KR20160129734A - Stitch length-adjusting device for a sewing machine and sewing machine with such a stitch length-adjusting device - Google Patents

Abstract

A stitch length-adjusting device (25) for a sewing machine has a stop unit (26) to indicate stopping parts for a lever body (27). The lever body can be reset by being pivoted between a forward stitch stopping point and a backward stitch stopping point on an adjusting axial line (28). A control device (25) is also has a stitch regulator gear (49) and on the one hand, the stitch regulator gear is connected to the lever body (27), on the other hand, connected to a shaft of a driving unit for a delivering device. An assembly frame (52) of the stitch regulator gear (49) is connected to the lever body (27) by rotary fixation, and therefore providing a stitch length-adjusting device with enhanced stability for indicating the length of stitches.

Description

TECHNICAL FIELD [0001] The present invention relates to a stitch length adjusting device for a sewing machine, and a sewing machine having such a stitch length adjusting device. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a sewing machine,

The contents of German patent application DE 10 2015 207 998.8 are incorporated by reference.

The present invention relates to a stitch length adjusting device for a sewing machine. The present invention also relates to a sewing machine equipped with such a stitch length adjusting device.

Stitch length adjusters for sewing machines are known from DE 100 13 414 C1.

An object of the present invention is to improve the stability of the stitch length indication by the stitch length adjusting device.

The above object is achieved by a stitch length adjusting device for a sewing machine according to the present invention,

This stitch length regulating device has a stop unit for specifying stops for the lever body,

A forward stitch stop position for specifying the transfer movement of the sewing work screw driver in the sewing work delivery direction,

- can be adjusted by pivoting about an adjustment axis between the reverse stitch stop positions for specifying the transfer movement of the sewing work screw conveyor opposite to the sewing workpiece delivery direction,

- a stitch regulator gear, which on the one hand is connected to the lever body and on the other hand to the transporter drive shaft,

The assembly frame of the stitch regulator gear is connected to the lever body in a rotationally fixed manner.

By specifying the transfer movements of the stitch length adjuster forwarding, the specification of each stitch length can be specified. According to the present invention, there is provided a rotary lock or torque blocking connection of an assembly frame of a stitch regulator gear to a lever body adjustable between stop positions for conveying movement specification, i.e. between the common axis of rotation of the lever body and the assembly frame It has been found that this leads to an increased stability of the stitch length adjuster and thus to a greater precision and stability of the stitch length specification. Unwanted relative movements between the stitch regulator gear and the lever body are avoided. It is also possible to have a one-piece design of a stitch regulator gear assembly frame with a lever body.

A stop unit is designed as an adjusting slide for the lever body,

- A forward stitch slide position for defining a forward stitch stop position for specifying the transfer movement of the sewing work screw driver in the sewing workpiece delivery direction,

- Adjustable slides, which can be adjusted by pivoting about an adjustment axis between the backstitch slide positions, which define a backward stitch stop position for specifying the transfer movement of the sewing work screw conveyor opposite to the sewing workpiece delivery direction , Results in a very precise positive coupling of explicit for the forward stitch and the reverse stitch stop position.

An adjustable shaft that slides along the adjustment axis, in which the lever body and the assembly frame are connected in a rotationally fixed manner, is a particularly suitable component for connecting the lever body to the assembly frame in a rotationally fixed or torque-free manner.

A setting drive portion operatively connected to the lever body for setting the lever body enables automatic adjustment between the forward stitch and the reverse stitch. The setting driver may be designed as a pneumatic cylinder.

A first forward stitch setting device for specifying a length of a large forward stitch in the direction of delivery of the sewing work by displacing at least one stop of the stall unit, and displacing at least one stop of the stall unit, Advance adjustment devices, including a second advancing stitch setting device for specifying a smaller advance stitch length of 2, increase the level of comfort when operating the sewing machine.

