without spoiling the sewing product, for example, by introduction
of folds, whereby at least one feed device (5) is arranged between
the supply device (3) and the sewing machine (2), along the entire
feed length, lying on the material for sewing, which draws at least
two sewed material layers from the supply device (13) and feeds the
same into the sewing machine (2).
Inventors: |
Stutznacker; Klaus;
(Frechen, DE) |
Correspondence
Address: |
Jones & Smith
2777 allen Parkway Suite 800
Houston
TX
77019-2129
US
|
Assignee: |
Nahmaschinenfabrik Emil Stutznacker
GmbH & Co KG
|
Family ID: |
33479379 |
Appl. No.: |
10/557119 |
Filed: |
May 5, 2004 |
PCT Filed: |
May 5, 2004 |
PCT NO: |
PCT/EP04/04744 |
371 Date: |
April 27, 2007 |
Current U.S.
Class: |
112/2 |
Current CPC
Class: |
D05B 11/00 20130101 |
Class at
Publication: |
112/2 |
International
Class: |
D05B 11/00 20060101
D05B011/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 20, 2003 |
DE |
103 23 065.3 |
Nov 20, 2003 |
DE |
103 54 348.1 |
Nov 20, 2003 |
DE |
203 17 988.9 |
Claims
1. Multi-needle chain-stitch sewing machine for the production of
mattress sheets, made from a sewing material, comprising several,
in particular at least three sewing material layers, preferably
with one sewing material layer made from an elastic material, for
example foamed material, and a cover layer with a sewing pattern,
with a sewing unit and a supply device for the sewing material
layers to be sewn, characterized in that between said supply device
(3) and said sewing unit (2) at least one feed device (5) is
arranged which rests against the sewing material over the whole
feed length between the supply device (3) and the sewing unit (2),
said feed device withdrawing at least two sewing material layers
from the supply device (3) and feeding the same up and into the
sewing unit (2).
2. Multi-needle chain-stitch sewing machine according to claim 1,
characterized in that the feed device (5) is formed as a conveyor
belt (10) which rests on the surface of the sewing material layer
(17) made from an elastic material which faces the cover sheet (19)
of the sewing material.
3. Multi-needle chain-stitch sewing machine according to claim 1,
characterized in that the feed device (5) consists of two conveyor
belts (10, 16) which are arranged oppositely and parallel to each
other and between which the sewing material is conveyable.
4. Multi-needle chain-stitch sewing machine according to claim 1,
characterized in that the sewing material is movable in relation to
the sewing unit (2) in a direction transversely with respect to the
conveying direction of the sewing material.
5. Multi-needle chain-stitch sewing machine according to claim 1,
characterized in that the supply device (3) includes a continuous
feed device, by means of which the sewing material layers, in
particular at least the lowermost sewing material layer and the
sewing material layer (17) made from an elastic material are
conveyable in the direction of the sewing unit (2).
6. Multi-needle chain-stitch sewing machine according to claim 5,
characterized in that the feed device is formed as a conveyor belt
(22), by means of which the sewing material layers are conveyable
in the direction of the sewing unit (2).
7. Multi-needle chain-stitch sewing machine according to claim 6,
characterized in that the conveyor belt (22) is arranged in a frame
(24) which is arranged for displacement in a direction extending at
right angles to the conveying direction of the sewing material
layers (17).
8. Multi-needle chain-stitch sewing machine according to claim 7,
characterized in that the displacement of the frame (24) is
synchronized with the displacement of the sewing material in the
feed device (5) in relation to the sewing unit (2).
9. Multi-needle chain-stitch sewing machine according to claim 6,
characterized in that the conveyor belt (22) of the supply device
(3) is extended up to the conveyor belt (10), by means of which the
sewing material may be fed to the sewing unit (2).
10. Multi-needle chain-stitch sewing machine according to claim 5,
characterized in that the sewing material layers may be placed on
the feed device (5) in the form of lap rolls (4) in such a manner
that the sewing material layers are taken up by the conveyor device
and conveyed to the sewing unit.
11. Multi-needle chain-stitch sewing machine according to claim 10,
characterized in that the lap rolls (4) are supported in brackets
in a manner to be fixed against any translational movement in the
conveying direction of the conveyor device.
