KR100443144B1 - Sewing machine, in particular sewing machine, with needle-thread clamp and cutter - Google Patents

Abstract

The present invention is a needle (9) that can be driven up and down reciprocating; Hook 10; A sewing work pressing plate 14 for holding and guiding the sewing work 13 under the needle 9 during the sewing operation; A drive mechanism 15 for the sewing workpiece pressing plate 14; Lower half 50 with cutting edge 56 in tip portion 58, upper half pivoted about lower half 50 about pivot hinge 55 and with cutting edge 57 in tip portion 59. 54, and elastically pressed onto the tip portion 59 of the upper half 54 to clamp and hold the distal piece 78 of the needle / thread 75, with the cutting edges 56, 57 at least A needle / thread clamp and cutter 21 comprising a needle / thread clamping shear 43 provided with a clamping jaw 64 which generally occupies a working position located above the recess 42 of the sewing workpiece pressing plate 14; A drive mechanism for pivoting the upper half 54 relative to the lower half from the first open position to the second closed position; And a mechanism for turning the needle / thread clamping shear 43 into a position away from the working position where the cutting edges 56, 57 are above the recess 42, in particular a buttonhole sewing machine. In such a sewing machine, the drive mechanism for pivoting the upper half 54 is configured as a closed drive device 23 which solely pivots the upper half 54 from an open first position to a closed second position, but with a movable stopper 69. Engage the upper half 54 to close the scissors 43; The drive mechanism 15 for pivoting the needle / thread clamping scissors 43 is configured as a pivot drive device 22 which only pivots the scissors 43 from the working position to the deviating position, but pivots from the working position to the deviating position. When the upper half 54 is supported against each other is provided with a fixed stopper 72, the fixed stopper 72 is the upper half 54 when the tip portion 59 of the upper half 54 is released from the needle (9) It is arranged to lean on it.

Description

Sewing machines with needle / thread clamps and cutters, in particular buttonhole sewing machines {SEWING MACHINE, IN PARTICULAR SEWING MACHINE, WITH NEEDLE-THREAD CLAMP AND CUTTER}

The present invention relates to a sewing machine with a needle / thread clamp and a cutter, in particular a buttonhole sewing machine.

DE 197 22 504 C1 (corresponds to US 5 931 106)

Needles which can be driven up and down along the travel path;

Hook;

A sewing workpiece pressing plate for holding and guiding the sewing workpiece under the needle during the sewing operation,

Sewing work piece holding plate with a recess through which the needle passes while creating a seam;

Drive for sewing work press plate;

Needle / thread clamp and cutter,

… The lower half with a cutting edge in the tip portion,

… An upper half pivoted about the pivot hinge about the lower half and having a cutting edge in the leading end, and

… Can be resiliently pressed on the leading end of the upper half to clamp and hold the distal end of the needle / thread,

… Clamping jaws are provided in which the cutting edge occupies a working position which is at least largely positioned over the recess of the sewing workpiece pressing plate.

Needle / thread clamps and cutters including needle / thread clamping shears;

A drive mechanism for turning the upper half to the lower half,

… The path of travel of the needle extends through the needle / thread receiving opening formed between the cutting edges,

… The tip of the upper half is released from the clamping jaw

From the first open position,

… The tip part is at least partially folded and overlapped,

… The tip of the upper half engages the clamping jaw to clamp the thread.

Drive mechanism to pivot to a second closed position; And

A mechanism for turning the needle / thread clamping shear away from the working position with the cutting edge above the recess

Disclosed is a general type of sewing machine, in particular a buttonhole sewing machine.

In such known sewing machines, the movement of operating the needle / thread clamping shear is obtained from the control cam and the hook / thread cutter. It implies the dependency that the movement pattern, which is a condition of process optimization in terms of control technology, cannot be done without causing any problems with needle / thread clamping shears. The manufacture, assembly, and adjustment of the working device is substantial. Due to the complex design, their devices are extremely sensitive to wear. Since a large number of components are required to implement the actuating device, this also affects the reliability of the work. In addition, maintenance and lubrication of the mechanical parts is required.

It is an object of the present invention to further develop such a general type of sewing machine such that a simplification with reduced cost and improved work reliability is obtained.