A short stitch adjustment device for specifying a short stitch length in the sewing workpiece delivery direction which is smaller than the forward stitch length by displacing the short stitch stop body for the short stitch lever body connected to the stitch adjuster gear, Enables additional specification of length. Such a short stitch may be used, for example, with a thread section at the end of the seam to be stitched.

The rotary fastening connection, in which the assembly frame of the stitch regulator gear is connected to the short stitch lever body in a rotationally fixed manner, ensures a suitably high degree of stability of the short stitch adjustment device.

The predefined stop position, in which the stop position of the short stitch lever body of the short stitch stop body can be specified by displacing the short stitch stop body relative to the stop body shaft, simplifies the adjustment of the short stitch length.

A short stitch setting driver operatively connected to the short stitch lever body for setting the short stitch lever body enables automatic setting of the sewing machine in a short stitch operation. The short stitch setting driving part can be designed as a pneumatic cylinder.

The stop position indication, which is performed by specifying the stop of the drive unit main body of the short stitch setting drive part of the stitch stop body whose short stitch position of the short stitch stop body of the short stitch stop body is short, is shorter than that of the short stitch lever body of the short stitch stop body Thereby avoiding a stop and thus reducing wear of the short stitch lever body.

A calibrating device for adjusting the length ratio between the forward stitch length and the backward stitch length enables fine adjustment of the lengths of the forward stitches on the one hand and back stitches on the other hand. It is then ensured that the needle penetrates exactly the same position for the forward stitch in the sewing work for the backward stitch. The calibrating device can be designed by eccentric adjustment of the stop unit and in particular by eccentric adjustment of the adjustment slide to specify the forward stitch and reverse stitch stop position of the lever body.

Advantages of a sewing machine having a stitch length adjusting device according to the present invention correspond to those already described above with respect to the stitch length adjusting device according to the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS Embodiments of the present invention will now be described in more detail with reference to the drawings.

Figure 1 shows a rear view of a sewing machine, in which the outer machine components are partially omitted,
Fig. 2 shows a front view of the sewing machine according to Fig. 1, namely a view from the operator side, in which a housing cover for closing the operator side of the sewing machine housing and internal and external machine components are omitted,
Fig. 3 shows a perspective view of the sewing machine according to Fig. 2,
Figure 4 shows the driving components of a sewing machine for driving upper and lower sewing work transfer and stitch forming tools,
Figure 5 shows a cross section according to line VV of Figure 1 of the components of the stitch length adjuster accommodated in a stand of the sewing machine housing, wherein the stitch length adjuster components are "large stitch lengths for forward stitches Quot; position,
Fig. 6 shows a view similar to Fig. 5 of the adjusting elements of the position of the "reverse stitch"
Figure 7 shows a detail view from the operator side of the sewing machine in the area of two adjustment wheels for setting on the one hand the forward stitch length and on the other hand the back stitch length,
Figure 8 shows a cross-section along line VIII-VIII of Figure 7,
Figure 9 shows a partial cross-sectional view of the area of the short stitch setting drive of the sewing machine from view direction IX of Figure 1, shown as the setting position of the "largest adjustable forward stitch length &
Fig. 10 shows a short stitch setting driving part at the position of "short stitch"
Figure 11 shows a cross section along line XI-XI in Figure 10;

The sewing machine 1 shown in Figs. 1 and 3, in which internal and external components are partially omitted, includes a base plate 2, a stand 3 arranged upright from the base plate, and an upper arm 4 ). The base plate 2, the stand 3 and the arm 4 are parts of the sewing machine housing 5 equipped with the base plate housing section 2a, the stand housing section 3a and the arm housing section 4a. The arm 4 has a head housing section 6a and ends at the head 6.

In the region of the head housing section 6a, the sewing machine 1 is provided with stitch forming tools, i.e. needle bars 7, which are not shown with sewing needles to be fastened in and gripper (8). The gripper 8 is arranged below the support plane 9 formed by the support plate 10. [ A part of the support plate 10 is a stitch plate 11 (see Fig. 4). The stitch plate (11) has a central through opening for the lower sewing work feeder (12). The lower sewing work conveyor has stitch holes for the passage of the sewing needles.

