Classifications

• • D—TEXTILES; PAPER
  • D05—SEWING; EMBROIDERING; TUFTING
  • D05B—SEWING
  • D05B65/00—Devices for severing the needle or lower thread
  • D05B65/02—Devices for severing the needle or lower thread controlled by the sewing mechanisms

Definitions

• the invention relates to a sewing unit with at least one lockstitch sewing machine for producing at least one seam on a sewing material, in particular for producing at least one darts on the sewing material, wherein the sewing unit provided with a driven material transport for a specific or determinable feed direction of the material relative to stitch forming tools is, which is provided for generating the at least one seam on the respective fabric, wherein the fabric transport has a pressure bar, with which the fabric is pressed against a sewing table and the fabric for generating a feed movement to the stitch pattern tools is moved past.
• darts In some sewing pieces so-called darts to be incorporated by means of the introduction of at least one rectilinear or curved seam running.
• the dart usually have the function to change a contour of the respective garment, for example, to tailor a shirt or blouse.
• such darts constitute an additional sewing process which is usually separate in industrial production, i. regardless of other sewing operations on the garment is executed.
• sewing machines which include a lockstitch sewing machine.
• the garments are therefore brought to the sewing plant for the production of darts, there processed accordingly and subsequently transported to a machine for subsequent further processing.
• the sewing material is usually introduced manually into the sewing unit.
• the feed of the material relative to the stitch pattern tools, in particular to the needle and needle bar and the gripper of the sewing machine of the sewing unit is generated by a motor and without the need for operator intervention.
• the feed of the material is done to produce a Drafts straight.
• the length of the required feed movement may vary.
• the material is often clamped by means of a pressure bar on a table top, wherein the pressure bar is usually movable in the X-Y direction. After completion of the sewing process on the respective sewing material this is detected by a removal device and led out in the feed direction of the sewing process from the sewing unit and stored at a stacking point.
• the invention is therefore an object of the invention to provide a way to allow for darts a stitch formation error-free seam beginning and still a short thread beginning, without the need for manual post-processing is required.
• a clamping device should be arranged on the pressure bar and be movable together with the pressure bar in the feed movement, wherein the Clamping device for clamping, in particular - but not exclusively - a separate terminals, a thread beginning of the upper thread is provided, and the sewing unit has a cutting element, which is arranged at least temporarily immediately after the beginning of sewing in a region between the clamping device and the presser foot to the Cut the upper thread between the clamping device and the sewing foot.
• the object is also achieved by a method according to claim 9.
• the seam has a short thread beginning, which makes no subsequent shortening of the thread beginning at the seam required.
• the thread beginning is preferably already shortened shortly after sewing and above all during the still running sewing process, without the sewing process this would necessarily be interrupted or slowed down.
• the sewing unit has a switchable cutting element which can be moved in and out of a range between the clamping device and the sewing material by at least one switching operation in a feed path of the upper thread located on the sewing material in order to sever the upper thread in this area. Since in this embodiment of the invention, the cutting element is only briefly in the region of the material, thereby, despite the separation process in unmittebarer near the fabric, the risk of damage to the fabric by the cutting element are kept as low as possible.
• the cutting element can also be only a single blade, preferably with only one cutting edge, which comes into contact with the upper thread by being arranged in the feed path of the sewing material.
• the advancing movement of the sewing material - and thus also of the already stitched upper thread - is thus used to shorten the free thread already during the production of the seam, without interrupting the sewing itself and without performing a cutting movement by the cutting element.
• this preferred embodiment of the invention no longer requires time for the execution of the sewing process.
• the advancing movement of the sewing material is additionally used for producing a relative movement between the cutting element and the upper thread leading to the severing of the upper thread.
• a particularly favorable development of the invention can provide that for the production of a dart on a later processed material, the upper thread is severed during or after the completion of the sewing process for the darts on a previously processed fabric, the previously processed fabric from the sewing unit is removed, the pressure bar is moved back into its receiving position and the open clamping device is arranged such that the free end of the upper thread due to the movement and positioning of the pressure bar is arranged in the clamping device, the clamping device is subsequently closed and then with the beginning of the sewing process for the sewing material to be processed is started while the clamping device is still closed.
• the upper thread in the clamping device without requiring a further process step or additional representational means are required.
• pressure bar should also be understood to mean pressure elements which have a non-strip-like configuration for clamping or pressing fabric against a worktop of the sewing unit Needles and possibly the leading them needle bars and grippers are understood, as they are customary in particular in lockstitch sewing machines for guiding upper and lower threads.
• Figure 1 is a perspective view of a sewing unit according to the invention with inserted into a feed device sewing material.