12. Multi-needle chain-stitch sewing machine according to claim 6,
characterized in that the sewing material layers may be laid on in
the form of lap rolls (4), with said lap rolls (4) being supported
in brackets in a manner fixed against any translational movement in
the conveying direction of the conveyor belt (22).
13. Multi-needle chain-stitch sewing machine according to claim 5,
characterized in that the feed device of the supply device (3) is
extended up and into the zone of a conveyor device (10), by means
of which the sewing material may be fed to the sewing unit (2).
14. Multi-needle chain-stitch sewing machine according to claim 13,
characterized in that the transport and handling device (28)
consists of a stand (30) having arranged therein one cross member
(35) for each lap roll (4), said cross members each including a
lifting device (34) for lifting and lowering a lap roll (4).
15. Multi-needle chain-stitch sewing machine according to claim 14,
characterized in that said cross members (35) are aligned
transversely with respect to the conveying direction of the supply
device (3) and are preferably supported for displacement in
relation to the stand (30).
16. Multi-needle chain-stitch sewing machine according to claim 14,
characterized in that the lifting device (34) consists of a
U-shaped gripper (39) with two legs (36) arranged on a web, which
legs comprise hook members for receiving a shaft (38).
Description
[0001] This invention relates to a multi-needle chain-stitch sewing
machine for the production of mattress sheets, made from a sewing
material comprising several, in particular at least three sewing
material layers, preferably with one sewing material layer made
from an elastic material, for example foamed material, and a cover
layer with a sewing pattern, by means of a sewing unit and a supply
device for the sewing material layers to be sewn.
[0002] Multi-needle chain-stitch sewing machines of this kind are
known from prior art and usually include a sewing unit having a
sewing material support with a pressure foot disposed above said
sewing material support and a needle bar having arranged therein a
plurality of needles. Below said sewing material support which is
formed as a perforated plate said sewing machine includes shuttles
in a number which particularly corresponds to the number of needles
and which are attached to a shuttle bar. Said shuttles and needles
are moved in an oscillating fashion in order to make chain stitches
and double-chain stitches in the sewing material supported on said
sewing material support. To this end, two threads, namely the upper
thread fed to the needles and the under thread fed to the shuttles,
are connected to each other. Multi-needle chain-stitch sewing
machines of this type have been tried and tested particularly for
the production of large-area sewing material in which several
sewing material layers are interconnected. By means of such
multi-needle chain-stitch sewing machines there are produced for
example mattress sheets which as a rule are made from a cover
layer, a non-tearing lower sewing material layer and an
intermediate sewing material layer from an elastic material. A
woven cloth or also a paper may serve as the non-tearing lower
sewing material layer.
[0003] Within said sewing unit said sewing material layers are
sewed together on one side and on the other side open or closed
ornaments are sewed in said cover layer to give the mattress sheet
an optically advantageous appearance.
[0004] In such multi-needle chain-stitch sewing machines the sewing
material layers to be sewed together are kept at the ready in a
supply device. From prior art it is known to have the sewing
material layers to be sewed together stored in said supply device
in the form of lap rolls, so that the same are withdrawn from said
lap rolls in accordance with the progress of the sewing operation
in the sewing unit. To this end stands are arranged in front of the
sewing machine, having supported therein shafts which extend in a
direction transversely of the sewing direction and each of which
serving to receive one lap roll of said sewing material layers.
[0005] To be able to sew different patterns in different places of
the sewing material the sewing material layers to be sewed together
are usually arranged in a sewing material frame which is movable
parallel to the needle bar or the shuttle bar and also in a feed
direction in relation to the needles or the shuttles.
[0006] Such an arrangement as it has been tried and tested in prior
art is already known from DE 196 10 979 C1. Ahead of the sewing
unit a catwalk is arranged serving as a basis for a person
monitoring the sewing operation. Under said catwalk the sewing
material layers are passed over deflection rollers and are supplied
thereafter to the sewing unit. The sewing material layers are
supported on a stand and are withdrawn by means of driven rollers
arranged upstream and downstream of the sewing unit. Therefore, the
sewing material layers are permanently subject to tension.
[0007] A further form of a multi-needle chain-stitch sewing machine
is known from U.S. Pat. No. 4,603,270 A1. In this multi-needle
chain-stitch sewing machine four sewing material layers are
provided in lap rolls and are sewed together in a sewing machine
with a plurality of needles.