The sewing machine housing 5 has a casting main housing part 13, which is designed to open on the operating side, as shown in the figures according to figures 2 and 3. The main housing portion 13 is designed as a single unit and includes a stand housing section 3a, an arm housing section 4a and a head housing section 6a. The main housing part 13 is configured to be castable without undercuts in a core-free form.

In order to close the operator side of the sewing machine housing 5, a housing cover 14 is used, which is shown in cross-section in a broken form in Fig. The housing cover 14 may be designed as a single piece, or alternatively it may also be designed as multiple parts. The housing cover 14 is made of plastic.

The stitch forming tools, that is, the needle bar 7 and the gripper 8, are driven by the arm shaft 15. The arm shaft drive motor 16 (see FIGS. 3 and 4) is operatively connected to the arm shaft 15 by a toothed belt 17.

The arm shaft driving motor 16 is attached onto the arm housing section 4a on the housing side on the back side of the operator. The arm shaft drive motor 16 is mounted in a recess of the sewing machine housing 5. The axial extension of the arm shaft drive motor 16 corresponds to the width of the stand housing section 3a.

The drive gear wheel 18 meshes with the toothed belt 17 (see FIG. 9), which is connected to the drive shaft 19 of the arm shaft drive motor 16 in a rotationally fixed manner. The arm shaft drive motor 16 is rigidly mounted in the housing of the area of the arm housing section 4a.

The drive shaft 19 of the arm shaft drive motor 16 extends parallel to the arm shaft 15. The drive shaft 19 has a greater distance from the support plane 9 than the arm shaft 15. [

The driving means, that is, the toothed belt 17, is arranged on the side of the arm shaft driving motor 16 opposed to the head housing section 6a. The drive motor 16 does not show the extension of the arm shaft 15. [ The drive shaft 19 is not aligned with the arm shaft 15.

The arm shaft gear 20 and the lower shaft gear 21 are engaged with the toothed belt 17. The toothed belt 17 slides between the drive gear 18 and the arm shaft gear 20 on a tension pulley 22. [ The arm shaft gear 20 is arranged between the arm wheel housing section 4a and the handwheel 23 of the sewing machine 1 which is connected in a rotationally fixed manner to the arm shaft 15. [ The lower shaft gear 21 is connected to the lower shaft 24 in a rotationally fixed manner, whereby the gripper 8 and other elements are driven.

The needle transfer shaft 24a is parallel to the arm shaft 15, whereby oscillatory movement of the needle bar slide 24b resulting from arm shaft rotation is performed. According to a known method, needle delivery is carried out as sewing work top delivery through the sewing machine 1.

On the one hand, by means of the needle bar slide 24b and on the other hand by means of the lower conveyor 12, the sewing machine 1 is enabled both for upper conveying and for lower conveying for the sewing work.

The sewing machine 1 has a stitch length adjusting device 25, and its components are shown in particular in Figs. By means of the stitch length adjuster 25, a large stitch length can be specified for forward transfer of the sewing work in the sewing workpiece conveying direction x (see FIG. 3), and the backward stitch length can be specified in the sewing workpiece conveying direction may be specified for the transfer of the sewing workpieces (-x) opposite to the shortening stitch length (x), and the short stitch length may be specified for the sewing workpiece delivery direction (x), particularly for the thread section. In addition, the length ratio between the forward stitch length and the backward stitch length can be corrected.

The stitch length adjuster 25 has a stop unit 26 for specifying stops for the lever body 27 that can be readjusted about the adjustment axis 28. [ The stop unit 26 is designed as a control slide for the bolt 29 of the lever body 27 and is also referred to as a jaw.

