JP4734010B2 - sewing machine - Google Patents

Abstract

The sewing machine to stitch a seam with an end section (54) of the looper thread (12) has a thread cutter (22) acting as shears, with two shear sections (23,24) and a linear drive (36) to swing them against each other for the thread cutting action. The drive is coupled to the shear sections by a drive lever (42) acting on an operating lever (32), with two arms in a positive fit within openings (30,31) in the shear sections, so that they are opened and closed by the drive mechanism.

Description

The present invention relates to a sewing machine according to the superordinate concept (so-called part, preamble part) of claims 1 and 2 .

  Non-Patent Document 1 describes an eyelet (hole) buttonhole sewing machine equipped with a thread trimming device. By this thread trimming device, needle thread (upper thread) and looper thread (lower thread), depending on circumstances. Cuts the gimp thread that is sewn together with the looper thread. The thread trimmer has two halves that can be rotated towards each other and is configured as a heel. To close the blade, the half is acted on by a linear drive. The action of moving the blade away from the blade is performed by the action of a preloaded spring. Fine dust is produced when the yarn is cut. Fine dust can strongly influence the mobility of the halves moving towards each other, so that the action of opening the blade by the spring is no longer ensured. As a result, the needle and scissors half collide and the needle breaks or else the sewing machine is damaged. This stiffness and the above results can also occur when the two halves are tightened too tightly during adjustment.

Durkopp Adler Aktiengesellschaft

  The object of the present invention is to improve the general type of sewing machine so that the operational safety of the thread trimmer is permanently secured.

According to the invention, this object is achieved by the features of claims 1 and 2 . The measures according to the invention ensure that the thread trimming device is not only forcibly closed for thread cutting but also forcibly opened by the drive.

The further development according to claims 1 and 2 and the additional further development according to claim 3 help to obtain a simple and positive coupling between the two halves of the heel.

According to a further development according to claim 2 and claims 4 and 5, for example, a linear drive is used for generating a pivoting movement of the rod half so that a pneumatically actuated piston / cylinder drive can be used. A simple method is ensured.

To remove easily thread cutting device from the sewing machine, with convenient means according to claim 2, 7, 8, by improvement according to claim 6 is made, the thread cutting device is limited even when removed Since the final position is taken, incorrect positioning that can lead to damage to the sewing machine is avoided when the machine is replaced with a new one.

  Details of the invention will become apparent from the following description of exemplary embodiments in connection with the drawings.

  As can be seen in FIG. 1, the eye-shaped buttonhole sewing machine is C-shaped and has an upper arm 1, a lower base plate 2 in the form of a housing, and a substantially vertical post 3 that couples both. The arm shaft 4 is supported on the arm 1 as usual. The arm shaft 4 can be driven by a drive motor (not shown). The drive of a vertical needle bar which has a needle 5 and can be displaced in the z direction is obtained from the arm shaft 4 as usual. The needle thread 6 is supplied by a needle 5 from a needle thread supply unit (not shown). Below the needle bar having the needle 5, a hook support portion 7 is disposed on the base plate 2 with a hook (not shown) that can be driven to rotate about a vertical axis 8. The action of the hook support 7 is carried out as is known, for example, from German patent application 19807771 (corresponding to US Pat. No. 6,950,066). A throat attachment 9 is provided on the base plate 2 above the hook support 7 so that the needle 5 penetrates and stitches.

  An xy table 10 is disposed on the base plate 2. The xy table is a cross slide that can be displaced in two horizontal coordinate directions, that is, in the x and y directions. The xy table 10 has a conventional configuration as known from, for example, German Patent Application No. 19807771 (corresponding to US Pat. No. 6,950,066). The operation of the xy table 10 is performed by an x driving unit and an y driving unit which are electrical positioning motors. These motors are generally preferably stepper motors, but may be adjustable DC motors. These drive units are not shown.

  A two-piece support plate is disposed on an xy table 10 composed of two partial support plates 11 and 11 '. These partial support plates 11 and 11 'are held on the xy table 10 by a positive fit, but can be removed. The partial support plates 11 and 11 'cover the hook support portion 7, and must be removed when the looper yarn 12 supplied from the looper yarn supply portion (not shown) is threaded. Gimp yarns can also be supplied, but are not particularly shown because they are generally known.

