JP2009261949A - Bobbin housing, hook with such bobbin housing, and sewing machine with such hook - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve a bobbin housing to ensure favorable work or safety of operation, and reliability of a sewing machine, while a preliminarily coiled thread structure can be easily inserted. <P>SOLUTION: The bobbin housing 25 has a housing pot 33 for accommodating the preliminarily coiled thread structure 26. The inner diameter of a bobbin container of the housing pot is adjusted in an area between a minimum inner diameter and an increased inner diameter. As a result, the preliminarily coiled thread structure can be easily inserted into the sewing machine in such a way that it is enclosed with preloading, while favorable safety of work with the sewing machine, and reliability of the sewing machine are ensured. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a bobbin housing according to the preamble portion (so-called portion) of claim 1. The invention further relates to a hook comprising such a bobbin housing and a sewing machine comprising such a hook.

  A bobbin housing of the type first described is disclosed in US Pat. This bobbin housing plays an excellent role in practice. Nevertheless, there is a continuing need to improve this type of bobbin housing with respect to its insertion behavior.

    DE102006009966A1

  Therefore, the object of the present invention is to ensure that good pre-wound thread structure can be easily inserted while ensuring good working or operational safety and sewing machine reliability. The first is to improve the bobbin housing of the type described.

  This object is achieved according to the invention by a bobbin housing having the features presented in claim 1.

  It has been found according to the present invention that the bobbin container of the housing pot or the variable inner diameter of the storage area allows the bobbin housing to fit the circumference of the pre-wound thread structure. This reduces tolerance requirements when adapting the inner diameter of the bobbin housing to the outer diameter of the pre-wound thread structure, reducing the tolerance requirements of the bobbin housing and manufacturing the pre-wound thread structure. It is advantageous for both. Due to the variable inner diameter, a situation is achieved in which, with less effort, the pre-wound thread structure is closely fitted into the bobbin container and is thus frictionally connected to the housing pot. This ensures a safe operating behavior of the sewing machine. When the pre-wound thread structure is used up from inside to outside, as is the case in general, the frictional fit is maintained until the pre-wound thread structure is almost completely used up. The

  The preloading means according to claim 2 is characterized in that in order to ensure that the pre-wound thread structure is surrounded by a housing pot with pre-loading force, the housing pot and the pre-wound thread structure Improve frictional contact between.

  The slit according to claim 3 can be a particularly inexpensive embodiment of this kind of preloading means, which can take advantage of the elastic material properties of the material from which the housing pot is made. The housing pot can in particular be made from metal.

  The slit according to claim 4 provides particularly reproducible elastic behavior when adjusting the inner diameter of the bobbin container.

  The slit according to claim 5 can ensure a sufficient adjustment of the inner diameter, even in the case of a housing pot material having a high elastic modulus.

  The slit provided in the outer peripheral region of the housing according to claim 6 reduces the labor for manufacturing the slit because the side surface of the housing pot generally has a relatively thin thickness in this outer peripheral region.

  The slit width according to claim 7 can be produced by a conventional manufacturing method. Since the only function of the slit is to divide it into two bottom wall portions adjacent to the slit, there is practically no lower limit to the width of the slit. Thus, the slit can be made, for example, by laser machining or wire erosion. A slit width of, for example, 50 μm or 100 μm can be obtained during laser processing.

  The conical expansion according to claim 8 facilitates the insertion of a pre-wound thread structure.

  The advantages of the hook according to claim 9 and the sewing machine according to claim 10 correspond to the advantages already discussed above with reference to the bobbin housing according to the invention.

FIG. 2 is a front view of a sewing machine showing some internal details of the sewing machine. FIG. 3 is a perspective view of a sewing machine hook with a sewing needle, a needle plate, and an inserted bobbin housing, each of which is shown in the correct position. It is another perspective view of a hook. FIG. 4 is a view of a hook bobbin housing. FIG. 4 is a view of a hook bobbin housing. FIG. 4 is a view of a hook bobbin housing. It is a snapshot when inserting the pre-wound thread structure into the bobbin housing. It is a snapshot when inserting the pre-wound thread structure into the bobbin housing. It is a snapshot when inserting the pre-wound thread structure into the bobbin housing. It is a snapshot when inserting the pre-wound thread structure into the bobbin housing.

