KR101537823B1 - Sewing machine - Google Patents

Abstract

The machine has a stand (3) connecting a base plate with an upper arm. An arm shaft is mounted in the arm. Grippers e.g. backstitch grippers, are mounted in the base plate. A main-drive motor (7) drives the arm shaft and the grippers. Thread levers (16, 17) are connected with needle bars (12). A material pressure rod (36) and a presser-foot (38) stay in drive connection with the arm shaft. A controllable needle bar-drive motor (18) is designed as a servomotor and stays in drive connection with the needle bars and the thread levers independent of the arm shaft.

Description

Sewing machine {SEWING MACHINE}

The present invention

A lower housing-type base plate,

An upper arm,

A column connecting the base plate to the arm,

An arm shaft supported by the arm,

A gripper supported on the base plate,

A main-drive-motor for driving the arm shaft and the gripper,

At least one actuatable needle bar,

A needle lever connected to the needle bar,

A material-presser drivingly connected to the arm shaft,

To a sewing machine including a sewing product-feeding-device.

In practice, at least one needle bar in this type of one or two needle acupuncture machine, which is generally distributed, is driven by the arm shaft through the crank mechanism, respectively. In this case, optimization of the time during which the needle is inserted into the sewing product in relation to the position with respect to the gripper tip portion and optimization of the needle thread tension by the thread lever is not possible.

It is an object of the present invention to construct such a general type of sewing machine so as to be able to optimize the movement and thread tension of the needle over the motion cycle of at least one needle bar including the needle.

According to the present invention, the object is achieved by providing at least one controllable needlebar-drive-motor formed of a servomotor, the needlebar-drive-motor comprising at least one needle bar and a thread lever connected to the at least one needlebar And the drive connection is independent from the arm axis.

By separating the drive of the at least one needle bar and each of the thread levers from the arm axis and separately driving the needle bars separately by the thread lever via a unique controllable needle bar drive motor, It becomes possible to configure the needle bar motion to optimize the stitch formation over one full motion cycle. The movement of the needle including, for example, the needle chamber can be precisely controlled such that the needle is inserted and held in the sewing product until the needle thread loop is received by the gripper tip portion. Thereafter, conversely, the needle bar including the needles and the associated thread levers move up from the bottom stitch position in an accelerated manner, so that the needle thread is pulled very quickly, resulting in improved stitch formation. On the other hand, the needle bar can be driven to form a snug in various lengths which can be required when decorating. Wherein each of the snap lengths is an integral multiple of each feed step, which can be easily implemented in a sewing machine that operates relatively slowly. Advantages can also be realized when stitching begins. Where the control device is programmed to stop before the needle bar and seal lever move to the top dead center. The driving of the needle bar and thus the lever is progressed in the reverse direction for the formation of the next stitch. Therefore, it is possible to pull out the needle thread less than when the first stitching of the needle is performed, and to start the stitching better. The corresponding means described above can be achieved by correspondingly programming the control device. Likewise, the stitch force can be programmed. However, the basis for this is to separate the needle bar drive and the seal lever drive from the arm shaft and thus the alternating upper supply as described.

The means according to the invention are particularly advantageous in a two-needle sewing machine. Here, by interrupting the drive motor, the needle bar can be disconnected from the seal lever. Therefore, in this case, there is no thread pulling which causes a trouble in stopping the needle.

Advantageous embodiments are disclosed in the dependent claims.

Other advantages and features of the invention are disclosed in the following description of an embodiment of the invention in accordance with the drawings.

According to the present invention, it is possible to construct a general type of sewing machine so as to be able to optimize the motion and thread tension of the needles over the motion cycle of at least one needle bar including the needles.

The sewing machine shown in the drawing is a two-needle-stitch-sewing machine. The sewing machine generally comprises an upper arm 1, a housing type lower base plate 2 and a vertical column 3 connecting the arm 1 and the base plate 2 in a C-shape. The arm 1 is provided with an arm shaft 4. A lower shaft 5 is rotatably supported on the base plate 2 and the lower shaft 5 is connected to the arm shaft 4 and the gear belt drive device 6 at a speed ratio of 1: A main-drive-motor 7 is mounted on the base plate 2 and the main-drive-motor 7 is connected to the lower shaft 5 by a gear-belt drive 8. Thus, the arm shaft 4 and the lower shaft 5 are driven at the same rotational speed by the main-drive-motor 7.

At the end of the arm shaft 4 existing outside the arm 1, a manual handle 9 is generally mounted. A position sensor 10 is mounted on the arm shaft 4 adjacent to the manual handle 9 which generally transmits signals at the same angular position as the arm shaft 4 rotates, The precise angular position of the arm axis 4 in the central control device 11 and accordingly the precise angular position of the lower axis 5 are also determined.

