JP2010000348A - Sewing machine and spool device for such sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve such a sewing machine named at first so that a spool housing can be facilely attached to a winding shaft of a spool device without requiring concessions with respect to stable friction engagement between the spool housing and the winding shaft. <P>SOLUTION: The problem is solved by the sewing machine including a stand, an arm including an arm shaft staying in drive-connection with a needle bar, and a spool device (8) rolls a thread spool of a thread reel. The spool device (8) has a spool shaft (24) to mount a spool housing (31). The spool shaft (24) has an inner hollow space that includes an internal thread (41), and an expanding-screwing body (46) that includes an external thread complementary to the internal thread. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a sewing machine according to the preamble portion of claim 1. The invention further relates to a sewing machine for this type of sewing machine.

  The first named sewing machine of this type is known for its public use. Between the spool housing of the spool to be wound and the winding shaft of the winding device, a defined frictional engagement must be ensured to ensure that the rotating winding shaft synchronizes the spool housing There is. In a winding device with good frictional engagement, the spool housing no longer fits well on the winding shaft, but often tends to tilt or requires a higher mounting force. It is.

  The object of the present invention is initially named so that the spool housing can be mounted neatly on the take-up shaft of the take-up device without having to make concessions for stable frictional engagement between the spool housing and the take-up shaft. To improve the sewing machine of this type.

  According to the invention, a winding shaft with an adjustable outer diameter, on the one hand, allows easy attachment of the spool housing to the winding shaft and on the other hand a stable frictional engagement between the spool housing and the winding shaft. It has been found that the contradicting demands of meeting can be met. The outer diameter of the winding shaft can be adjusted by widening the winding shaft with a screwed body so that both conditions are met, i.e. on the one hand mountability and on the other hand stable frictional engagements are simultaneously satisfied.

  The tapered recess space according to claim 2, particularly the tapered female screw according to claim 3, has an expansion effect when the screwed body is screwed into the taper.

  The internal thread according to claim 4 is a variation of the internal thread with a decreasing internal thread diameter that can be manufactured inexpensively. The production of this type of internal thread with a conically tapered thread is particularly beneficial if the conically tapered thread is a cut portion of the tap used to form the internal thread.

  Therefore, the screw according to claim 5 can be manufactured at low cost.

  A blind thread according to claim 6 results in a rigid winding shaft. The recessed space portion having a larger diameter than the blind screw may be configured in particular as a hole extending across the winding shaft.

  The screw pin according to claim 7 is inexpensive.

  The long-axis direction slit according to claim 8 can increase the outer diameter by extending the winding shaft. Alternatively, the winding shaft may be formed of an elastic material, whereby the expansion effect is achieved even if this type of longitudinal slit is not provided.

  The conical tapered recess space portion according to claim 9 enables interaction with the screw-in body without the need to provide a conical tapered female thread portion. This facilitates the manufacture of the winding shaft. Instead of a conical taper, concavity or female threaded non-linear taper, such as a convex, concave, or otherwise curved taper, is also envisioned. Secondly, the expansion effect also depends non-linearly on the screwing depth of the screwed body.

  The guide portion according to the tenth aspect can allow the screwed body to interact with the tapered recess space without bringing the male screw of the screwed body into contact with the tapered recess space. This protects the screw-in body. The guide portion may taper conically or in any other non-linear manner.

  The elastic body according to claim 11 has an expansion effect when the elastic body is compressed between the screwed body and the blind end of the screw. In one embodiment of this style configured with an elastic body, the recessed space may generally be designed without having a tapered recessed space portion. In that case, the expansion effect is achieved only by applying a radial force by the elastic body on the winding shaft that surrounds the radial force, when the elastic body is compressed by the screwed body. Produced.

  The advantages of the winding device according to claim 12 are the same as already explained above by referring to the sewing machine.

  Embodiments of the present invention will be described in more detail below with reference to the drawings.