A workpiece clamp 13 is provided with a two-arm pivot support lever 14. An upper clamping plate 15 is provided at the free end of the support lever 14. The pivoting movement of the support lever 14 and thus the upper clamping plate 15 is performed by a drive part (not shown) located on the base plate 2, which drive part is published in European Patent Application No. 1349993 (US Pat. No. 6,647,905). (Corresponding to the description). A lower clamping plate 16 is assigned to the upper clamping plate 15. The lower clamping plate 16 is fixed to the partial support plate 11. The space above the partial support plates 11 and 11 'is covered by a cover 17, which of course makes the lower clamping plate 16 free and is adjacent thereto.

  A button hole cutting device 18 is provided downstream of the upper clamping plate 15 in the y direction, that is, between the upper clamping plate and the column 3. The cutting device 18 is arranged on the base plate 2 and cannot move in the z direction, and is positioned on the arm 1 vertically above the knife 19 and returns downward and again upwards toward the knife 19 in the z direction. And an anvil 20 that can be driven. An arrangement of this type is known, for example, from DE 199 16 660 (corresponding to US Pat. No. 6,220,192) and can be referred to. The workpiece 21 to be sewn is inserted into the workpiece clamp 13 between the upper clamping plate 15 and the lower clamping plate 16.

  A thread trimming device 22 in the form of a scissors is attached to the partial support plate 11 seen on the right side of FIG. The thread trimming device 22 includes a first lower half 23 and a second upper half 24, which are fixed to the partial support plate 11 by screws, which are on the partial support plate 11. Used as a joint 25 for fixing, adjusting and rotatingly joining the halves 23, 24 of the heel. At one end, the scissors halves 23, 24 have a first blade 26 and a second blade 27 that can be moved towards each other for cutting.

On the opposite side of the two blades 26, 27 , ie beyond the joint 25 when viewed from the blades 26, 27 , the two arms 28, 29 of different lengths, ie the first half 23 of the first half 23. One long arm 28 and a second short arm 29 of the second half 24 are provided. The arms 28 and 29 having different lengths have a so-called jaw shape, and have recesses 30 and 31 facing each other and opening, that is, a first recess 30 and a second recess 31. A two-arm actuating lever 32 is engaged with these recesses 30, 31 and is attached to the support plate 11 by a shaft 33 passing therethrough substantially in the middle. The two-arm actuating lever 32 has a first lever arm 35, which is securely engaged with the first recess 30 of the first half 23 at its end. Further, the two-arm lever 32 has a second lever arm 34 that securely engages with the second recess 31 of the second half 24 at the end. When the actuating lever 32 pivots about its axis 33, the halves 23, 24 of the heel are forcibly pivoted with respect to the other about the joint, thereby cutting the thread. The operation of closing the thread trimming device 22 and opening the thread trimming device 22 is performed with reliable guidance.

  The two-arm actuating lever 32 can be rotationally driven by a linear drive unit 36 in the form of a pneumatically actuated piston / cylinder driving device. The drive 36 has a cylinder 37 which is stationary with respect to the xy table 10 and its piston rod 38 can move linearly when the cylinder 37 is pneumatically actuated accordingly. The pneumatic operation of the cylinder 37 is performed using a solenoid valve (not shown) that can be triggered by a sewing machine control system. Compressed air is supplied from a compressed air source (not shown).

  Near its free end, the piston rod 38 is guided by a guide bearing 39. A drive block 40 is attached to the piston rod 38 with a groove 41 that extends vertically and across the direction of movement of the piston rod 38. One end of the drive lever 42 is guided in the groove 41 by a guide roll 43. The other end of the drive lever 42 is non-rotatably joined to the shaft 33 by a tightening connecting portion 44. The drive block 40 is supported by a sliding plate 45 disposed below the piston rod 38 so as to be displaceable. When the piston rod 38 is unwound from the cylinder 37 (to the right in FIGS. 3 and 5), the drive block 40 and the drive lever 42 are moved from the position indicated by the solid line in FIG. The lever 32 is pivoted counterclockwise, whereby the heel constituting the thread trimmer 22 is closed, ie moved to the working position seen in FIG.

