JP2008302222A - Sewing machine and method for operating such sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To develop a sewing machine so as to obtain increased flexibility in fabric feed for adaptation to different sewing conditions. <P>SOLUTION: The sewing machine has a feed unit for intermittent feeding of fabric. The feed unit has at least one upper feeder and at least one lower feeder providing an intermittent frictional feed contact with an upper side or underside, respectively, of the fabric. A feed length of the feeders may be modified by means of mechanical upper feed and lower feed adjustment devices. These adjustment devices are adjusted by adjustment drives. A control device is in signal connection with the lower feed adjustment drive and the upper feed adjustment drive and has a storage device in which data regarding sewing sequences to be executed as well as adjustment data assigned to these sewing sequence data are stored for independently actuating the adjustment drives when the sewing sequence is executed. As a result, a sewing machine with increased flexibility of the fabric feed is obtained to ensure adaptation of different sewing requirements. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a sewing machine provided with a feeding unit for intermittent feeding of the fabric according to the preamble part or the so-called part of claim 1. Furthermore, the present invention relates to various operating methods for this type of sewing machine.

EP0512145B1

  A sewing machine of the above type is disclosed in Patent Document 1. This disclosure describes the adjustment of stitch length by correspondingly changing the feed values of the upper and lower feeders.

  Many, especially complex sewing tasks or operations require more flexible fabric feed adjustments for individual sewing conditions than those provided by known sewing machines.

  The object of the present invention is therefore to develop a sewing machine of the above type so that more flexibility in fabric feeding can be obtained for adaptation to different sewing requirements.

  This object is achieved according to the invention by a sewing machine with the features described in claim 1.

  The invention is based on the fact that a mechanism for changing the feed length of the lower and upper feeders already known per se can be automated by using the corresponding adjusting drive. The change of the feed length is currently performed by activating the respective adjustment drive via the control device. The control device may be in signal connection with an external sensor and / or the adjustment drive can be directly influenced by the control device via a sewing machine control element such as a foot switch, knee lever or button You may do it. In this way, the fabric feed can be flexibly adapted to, for example, a seam pattern. For example, adjust the stitch length in the corner area between two seams that end together to form a corner so that the seam ends at the corner so that the last seam has the same length as the previous seam. sell. The control device allows this type of feed length adjustment to be performed over the entire sewing sequence as each adjustment data required for the adjustment drive is read. The feed may also be adjusted to various sewing parameters such as changes in the sewing direction with respect to the weft and warp angles of the fabric or various fabric configurations. To define different feed length ratios (hereinafter referred to as gathering feed values) between the upper and lower feeders in addition to the various feed lengths, eg different stitch lengths Is also possible. The feed length can also be changed to obtain the desired optical or visual effect in the sewing process.

  The sewing machine according to claim 2 not only makes it possible to adjust the length or feed length ratio of the upper feeder with respect to the length or feed length ratio of the lower feeder, It is possible to adjust the feed lengths of the side feeders relative to each other (hereinafter referred to as setting different ruffling feed values). An additional lower feed adjustment device operated via the control device allows further flexibility to be obtained when setting another feed value via the inventive sewing machine.

  It has been found that the guide slider mechanism used as the adjusting device according to the third aspect is suitable due to their mechanical rigidity.

  The adjusting device according to claim 4 can be incorporated into the sewing machine with minimal effort.

  The step motor according to claim 5 ensures the feed change which can be adjusted precisely or finely.

  The adjustable drive housing according to claim 6 provides a compact sewing machine.

  The arrangement according to claim 7 enables the tension of the yarn to be automatically adapted to the stitch length which is set in particular using a control device.

  Another object of the present invention is to provide a method of operating the sewing machine of the invention.

  This object is achieved according to the invention by the operating method according to claims 8 and 9 and for the sewing machine according to claim 2 by the operating method according to claim 10.

  The advantages of these operating methods correspond to the advantages as described above for the inventive sewing machine.

  Embodiments of the present invention are described in detail below with reference to the drawings.