FIG. 2 is a schematic front view of a sewing machine including a winding device for winding a spool from a reel of twisted yarn. FIG. 2 is an enlarged perspective view of the sewing machine winding device according to FIG. 1. FIG. 3 is a detailed view of components of the winding device provided with an engagement body for stopping the rotational movement of the winding wheel of the winding device, as viewed from the direction III in FIG. 2. It is a top view of the winding device before the winding process start which fixes the thread | yarn which should be wound under a hook knife. FIG. 5 is a view similar to FIG. 4 of the winding device immediately after the start of the winding process. FIG. 2 is a view of a part of the sewing machine according to FIG. 1 as seen from a direction VI in FIG. 1. It is sectional drawing along line VII-VII in FIG. 6 which clarifies the detailed part of the drive part of a winding apparatus. FIG. 8 is a view similar to FIG. 7, showing a further position of the winding device driving unit during the winding process. FIG. 8 is a view similar to FIG. 7, showing a further position of the winding device driving unit during the winding process. FIG. 8 is a view similar to FIG. 7, showing a further position of the winding device driving unit during the winding process. FIG. 8 is a view similar to FIG. 7, showing a further position of the winding device driving unit during the winding process. FIG. 8 is a view similar to FIG. 7, showing a further position of the winding device driving unit during the winding process. FIG. 3 is a view similar to FIG. 2 of another embodiment of the winding device. FIG. 8 is a view similar to FIG. 7 of an enlarged portion of a hook of an engaging body of a winding device for explaining another embodiment of the winding device, wherein the engaging body engages with a winding wheel; It is a figure. It is sectional drawing of the major axis direction which passes along the winding apparatus which concerns on FIGS. 1-13 in the cross section parallel to drawing concerning FIG. FIG. 16 is an enlarged view of a detail portion XVI in FIG. 15. FIG. 17 is a view similar to FIG. 16 of another embodiment of the winding shaft of the winding device. FIG. 17 is a view similar to FIG. 16 of another embodiment of the winding shaft of the winding device.

  The sewing machine 1 has a housing 2 having an arm 3 and a stand 4. A needle bar 5 having a sewing machine (needle) 6 is driven up and down by an arm shaft extending into the arm 3. A sewing thread having a predetermined thread tension is supplied by the thread guide device 7.

  The sewing machine 1 has a winding device 8 for winding a yarn spool from a reel of twisted yarn 9. The yarn 10 to be wound is supplied by the extension 11 and the yarn guide component of the yarn guide device 7 of the winding device 8.

  2 and 3 show details of the winding device 8. The friction wheel 12 of the winding device 8 can be driven by the arm shaft of the sewing machine 1 to rotate the winding device 8, as will be described below. The friction wheel 12 is formed by an O-ring mounted on the winding wheel 13. The winding wheel 13 is a component made of plastic such as polyurethane and formed by injection molding.

  In the current position of the winding device 8 shown in FIG. 2, a hook 15 is formed at the free end of the engagement body 14 and is in engagement with the receiver 16 of the winding wheel 13. , Thereby forming a receiver for the engaging body 14. In the engagement position of the engagement body 14 in the receptacle 16 shown in FIG. 2, the combined rotational movement of the winding wheel 13 and the friction wheel 12 and consequently the winding movement of the winding device 8 Stop.

  In the engaged position, the engaging body 14 contacts the receiving body 13 so as to be elastically damped by the damping element 17. The damping element 17 is made of elastomer and is fastened in the latch receiver of the winding wheel 13 by a latch foot 18 complementary to the latch receiver, so that the damping element 17 is tightly attached to the winding wheel 13 Combine with. When the winding wheel 13 is braked by the hook 15 that is engaged, the damping element 17 has a deceleration distance resulting from the compression of the damping element 17 when the winding wheel 13 is braked. Bring. This deceleration distance has the result of reducing the pawl on the acceleration when the winding wheel 8 is braked, thereby reducing the force applied when the winding process is finished.

