JP5380094B2 - Sewing machine and thread winding device for this type of sewing machine - Google Patents

Description

The present invention relates to a sewing machine according to the preceding stage of claim 1 (so-called part, preamble part). The invention further relates to a thread winding device for this type of sewing machine.

The types of sewing machines listed at the beginning have been used for a long time and are publicly known. At the end of the winding process, the yarn winding device stops at a predetermined peripheral position around the winding shaft, so that the initial position is reproduced and in the next winding process the yarn to be wound is taut. It is necessary to ensure that it is held in a state. When a known spooling device is braked to the corresponding predetermined peripheral position after the end of the winding process, this imposes a high load on the components of the spooling device.

The object of the present invention is to develop a sewing machine of the type mentioned at the outset so as to extend the service life of the spooling device.

According to the present invention, when the bobbin winding device is braked toward the end of the winding process, when the engagement of the engaging body is caused by the damping element, the load imposed on the components of the bobbin winding device is reduced. It became clear. Accordingly, the braking distance when the rotation of the spooling device is stopped becomes longer. This braking distance can significantly reduce the force load on the components affected by the braking of the spooling device. The service life of the spooling device is significantly extended.

A modification of the damping element according to claims 2 and 3 slightly modifies the geometry of the known spooling device. It is also possible to attach the damping element later to an existing spool device relatively easily.

The elastic element according to claim 4 ensures a particularly long service life of the spooling device.

In the elastic elements, for example metal or plastics material, in particular good as polyurethane.
The damping element according to claim 5 allows the material of the damping element to be optimized with regard to its damping characteristics.

The design of the spooling device according to claim 6 results in a captive damping element.

The spooling device according to claim 7 ensures automatic braking of the spooling device towards the end of the winding process. As soon as the spool on which the thread is wound reaches a predetermined diameter, the spool triggers the braking function of the thread winding device.

With the design of the spooling device according to claim 8, it is no longer necessary to adjust the engagement body relative to the adjustment body.

The advantage of the spooling device according to claim 9 corresponds to the advantages described above with respect to the sewing machine.
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

1 is a schematic front view of a sewing machine including a thread winding device that winds a thread from a thread spool onto a spool. FIG. Fig. 2 shows an enlarged perspective view of the thread winding device of the sewing machine according to Fig. 1. FIG. 3 shows a detailed view of the components of the thread winding device as seen from the direction of FIG. 2 in FIG. 2, including an engagement body that stops the rotational movement of the winding wheel of the thread winding device. FIG. 2 shows a plan view of a thread winding device in which the thread to be wound is clamped under the hook knife before the start of the winding process. FIG. 5 shows a view of a thread winding device similar to FIG. 4 just after the start of the winding process. FIG. 4 shows a plan view of the part of the sewing machine according to FIG. 1 as viewed from the direction IV in FIG. 1. The figure which cuts along line VII-VII of FIG. 6 and clarifies the detail of the drive part of a bobbin winding device is shown. Fig. 8 is a view of another current position of the drive unit of the spooling device in the winding process, similar to Fig. 7; Fig. 8 is a view of another current position of the drive unit of the spooling device in the winding process, similar to Fig. 7; Fig. 8 is a view of another current position of the drive unit of the spooling device in the winding process, similar to Fig. 7; Fig. 8 is a view of another current position of the drive unit of the spooling device in the winding process, similar to Fig. 7; Fig. 8 is a view of another current position of the drive unit of the spooling device in the winding process, similar to Fig. 7; Fig. 3 shows a view of another embodiment of a spooling device similar to Fig. 2; FIG. 8 is an enlarged cross-sectional view of a hook engaged with a winding wheel of an engaging body of a similar spooling device to that of FIG. 7 for explaining another embodiment of the winding device.

The sewing machine 1 has a housing 2 including an arm portion 3 and a pedestal column portion 4. The needle bar 5 including the sewing needle 6 is driven up and down via an arm shaft extending to the arm portion 3. A sewing thread to which a predetermined thread tension is applied is supplied via the thread guide device 7.

The sewing machine 1 has a yarn winding device 8 for winding the yarn from the yarn spool 9 onto a yarn spool. The yarn 10 to be wound is supplied to the yarn winding device 8 via the extension portion 11 and the yarn guide member of the yarn guide device 7.