[0008] Finally, U.S. 6,170,414 B1 discloses a further multi-needle
chain-stitch sewing machine for sewing together several sewing
material layers which in turn are arranged in the form of lap rolls
in a supply device where they are withdrawn from.
[0009] In all the above-described multi-needle chain-stitch sewing
machines the withdrawal of the sewing material layers from the lap
rolls over the entire distance from the lap rolls to the sewing
unit takes place under tension, which fact is particularly
disadvantageous for the middle one of the sewing material layers
made from an elastic material, because in such an arrangement this
sewing material layer is usually sewed under tension, so that the
middle one of the sewing material layers will relax after the
sewing unit and cause folds in the cover layer which is less
elastic. This drawback is only avoided in the multi-needle
chain-stitch sewing machine according to DE 196 10 979 C1.
[0010] In view of this prior art the invention is based on the
problem of further developing a multi-needle chain-stitch sewing
machine in a way such that the above-mentioned drawbacks of prior
art are prevented by making it possible for the sewing material
layers to be fed to the sewing machine in a particularly simple and
inexpensive manner, without the result of the sewing operation
being spoiled for example by the introduction of folds.
[0011] The solution of this problem provides that at least one feed
device is arranged between the supply device and the sewing unit,
which feed device rests against the sewing material along the
entire feed distance and withdraws at least two sewing material
layers from the supply device and feeds the same to the sewing
unit.
[0012] According to the invention the multi-needle chain-stitch
sewing machine includes a feed device that extends from the supply
device to the sewing unit and rests against the sewing material
layers along the entire feed distance between the supply device and
the sewing unit, in order to feed the sewing material layers to the
sewing unit with as less tension as possible, while any tension
within the sewing material layers is avoided also in the section of
the feed distance between the supply device and the sewing unit.
Accordingly, the multi-needle chain-stitch sewing machine according
to the present invention has a simple construction in the region of
the feed distance and therefore allows the sewing material layers
to be sewed together substantially without any tension in the
sewing unit.
[0013] Preferably, the feed device is formed as a conveyor belt
which rests on surfaces of the sewing material layer made from an
elastic material and facing the cover layer of the sewing material,
whereby the elastic material is frictionally conveyed. By this form
of construction an advantage is obtained in particular that the
elastic material which has a tendency to tension is not stretched
within the feed distance and is thus fed to the sewing unit in a
non-stretched condition. On the other hand, the additional sewing
material layers have less tendency to stretch, so that the
above-described problem occurs to a smaller extent.
[0014] In this form of construction a conveyor belt is provided
that is arranged within the feed distance. In this form of
construction the uppermost layer that is required for the feeding
operation is formed by the second sewing material layer which for
example consists of a non-tearing paper or woven cloth with limited
extensibility which is constantly fed to the sewing machine and
which may be kept under tension, without leading to the material
being stretched.
[0015] A further development of the invention provides that that
feed device consists of two conveyor belts which are arranged on
opposite sides and extend parallel and between which the sewing
material or the sewing material layers are conveyable. This form of
construction particularly offers an advantage that the conveying of
the sewing material layers may be effected much more accurately
between two conveyor belts, so that possible extensions
particularly in the elastic material may be further reduced. In
addition, such a construction has the advantage that the start-up
of the multi-needle chain-stitch sewing machine with fresh sewing
material layers is considerably simplified, because any complicated
introduction of the non-tearing and non-stretching sewing material
layer is not necessary to an extent that the feed device
automatically takes up and conveys sewing material layers that are
fed together.
[0016] The sewing material is arranged to be movable in relation to
the sewing unit in a direction extending transversely with respect
to the feeding direction of the sewing material. To this end it is
preferably provided that the sewing material is guided on a
conveyor carriage which is movable transversely with respect to the
sewing material feeding direction. On the other hand, the needle
and shuttle bars are fixed. By the relative movement of the sewing
material with respect to the sewing unit the variability of the
patterns that may be sewed is considerably increased. The feed
length which is arranged upstream of the sewing unit and the supply
device which is connected to the feed length are movable together
with the sewing material support.
[0017] According to a further feature of the invention it is
provided that the supply device includes a conveyor belt where for
example at least the lowermost sewing material layer and the sewing
material layer made from an elastic material may be placed on in
the form of a lap roll, with said lap rolls being fixedly supported
in brackets to be fixed against any translational movement in the
direction of the conveyor belt.
[0018] Consequently, said supply device includes a conveyor belt.