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

  The sewing machine 1 includes a base plate 2 having a stand 3 extending upward from the base plate, and a bending arm 4 (see FIG. 1). The arm 4 terminates at the head 5. In the arm 4, the arm shaft 6 is rotatably mounted in order to drive a crank drive 7 having a thread lever 8 by the head 5. The crank drive 7 is drivably connected to a needle bar 9 that is detachably mounted on the head 5. The needle bar 9 is provided with a sewing needle 10 at its lower end. The sewing needle 10 can be moved up and down using the crank drive 7. In this process, the sewing needle 10 passes back and forth through the operating space. The eye of the sewing needle 10 guides the upper thread 13 supplied by the spool 12 via the thread tension device and the thread lever 8.

  The support plate 16 (see FIG. 2) is attached to the base plate 2 using screws inserted through the screw holes 14 and 15, and a fabric 17 on one side is disposed on the support plate 16 (see FIG. 1). The support plate 16 has a feed dog opening 18 configured to allow the feed dog 19 to pass therethrough. The feed dog 19 has a needle hole 20 shown in FIG. 1 through which the sewing needle 10 passes. The feed dog 19 is driven by a feed / lift gear arranged below the base plate 2.

  A hook is disposed below the support plate 16, and the hook includes a hook body 22 having a hook tip 23 (see FIG. 2). The bobbin housing 25 is rotatably attached to the pot-shaped housing container 24 of the hook body 22 and stores a thread supply or a thread supply material in the form of a pre-wound thread structure 26 (FIGS. 7-10). See). In order to attach the bobbin housing 25, the hook body 22 has an outer peripheral groove (see FIG. 2), and an attachment rib 24a (see FIG. 4) of the bobbin housing 25 is accommodated in the outer peripheral groove with a certain amount of clearance. The The pre-wound thread structure 26 is also simply referred to as a bobbin. The bobbin 26 provides a bobbin thread 27. The bobbin thread 27 extends from the bobbin 26 to the outlet opening 28 (see FIG. 2) along a thread path described in detail below. The bobbin thread or hook thread 27 extends from the outlet opening 28 through the needle hole 20 and the opening 18.

  The hook body 22 is firmly connected to a shaft having a vertical axis 29 (see FIG. 1) extending parallel to the needle bar 9. This shaft is rotatably attached to a mounting block 30 that is screwed to the base plate 2. A drive shaft 31 is further attached to the mounting block 30, and the drive shaft is connected to a gear drive disposed inside the mounting block 30. The drive shaft 31 is drivably connected to the arm shaft 6 via a belt drive 32. Thus, the hook 21 is driven for rotation about the vertical axis. Therefore, the hook 21 is a vertical hook.

  The bobbin housing 25 has a housing pot 33 for receiving the bobbin 26, and the housing pot is illustrated in different views in FIGS. Further, the bobbin housing 25 has a housing cover 34 (see FIG. 3) for covering the bobbin 26. The housing cover 34 is an articulated joint that defines a slewing bearing with a horizontal pivot between the closed or operating position shown in FIG. 10 and the bobbin insertion position shown in FIGS. Is attached to the housing pot 33 in a pivotable manner.

  The inner diameter (see FIG. 4) of the bobbin receptacle or bobbin receptacle 35 of the housing pot 33 can be adjusted in a range between the minimum inner diameter ID shown in FIGS. 4 to 6 and the increased inner diameter. It is. For this purpose, the housing pot 33 has a slit 36 that extends from the housing pot side surface 37 to the bottom wall 38 of the housing pot 33. The housing pot 33 (and thus also the bottom wall 38) is circular in shape. With respect to the center 39 of the bottom wall 38, the slit 36 is seen from the bottom left side of FIG. 4 and radiates beyond the center 39 of the bottom wall 38 from the region of the bottom wall 38 that is completely divided by the slit 36. Extend in the direction. The portion of the slit 36 extending beyond the center 39 passes approximately 2/3 of the other radius of the bottom wall 38 between the center 39 and the housing pot side wall 37. At this end near the bottom wall, the slit 36 terminates at a rounded end 40. In the region of the center 39, the slit 36 passes through a circular through opening 41 which is an auxiliary mounting hole.

  The slit 36 terminates in a housing pot side surface 37 in the outer peripheral region between a housing stop 42 and the end 43 of the mounting rib 24a facing the housing stop 42.