2 and 3 show details of the bobbin winding device 8. FIG. As will be described below, the friction wheel 12 of the bobbin winding device 8 can be driven by the arm shaft of the sewing machine 1 and rotates the bobbin winding device 8. The friction wheel 12 is formed by an O-ring placed on the winding wheel 13. The winding wheel 13 is made of a plastic material such as polyurethane and is designed as an injection molded part.

At the current position of the bobbin winding device shown in FIG. 2, the engaging body having the hook 15 formed at the free end is engaged with the receiving port 16 of the winding wheel 13. The receiving port 16 of the winding wheel 13 forms a receiving body for the engaging body 14. In the engagement position of the engagement body 14 at the receiving port 16 shown in FIG. 2, the common rotational movement of the winding wheel 13 and the friction wheel 12, and hence the winding movement of the yarn winding device 8 are stopped.

In the engagement position, the engagement body 14 is elastically braked via the damping element 17 and comes into contact with the receiving body 13. The damping element 17 is made of an elastomer and is hooked into a hooking recess of the winding wheel 13 by a hooking leg portion 18 complementary thereto, and is firmly connected to the winding wheel 13. When the winding wheel 13 is braked by the engaged hook 15, a braking distance is generated in the damping element 17 due to compression of the damping element 17 during braking of the winding wheel 13. Since this braking distance reduces the braking acceleration during braking of the bobbin winding device 8, the force load is reduced toward the end of the winding process.

The engagement body 14 is rigidly connected to an adjustment body 19 that includes a switch cam with a switch edge 20. In the winding process, the engagement lever 14 and the adjustment body 19 are firmly connected with a release lever 21 having a spool entraining surface 22 that comes into contact with the outer wall of the thread spool around which the thread is wound. The engaging body 14, the adjusting body 19, and the release lever 21 can pivot around a common pivot shaft 23 that is parallel to the winding shaft 25 of the bobbin winding device 8. The winding shaft 25 is defined by the winding shaft 24.

The free leg portion of the leaf spring 26 contacts the outer peripheral wall of the switch cam. Opposing end portions of the leaf spring 26 are fixed to the carrier 28 of the bobbin winding device 8 via a release spring 27. The carrier 28 is fastened to the housing.

A spool receiving port 29 extending circumferentially around the winding shaft 24 is arranged for rotation within the carrier 28. A hook knife 30 is disposed around the spool receptacle 29 to clamp the thread 10 to be wound. In the winding process, the spool housing 31 is placed on the winding shaft 24.

4 and 5 show the start of the winding process. FIG. 4 shows the rotational position of the spool receptacle 29 when the yarn winding device 8 is switched off, in other words, before starting the winding process. The thread 10 to be wound on the winding shaft 24 has already been cut to the desired length by the hook knife 30, and the spool receptacle 29 is held so that the thread 10 is held tight at the start of the winding process. Clamped in the direction. FIG. 5 shows the start of the winding process when the spool receptacle 29 has rotated approximately one fifth of the full rotation in the clockwise direction.

In FIG. 6, the detail of the drive part of the thread winding apparatus 8 is shown. For this reason, the friction wheel 12 interacts with the front wall 32 of the toothed belt pulley 33 which is a part of the belt driving unit of the sewing machine 1. The toothed belt pulley 33 is connected to the arm shaft 34 of the sewing machine 1 and rotates therewith.

  7 to 12 show a series of current positions of the drive unit of the yarn winding device 8 during the winding process.

FIG. 7 shows the bobbin winding device 8 in the switch-off state before starting the winding process, in other words, the bobbin winding device in the position shown in FIG. The hook 15 of the engagement body 14 is located at the receiving port 16 of the winding wheel 13 via the damping element 17. In the position according to FIG. 7, it is not possible to rotate the spooling device 8 about the winding shaft 25 because the engaged hook 15 prevents this. FIG. 7 also shows how the leaf spring 26 is attached to the support 35 connected to the winding shaft 24. Further, the support 35 is connected to the winding wheel 13. In the switch-off position according to FIGS. 4 and 7, the release spring 27 pulls the winding wheel 13, so that the friction wheel 12 is separated from the front wall 32 of the toothed belt pulley 33 and the friction wheel 12 is separated from the toothed belt pulley 33. So that there is no frictional connection between them. Therefore, the thread winding device 8 is not driven.