The sewing material layers are placed on this conveyor belt in the
form of lap rolls and are fixed against any translational movements
in the conveying direction. With this construction the withdrawal
of the sewing material layers from the lap rolls is not effected
under tension but through frictional connection between the
conveyor belt and the sewing material layer. This too, contributes
to substantially avoid stretching at least of the sewing material
layer made from an elastic material.
[0019] In order to be able to follow the movements of the sewing
material in the sewing unit transversely with respect to the
conveying direction and particularly to avoid any shearing strain
within the sewing material it is provided that the conveyor belt is
arranged in a frame which is arranged for displacement in a
direction extending at right angles to the conveying direction of
the sewing material. The displacement of the frame is synchronized
with the displacement of the sewing material in relation to the
sewing unit.
[0020] Finally, according to a further feature of the invention it
is provided that the conveyor belt of the supply device is extended
up to the conveyor belt, by means of which the sewing material may
be fed to the sewing unit. Accordingly, the conveyor belts in the
feed distances between the sewing machine and the supply device on
one side and within the supply device on the other side are formed
separately, which fact particularly simplifies the handling of the
multi-needle chain-stitch sewing machine, since long lengths of
conveyor belts and problems inherent to them like slippage and
incorrect conveying are avoided. In contrast thereto, a transfer
station between two conveyor belts can be handled much easier. In
addition, this configuration leads to the advantage that the
structure of such a multi-needle chain-stitch sewing machine is
substantially simplified. At the same time it is possible to
mechanically uncouple the conveyor belt lengths, so that for
example a purely electronic coupling of the movements of the
conveyor belts in the conveying direction and in the opposite
direction as well as transversely with respect to the conveying
direction is readily possible.
[0021] Moreover, the above-described multi-needle chain-stitch
sewing machine has the advantage that compared to prior art a
smooth reverse motion of the sewing material in relation to the
original conveyor device is possible, since by the configuration of
the multi-needle chain-stitch sewing machine with the conveyor
devices that almost fully rest against the sewing material layers
over the entire feed distance the capability of reversing the
sewing material conveying direction is considerably improved by the
sewing material being kept under a constantly low tension also
during the reverse motion of the conveyor devices, which is
required for performing particular sewing operations.
[0022] Further features and advantages of the present invention
will become apparent from the following description of the attached
drawings showing a preferred embodiment of the multi-needle
chain-stitch sewing machine according to the present invention. In
the drawings it is shown by:
[0023] FIG. 1 a multi-needle chain-stitch sewing machine with an
upstream supply device and a downstream winding station in a
lateral view;
[0024] FIG. 2 the multi-needle chain-stitch sewing machine with the
upstream supply device and the downstream winding station in a top
view;
[0025] FIG. 3 a conveyor device arranged upstream of a sewing unit
of the multi-needle chain-stitch sewing machine, in a partly
sectional side view; and
[0026] FIG. 4 the supply device according to FIG. 1 in a detailed
side view.
[0027] In FIG. 1 a multi-needle chain-stitch sewing machine 1 is
shown in a side view. This multi-needle chain-stitch sewing machine
1 comprises a sewing unit 2 and a supply device 3 having arranged
therein lap rolls 4 of the sewing material layers 17, 19 to be
sewed together in sewing unit 2.
[0028] Between the supply device 3 and the sewing unit 2 a feed
device 5 is arranged through which at least a part of the sewing
material layers 17, 19 is fed to the sewing unit 2.
[0029] The sewing material layers withdrawn from the sewing unit 2
and sewed together are shown as sewed material 6 in FIG. 1. The
multi-needle chain-stitch sewing machine 1 has a downstream winding
station 7 in which the finished sewed material 6 is wound up.
[0030] Furthermore, the multi-needle chain-stitch sewing machine 1
comprises a thread supply device 8 which is arranged between the
conveyor device 5 and the supply device 3 and includes a cantilever
arm 9 which reaches up and into the zone above the sewing unit 2,
in order to feed the thread to be withdrawn to the sewing unit
2.
[0031] The conveyor device 5 is shown in greater detail in FIG. 3
and consists of a first conveyor belt 10 which continuously moves
over a plurality of deflection rollers 11 and further over a
driving roller 12 which is driven via a belt 13 which is positively
and/or non-positively driven by a driving motor not further shown.