  The engagement body 14 is firmly coupled to a switch body 19 configured with a switch cam having a switch edge 20. Tightly coupled to the engagement body 14 and the switch body 19 is a release lever 21 with a spool tuning surface 22 that contacts the side wall of the wound thread spool during the winding process. The engaging body 14, the switch body 19, and the release lever 21 can pivot about a common pivot shaft 23 parallel to the winding shaft 25 of the winding device 8, and the winding shaft 25 is wound around the winding shaft 24. Is defined by

  The free leg portion of the leaf spring 26 is in contact with the outer peripheral wall of the switch cam 19. The opposite end of the leaf spring 26 is attached to a support 28 fixed to the housing of the winding device 8 by a return spring 27.

  A spool receiver 29 extending circumferentially around the winding shaft 24 is arranged for rotation within the support 28. A hook knife 30 for grasping the thread 10 to be wound is arranged at the outer peripheral position of the spool groove 29. During the winding process, the spool housing 31 is attached to the winding shaft 24. The spool housing 31 is connected to the winding shaft 24.

  4 and 5 illustrate the disclosure of the winding process. FIG. 4 shows the rotational position of the spool receiver 29 when the winding device 8 is switched off, in other words, before starting the winding process. The yarn 10 to be wound on the winding shaft 24 has already been cut to the desired length by the hook knife 30 and is gripped against the spool receiver 29 so that the yarn 10 is wound. It is held firmly at the start of the removal process. FIG. 5 shows the start of the winding process when the spool receiver 29 executes only one fifth of the complete rotation in the clockwise direction.

  FIG. 6 shows details of the drive unit of the winding device 8. In order to drive the winding device 8, the friction wheel 12 interacts with the front wall 32 of the belt pulley 33 with toothed projections, which is part of the belt drive of the sewing machine 1. The belt pulley 33 with tooth-like projections is coupled to the arm shaft 34 of the sewing machine 1 for rotation together.

  7 to 12 show the order of the drive unit (current) position of the winding device 8 during the winding process.

  FIG. 7 shows the winding device 8 switched off before the start of the winding process, in other words the winding device 8 in the position shown in FIG. The hook 15 of the engagement body 14 is arranged in the receptacle 16 of the winding wheel 13 via a damping element 17. In the position according to FIG. 7, the winding device 8 cannot rotate around the winding shaft 25 because this is hindered by the engaged hook 15. FIG. 7 also illustrates how the leaf spring 26 is mounted on the mounting body 35 coupled to the winding shaft 24. The mounting body 35 is coupled to the winding wheel 13 in order. In the switched-off position according to FIGS. 4 and 7, the return spring 27 pulls the winding wheel 13, so that the friction wheel 12 moves away from the front wall 32 of the belt pulley 33 with teeth, thereby causing the friction wheel 12 to move. There is a gap from the belt pulley 33 with the tooth-like projections, and therefore it is not in frictional engagement therewith, so that the winding device 8 is not driven.

  FIG. 8 shows the winding device 8 switched to the on position. The winding device 8 pivots the release lever 21 about the pivot shaft 23 so that the hook 15 of the engagement body 14 is disengaged from the receptacle 16 and thereby the winding wheel 13 is released from the engagement body 14. To turn it on. This pivot movement causes the leaf spring 26 to shift to the upper right in FIG. 8 by the switch cam of the switch body 19, and as a result, the leaf spring 26 moves the winding wheel 13 to the right in FIG. 8 via the mounting body 35. In other words, until the friction wheel 12 is placed against the front wall 32 of the belt pulley 33 with tooth-like protrusions in the direction opposite to the preload of the return spring, in other words, the winding device 8 is wound. It is displaced until it can be driven by the arm shaft 34 for winding around the take-up shaft 25.