  The sewing machine 1 has an arm 2, a base plate 3, and a stand 3 a connected to the arm 2 and the base play 3. The free end of the arm 2 carries the head 4.

  An arm shaft 5 is attached to the arm 2 and can be driven for rotation by a main drive source (not shown in detail). The needle bar 6 attached to the head 4 can be driven by the arm shaft 5 for vertical vertical movement. The needle 7 is attached to the lower end of the needle bar 6. When the sewing machine 1 is operated, the needle 7 passes through the sewing hole in the sewing plate 8 inserted in the support plate 9 of the base plate 3. The hook is arranged under a sewing plate 8 which is linked to a needle 7 for loop formation and is driven by a deflection gear and a hook shaft (not shown in detail). Similarly, the hook drive is also pulled out by the arm shaft 5. During seam formation, the fabric is held in place by a fabric retainer 11 attached to the lower end of the retainer bar 12.

  The feeding unit 14 is used for intermittent feeding of the fabric in the sewing direction 13 indicated by the arrow moving from right to left in FIG. 12, and the feeder of the feeding unit 14 shown by the scale enlarged in FIG. Placed in frictional contact with the fabric. The upper feeder 15 engages the upper side of the fabric, which is shown on the one hand in the zero position and compared to this, is displaced towards the left as indicated by 15 '. Large displacement position is shown.

  The two lower feeders, strictly speaking, the first lower feeder 16 and the second lower feeder 17 are in contact with the bottom surface of the fabric. The first lower feeder 16 is shown on the left hand side of FIG. 12, while the second lower feeder 17 is shown on the right hand side of FIG. The two lower feeders 16, 17 have contacts along the sewing direction 13 that are spaced apart from each other to provide friction feed contact to the bottom surface of the fabric. The feeders 16, 17 are shown on the one hand in the zero position and, in comparison, are shown in a large displacement position displaced towards the left, as indicated by 16 ′, 17 ′.

  The feeders 15-17 each have a serrated cross section 18a to provide intermittent friction feed contact to the fabric.

  The displacement of all three feeders 15-17 in the sewing direction is controlled, as will be explained below with reference to the feed length of one of the lower feeders 16, 17 using FIGS. Each feeder 15-17 can be defined individually.

  The first step motor 18 is used for adjusting the feed length, and the step motor 18 is firmly fixed to the base plate 3. The first step motor 18 is transmission-connected to the first lower feeder 16. The contact body 19 having a spiral outer peripheral support wall 20 is rotatably connected to the drive shaft of the first step motor 18, and thus the contact wall 20 has an outer peripheral portion having a variable radius. The contact body 19 is a cam disk that can be driven for rotation. The contact wall 20 abuts each of the adjusting body or counter body in the form of a needle bearing 21 held by a fork-shaped deflection rod 22. The needle bearing 21 thus forms a sliding body that interacts with the contact wall 20. The deflection rod 22 is joined to the guide slider adjusting body 24 via the joint 23, and then the guide slider adjusting body 24 is rotatably connected to the slide guide 25. The slide block 26 can be displaced along the slide guide. The slide block 26 is then connected to a triangular lever 27. The triangular lever 27 is oscillated using an eccentric shaft 28. Depending on the guide direction of the slide guide 25, this swing is converted into a higher or lower rotational swing of the transmission shaft 29 about its longitudinal axis.

  FIGS. 10 and 11 in addition to FIG. 7 include the first step motor 18 and show the lower feed adjustment device 30 in the “slight displacement” position, where it is transmitted to the transmission shaft 29 during operation. The adjustment angle amount is substantially zero. When the sewing machine is operated, the assigned lower feeder is held substantially in its zero position. In the “slight displacement” position, the outermost end of the contact wall 20 presses the needle bearing 21 and is therefore arranged at the maximum distance from the drive shaft of the first stepping motor 18.