1 is a rear view of a button-line sewing machine for sewing a linin buttonhole;

2 is a partially enlarged view of the sewing machine according to arrow II of FIG. 1;

3 is a side view of the area seen in FIG. 2 along arrow III in FIG. 2;

FIG. 4 is a view as seen in FIG. 3 along arrow IV of FIG. 3, wherein the needle / thread clamping shear in the first open position is shown in the disengaged position;

FIG. 5 is a view similar to FIG. 4 with the needle / thread clamping scissors in the second closed position shown in the working position;

FIG. 6 is a cross-sectional view of the section seen in FIG. 5 along the VI-VI line of FIG. 5, rotated 90 ° clockwise relative to FIG. 5;

FIG. 7 is a view along arrow VII of FIG. 3, partially cut open; FIG.

FIG. 8 is a view corresponding in part to FIG. 7 with the position of the needle / thread clamping shear changed;

9 is an enlarged detail of FIG. 5 with the end pieces of the thread sewn by the initial zigzag stitch;

FIG. 10 corresponds to FIG. 9 showing the buttonhole completed with the needle / thread clamping scissors in the second closed position in the working position before the cutting operation is performed by the needle / thread clamping scissors;

FIG. 11 shows the needle / thread clamping scissors along arrow X I of FIG. 5 at the start of the needle / thread cutting operation; FIG.

FIG. 12 corresponds to FIG. 11 with the needle / thread cut and the distal end clamped;

<Description of the code | symbol about the principal part of drawing>

1: arm, 2: base plate,

4: arm shaft, 8: needle bar,

9: needle, 12: support,

13: sewing workpiece, 14: pressing plate,

21: needle / thread clamp and cutter, 22, 23: piston / cylinder drive,

25, 26: solenoid valve, 28, 39: compressed air supply conduit,

30: control unit, 35: fabric push bar,

36: bearing box, 42: recess,

43: needle / thread clamping scissors, 44: pivoting lever,

47, 65: piston, 48, 66: pocket hole,

49: readjustment spring, 50: upper half,

52: bearing bolt, 54: lower half,

56, 57: cutting edge, 58, 59: tip portion,

60: clamping spring, 67: guide section,

69: movable stopper, 72: fixed stopper,

74: pin, 75: needle / thread,

76: zigzag stitch, 78: end piece,

79 buttonhole shim, 80, 81: stay stitch

Such an object is achieved according to the invention by the features of the features of claim 1.

The gist of the present invention is that only two positions of the needle / thread clamping shear are continuously triggered, which can be done by two very simple drive devices triggered separately. It helps to reduce the number of parts needed, as a result of wear and cost, thereby increasing the reliability of the work. Preferred embodiments will be apparent from the dependent claims.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As can be seen from FIG. 1, a stitch group sewing machine in the form of a 2-thread lock stitch machine, ie a buttonhole sewing machine which is particularly suitable for linen buttonholes, is typically arm 1. And a base plate in the form of a housing. In the arm 1, the arm shaft 4, which is rotationally driven by the motor 3, has a needle 9 which can be rotated in the bearings 5, 6 and moved vertically via the crank drive 7. The needle bar 8 is operated to reciprocate in the z direction along a straight path of travel.

A conventional needle jogging drive (not shown) may be available which produces a needle jogging motion thereby producing a zigzag stitch for a buttonhole seam, for example.

The hook 10 with a thread supply device (not shown) is mounted to the base plate 2 so as to rotate about the shaft 11. Typically, the operation of the hook 10 is obtained from the arm shaft 4 in synchronization with the movement of the needle bar 8. The design of the hook 10 and the hook / thread cutter is for example as specified and specified in DE 197 22 504 C1 (corresponding to US 5 931 106).

Underneath the needle bar 8 a support 12 is formed on the upper side of the base plate 2, the sewing workpiece is guided and moved by the pressing plate 14 on the support 12. In order to move the pressing plate 14 in the x direction, a pressing plate driving mechanism 15 is provided. Such a press plate drive mechanism 15 has a cartridge 16 which is arranged in the arm 1 and which can be moved in the x direction on the guide 17. The cartridge 16 is connected to the pressing plate 14 by a connecting rod 18. The cartridge 16 is operated via the synchronous belt drive 20 by a stepper motor 19.

in the y direction, the needle / thread clamp and the cutter 21 are disposed beside the needle bar 8; The needle / thread clamp and cutter 21 will now be described. The needle / thread clamp and cutter 21 are provided with two pneumatically actuated piston / cylinder drive devices 22, 23 operated by solenoid valves 25, 26 attached to the central control unit 24. The solenoid valves 25 and 26 are supplied with compressed air from the compressed air source via the compressed air supply line 27. Pneumatically actuated piston / cylinder drive devices 22, 23 are connected to solenoid valves 25, 26 by flexible compressed air feed conduits 28, 29.