  The thread 10 is now wound in the spool housing 31. In this process, the spool tuning surface 22 of the release lever 21 is in contact with the outer side wall of the spool formed by the thread 10. In the order according to FIGS. 8 to 9, the release lever 21 thus pivots more and more clockwise around the pivot shaft 23 due to the increased circumference of the wound spool. Due to the hard connection, the switch body 19 and the engagement body 14 simultaneously pivot as shown in FIG.

  FIG. 9 shows the position where the thread spool has almost reached the desired thickness. The free end of the leaf spring 26 is substantially in contact with the switch edge 20 of the switch cam of the switch body 19.

  FIG. 10 shows another position when the winding device 8 is switched off. The free end of the leaf spring 26 is offset beyond the switch edge 20 of the switch body 19. This loosens the leaf spring 26 and increases the pulling force of the return spring 27 in response to the opposite tension of the leaf spring 26. The free end of the leaf spring 26 pushes against the switch body 19, so that the pivoting movement of the switch body 19 and thus the pivoting movement of the engagement body 14 continues in the clockwise direction according to FIGS.

  FIG. 11 shows the position of the winding device 8 just before the hook 15 engages the receiver 16 of the winding wheel 13. The hook 15 is then guided by the helical guide wall 36 of the winding wheel 13. This confirms that the friction wheel 12 is drivably coupled to the belt pulley 33 with tooth-like protrusions until just before the end of the winding process.

  FIG. 12 shows the end of the off-switching process, that is, the position of the winding device 8 corresponding to the position of FIG. 7 in the range in which the drive unit is involved. The only difference is that at the (current) position according to FIG. 12, the winding spool is provided in the spool housing 31 on the winding device 8.

  In the transition between the positions according to FIGS. 11 and 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. This results in braking the acceleration of the winding wheel 13, which is reduced by the braking distance provided by the damping element 17, and thus the force exerting on the components of the winding device 8. This results in a reduction of

  FIG. 13 shows another embodiment of the winding device 8. Components identical to those already described above with reference to FIGS. 1 to 12 have similar reference numerals and will not be described again in detail.

  In the embodiment according to FIG. 13, the engagement body 14 and the switch body 19 are not integrated into one component, in other words, in the case of the embodiment according to FIGS. Two components mounted separately on the pivot shaft 37. In this case, the engagement body 14 is movable in response to the switch body 19 in the circumferential direction around the pivot shaft 23. In contrast, the engagement body 14 and the switch body 19 of the embodiment of the winding device 8 according to FIGS. 1 to 12 are part of the same component and are therefore installed together circumferentially around the pivot axis. It was done.

  FIG. 14 shows a view similar to FIG. 7 of an enlarged portion of the hook 15 in another form of the engagement body 14, where the hook 15 is in engagement with the receiver 16 of the winding wheel 13. The boundary of the damping layer 38 is indicated by a dotted line in FIG. 14, and the damping layer 38 is attached to the winding wheel 13, in other words to the receiver in the range of the receiver 16. The damping layer 38 replaces the damping element 17.

  A similar damping layer 39 may alternatively or additionally be attached to the hook 15, as also indicated by the dotted line in FIG. The thickness and material of the damping layers 38 and 39 are selected according to the requirements imposed on the damping of the acceleration force when the winding wheel 13 of the winding device 8 is braked.

  The damping element 17 or damping layers 38, 39 may be made of elastomer, elastomeric foam, or rubber. The damping element 17 may also be an elastic element such as a leaf spring. This type of elastic element may also be made of plastic. Finally, the entire winding wheel 13 may be made of a similar damping or elastic material, whereby the damping element and the winding wheel are formed as a one-piece component. The one-piece design of the winding wheel 13 having the function of a damping element at the same time is shown in FIG.

  FIGS. 15 and 16 show two horizontal longitudinal cross-sections through the installed winding device 8 according to the embodiment of FIGS. Constructed with a take-off shaft. The winding shaft 24 is recessed and has an inner recessed space and a longitudinal slit 40 extending along the winding shaft 24. The inner wall of the recessed winding shaft 24 is designed as a female screw 41.