The lever main body 27 is opposite to the forward stitch stop position and the sewing work delivery direction x shown in Fig. 5 for specifying the transmission movement of the sewing work feeder 12 in the sewing workpiece delivery direction x And between the reverse stitch stop positions shown in Fig. 6 for specifying the transfer movement of the stitch worker 12. The forward stitch stop position is the forward stitch slide position, where the bolt 29 is held in abutment against the forward stitch curved section 30 of the adjustment slide 26. The reverse stitch stop position is designed as a reverse stitch slide position in which the bolt 29 is held against the backward stitch curvilinear section 31 of the adjustment slide 26.

In order to adjust the lever body 27 between the forward stitch stop position and the reverse stitch stop position, a setting driving section 32 designed as a pneumatic cylinder with a piston 33 is used. The piston 33 is fully retracted to the forward stitch stop position according to FIG. 5 and extends to the reverse stitch stop position according to FIG. 6 and the lever body 27 of FIGS. 5 and 6 moves to the reverse stitch stop position, As shown in FIG. The piston 33 is therefore supported on the curved surface 34 of the lever body 27.

Figures 5 and 6 show the stop unit 26, i.e., the adjustment slide, at the position of "large stitch length ". For the purpose of specifying the length of the large forward stitch length at the position according to Fig. 5 and the corresponding large back stitch length at the position according to Fig. 6, a first advance adjustment device 35 is used. The first advance adjustment device is formed by an adjustment wheel, which cooperates with an axially displaceable threaded spindle.

The spherical free end 36 of the threaded spindle is supported on the lever surface 37 of the stop unit 26 to specify its position of the "large stitch length ". In this "large stitch length" position, the stop unit 26 is pretensioned by a prestressing spring. By setting the adjustment wheel 35, the position can be finely adjusted and thus a large stitch length can be defined.

By the additional setting driver 38, the stop unit 26 is reset (reset) between the position of the " large stitch length "shown in FIGS. 5 and 6 and the position of the & ). At the location of the "small stitch length ", the piston 39 of the setting drive 38 designed as a pneumatic cylinder also extends and the additional lever surface 41 thereof is connected to the threaded spindle < The curved surface 40 of the stop unit 26 is pushed until it abuts and is supported on the spherical free end 42 of the stop unit 26. The second advance adjustment device 43 is also designed as a first advance adjustment device 35 as an adjustment wheel.

When adjusting between the positions of "large stitch length" and "small stitch length ", the stop unit 26 is pivoted about the eccentrically mounted calibration shaft 44. The calibration shaft 44 is part of a calibrator 45 for adjusting the length ratio between the forward stitch length and the backward stitch length. The eccentric portion 46 is mounted on the calibration shaft 44 and fixed by the calibration adjusting screw 47 (see FIG. 8). By releasing the calibration adjusting screw 47, the eccentric portion 46 can be rotated about the calibration shaft 44. The calibration adjusting screw 47 is accessible from the outside through the long hole 48 on the user side. The z-extension of the elongated aperture 48 defines the calibration adjustment zone of the eccentric portion 46.

In an alternative embodiment, not shown, of the calibrating device 45, the eccentric portion 46 is releasably connected to the stop unit or adjustment slide 26 by a calibration adjusting screw. In this variant, there is an adjustment of the stitch length by the common rotation of the adjustment slide 26 and the eccentric portion 46 about the calibration shaft 44. In this variant, the calibration adjusting screw is accessible from the outside through a curved elongated hole which specifies an allowable calibration adjustment range of the eccentric portion 46.

A portion of the stitch length adjuster 25 is a stitch adjuster gear 49, which is designed in a manner known as a tap gear. The stitch regulator gear 49 is connected to the lever body 27 on the one hand and to the transmission drive shaft 51, which on the other hand is shown as a stitch regulator shaft, also through the transmission lever 50 and the lever joint. The stitch regulator shaft 51 is designed as a pivot shaft. The pivot angle of the stitch regulator shaft 51 about the longitudinal axis of the stitch regulator shaft is measured for the transfer movement of the lower sewing work traveler 12 in the direction of the sewing workpiece transfer or in the opposite direction . By further deflection, the stitch adjuster shaft 51 is connected to the lower sewing work feeder 12.