  In contrast, FIGS. 8 and 9 show the “large displacement” position of the first lower feed adjustment device 30. In this “large displacement” position, the innermost end of the contact wall 20 presses against the needle bearing 21 and is therefore arranged at a slight distance from the drive shaft of the step motor 18. Between these two positions, i.e. between the "slight displacement" position and the "large displacement" position, the drive shaft of the first step motor 18 makes a relative rotation of approximately 225 [deg.]. Since the step motor 18 has a high step accuracy, all intermediate positions between the “large displacement” position and the “slight displacement” position can be adjusted substantially continuously.

  In the “large displacement” position, the slide block 26 is guided by the slide guide 25 in a guide direction extending upward at an angle of approximately 45 ° as shown in FIG. Thereby, the maximum rotation angle adjustment amount is transmitted to the transmission shaft 29. In the middle of the stitch, the assigned lower feeder is then displaced between the relatively “large displacement” position shown in FIG. 12 and the zero position.

  At the intermediate position of the first lower feed adjustment device 30 between the displayed “small displacement” position and “large displacement” position, the first lower feeder 16 therefore has zero position, zero position and “large displacement”. It is displaced between the positions arranged between the “position” and the position. Similarly, all intermediate positions are possible depending on the position of the first stepping motor 18 between the maximum feed and zero feed shown in FIG.

  The second lower feed adjustment device 31 is used for controlled adjustment of the feed length of the second lower feeder 17. The second lower feed adjustment device has a second step motor 32, which is also attached to the base plate 3 below the support plate 8. The second step motor 32 is transmission-connected to the second lower feeder 17. In addition to the mechanical operation of the second lower feed adjustment device 31, the configuration corresponds to those of the first lower feed adjustment device 30, but the second lower feed adjustment device 31 is configured as a hollow shaft. Acting on the transmission shaft 33 extending inside the transmission shaft 29 of the first lower feed adjustment device 30 and being independently rotated around the common longitudinal axis of the two shafts 29, 30 through a predetermined angle value. There is a difference.

  The transmission shafts 29 and 33 act on one of the lower feeders 16 and 17 independently of each other, and the rotation of the second step motor 32 has been described above with respect to the first lower feed adjustment device 30. In this way, a predetermined adjustment of the feed length of the lower feeder operated by the second lower feed adjustment device 31 is made possible.

  FIG. 5 shows the second lower feed adjustment device 31 in a position corresponding to the position of the first lower feed adjustment device 30 described in FIGS. 10 and 11, that is, in a “slight displacement” position. The rotation of the second step motor 32 causes the second lower adjustment device 31 to be displaced to the “large displacement” position substantially continuously.

  The upper feed adjusting device 34 is used for adjusting the feed length of the upper feeder 15. The upper feed adjusting device 34 has a third step motor 35, which is also attached below the support plate 9 and fixed to the base plate 3. The third step motor 35 is connected to the upper feeder 15 by transmission. The mechanical transmission from the step motor 35 to the upper feeder 15 corresponds to that described above for the two lower feed adjustment devices 30,31. In contrast to the lower feed adjustment devices 30, 31, the upper feed adjustment device 34 has a tension rod 36 used as a transmission member between the needle bearing 21 and the guide slider adjustment body 24, and the tension rod 36 Extends inside the stand 3a. In accordance with the rotational position of the third step motor 35, the corresponding angle adjustment amount is transmitted to the transmission shaft 37 of the upper feed adjusting device 34, which in turn is connected to the upper feeder via the push rod 37a. 15 is mechanically coupled. The transmission shaft 37 extends along the arm 2.

  The three step motors 18, 32 and 35 are all accommodated in a housing (not shown) surrounding the base plate 3.

  The control device 38 shown schematically in FIG. 1 is in signal connection with the two lower feed adjustment devices 30, 31 and the upper feed adjustment device 34. In addition to data relating to the sewing sequence to be executed, the control device 38 assigns adjustment data assigned to these sewing sequence data and required to operate the step motors 18, 32 and 35 when the sewing sequence is executed. It has a storage device 39 for storing.

  The independent possibility of adjusting the feed lengths of the feeders 15 to 17 using the adjusting devices 30, 31 and 34 provides the adjustability including the following main adjustability.