  The female screw 41 is designed as a blind screw. A blind portion 42 of the female screw 41 is adjacent to a hole 43 that extends across the winding shaft 24. The longitudinal slit 40 extends from the free end 44 of the winding shaft 42 to the hole 43. The holes 43 reduce the wall thickness of the take-up shaft 24 with slits, so that the take-up shaft 24 can be opened by bending or expanding in the area with the slits.

  The blind part 42 is at the same time the threaded part of the female thread 41, the threaded part tapering conically towards the hole 43. The internal thread diameter of the internal thread 41 therefore decreases as the distance from the free end 44 of the winding shaft 24 increases.

  The conically tapered threaded portion 42 is adjacent to the parallel threaded portion 45 of the internal thread 41 where the internal thread diameter does not change to the free end 44.

  The winding shaft 24 has a threaded body 46 designed as a threaded pin. The threaded body 46 has a male thread 47 complementary to the female thread 41 within the parallel threaded section 45, ie, complementary to the female thread section having the largest female thread diameter.

  Toward the free end 44, the screw-in body 46 has a recess 48 made to the contour of the (screw) that can be engaged by the screw.

  The screw-in body 46 allows the outer diameter of the take-up shaft 24 to be precisely adjusted to the inner diameter of the corresponding spool housing 31 receptacle so that the spool attached to the take-up shaft 24 is being taken up. Can be reliably tuned by the rotating winding shaft 24, while ensuring that the spool housing 31 is well attached to the winding shaft 24. The frictional interaction between the spool housing 31 and the winding shaft 24 can be adjusted by adjusting the outer diameter of the winding shaft 24 in this way. This is performed as follows.

  As long as the threaded body 46 is simply screwed to the parallel threaded portion 45 of the female thread 41, the take-up shaft 24 ensures that the spool housing 31 can be conveniently attached to the take-up shaft 24 in any case. Has the smallest outer diameter. At this minimum outer diameter of the winding shaft 24, the frictional engagement between the winding shaft 24 and the attached spool housing 31 is generally sufficient to ensure reliable tuning of the spool housing 31. is not. The threaded body 46 is now screwed into a conically tapering threaded portion 42 during a repetitive process, and the screw tool guides from the free end of the winding shaft 24 through the recess of the winding shaft to the recess 48. Is done.

  The more the screw 46 is screwed into the conically tapered threaded portion 42, the more the walls forming the take-up shaft 24 are pushed away by the screw 46 and during each screwing process. In each case, the outer diameter of the winding shaft 24 is increased by a certain amount. Eventually, the longitudinal slit 40 extends toward the free end 44 of the winding shaft 24. In each case, the threaded body 46 is screwed onto a threaded portion 42 that tapers by a certain amount so that the frictional engagement between the attached spool housing 31 and the take-up shaft 24 is reliable. A test was conducted to determine if it was sufficient to ensure synchronization. If this condition is met, the screw-in body 46 is no longer screwed in any further.

  The conical threaded portion 42 may be formed by a cut portion of a tap that cuts the parallel threaded portion 45. This is a very cost effective variant for producing a threaded portion 42 that tapers in a conical shape.

  17 and 18 represent two further embodiments of the expandable winding shaft 24.

  In the embodiment according to FIG. 17, the conically tapered threaded portion 42 is replaced by a conical tapered recess space portion 49. The tapered recess space portion 49 is installed between the parallel threaded portion 45 and the blind recess space portion 43. In the embodiment according to FIG. 17, the screw-in body 46 has a guide part 50 that tapers towards the blind recess space part 43 when the screw-in body 46 is screwed. On the other hand, the tapered hollow space part of the winding shaft 24 and the guide part 50 of the screwed-in body 46 on the other hand are not equipped with yarn. When the screwed body 46 according to FIG. 17 is screwed into the female screw 41, the guide part 50 comes into contact with the tapered recess space part 49 as soon as the screwed body 46 is screwed to a sufficient depth. When the screw-in body 46 is further screwed into the female screw 41, the guide portion 50 interacts with the tapered recess space portion 49 to widen the winding shaft 24 so that its outer diameter can be adjusted. . (Comparison with the description of the embodiment according to FIGS. 15 and 16)