  In the illustrated embodiment, the slit 36 has a slit width of 0.25 mm in a direction perpendicular to its radial extension. Other slit widths can be considered as well. In an alternative embodiment of the slit, the slit has practically zero width. In other words, the two walls of the bottom wall that delimit the slit abut against each other after the slit is formed. Other slit widths in the range between 0 and for example 0.5 mm can be considered as well.

  On the upward direction, in other words, on the side away from the bottom wall 38, the bobbin container 35 terminates in a conical extension 44.

  The bobbin 26 is inserted into the bobbin housing 25 as follows. In the first step, the bobbin 26 is placed and positioned on the conical extension 44 of the housing pot 33 when the housing cover 34 is opened (see FIG. 7). At that time, pressure is applied to the bobbin 26 from above in the direction of the bottom wall 38 of the bobbin housing 25 (see direction arrow 55). This pressure causes the bobbin 26 to slightly increase the inner diameter of the housing pot side 37, and thus the housing pot 33, thereby expanding the slit 36 extending to the housing pot side 37 to a corresponding extent. The resulting inner diameter of the bobbin container 35 then expands slightly relative to the minimum inner diameter ID and corresponds to the outer diameter of the bobbin 26. The bobbin 26 is now fully inserted into the housing pot 33 from above until the bobbin 26 contacts the bottom wall 38 (see FIGS. 8 and 9). The cover 34 is immediately closed (see FIG. 10).

  The housing pot 33 is made of an elastic material, and is made of metal in this embodiment. This ensures that the housing pot 33 applies a preload force to the outer peripheral wall of the bobbin 26 after expansion of the inner diameter of the bobbin container 35. This preload force is determined by the degree of expansion of the inner diameter after insertion of the bobbin 26, the length of the slit 36, and the thickness of the housing pot and the material parameters of the housing pot material. The preload force applied to the bobbin 26 by the expanded inner diameter of the housing pot provides a stable friction fit between the bobbin 26 and the housing pot 33, thus preventing rotation of the bobbin 26 relative to the housing pot 33. .

  The bobbin 26 is depleted from the inside to the outside, so that the friction fit between the outer periphery of the bobbin 26 and the inner wall of the bobbin container 35 is maintained until the bobbin 26 is virtually completely depleted.

DESCRIPTION OF SYMBOLS 1 Sewing machine 21 Hook 22 Hook body 24 Housing container 24a Mounting rib 25 Bobbin housing 26 Pre-wound thread structure 33 Housing pot 35 Bobbin container 36 Slit 37 Housing pot side surface 38 Bottom wall 39 Center 42 Housing stopper 43 End 44 Expansion Part

Claims (10)

In a bobbin housing (25) comprising a housing pot (33) for receiving a pre-wound thread structure (26),
Bobbin housing, characterized in that the inner diameter of the bobbin container (35) of the housing pot (33) is adjustable in a range between the minimum inner diameter (ID) and the increased inner diameter.   The bobbin housing according to claim 1, wherein the bobbin container (35) is preloaded by the preload means in a state of a minimum inner diameter (ID).   The housing pot (33) is provided with a slit (36) extending from the housing pot side (37) to the bottom wall (38) of the housing pot (33). Bobbin housing.   4. Bobbin housing according to claim 3, characterized in that the bottom wall (38) is circular and the slit (36) extends radially.   Bobbin housing according to claim 3 or 4, characterized in that the slit (36) extends beyond the center (39) of the bottom wall (38).   A slit (36) on the housing pot side surface (37) is formed between the end (43) of the mounting rib (24b) for attaching the housing pot (33) to the housing container (24) and the housing stopper (42). The bobbin housing according to any one of claims 3 to 5, wherein the bobbin housing terminates in an outer peripheral region therebetween.   The bobbin housing according to any one of claims 3 to 6, characterized in that the slit (36) has a slit width in the range between 0 and 0.5 mm.   The housing pot side (37) defining the outer periphery of the bobbin container (35) has a conical extension (44) on the side away from the bottom wall (38) of the housing pot (33). The bobbin housing as described in any one of -7.   A hook (21) comprising a hook body (22) and a bobbin housing (25) according to any one of claims 1-8.   Sewing machine (1) comprising a hook (21) according to claim 9.

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