In the arm 1, two needle bars 12 and 13, that is, a first needle bar 12 and a second needle bar 13 are arranged in parallel to the xyz-plane, y is the longitudinal direction of the sewing machine, z The vertical moving direction of the needle bars 12, 13, x defines the sewing direction. Generally, the needle bars 12, 13 include needles 12a, 13a for guiding a needle thread, not shown. The driving of the needle bars 12 and 13 is basically performed through a known crank mechanism, namely, the first crank mechanism 14 and the second crank mechanism 15. [ Of course, the first thread lever 16 or the second thread lever 17 is synchronously driven to the first and second needle bars 12, 13. The driving of the crank mechanisms 14 and 15 is not performed by the arm shaft 4 as in the general case but by the needle bar driving motors 18 and 19 independent of each other, that is, the first needle bar driving motor 18) or the second needle bar-drive-motor (19). The motors 18 and 19 are servo motors, in particular step motors, connected to the control device 11 and controllable therewith. Drive of the first crank mechanism 14 and hence the first needle bar 12 by the first motor 18 is controlled by the first gear-belt drive device 20 and the first crank mechanism- And the first crank mechanism-shaft 21 is supported on the first bearing 22 in the arm 1. The first crank mechanism- The second crank mechanism 15 is driven from the second needle bar-drive-motor 19 via the second crank mechanism-shaft 24 by the second gear-belt drive device 23, The mechanism-shaft 24 is fixed to the second bearing 25 in the arm 1, but freely rotatably supported. The seal levers 16, 17 are driven by the crank mechanism-shafts 21, 24.

And each gripper 27, 27a is driven from the lower shaft 5 through each angle-gear device 26, 26a in general. The grippers 27 and 27a are generally staple-grippers each including a reel (not shown) including a gripper chamber-feeder. In addition, the lower-feeding device 30 existing next to the grippers 27, 27a is driven from the lower shaft 5 through the eccentric-drive-device 28 and the shaft-device 29, respectively, Only one of the supply devices is shown. The lower-feeder 30 is formed such that the normal feed movement in the sewing direction (x-direction) is performed in the raised state and the opposite movement is performed in the lowered state.

The arm shaft 4 terminates in the second crank mechanism-shaft 24 before the second crank mechanism 15 as seen from the manual handle 9 and is supported on the arm shaft-bearing 32 here, (25). ≪ / RTI > An alternating top feed eccentric-gear arrangement 33 for driving the oscillation axis 34 is connected to the arm axis 4 adjacent to the arm axis-bearing 32, The material-presser-rod 36 and the upper feed-rod 37 are alternately driven via the vibrating lever-driving device 35. [ When the presser base 38 mounted on the material-presser-rod 36 presses the sewing product present on the gripper 27 on the base plate 2 onto the shear plate 39, the upper feed- Is raised from the sewing product. On the other hand, if the pressurizing base 38 after the stitching is raised, the feeder base 40 present in the upper feed-rod 37 is lowered onto the sewing product so that the sewing product can be sewn together with the lower- x. The eccentric-gear arrangement 33 forms a so-called hopper gear arrangement with the oscillating lever-drive device 35 connecting the oscillating-axis 34 and the oscillating-axis 34 with the rods 36, do.

The control device 11 is programmable. The control device 11 is connected to the main-drive-motor 7, the needle bar-drive-motors 18, 19 and the position sensor 10. The various functions described at the beginning through the control device 11 can be controlled.

1 is a vertical cross-sectional view through a sewing machine according to the present invention corresponding to the cutting line I-I of Fig. 2; Fig.

Figure 2 is a front view of the sewing machine according to arrow (II) of Figure 1 with the end side cover removed;

3 is a vertical cross-sectional view through the sewing machine;

Figure 4 is a vertical section vertical section through a sewing machine along the cutting line (IV-IV) of Figure 2;

5 is a front view of the sewing machine according to arrow V in Fig.

Description of the Related Art

1: upper arm

2: Housing-type lower base plate

3: vertical column

4: arm shaft

5: Lower shaft

6: Gear belt-drive unit

7: Main-drive-motor

8: Gear belt-drive unit

Claims (5)

A lower housing-type base plate 2, An upper arm 1, A column 3 connecting the base plate 2 to the arm 1, An arm shaft 4 supported by the arm 1, Grippers 27 and 27a supported by the base plate 2, A main-drive-motor 7 for driving the arm shaft 4 and the gripper 27, At least one actuatable needle bar (12, 13) Thread levers 16 and 17 connected to the needle bars 12 and 13, A material-pusher 36, 38 'driven and connected to the arm shaft 4, A sewing machine comprising a sewing product-feeding-device, The needle bar drive motor (18, 19) comprises at least one needle bar (12, 13) and at least one controllable needle bar drive motor Is driven and connected to a thread lever (16, 17) connected to one needle bar (12, 13), and the drive connection is independent of the arm shaft (4). The needle bar according to claim 1, wherein the first needle bar (12) is supported by a first crank mechanism (21) through a first crank mechanism (14) and a first thread lever (16) And the second needle bar 13 is connected to the motor 18 via the second crank mechanism 15 and the second thread lever 17 via the second crank mechanism- Is connected to a drive-motor (19). 3. A motor according to claim 1 or 2, further comprising a position sensor (10) for measuring the number of revolutions of the arm shaft (4) and the gripper (27) Wherein the drive-motor (18, 19) and the position sensor (10) are connected to a common control device (11). 2. A two-needle sewing machine according to claim 1, characterized in that an upper supply device (37, 40) is provided which is in driving connection with the arm shaft (4). The two-needle sewing machine according to claim 4, wherein the material pressurizer (36, 38) and the upper feed device (37, 40) are connected to the arm shaft (4) via an eccentric-

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