  In the embodiment according to FIG. 18, a cylindrical elastomer body 51 is arranged between the screwed body 46 and the tapered hollow space portion 49. The outer diameter of the elastomer body 51 is slightly smaller than the inner diameter of the female screw 41. The outer diameter of the elastomer body 51 is larger than the tapered diameter of the tapered recess space portion 49. When the screwed body 46 is screwed into the embodiment according to FIG. 18, the screwed body 46 comes into contact with the elastomeric body 51, and the elastomeric body 51 that is not initially loaded is the screwed body 46 and the tapered recess space portion. 49 is supported at a screwed position of the screwed body 46 in particular. When the screw body 46 is further screwed into the female screw 41, the elastomer body 51 is compressed in the direction along the winding shaft 24. This causes the elastomeric body 51 to exert a radial force on the winding shaft 24 that surrounds it, causing the winding shaft 24 to expand and leave. The radial force exerted on the winding shaft 24 by the elastomeric body 51 depends on the screwing depth of the screwing body 46, thus ensuring a precise adjustment of the winding shaft 24 extension and thus its outer diameter. . The function of the embodiment according to FIG. 18 is therefore similar to that of the embodiment according to FIGS.

  Although not shown, in another embodiment similar to the embodiment according to FIG. 18, the recess space of the winding shaft 24 is not tapered. Thus, the expansion of the winding shaft 24 is achieved only by a radial force created by the compression of the elastomeric body 51, which is applied on the winding shaft 24 surrounding the elastomeric body 51.

Claims (12)

A stand (4);
An arm (3) having an arm shaft (34) drivably coupled to the needle bar (5);
A sewing machine (1) comprising a driven winding device (8) for winding a spool from a reel of twisted yarn (9),
The winding device (8) includes a winding shaft (24) for attaching a spool housing (31).
The winding shaft (24)
An inner cavity with a female screw (41);
A sewing machine comprising the female screw (41) and an expanding screw-in body (46) having a complementary male screw.   The sewing machine according to claim 1, characterized in that the inner diameter of the inner hollow space of the winding shaft (24) decreases with increasing distance from the free end (44) of the winding shaft (24).   Sewing machine according to claim 2, characterized in that the female thread diameter of the female thread (41) decreases as the distance from the free end (44) of the winding shaft (24) increases.   4. Sewing machine according to claim 3, characterized in that the female thread (41) is configured with a threaded part (42) that tapers in a conical shape.   5. Sewing machine according to claim 4, characterized in that the conically tapered threaded part (42) is adjacent to a parallel threaded part (45) whose female thread diameter does not change.   The female screw (41) is a blind screw, and the hollow space portion (43) of the winding shaft (24) is adjacent to the blind portion (42) of the female screw (41), and the hollow space portion (43) is blind. Sewing machine according to any one of the preceding claims, characterized in that it has a diameter that is increased depending on the part (42).   The sewing machine according to claim 1, wherein the screw-in body is formed by a threaded pin.   Sewing machine according to any one of the preceding claims, characterized in that the winding shaft (24) comprises at least one longitudinal slit (40).   Sewing machine according to any one of claims 2 to 8, characterized in that the inner recess space is configured with a conical tapered recess space portion (49).   10. Sewing machine according to claim 9, characterized in that the screw-in body (46) is configured with a guide part (50) interacting with the tapered recess space part (49).   Sewing machine according to any one of the preceding claims, characterized by an elastomeric body (51) between the blind part (42) of the recessed space part (49) and the screwed body (46).   The winding device for a sewing machine according to any one of claims 1 to 11.

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