The solenoid valves 25, 26 are triggered via the corresponding electrical control lines 31, 32 by the microprocessor control device 30 attached to the central control unit 24. In this way, the motor 3 and the stepper motor 19 are triggered by the control device 30 via the corresponding control lines 33 and 34.

As can be seen in particular from FIG. 2, the sewing machine has a fabric push bar 35 that can be mounted to the arm 1 and moved vertically along the z direction, the fabric push bar 35 not shown. It works as usual. The fabric push bar 35 and the needle bar 8 are parallel to each other.

The bearing box 36 is fixed to the lower end of the fabric pressing bar 35. On the bearing box 36 the pressure roller 38 is held on the bolt 39 so that it can rotate freely. When the fabric push bar 35 is moved downward in the direction towards the base plate, the pressure roller 38 is mounted on the connecting rod 18 on the one hand and on the other hand via the pressing lever 41 on the other hand. It is supported against the pressing plate holder 40 coupled to). When the fabric pressing bar 35 is moved downward as described above, the pressing plate 14 on which the sewing work 13 is placed is pressed down so as to be held on the support 12 of the base plate 2. The pressing plate 14 is provided with a recess 42 extending in the x direction for the passage of the needle.

The arm 1 may be further provided with a buttonhole cutter, for example as known from the above-mentioned DE 197 22 504 C1 (corresponding to US 5 931 106).

As will be described later, according to FIG. 2, the needle / thread clamp and cutter 21 can be pivoted about an axis 45 extending in the x direction by the insertion of the pivotal lever 44. Needle / thread clamping scissors 43 mounted thereon. Such needle / thread clamping scissors 43 are respectively moved from the working position (FIGS. 2, 3, and 5) to the disengaged position (FIG. 4) and vice versa by the pivoting lever 44. Can be. For that purpose, the lever 44 is pivoted by a lever 46 mounted on the shaft 45 and operated by one of the drive devices 22, 23 described above, ie by the swing drive device 22.

Such pivotal drive device 22 is a unidirectional actuated piston / cylinder drive device with a piston 47 formed in pocketed hole 48 in bearing box 36, in which case the pocketed hole 48 is a drive device. It serves as a cylinder of (22) and is open toward the lever 46 side. The attached flexible compressed air supply conduit 28 opens into such a pocketed hole 48. The piston 47 is directly supported by the lever 46. The preloaded spring 49 in the form of a coil compression spring respectively attached to the bearing box 36 on the one hand and to the scissors 43 on the other hand restores the pivotal lever 44 to the scissors 43. To return to the working position.

Such scissors 43 have a lower half 50 jointed to the lower end of the pivoted lever 44 opposite the shaft 45 by a fork bearing arm 51 and a bearing bolt 52, in which case The shaft 45 and the bearing bolt 52 are arranged up and down with each other along the z direction as can be seen from FIG. 2. The lower half 50 has an additional arm 53 on which the readjustment spring 49 hangs.

The upper half 54 of the scissors is jointly connected to the lower half 50 by a scissors hinge 55.

The upper and lower halves 50, 54 have cutting edges 56, 57 near their leading edges that overlap each other during the cutting operation to perform the cutting motion. The upper and lower halves 50, 54 of the scissors have tip portions 58, 59 that are thin in the vicinity of the cutting edges 56, 57. On top half 54 a clamping spring 60 of the type of leaf spring is arranged; The clamping spring 60 is engaged with the upper and lower halves 50, 54 by a scissors hinge 55. The leaf spring 60 is mounted so as not to pivot about the lower half 50 about the scissors hinge 55. For that purpose, the leaf spring 60 is mounted on the lower half 50 and passes through a hole 62 of sufficient size in the upper half 54 and then fixed within the elliptical hole 63 in the clamping spring 6. Retained by pin 61. The hole 62 in the upper half 54 is sized to be large enough to allow the upper half 54 to pivot as needed for the lower half 50 mounted so as not to pivot. The clamping spring 60 has a clamping jaw 64 at its end facing the securing pin 610 towards the tip portion 58, 60.