The deflection rollers 11 and the driving roller 12 of the conveyor
belt 10 are arranged in the lower region of the conveyor device 5
and have a wrapping angle of partly more than 180.degree. of the
individual deflection rollers 11 and the driving roller 12.
[0032] In the upper region of the conveyor device 5 the conveyor
belt 10 is passed over a baffle plate 14, of which the end 15 is
formed with a pointed cross section in the direction of the sewing
unit 2.
[0033] Further, in the conveyor device 5 a second conveyor belt 16
is provided which is arranged to extend in parallel with the first
conveyor belt 10 in the region of the feed length for the sewing
material layers 17, particularly those made from an elastic
material. The spacing between the two conveyor belts 10 and 16 is
variable corresponding to the sewing material layers 17 to be
conveyed, so that sewing material layers 17 of a greater thickness
may be conveyed as well without any considerable compression
parallel to the surface normal of the sewing material layers
17.
[0034] The transport direction of the conveyor belt 10 is shown by
means of an arrow 18 on a lower deflection roller 11, with both
conveyor belts 10 and 16 being driven in a reversible fashion, in
order to feed the sewing material layer 17 towards or away from the
sewing unit 2, depending on the sewing pattern that has to be
produced.
[0035] The sewing material layer 17 illustrated in FIG. 3 consists
of a lower layer of non-tearing paper not further shown and of a
sewing material layer 17 made from an elastic material, namely a
foamed material, on top of it. These two layers are fed to the
sewing unit 2 together with a sewing material layer 19 which is
also tension- or tearing-resistant and is formed as a cover layer.
The sewing material layer 19 is stored in a lap roll not further
shown in the region of the feed device 5 and is fed to the sewing
unit 2 via a deflection roller 20 and a driving roller 21 driven by
the belt 13, said sewing material layer 19 being placed onto the
sewing material layer 17 directly after the end 15.
[0036] Finally, in FIG. 3 a third conveyor belt 22 is shown which
is assigned to the supply device 3 and which will be described in
the following.
[0037] The feed device of the sewing material layers 17, 19 is
shown in FIG. 3 by means of arrow 23, the entire feed device 5
being supported in the multi-needle chain-stitch sewing machine 1
for limited displacement at right angles with respect to the
conveying direction of the sewing material layers 17, 19, in order
to be capable of performing also closed, circular or similar sewing
patterns in the sewing material layer 19 and accordingly also in
the sewing material layer 17.
[0038] The supply device 3 is shown in detail in FIG. 4 and
includes the conveyor belt 22 already mentioned above, which is
arranged within a frame 24 (FIG. 2) that is supported on rails 25
extending transversely with respect to the conveying direction of
the conveyor belt 2 and is movable along these rails 25
transversely with respect to the conveying direction of the
conveyor belt 22, said capability of displacement being limited
corresponding to the capability of transverse displacement of the
feed device 5.
[0039] The conveyor belt 22 is driven by means of a driving motor
26, of which the running direction may be reversed, so that the
conveyor belt 22, too is reversible.
[0040] On its rear end associated with the driving motor 26 the
frame 24 includes a support 27 for receiving the first lap roll 4
with the first tearing- or tension-resistant sewing material layer,
with said layer consisting for example of non-tearing paper or a
woven fabric which has only a low coefficient of extension and with
said lap roll directly resting on the conveyor belt 22 by the outer
surface area thereof. The first sewing material layer withdrawn
from this lap roll fully rests on the conveyor belt 22 and extends
through the conveyor device 5 at least up to the sewing unit.
[0041] The supply device 3 further includes a transport and
handling device 28 which is formed as a portal frame 29 arranged
above frame 24. This portal frame 29 includes four perpendicularly
aligned posts 30 and two horizontally aligned longitudinal supports
31, each of which interconnecting two posts 30, said longitudinal
supports 31 being arranged to extend parallel to each other and
parallel to the conveying direction of the conveyor belt 22 and
being interconnected by means of cross members 32.
[0042] The portal frame 29 is anchored to the floor 33 and has a
width between the longitudinal supports 31 which is larger than the
width of the frame 24, so that this frame 24 may be displaced
within the portal frame 25 corresponding to the above description
at right angles to the conveying direction.