  First of all, since the feed lengths of all three feeders 15-17 are modified or changed in synchronism with each other, all three feeders 15-17 are first common feed lengths. Then, the second common feed length is moved. Thus, in this case, the feed length of the sewing machine 1 and thus the entire stitch length is changed.

  Secondly, the feed paths of the two lower feeders 16, 17 can be changed synchronously. The feed length of the upper feeder remains either constant or is changed by an amount different from the feed length change of the lower feeders 16,17. This type of adjustment results in a change in the difference between the feed paths covered by the lower feeders 16, 17 on the one hand and by the upper feeder 15 on the other hand when feed travel is carried out. This adjustment is hereinafter referred to as the differentiability of the feed of the sewing machine 1 or the change of the gathering feed value. This different possibility allows the gathering of the upper fabric sent by the upper feeder 15 to be changed relative to the lower fabric sent by the lower feeders 16,17.

  Third, it is possible to change the feed length of the two lower feeders 16, 17 only relative to each other, thus changing the ruffling to the lower fabric in the feeding process. Enabled, the pleats are created by the lower feeders 16,17. This adjustable fabric feed characteristic of the sewing machine 1 will be referred to in the following as the differential or modification of the ruffling feed value.

  These three general adjustability, i.e. "feed length change", "difference possibility" and "difference" can overlap each other to any desired degree.

  In the first exemplary operating method of the sewing machine 1, the first feed value is supplied to all three step motors 18, 32, 35 via a control device 38 for moving the fabric using the feeders 15-17. Initially set by operating in synchrony. The fabric is then sewn while this first feed value, i.e. the first stitch length, is set. Next, a second feed value different from the first feed value is set by operating the step motors 18, 32, 35 for moving the fabric in synchronism with the feeders 15-17. The fabric is then sewn at the resulting second feed value, eg, higher than the first feed value, and thus the resulting seam has a longer stitch length than the previous stitch.

  This controlled change in feed value can be caused by an additional sensor of the sewing machine 1, such as a photoelectric sensor, or in a fabric where only a few stitches are required to reach the end of the stitch. Performed on the basis of the signal value detected by the contact probe for detecting the end, thereby ensuring that the final stitch is finished in place (by adapting the corresponding stitch length) On the other hand, it is also ensured that the length of this final stitch is approximately equal to the length of the previous stitch. Differences in stitch length are undesirable for optical to visual reasons. Furthermore, when sewing a corner seam, it is no longer necessary to reduce the stitch length in that corner area.

  The tension or tension of the yarn is also automatically adapted to a predetermined stitch length using the control device 38. To do so, the control device 38 activates the electronic thread tensioning device of the sewing machine 1 and thereby increases the yarn tension, especially when the stitch length is increased. .

  Another alternative or additional method of operating the sewing machine 1 takes advantage of the possibility of differences. Initially, the first gathering feed value is set to move the fabric using the feeders 15-17, for example, the fabric feed value provided by the upper feeder 15 is provided by the lower feeders 16,17. This is different from the fabric feed value. The fabric is then sewn at this first gathering feed value. The second gathering feed value is then either adjusted by adjusting the step motor 35 of the upper feeder 15 or by adjusting the step motors 18, 32 of the two lower feeders 16, 17 in tune. The second gathering feed value is different from the first gathering feed value. This adjustment is made so that, for example, when the second gathering feed value is set, the feed difference between the upper feeder 15 and the two lower feeders 16 and 17 becomes larger than before, and as a result As the fabric is gathered more closely than before in the next sewing process. This effect is to achieve the desired visual sewing effect, or to supplement the different gathering behavior or style of the fabric, for example when creating a seam with a change in the direction of the fabric with the preferred direction of friction. Used for.