As can be seen from FIGS. 4, 9 and 10 on the one hand and from FIG. 5 on the other hand, the upper half 54 has two positions relative to the lower half 50, namely the closed position (FIG. 5) and Occupies an open position (FIGS. 4, 9, and 10). Closing the scissors 43, i.e., pivoting the upper half 54 to the closed position shown in FIG. Is achieved). The piston 65 of the drive device 23 can be moved in the x direction in the pocket-shaped hole 66 constituting the cylinder in the bearing box 36. Flexible compressed air delivery conduit 29 also opens into pocketed aperture 66. The piston has a guide section 67 which protrudes beyond the pocket bore 66, which guide section 67 is formed in the bearing box 36 near its end towards the side away from the pocket bore 66. The movement is guided within 68). The stopper 69 is mounted to the guide section 67 by a set screw (in the immediate vicinity of the pocket-shaped hole 66). Such stopper 69 can be moved in the x direction, thereby closing the scissors 43 by turning the upper half 54 upon operation of the closing drive device 23 by compressed air. On the guide section 67 a preloaded compression spring is mounted between the bearing 68 and the stopper 69 to serve as a reconditioning spring 71 for the piston 65 with the movable stopper 69. Downstream of the movable stopper 69 in the y direction, a fixed stopper 72 is screwed onto the bearing.

The upper half 54 causes the scissors 43 to close and correspondingly engages the stopper 69 when the drive device 23 is operated to pivot the upper half 54 from the open position shown in FIG. 4 to the closed position shown in FIG. 5. It has a curved arm 73 with a pin 74 to make. When the scissors 43 are pivoted out of the working position shown in FIG. 5 to the disengaged position shown in FIG. 4, the pin 74 is supported against the stationary stopper 52, with the result that the upper half 54 is again opened. Is wheeled into position.

The job format is as follows:

The sewing work piece 13 is placed on the support 12, and the pressing plate 14 is lowered onto the sewing work piece 13 by the pressing bar 35, and after that, the sewing work piece 13 is pressed down. And clamp between the support 12. In that case, the needle 9 is above the pressing plate 14. The thread 75 guided by the needle 9 is closed as shown in FIG. 5 and extends in the direction toward the tip portions 58, 59 of the scissors 43 in the working position. As can also be seen from FIG. 5, the scissors 43 are arranged upstream of the needle 9 (shown by schematic outline only) (when viewed in the sewing workpiece conveyance direction in the x direction). Thus, the scissors 43 do not collide with the needle 9.

As the operation of the sewing machine is started, i.e. at the beginning of the sewing operation, a first zigzag stitch 76 is made, as schematically shown in FIG. As the pressing plate 14 moves forward in the x direction, the sewing work 13 is also moved in the x direction. When generating the first zigzag stitch 76, the distal end 78 of the needle / thread 75 reached from the eye 77 of the needle 9 to the tip portions 58, 59 of the scissors 43 is zigzag. It is sewed by the stitch 76. The sewing workpiece 13 moved in the x direction also pulls the end piece 78 in the x direction so that the end piece 78 is securely sewn by the zigzag stitch 76. Before the end piece 78 is fully sewn by the zigzag stitch 76, the control device 30 triggers the pivot drive device 22 to push the piston 47 out of the pocket-shaped hole 48, thereby creating a scissors ( 43 is pivoted to the disengaged position shown in FIG. 5. During such pivoting movement, the pin 74 of the upper half 54 is supported against the stationary stopper 72, whereby the upper half 54 is simultaneously shown in FIG. It will pivot to the indicated open position. Such an open movement is possible because the movable stopper 69 is in the retracted position according to FIG. 3. 9 also shows the end piece 78 sewn completely by the zigzag stitch 76 in the meantime. The buttonhole shim 79 is completed by creating an additional zigzag stitch 76 and a two block stay stitch as shown in FIG. Immediately before the shim 79 is completed, the swing drive device 22 reduces its pressure by the control device 30, whereby the open scissors 43 are disengaged by the deflection readjustment spring 49. Is turned to the working position, as shown in FIG. 10. The sewing operation can be completed during such an operation, since the needle 9 can pass through the opening 56a between the cutting edges 56, 57 which are separated from each other in the upper half 50 and the lower half 54. When viewed in the x direction, the cutting edge 57 is located on one side of the needle 9 and the cutting edge 56 is located on the other side of the needle 9, respectively.

After the sewing operation is finished, that is, after the operation of the sewing machine is stopped, the needle / thread 75 is cut by the pressing of the closing drive device 23, whereby the upper half 54 is driven by the movable stopper 69. It will be moved to the closed position shown in 5. Since the scissors 43 lean on the very thin pressing plate 14 in the vicinity of the recess 42, the cutting of the needle / thread 75 is made with a short distance of about 0.5 mm from the sewing workpiece 13. Will be done. The process of the cutting operation and the clamping operation will be clearly understood from FIGS. 11 and 12, which shows the start of the closing operation immediately after the needle / thread 75 has been cut, while FIG. 12 shows the needle in between. The distal piece 78 of the thread 75 shows a closed scissors 43 which are clamped.