FIG. 8 shows the switch-on position of the thread winding device 8. By rotating the release lever 21 around the pivot shaft 23 to disengage the hook 15 of the engagement body 14 from the receiving port 16 and to disengage the winding wheel 13 from the engagement body 14, the bobbin winding device 8 is switched on. By this turning motion, the leaf spring 26 is moved to the upper right side in FIG. 8 by the switch cam of the adjusting body 19 until the friction wheel 12 contacts the front wall 32 of the toothed belt pulley 33. 8 until the leaf spring 26 moves the winding wheel 13 through the support 35 against the bias of the release spring 27 until it can be driven by the arm shaft 34 to wind around the winding shaft 25. Move to the right.

Here, the thread 10 is wound into the spool housing 31. For this purpose, the spool entraining surface 22 of the release lever 21 is in contact with the outer peripheral wall of the spool formed by the yarn 10. Therefore, in the sequence according to FIGS. 8 to 9, the release lever 21 further pivots around the pivot shaft 23 in the clockwise direction as the diameter of the spool wound with the yarn increases. Since the connection is firm, the adjusting body 19 and the engaging body 14 also turn simultaneously as shown in FIG. 8 (see below).

FIG. 9 shows the current position where the thread spool has substantially reached its desired thickness. The free end of the leaf spring 26 substantially contacts the switch edge 20 of the switch cam of the adjusting body 19.

FIG. 10 shows another current position of the switch-off process of the bobbin winding device 8. The free end of the leaf spring 26 is moved beyond the switch edge 20 of the adjusting body 19. As a result, the leaf spring 26 can be relaxed and the tension of the release spring 27 can be increased with respect to the opposing elastic force of the leaf spring 26. The free end of the leaf spring 26 presses the adjustment body 19 so that the turning movement of the adjustment body 19 and hence the turning movement of the engagement body 14 continues in the clockwise direction according to FIGS.

FIG. 11 shows the current position of the thread winding device 8 immediately before the hook 15 engages with the receiving port 16 of the winding wheel 13. The hook 15 is guided by the spiral guide wall 36 of the winding wheel 13. This ensures that the friction wheel 12 remains connected to the toothed belt pulley 33 in a shape-constrained (positive) manner until just before the end of the winding process.

FIG. 12 shows the end of the switch-off process, in other words the position of the bobbin winding device 8 corresponding to the position according to FIG. The only difference is that in the current position according to FIG. 12, the spool housing 31 has a fully wound spool.

In the transition between the current positions between FIG. 11 and FIG. 12, the damping element 17 increases the braking distance of the winding wheel 13 when the winding wheel 13 is braked by the engaged hook 15. Corresponding to the braking distance provided by the damping element 17, this reduces the braking acceleration of the winding wheel 13 and thus correspondingly reduces the force load on the components of the winding device 8.

FIG. 13 shows another modification of the bobbin winding device 8. Components corresponding to the components described above with reference to FIGS. 1 to 12 are denoted by the same reference numerals, and description thereof is omitted.

In the embodiment according to FIG. 13, the engagement body 14 and the adjustment body 19 are not combined into one component. In other words, they are two components that are integrally connected to each other as in the embodiment according to FIGS. In this case, the engagement body 14 can be moved in the circumferential direction around the pivot shaft 23 with respect to the adjustment body 19. In contrast, the engagement body 14 and the adjustment body 19 of the embodiment of the spooling device 8 according to FIGS. 1 to 12 are segments of the same component and are adjusted together circumferentially around the pivot axis 23. The

FIG. 14 is an enlarged view of a hook 15 which is a modification of the engaging body 14 and is similar to FIG. Here, the hook 15 is engaged with the receiving port 16 of the winding wheel 13. FIG. 14 shows the boundary of the attenuation layer 38 with a dotted line. The attenuation layer 38 is applied to the winding wheel 13, in other words, the receiving body in the region of the receiving port 16. In this case, the attenuation layer 38 replaces the attenuation element 17.