  Another method of operation that may be performed by the sewing machine 1 in addition to or instead of the above method of operation incorporates the advantage of “difference”. Initially, the first pleat feed value is set to move the fabric using the two lower feeders 16, 17, for example, the fabric feed value provided by the first lower feeder 16 is the second This is different from the fabric feed value of the lower feeder 17. When the first pleat feed value is set, the feed provided by the second lower feeder 17 is particularly slightly higher than the feed provided by the first lower feeder 16. At that time, the fabric is sewn with this first pleat feed value. The second pleat feed value is then set, for example, by actuating one of the two step motors 18, 32 of the lower feeders 16, 17 correspondingly. Different from pleat feed value. For example, the adjustment may be such that the feed difference between the two lower feeders 16, 17 is higher than before so that a pleated fabric can be obtained using the two lower feeders 16, 17. It is done. The fabric is then sewn at the second pleat feed value. Furthermore, this third method of operation is used to achieve a special visual sewing effect or to compensate for changes in the fabric properties during the sewing process, especially when creating seams with changes in direction. .

  Changes in fabric parameters that can be compensated for by the possibility of differing or changing the difference include, for example, changes in the weave of the fabric, changes in the material composition of the fabric, or changes in the degree of kinking of the weft and warp.

  The operation of the step motors 18, 32, 35 is automatically executed by the control device when the sewing program or the sewing sequence is executed. Alternatively or in addition, this operation is carried out directly by the operator, for example via a foot switch or knee lever or button, thus allowing the operator to stitch the stitch to any desired degree in the sewing process. Allows to change length, possibility of difference or difference. This type of direct actuation, in particular, allows the operator to make quick corrections that are generally required when inserting a sleeve to compensate for cutting tolerances.

  In particular, changes in sewing behavior or style are compensated for, and these changes are due to angular changes in the sewing direction between the warp and weft directions of the fabric. This type of correction can occur in a continuously adjustable manner, for example when sewing bent seams.

  Alternatively, instead of using an external sensor, the feed value may be changed based on internal parameters such as the number of stitches or stitch paths to be sewn.

A side view of a sewing machine provided with a base plate is shown. The top view of the sewing machine described in FIG. 1 is shown. The bottom view of the sewing machine described in FIG. 1 is shown. Fig. 4 shows a front view of the sewing machine along direction IV in Fig. 3. FIG. 5 shows a cross-sectional view along the line V-V in FIG. 3. FIG. 3 shows a cross-sectional view along line VI-VI in FIG. 2. Sectional drawing along line VII-VII in FIG. 3 is shown. FIG. 1 shows a side view of the base plate from the same direction as FIG. 1 and the mechanical components are missing compared to FIG. 1 so that only the mechanical connection of the mechanical lower feed adjustment device is shown. The side feed adjustment device is in the “large displacement” position. FIG. 9 shows a cross-sectional view along the line IX-IX in FIG. 8. FIG. 9 shows the same view as the side view of FIG. 8 with the lower feed adjustment device in the “small displacement” position. FIG. 11 shows a cross-sectional view along the line XI-XI in FIG. 10. FIG. 5 shows an enlarged cross-sectional view of FIG. 4, specifically showing a feeder used for feeding the fabric.

Explanation of symbols

1 Sewing Machine 13 Sewing Direction 14 Feed Unit 15 Upper Feeder 16 Lower Feeder 17 Lower Feeder 18 Lower Feed Adjustment Drive 19 Cam Disk 20 Outer Peripheral Area 21 Adjusting Body 24 Guide Slider Adjusting Body 30 Lower Feed Adjusting Device 31 Lower Side feed adjustment device 32 Lower side feed adjustment drive 34 Upper side feed adjustment device 35 Upper side feed adjustment drive 38 Control device 39 Storage device

Claims (10)