[0043] Furthermore, the longitudinal supports 31 in the portal
frame 29 have provided thereon lifting means 34 which consist of
cross members 35 that may be displaced in the portal frame 29 in a
direction transversely with respect to the conveying direction of
the conveyor belt 22, on which cross members grippers 39 may be
lowered through Bowden cables not further shown. The grippers 39
include a web extending parallel to the cross members 35 and on the
ends thereof legs 36 that extend at right angles to the web and
that carry on the free ends thereof hook members not further shown
for receiving a shaft 38 passing through the respective lap roll 4
of the sewing material layer 17.
[0044] In the region of the frame 24 a guiding device 37 is
arranged for each lap roll 24 in which the respective lap roll 4 of
the sewing material layer 17 may be placed. Such a guiding device
37 makes it possible for the lap roll 4 to be placed on the
conveyor belt 2 by the outer surface area thereof 2 or on the first
sewing material layer of the first lap roll 4 already supported
thereon.
[0045] The guiding device 37 may be configured so that on both
sides of the conveyor belt 22 a web with a perpendicularly
extending slot for receiving shaft 28 is arranged, with the shaft
38 being guided for rotation within said slot, so that the sewing
material layer may be withdrawn from the lap roll 4 over the
conveyor belt 22, while any translational movement of the lap roll
4 is avoided.
[0046] As an alternative, the guiding device 37 may consist of
mutually spaced guide members overlapping the conveyor belt 22 and
serving to receive the lap roll 4 and including guide rollers
abutting the outer surface area of the lap roll 4 for guiding the
sewing material layers during withdrawal thereof with as less
friction as possible.
[0047] The handling of the above-described transport and handling
device 28 is as follows:
[0048] A lap roll 24 is provided in the zone laterally of the
portal frame 29 and is fitted with the shaft 38 (FIG. 2) which
passes through the center of the lap roll 4.
[0049] Thereafter, the cross member 35 is moved out and the
U-shaped gripper 39 (FIG. 4) lowered by the lifting device 34,
until the legs 36 of the gripper 39 may be connected to the shaft
38 by means of hook members not further shown. Then the lap roll 4
is lifted and the cross member 35 moved back into the portal frame
29 in a manner such that the lap roll 4 is arranged above a further
lap roll 4 just being processed. After the use-up of the lap roll 4
just being processed the lap roll 4 arranged above said used-up lap
roll 4 may be lowered within a very short time and the sewing
material layer 17 withdrawn from it forwarded to the working
process. After the lowering of the lap roll 4 the above-described
operation is repeated, i.e. a further lap roll 4 stored above the
lap roll 4 just being processed.
[0050] The same of course applies to all lap rolls 4 illustrated in
FIG. 4.
[0051] The sewing material layers 17 withdrawn from the lap rolls 4
rest on the conveyor belt 22 and are conveyed to the region of the
two conveyor belts 10 and 16 which take up and feed the end of the
sewing material layers 17 in the direction of the sewing unit 2. A
short distance ahead of the sewing unit 2 the sewing material
layers 17 thus conveyed are united with the cover layer 19 and
together are fed to the sewing unit 2 for being sewed together.
[0052] The construction of the multi-needle chain-stitch sewing
machine of the invention according to the above-described
embodiment makes it possible for the sewing material layers 17, 19
to be fed almost in a non-stretched condition, and at the same time
the sewing process is simplified, because the sewing material
layers 17,19 may be conveyed both in a direction transversely with
respect to the normal sewing direction and in the normal sewing
direction and also in a reversed sewing direction, without the
sewing material layers 17, 19 being extended or upset. To this end
it is provided that the conveyor belts 10, 16 and 22 are
electronically interconnected in such manner that the conveying
directions of all the conveyer belts 10, 16, 22 are coordinated
with each other. The same also applies to the driving roller 21
feeding the cover layer 19 to the sewing unit 2. In addition to the
conveyor belts 10, 16 and 22 also the cross displacement devices of
the feed device 5 and of the frame 24 of the supply device 3 are
electronically interconnected.
[0053] The invention is not limited to the above-described
embodiment. Various changes and modifications are possible within
the scope of the present invention. For example, the conveyor
device 5 may also have only the conveyor belt 10. In such a case
the lowermost sewing material layer forms the abutment for the
conveying of the central sewing material layer 17 made from an
elastic material. In addition, at least one of the illustrated
conveyor belts 10, 16, 22 may be formed by a plurality of mutually
aligned juxtaposed rollers which also rest against the sewing
material layers 17 and which serve to convey said sewing material
layers 17.
* * * * *