Fixing means 46 for the drive lever 42 is provided on the partial support plate 11 that supports the thread trimming device 22. Securing means 46 is held in an open position as seen in Figures 3 and 4 the drive lever 42, also the thread cutting device driving lever 42 when the portion supporting plate 11 including a thread cutting device 22 is lifted from the xy table 10 22 in the rest position. The fixing means 46 has a fixing lug 47 in the form of a leaf spring, one end of which is near the guide bearing 39 on the lower side of the partial support plate 11 by means of a screw, i.e. on the side facing the linear drive 36. It is fixed. The lug 47 is between the open position, that is, the rest position of the thread trimming device 22 as seen by a solid line, and the position of the drive lever 42 indicated by the broken line, which is the closed position of the thread trimming device 22, that is, the working position. Extends over the entire operating path. The drive lever 42 has a cylindrical safety bolt 49 on the side facing the guide roll 43 and on the side facing the partial support plate 11. A release portion 50 in the form of a pin having a cup-shaped head is attached to the drive block 40 and presses the fixed lug 47 when the partial support plate 11 is inserted into the xy table 10, as seen in FIG. The fixed lug is pushed upward in the direction toward the partial support plate 11. However, when the partial support plate 11 is removed from the xy table 10, the fixed lug 47 is not pressed further, and the fixed lug 47 is flexible downward due to the configuration of the leaf spring as seen in FIG. Deflection.

The fixing lug 47 has a projection 51, which has a fixing surface 52 and is positioned in the displacement path of the guide roll 43, and behind the fixing surface 52, a safety bolt 49 opens the thread trimmer 22. It can rest at the rest position of the drive 36 seen in FIG. 3 corresponding to the position. As described above, when the partial support plate 11 is lifted from the xy table 10 together with the thread trimming device 22, the fixed lug 47 is detached from the release portion 50, so that the fixed lug 47 bends downward and the safety bolt 49 is fixed to the fixed lug 47. It moves behind the fixed surface 52. Therefore, inadvertent rotation or adjustment of the drive lever 42 is eliminated when the thread trimming device 22 is detached. When the partial support plate 11 is again placed in the xy table 10 together with the thread trimming device 22, the guide roll 43 is forcibly inserted into the groove 41 of the drive block 40. Accordingly, malfunctions and damages of the thread trimming device 22 resulting therefrom are eliminated.

  After the workpiece 21 is supplied to the eye-shaped buttonhole seam 53, the tail piece 54 of the looper thread 12 extends from the throat attachment to the eye-shaped buttonhole seam 53. By the action of the linear drive 36 described above, the thread trimmer 22 is moved from its open position as seen in FIG. 3 to its closed position as seen in FIG. Cut near the buttonhole seam 53. The piston rod 38 is then pushed again into the cylinder 37, so that the thread trimming device 22 is opened. For clarity, only the looper thread 12 is shown cut.

FIG. 2 is a longitudinal side view of an eye-shaped buttonhole sewing machine with the xy table shown relative to the needle in a position for insertion of a workpiece to be sewn. FIG. 2 is an enlarged view of the open area of the xy table as seen from the direction of arrow II in FIG. FIG. 3 is an enlarged view in which details of FIG. 2 are partially broken and opened. FIG. 4 is a side view of the yarn trimming device viewed from the direction of arrow IV in FIG. 3. It is the figure which expanded the cross section cut | disconnected along the line of FIG. 3, and the thread trimming apparatus exists in a rest position. FIG. 6 is a detailed view of FIG. 5 in a state in which the thread trimming device is detached from the xy table, and in this state, the fixing means secures the thread trimming device in the rest position. It is a top view of the thread trimming apparatus in the closed state after the thread is cut.

DESCRIPTION OF SYMBOLS 1 Arm 2 Base plate 5 Needle 6 Needle thread 7 Hook support part 9 Throat attachment 10 xy table 12 Looper thread 13 Workpiece clamp 23 1st half body 24 2nd half body 26 1st blade 27 2nd blade 30 Recessed part 31 Recess 32 Actuation lever 36 Drive part 42 Drive lever 46 fixing means 47 Fixing lug 50 Release part 53 Seam 54 Looper thread tail piece

Claims (9)