To create another button hole shim, the sewing workpiece 13 is moved relative to the needle 9 in the x direction so that the distal piece 78 of the needle / thread 75 is oriented in the opposite direction to the sewing workpiece 13. This results in the end piece 78 being covered so that it can be properly sewn by the first zigzag stitch 76 as described above. Thus, the end pieces are oriented in the x direction. In other words, the distal piece is not moved even when the scissors 43 are turned from the working position to the release position, and together with this, the opening operation of the scissors 43 is started only after the turning movement in the opposite direction is started.

Sewing machines with needle / thread clamps and cutters according to the invention, in particular buttonhole sewing machines, are operated by two very simple drives in which only two positions of the needle / thread clamping scissors are continuously triggered, which are triggered separately. It is configured to be done. It reduces the number of parts needed and hence wear and cost of the parts, thereby increasing the reliability of the work.

Claims (8)

Needle 9, which can be driven up and down reciprocally along the movement path; Hook 10; As a sewing workpiece pressing plate 14 for holding and guiding the sewing workpiece 13 under the needle 9 during the sewing operation, Sewing workpiece pressing plate 14 with recesses 42 through which needle 9 passes while creating shim 79; Drive mechanism 15 for the sewing workpiece pressing plate 14; Needle / thread clamp and cutter 21, … The lower half 50 with the cutting edge 56 in the tip portion 58, … An upper half 54 pivoted about the pivot hinge 55 about the lower half 50 and having a cutting edge 57 in the leading end 59, and … Can be elastically pressed onto the tip portion 59 of the upper half 54 to clamp and hold the distal piece 78 of the needle / thread 75, … Clamping jaws 64 are provided in which the cutting edges 56, 57 occupy a working position which is at least substantially positioned above the recesses 42 of the sewing workpiece pressing plate 14. Needle / thread clamp and cutter 21 including needle / thread clamping shear 43; As a drive mechanism for turning the upper half 54 relative to the lower half 50, … The travel path of the needle 9 extends through the needle / thread 75 receiving opening 56a formed between the cutting edges 56, 57, … The tip portion 59 of the upper half 54 is released from the clamping jaw 64. From the first open position, … The tip portions 58, 59 are at least partially folded and overlapped, … The tip portion 59 of the upper half 54 engages with the clamping jaw 64 to clamp the thread. Drive mechanism to pivot to a second closed position; And Mechanism for pivoting the needle / thread clamping scissors 43 from a working position where the cutting edges 56, 57 are above the recess 42. In sewing machines, especially buttonhole sewing machines, The drive mechanism for pivoting the upper half 54 is configured as a closed drive device 23 which merely pivots the upper half 54 from the open first position to the closed second position, and is moved by the movable stopper 69. Engagement with (54) to close the scissors (43); The drive mechanism 15 for pivoting the needle / thread clamping scissors 43 is configured as a pivot drive device 22 which only pivots the scissors 43 from the working position to the deviating position, but pivots from the working position to the deviating position. When the upper half 54 is supported against each other is provided with a fixed stopper 72, the fixed stopper 72 is the upper half 54 when the tip portion 59 of the upper half 54 is released from the needle (9) Sewing machine, characterized in that arranged to lie on the top. Sewing machine according to claim 1, characterized in that the swing drive (22) and / or the closed drive (23) is a pneumatically actuated piston / cylinder drive. The sewing machine according to claim 2, wherein the one or more piston / cylinder drive devices are operated in one direction. A sewing machine as claimed in claim 1, wherein a readjustment spring (49) is provided for pivoting the scissors (43) from the disengaged position to the working position. 2. A sewing machine as claimed in claim 1, wherein a reconditioning spring (71) is provided for pushing back the movable stopper (69). 2. Sewing machine according to claim 1, characterized in that the upper half (54) has a pin (74) which is supported against the movable stopper (69) on the one hand and against the stationary stopper (72) on the other hand. The needle / thread clamping shear (43) is mounted on a bearing box (36); Sewing machine, characterized in that the drive device (22, 23) is formed on the bearing box (36). 8. A sewing machine as claimed in claim 2 or 7, wherein the piston / cylinder drive device is formed on a bearing box.