• FIG. 2 is a detailed representation of FIG. 1 in the region of the sewing machine and the pressure bar of the sewing unit located in a starting position; FIG. but without representation of the sewing material;
• FIG. 3 is a detailed view of FIG. 2 of the removal device of
• FIG. 4 shows an illustration of the sewing unit from FIG. 2 in a method state in which a clamping device clamps the thread beginning and a presser foot is countersunk;
• FIG. 5 shows a further illustration according to FIG. 2 of the sewing unit, after the beginning of the
• Fig. 6 is a partial view of the sewing unit according to the invention from a further perspective, after the thread beginning of the upper thread is shortened and the cutting element is withdrawn;
• Fig. 7 shows a further partial view of the sewing unit in a region in which a suction device for extracting a separated thread section is arranged.
• the embodiment shown in Fig. 1 of a sewing unit 1 according to the invention for the production of darts has a arranged on a countertop 2 sewing machine 3.
• the sewing machine 3 may be a conventional lockstitch Be sewing machine.
• Such a sewing machine is provided with known stitch imaging tools, including especially at least one arranged on a needle bar and guided by this needle for an upper thread and a rotary gripper for a lower thread belong.
• the stitch forming operations using the stitch pattern tools done on for lockstitch sewing machines in a conventional and conventional manner.
• the sewing machine 3 with its stitch pattern tools is arranged in the region of a longitudinal edge 4 of the worktop 2 and transversely to this longitudinal edge 4.
• a feed table 7 Its table surface is on the size of the supplied, provided as sewing blanks 9, tuned.
• the feed table 7 serves to receive blanks 9 and subsequent transfer of the respective blank 9 to a predetermined position on the worktop 2, from where the blank 9 is then automatically fed to the sewing process.
• the feed table 7 can be moved either manually or by a motor to the work surface 2 and can be reset again.
• the fabric transfer 10 has, inter alia, the function of an alignment aid of the respective blank with respect to the extension length the blank 9 in a direction transverse to the longitudinal edge 4 during the sewing process.
• the substance takeover has a drive 12, with which a parallel to the longitudinal edge 4 of the worktop 2 extending angle 14 of the substance transfer is parallel to this longitudinal edge 4 slidably.
• this drive 12 is designed as a spindle stepping motor whose rotational drive movement leads by a suitable gear to a linear displacement movement of the angle 14, whereby different depth arrangements a blank are adjustable. This adjustment depth can be at a Control of the sewing unit 1 are preset, whereby the drive performs this input before a sewing or a series of sewing operations.
• a needle bar 16 which is movable up and down by means of a pneumatic drive, is provided, the needles of which are directed to corresponding recesses in the work surface 2, which are located immediately in front of the horizontal leg 14a of the angle 14.
• the feed device 1 1 is provided for receiving the respective sewing material 9 for the sewing operation and for advancing the workpiece 9 during the sewing process.
• the feed direction 19 can run parallel to the plane of the essentially flat upper side of the worktop 2, at least in a rectilinear direction.
• the feed direction 19 can be movable in an X-Y plane parallel to the upper side of the worktop 2.
• the feed device 1 1 of the embodiment is provided with a movable along the feed direction 19 pressure bar 18, with which the respective fabric 9 is received and movable relative to the stitch pattern tools.
• the pressure bar 18 is thus movable in the feed direction 19 from a first to a second end position, wherein the fabric is inserted and picked up in the first end position and removed in the second end position.
• the first end position corresponds to the position of the blank that this has when taking over the blank from the fabric transfer 10 by the feed device 1 1, before the feed device 1 1 moves in the direction of advance 19.
• the second end position corresponds to the position of the feed device 1 1 or the blank 9, this this occupies after completion of the movement of the feed device 1 1 on the other side of the sewing machine 3, after the proposed seam is introduced into the fabric 9.
• a return from the second to the first end position is preferably carried out directly, ie along a distance line between the second to the first End position.
• a drive may be provided for each of the two feed directions, in particular in each case an electric stepper motor. By superimposing the drive movements of the two stepper motors, each predetermined feed movement within the XY plane can be achieved.
• the illustrated in the preferred embodiment preferably as elongated strip-like and formed in cross-section substantially as an angular component pressure bar 18 can be moved up and down by means of a suitable further drive.
• this drive of the pressure bar 18 is designed as a pneumatic cylinder.
• a gap for receiving or for the subsequent removal of the material 9 is released between the pressure bar 18 and a counter plate arranged underneath, which is referred to below as a table top.
• the top of the worktop 2 serves as such a table top.
• the pressure bar 18 - seen in the feed direction - at least with the provided for receiving the material section, essentially in front of the sewing machine 3 and their stitch imaging tools, so that the respective fabric 9 before the sewing process in front of the stitching tools in a predetermined manner can be arranged and clamped.
• the pressure bar 18 moves in the direction of the second end position and in this case leads the fabric 9 with and the stitch pattern tools for seam formation.
• the pressure bar 18 is located together with the then sewn fabric behind the sewing machine and their stitch pattern tools.
• a clamping device 25 is attached to the pressure bar 18 and movable together with the pressure bar 18 during the advancing movement.
• the clamping device 25 is arranged on the pressure bar 18 such that the clamping device 25 with respect to the X direction of the possible feed movements at least approximately at the level of the presser foot 28th located.