The assembly frame 52 of the stitch regulator gear 49 is connected to the lever body 27 in a rotary or torque-locking manner, cooperating with the adjustment slide 26. Therefore, rotation of the assembly frame 52 relative to the lever body 27 is not possible. The rotary fastening connection is performed by an adjustment shaft 53 that slides along the adjustment axis 28. In an alternative embodiment, the lever body 27 and the assembly frame 52 are positioned at precisely determined positions relative to each other, e. G., Via pin connections or screw connections, without releasing the fastening that causes a degree of freedom of displacement about the adjustment axis. Lt; / RTI > As a further alternative, it is possible to design the lever body 27 as a single piece with the assembly frame 52 of the stitch regulator gear 49.

The stitch adjuster gear 49 transmits the driving movement transmitted by the arm shaft 15 to the driving movement of the transmitting lever 50 via the eccentric lever 53a.

Referring to Figs. 9 and 10, a short stitch adjusting device 54 is hereinafter described for specifying a short stitch length in the sewing workpiece conveying direction x. Short stitch lengths are used especially for the thread section at the end of the seam. The short stitch length is smaller than the above-mentioned short forward stitch length.

Figure 9 shows a short stitch adjustment device 54 in the neutral position. In the neutral position, the piston 55 of the short stitch setting driver 56 designed as a pneumatic cylinder is retracted. The piston 55 represents the driving unit main body of the short stitch setting driving unit. The curved surface 57 of the short stitch lever body 58, which is pre-stressed by the pre-stressed spring, abuts against the free end of the piston 55 and is supported.

The short stitch lever body 58 is connected to the adjusting shaft 53 in a rotary or torque locking manner so that the lever body 27, which cooperates with the adjusting slide 26 through the bolt 29 It is connected by a rotary attachment method.

Fig. 10 shows a short stitch adjustment device 54 at the position of "short stitch for thread section ". The piston 55 of the short stitch setting driver 56 extends and thus the short stitch lever body 58 is pivoted counterclockwise about the adjustment shaft 53 in Figures 9 and 10. [

There is a corresponding adjustment of the stitch regulator gear 49 which induces short stitch drive of the stitch regulator shaft 51 by pivoting the short stitch lever body 58. [

The specification of the short stitch length is performed by the short stitch stop body 59. 10 and 11, the peripheral band 60 of the piston 55 of the short stitch setting driver 56 is located at the position of the short stitch stopper main body 59 Collides against the curved counter surface 61, whereby the position of the striking piston and hence the short stitch lever body 58 is defined and defined. The short stitch stopper main body 59 is pivotable about the pivot axis 62 provided by the assembly screw 63 for the short stitch stopper main body 59. [ Thus, the assembly screw 63 represents the stopper body shaft.

The specification of the stop position is performed by the corresponding pivoting of the short stitch stop body 59 about the stopper body shaft 63. [ This pivoting is accomplished by rotating the threaded pin 64, which is supported on the machine side that is rotated by the short stitch stop body 59 and abuts against the housing fastening wall 65. From the outside, the adjustment head 66 of the threaded pin 64 is freely accessible.

The drive units 16, 32, 38 and 56 are controlled by the central control unit 67 indicated by the broken lines in Fig.

The sewing machine 1 enables a stitch count of more than 2,000 stitches per minute and a stitch count of typically 3,000 stitches per minute.

By the sewing machine 1, sewing works having a material thickness of more than 4 mm can be stitched.

The needle thickness of the sewing machine 1 may be greater than 1.1 mm in diameter (needle nominal dimension 110). The needle thickness may be greater than 1.25 mm, greater than 1.5 mm, greater than 1.75 mm and greater than 2 mm.