A sewing machine for making a seam (53) having a tail piece (54) of a looper thread (12),
-An arm (1);
A needle (5) for guiding the needle thread (6), which can be driven in the z direction by an arm shaft (4) supported by the arm (1);
-A base plate (2);
An xy table (10) displaceable in the x and y directions on the base plate (2);
A workpiece clamp (13) arranged on the xy table (10);
A rotationally-driveable hook bearing (7) arranged on the base plate (2) with a throat attachment (9) arranged below the needle (5) for the supply of the looper thread (12) )When,
A thread-shaped thread trimming device (22) arranged on the xy table (10), the thread trimming device comprising a first half (1) with a first blade (26) 23) and a second half (24) with a second blade (27), these two halves rotating towards each other to open and close the blades (26, 27) Furthermore, the first and second halves (23, 24) are used to perform the cutting operation of the first and second blades (26, 27) by closing the blades (26, 27). ) Ri formed by a drive unit for the rotating towards each other (36),
The drive unit also operates a linear drive unit to open the blades (26, 27) (36) to Thus the drive unit as provided (36) a first half (23) and a second half ( 24) and the sewing machine connected to
The first and second halves (23, 24) of the heel are connected to each other by one pivoted actuating lever (32) connected to the drive part (36) so as to be pivotable,
The actuating lever (32) has two arms, and both end portions thereof engage with mutually facing recesses (30, 31) of the first and second halves (23, 24) of the rod. A sewing machine characterized by A sewing machine for making a seam (53) having a tail piece (54) of a looper thread (12),
-An arm (1);
A needle (5) for guiding the needle thread (6), which can be driven in the z direction by an arm shaft (4) supported by the arm (1);
-A base plate (2);
An xy table (10) displaceable in the x and y directions on the base plate (2);
A workpiece clamp (13) arranged on the xy table (10);
A rotationally-driveable hook bearing (7) arranged on the base plate (2) with a throat attachment (9) arranged below the needle (5) for the supply of the looper thread (12) )When,
A thread-shaped thread trimming device (22) arranged on the xy table (10), the thread trimming device comprising a first half (1) with a first blade (26) 23) and a second half (24) with a second blade (27), these two halves rotating towards each other to open and close the blades (26, 27) Furthermore , the first and second halves (23, 24) are used to perform the cutting operation of the first and second blades (26, 27) by closing the blades (26, 27). ), And a drive unit (36) for rotating them toward each other,
The drive part (36), the first half (23) and the second half (24) are provided so that the operation of opening the blades (26, 27) is also brought about by the drive part (36) which is a linear drive part. In a sewing machine connected to
The first and second halves (23, 24) of the heel are connected to each other by one pivoted actuating lever (32) connected to the drive part (36) so as to be pivotable,
The drive unit is a linear drive unit (36) connected to the operation lever (32) by a drive lever (42),
Fixing means (46) for the drive lever (42) when the drive lever (42) is detached from the drive part (36) is provided, and the fixing means (46) is provided with the drive lever (42). A sewing machine comprising a fixed lug (47) for blocking the drive lever (42) at the end position when the drive unit (42) is in a detached state from the drive unit (36). The actuating lever (32) has two arms, and both end portions thereof engage with mutually facing recesses (30, 31) of the first and second halves (23, 24) of the rod. The sewing machine according to claim 2, wherein: The drive unit is characterized in that the drive lever (42) is a linear drive unit which is connected with the actuating lever (32) (36), the sewing machine according to claim 1. The aforementioned linear drive (36), characterized in that the displaceable driving block having a guide for the driving lever (42) (40) are provided, one of claims 2-4 one The sewing machine according to Item . The drive lever (42) is characterized by being removably coupled with the linear drive unit (36), the sewing machine according to any one of claims 2-5. The drive lever (42) is fixed means of the drive lever (42) for (46) is provided as it is disengaged from the driving unit (36), said securing means (46), the drive lever (42) 5. The sewing machine according to claim 4 , further comprising a fixing lug (47) that blocks the drive lever (42) in the end position when the drive lever (36) is detached from the drive part (36) . The drive unit (36) is released portion where the fixing lug (47) is disengaged from the drive lever (42) when said drive lever (42) is connected with the driving unit (36) (50) The sewing machine according to claim 2, 3 or 7 , characterized by comprising: Wherein the sewing machine is eye-shaped button sewing machine, sewing machine according to any one of claims 1 to 8.

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