• the clamping device 25 has a clamping element 26 with a flat clamping surface which can be pressed against a counter-clamping element 27.
• the clamping element 25 can be pressed against the counter-clamping element 27 and lifted off again by a drive assigned to it alone, for example an electric motor or a pneumatic drive. By means of this movement, the free thread beginning 30a of the upper thread 30 guided through the needle 29 can be pressed by the clamping element 26 against the counter-clamping element 27.
• the sewing unit is provided with a cutter 33 for shortening the thread beginning 30a the upper thread 30.
• the cutting device 33 has a cutting element 34 designed as a blade, the cutting edge 35 of which runs essentially transversely to the X feed direction.
• the cutting edge 35 is in this case formed on that side edge of the blade, which represents with respect to the X-feed direction, the rear side edge of the blade.
• the cutting element 34 is additionally provided with a drive assigned to it, with which the cutting element 34 can be inserted and carried out in the vicinity of the needle substantially transversely to the X feed direction and parallel to the Y feed direction.
• the material to be sutured 9 is placed on the feed table 7 and transferred by means of the feed table 7 to the substance transfer 10.
• the sewing material 9 may for example be a blank for a ladies blouse.
• the pressure bar 18 and the presser foot 28 are at the top and the feed table 7 is extended.
• the fabric transfer 10 the fabric 9 is held and the feed table 7 moves back by a drive movement of its drive to its original position.
• the sewing process can begin.
• the pressure bar 18 is in this case pressed by a pneumatic cylinder down against the table top and the fabric 9.
• the XY drive of the pressure bar 18 then positioned this on "seam beginning".
• the free end 30a of the needle thread 30 is above the counter-clamping element 27 of the pressure bar 18.
• the free end 30a has been cut in the previous seam production on another fabric under the needle plate as close to the needle hole by means of a not shown and arranged below a throat plate further cutting element.
• the needle thread end 30a produced in this way should protrude out of the needle 29 with such a length that a secure sewing of the seam now waiting to be produced is ensured.
• Fig. 4 it is shown that the presser foot 28 is then moved downwards. Simultaneously with the presser foot 28, the clamping device 25 is actuated. As a result, the free end 30 a of the needle 29 coming upper thread 30 in the region of the thread beginning 30 a between the clamping element 26 and the counter-clamping element 27 is clamped to the pressure bar 18. The thread beginning 30a is thus taken in the feed movement of the pressure bar 18 of this.
• the sewing foot 28 is not shown for clarity.
• the pressure bar 18 moves the fabric 9 in the feed direction, in the illustration of Fig. 5 from right to left.
• the cutting element 34 of the cutting device 33 is actuated, whereby it is moved from a waiting position to a separating position. This movement takes place by a feed movement from the waiting to the separating position, which is aligned substantially parallel to the Y direction and perpendicular to the X direction of the feed movement of the pressure bar 18.
• the movement of the cutting element 34 from one to the other end position takes place after at least the first stitch of the sewing and stitching process and before the last stitch of the seam formation are carried out without interruption.
• the cutting element 34 is moved with its cutting edge 35 into a region between the clamping device 25 and the sewing material 9. Due to the progressive advancing movement of the sewing material 9, in this case the tensioned end region of the upper thread 30 is guided against the blade and against the cutting edge 35 pressed, which leads to the severing of the upper thread 30 near the first puncture site of the needle 29 and close to the presser foot 28. In this way, a remaining on the fabric 9 short initial piece of the upper thread 30 has been generated. According to the illustration of FIG. 6, the cutting element is pulled back into its waiting position immediately after severing the upper thread 30.
• This retraction is carried out automatically and by the control of the sewing unit, for example, depending on a certain number of stitches after transfer of the cutting element 34 in the separation position.
• the clamping device 25 remains closed during the withdrawal of the cutting element 34 and thus keeps the severed thread end during the further sewing process on. Since the clamping device 25 is attached to the pressure bar 18, the clamping device 25 performs together with the pressure bar 18 and their feed motion. As a result, in the course of the feed movement, the clamping device 25 is also guided past a suction device 37.
• the control causes an opening clamping device 25 by pivoting the clamping member 26 and by a pulse suction air sucks the suction device 37 from the separated thread residue 30b, previously the free end 30a of Upper thread represented.
• the seam is now sewn ready.
• the fabric 9 can then be removed automatically or manually and the pressure bar 18 are moved back to receive a new blank / Nähguts 9 back to its original position.
• the sewing process can then be repeated one or more times in the same way, each time with a new blank / sewing material 9.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Sewing Machines And Sewing (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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Citations (7)

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• 2018
  • 2018-02-15 EP EP18709257.2A patent/EP3583261B1/de active Active
  • 2018-02-15 PT PT187092572T patent/PT3583261T/pt unknown
  • 2018-02-15 DE DE102018001176.4A patent/DE102018001176A1/de active Pending
  • 2018-02-15 CN CN201880015277.8A patent/CN110892104B/zh active Active
  • 2018-02-15 WO PCT/EP2018/000062 patent/WO2018149547A1/de unknown
  • 2018-02-15 ES ES18709257T patent/ES2939938T3/es active Active

Patent Citations (7)

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