Alternatively or in addition, a corresponding damping layer 39 may be applied to the hook 15, as shown in dotted lines in FIG. The selection of the thicknesses of the damping layers 38 and 39 as well as the selection of the material depends on the requirements for reducing the acceleration force when the winding wheel 13 of the bobbin winding device 8 is braked.

The damping element 17 or the damping layers 38, 39 may be made of elastomer, elastomeric foam or rubber. The damping element 17 may also be configured as an elastic element such as a leaf spring. This type of elastic element may be made of metal or plastic material. Finally, the entire winding wheel 13 may be made of a damping material or an elastic material, and the damping element and the winding wheel may be integrated. FIG. 12 shows such an integrated design of the winding wheel 13 in which the winding wheel 13 also has the function of a damping element.

DESCRIPTION OF SYMBOLS 1 Sewing machine 2 Housing 3 Arm part 4 Leg column part 5 Needle bar 6 Sewing needle 7 Thread guide device 8 Thread winding device 9 Yarn piece 10 Thread 11 Extension part 12 Friction wheel 13 Winding wheel, Receptor body 14 Engagement body 15 Hook 16 Receptor DESCRIPTION OF SYMBOLS 17 Damping element 18 Latching foot part 19 Adjustment body 20 Switch edge 21 Release lever 22 Spool entraining surface 23 Pivot shaft 24 Winding shaft 25 Winding shaft 26 Leaf spring 27 Release spring 28 Carrier 29 Spool receptacle 30 Hook female 31 Spool Housing 32 Front wall of toothed belt pulley 33 Toothed belt pulley 34 Arm shaft 35 Support 36 Spiral guide wall 37 Pivot shaft 38 Damping layer 39 Damping layer

Claims (9)

Pedestal (4);
An arm part (3) comprising an arm shaft (34) drivably connected to the needle bar (5);
A thread winding device (8) for winding the thread from the spool (9) onto a spool;
A sewing machine (1) comprising:
A friction wheel (12) that can be driven by the arm shaft (34) by the bobbin winding device (8), and a receiving body (13) that is connected to the friction wheel to rotate together with the friction wheel (12). Engagement body (14) interacting with mouth (16)
In the engagement position of the engagement body (14) in the receiving port (16), the winding rotary motion of the friction wheel (12) is stopped.
In the sewing machine (1), the engagement body (14) is elastically braked via the damping element (17; 38; 39) and comes into contact with the receiving body (13). .   The damping element comprises a damping layer (38) applied to the receptacle (13), at least in the region of the receptacle (16) for the engagement body (14). Item 2. The sewing machine according to Item 1.   The damping element (3) according to claim 1 or 2, characterized in that the damping element comprises a damping layer (39) applied to the engagement body (14) at least in the region of the contact surface with the receptacle (16). Sewing machine. The damping element (17) is characterized in that it is configured as an elastic element, the sewing machine according to any one of claims 1-3. The damping element (17) is configured as a separate component from the receptacle (13) and is connected to the receptacle (13) in a particularly frictional or shape-constrained manner. characterized sewing machine according to claim 1 or 4. The damping element, characterized in that it is formed with said receptacle body integrally, the sewing machine according to any one of claims 1-4. The bobbin winding device (8) further includes
A spring-biased adjustment body (19) for moving the friction wheel (12) from a rest position to a drive position in order to operate the bobbin winding device (8), between a non-actuated position and an actuated position; And a pivotable surface (22) that is rigidly connected to the regulator (19) and brought into contact with the outer wall of the spool wound with a thread. Release lever (21),
With
As a result of an increase in the diameter of the spool around which the thread is wound, the release lever (21) pivots, whereby the adjustment body (19) moves from the operating position to the non-operating position. Forming a body (19),
The engagement body (14) is firmly connected to the adjustment body (19) and the release lever (21) so that they can pivot together, and the engagement position of the engagement body (14) is the adjustment body (19). The sewing machine according to any one of claims 1 to 6 , wherein the sewing machine corresponds to a non-operating position. The sewing machine according to claim 7 , characterized in that the engaging body (14) and the adjusting body (19) are segments of the same component. A thread winding device for a sewing machine according to any one of claims 1 to 8 .

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