-A feeding unit (14) for intermittent feeding of fabric,
-At least one upper feeder (15) providing intermittent friction feed contact with the upper side of the fabric;
-At least one lower feeder (16, 17) providing intermittent friction feed contact with the underside of the fabric;
A feeding unit (14) comprising:
A mechanical upper feed adjustment device (34) for adjusting the feed length of at least one upper feeder (15);
A mechanical lower feed adjustment device (30, 31) for adjusting the feed length of at least one lower feeder (16, 17);
An upper feed adjustment drive (35) for adjusting the upper feed adjustment device (34);
A lower feed adjustment drive (18, 32) for adjusting the lower feed adjustment device (30, 31);
In a sewing machine (1) comprising:
A control device (38) for signal connection to the lower feed adjustment drive (18, 32) and the upper feed adjustment drive (35), when not only the sewing sequence to be executed but also the sewing sequence is executed A sewing machine characterized by a control device (38) having a storage device (39) for storing data with respect to the adjustment data assigned to these sewing sequence data for independently operating the adjustment drive (18, 32, 35) . The feed unit (14)
-At least one additional lower feeder (17, 16) providing intermittent friction feed contact with the underside of the fabric;
-An additional mechanical lower feed adjustment device (31, 30) for adjusting the feed length of the additional lower feeder (17, 16);
An additional lower feed adjustment drive (35, 32) for adjusting the additional lower feed adjustment device (31, 30);
-The two lower feeders (16, 17) have contact portions along the sewing direction (13), which contact portions provide feed contact with the underside of the fabric In order to be spaced apart from each other,
The control device (38) is also signal-connected to the additional lower feed adjustment device (31, 30),
-Additional adjustment data is stored in the storage device (39), and these additional adjustment data are executed to activate the additional lower feed adjustment drive (35, 32) when the sewing sequence is executed. Assigned to data on the power sewing sequence,
The sewing machine according to claim 1, wherein:   The adjusting device (30, 31, 34) is guided by a slider mechanism having at least one guide slider adjusting body (24) which is displaceable along the adjusting direction (18, 32, 35) of the respective adjusting drive. The sewing machine according to claim 1 or 2, wherein   At least one adjusting device (30, 31, 34) has a cam disk (19) which can be driven for rotation by means of an assigned adjusting drive (18, 32, 35), which cam disk (19) The adjustment body (21) has an outer peripheral area (20) whose radius changes over the outer periphery, and the adjusting body (21) contacts the area of the outer peripheral area (20) to adjust the feed length, and the adjusting body (21) Sewing machine according to claim 3, characterized in that it is mechanically connected to the assigned feeder (15-17).   The sewing machine according to any one of claims 1 to 4, characterized by a step motor (18, 32, 35) as an adjustment drive.   Sewing machine according to any one of the preceding claims, characterized in that at least one adjusting drive (18, 32, 35) is accommodated in the housing of the sewing machine (1).   The sewing machine according to claim 1, wherein the control device is connected to a thread tension device. In the operating method of the sewing machine according to any one of claims 1 to 7,
-Setting a first feed value for moving the fabric using at least one upper feeder (15) and at least one lower feeder (16, 17);
-Sewing the fabric with the first feed value;
-Setting a second feed value for moving the fabric using at least one upper feeder (15) and at least one lower feeder (16, 17), the second feed value being the first feed value; And different steps
-Sewing the fabric with the second feed value;
A method of operating a sewing machine comprising: In the operating method of the sewing machine according to any one of claims 1 to 7,
-Setting a first gathering feed value for moving the fabric using at least one upper feeder (15) and at least one lower feeder (16, 17), the first gathering feed value being the upper A step which is the ratio between the feed lengths of the feeder (15) and the lower feeder (16, 17);
-Sewing the fabric with the first gathering feed value;
-Setting a second gathering feed value for moving the fabric using at least one upper feeder (15) and at least one lower feeder (16, 17), the second gathering feed value being A step different from the one-gathering feed value,
-Sewing the fabric with the second gathering feed value;
A method of operating a sewing machine comprising: In the operating method of the sewing machine according to any one of claims 2 to 7,
-Set the first pleat feed value for moving the fabric using the two lower feeders (16, 17), the first pleat feed value being one lower feeder (16) and the other A step which is the ratio between the feed lengths with the lower feeder (17),
-Sewing the fabric with the first pleat feed value;
-Setting a second pleat feed value for moving the fabric using the two lower feeders (16, 17), the second pleat feed value being different from the first pleat feed value When,
-Sewing the fabric with the second pleat feed value;
A method of operating a sewing machine comprising:

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