The thread thickness can be thicker than 0.3 mm in diameter. In particular, the thread thickness may be thicker than the nominal dimension 60 (60 m thread is 1 g weight). In particular, the thread thickness may be greater than 0.5 mm, greater than 0.7 mm, greater than 0.9 mm, or greater than 1 mm in diameter.

Claims (13)

A stitch length-adjusting device (25) for a sewing machine (1)
And a stop unit 26 for specifying stops for the lever main body 27. The lever main body is provided with a plurality of levers Adjustment between the forward stitch stop position for specifying the transfer movement and the reverse stitch stop position for specifying the transfer movement of the (-x) sewing work feeder 12 opposite to the sewing work delivery direction (x) Can be adjusted by pivoting about an axis 28,
And a stitch adjusting gear 49 which is connected on the one hand to the lever body 27 and on the other hand to a transporter drive shaft 51 ,
The assembly frame 52 of the stitch adjuster gear 49 is connected to the lever body 27 in a rotationally fixed manner. The method according to claim 1,
The stop unit 26 is designed as an adjustment slide for the lever body 27 and the lever body is adapted to move the transfer of the sewing work screw 12 in the sewing workpiece delivery direction x (- x) of the sewing work rollers (12) opposite to the sewing workpiece conveying direction (x), for defining the forward stitch stop position, Is adjustable by pivoting about an adjustment axis (28) between backward stitch slide positions, which form a backward stitch stop position. The method according to claim 1,
Characterized in that the lever body (27) and the assembly frame (52) are connected in a rotationally fixed manner, with an adjustment shaft (53) sliding along the adjustment axis (28). The method according to claim 1,
And a setting drive part (32) operatively connected to the lever body (27) for setting the lever body. The method according to claim 1,
Characterized by a first advancing stitch setting device (35) for specifying a large advance stitch length in the sewing workpiece delivery direction (x) by displacing at least one stop (30, 31) of the stop unit (26) A stitch length adjusting device. 6. The method of claim 5,
A second forward stitch setting device 43 for specifying a second, smaller forward stitch length of the sewing workpiece delivery direction x by displacing at least one stop 30, 31 of the stop unit 26 ) Of the stitch length adjusting device. The method according to claim 1,
The short stitch stopper main body 59 for the short stitch lever body 58 connected to the stitch adjuster gear 49 is displaced so that the short stitch stopper main body 59 is shorter than the forward stitch length, Characterized by a short stitch setting device (54) for specifying the stitch length. 8. The method of claim 7,
Wherein the assembly frame (52) of the stitch adjuster gear (49) is connected to the short stitch lever body (58) in a rotationally fixed manner. 8. The method of claim 7,
The stop position of the short stitch lever body 58 of the short stitch stopper main body 59 can be specified by displacing the short stitch stopper main body 59 about the stator main shaft 63 , Stitch length adjuster. 8. The method of claim 7,
And a short stitch setting driver (56) operatively connected to the short stitch lever body (58) for setting the short stitch lever body. 11. The method of claim 10,
The specification of the stop position of the short stitch lever main body 58 of the short stitch stopper main body 59 is performed by specifying the stop of the drive main body 55 of the short stitch setting driver 56 of the short stitch stopper main body 59 And the length of the stitch is adjusted. The method according to claim 1,
Characterized by a calibrating device (45) for adjusting the length ratio between the forward stitch length and the backward stitch length. A sewing machine 1 having a stitch length adjusting device 25 for a sewing machine 1 has a stop unit 26 for specifying stops for the lever body 27. The lever body has a stitch length adjusting device 25, A forward stitch stop position for specifying the transfer movement of the sewing work feeder 12 in the delivery direction x and a forward stitch stop position for specifying the forward movement of the sewing work feeder 12 , And a backward stitch stop position for specifying the transferring movement of the backstitch stitch stop position,
The stitch regulator gear 49 is connected to the lever body 27 on the one hand and to the transporter drive shaft 51 on the other hand,
- the assembly frame (52) of the stitch regulator gear (49) is connected to the lever body (27) in a rotationally fixed manner.

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