JP2013034493A - Sewing machine shuttle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sewing machine shuttle capable of easily separating a needle thread from a shuttle stopper without relation to the thickness of thread when sewing.SOLUTION: A sewing machine shuttle comprises a shuttle stopper 40 having a groove 44 extending in a radial direction about an axis. The groove 44 is defined with a lower wall part 41 and an upper wall part 42 both defining a side wall; and a bottom wall part 43 defining a bottom wall. The groove 44 allows the insertion of a tip of a shuttle stopper piece 7, which stops the rotation of the inner shuttle according to a shuttle race cover. The bottom wall part 43 has a notched part 45. When sewing, a needle thread 8 passes through a gap between a tip of the shuttle stopper piece 7 and a wall surface of the bottom wall part 43. Since the needle thread 8 moves back to the notched part 45, the needle thread is not caught at the gap and therefore not subjected to stresses such as winding and stretching, and the needle thread is easily separated from the shuttle stopper 40.

Description

  The present invention relates to a shuttle used for a sewing machine.

  Conventionally, a sewing machine is provided with a hook below the needle plate. The hook includes an outer hook that rotates integrally with the shaft according to the vertical movement of the sewing needle, and an inner hook that is supported by the outer hook and that can rotate independently of the outer hook. The inner hook is provided with a hook stopper portion, which engages with a hook stopper provided in the sewing machine, on the outer peripheral portion. The hook stop piece stops the inner hook so that the inner hook does not rotate following the outer hook. The sewing machine uses the outer hook to catch the upper thread that has passed through the cloth with the sewing needle, and sews the upper thread on the lower thread that is held by the inner hook in the stopped state.

  The hook stopper has two side walls that can be brought into contact with the hook stopper on both sides in the rotational direction of the outer hook, and a bottom wall that makes it easier for the outer hook to catch the upper thread loop formed by the sewing needle. For example, see Patent Document 1). The hook stop piece protrudes into the groove formed by the side wall portion and the bottom wall portion to stop the driven rotation of the inner hook. When sewing, the outer hook guides the upper thread so as to surround the lower thread located in the groove of the inner hook stopper, and entangles the upper thread and the lower thread. When the balance of the sewing machine pulls up the upper thread, the upper thread passes through the gap between the tip of the hook stopper and the bottom wall in the groove and is released from the hook, and the entangled lower thread is guided to the cloth to sew the cloth.

Utility Model Registration No. 2590041

  When sewing with a thicker thread than before, the resistance applied to the upper thread increases when the upper thread passes through the gap between the tip and bottom wall of the hook stopper, and the upper thread bends or stretches. The tone may not be stable.

  An object of the present invention is to provide a sewing machine hook in which the upper thread can be easily detached from the hook stopper regardless of the thickness of the thread when sewing.

  The sewing machine hook according to the present invention is supported by a shaft provided below the needle plate of the sewing machine, and an outer hook that rotates integrally with the shaft in accordance with the vertical movement of the sewing needle, and is supported by the outer hook and the outer hook. An inner hook that is rotatable independently of the hook, and that has a hook stopper portion that engages with a hook stopper piece attached to the sewing machine, and the rotation of the outer hook is restrained by the hook stopper piece; Is provided. In the hook for a sewing machine, the hook stopper is provided on the downstream side in the rotation direction when the outer hook rotates in the forward direction, and a lower wall portion provided at a position facing the hook stopper, and the rotation of the outer hook. An upper wall provided at a position facing the hook stopper on the upstream side in the direction, and a wall between the lower wall and the upper wall connected by a wall surface along the rotational direction to connect the lower wall and the upper A bottom wall part that forms a groove with which the hook stop piece engages with the wall part, and is formed with a notch part in which at least a part of the outer peripheral edge with respect to the shaft is cut out toward the inner peripheral side; Is provided.

  The sewing machine hook of the present invention draws the upper thread entangled with the lower thread from the hook to the needle plate, so that when the upper thread passes through the gap between the hook stop piece and the groove, the upper thread is in the notch formed on the bottom wall. Can be evacuated. Therefore, the upper thread can be easily detached from the hook stopper without being caught in the gap and causing stress such as bending and pulling.

  In the sewing machine shuttle, the width in the rotation direction of the bottom wall portion in the portion where the notch portion is formed may be larger on the inner peripheral side with respect to the shaft than on the outer peripheral side. When the sewing machine scale pulls the upper thread onto the needle plate during sewing, the upper thread is likely to enter the notch because the notch is wider toward the outer periphery. The notch guides the entered upper thread along the edge to the inner circumferential end. Therefore, the upper thread can enter the notch at the innermost end, so that it can be reliably retracted to the notch when passing through the gap between the tip of the hook stopper and the wall of the bottom wall in the groove. . Therefore, the upper thread can be easily detached from the hook stopper without being caught in the gap and causing stress such as bending and pulling. Further, since the bottom wall portion is wider toward the inner peripheral side, sufficient rigidity can be secured even if the notch portion is formed.

  In the sewing machine shuttle, the notch portion may be formed in the bottom wall portion at a position shifted from a position where the tip end portion of the sewing needle faces the bottom wall portion when the sewing needle moves up and down. The wall surface of the bottom wall portion exists at a position overlapping with the trajectory of the vertical movement of the sewing needle. When the sewing needle moves downward, the tip end portion of the sewing needle surely faces the wall surface of the bottom wall portion. Therefore, the bottom wall portion can function reliably as a wall surface for positioning the upper thread so that the sword tip of the outer hook catches the upper thread during sewing.

  In the sewing machine shuttle, the notch portion may be formed on the bottom wall portion closer to the upper wall portion than the lower wall portion. The upper thread is close to a position near the upper wall portion on the upstream side in the rotation direction at the hook stop portion by the guidance of the outer hook during sewing. Therefore, when the upper thread passes through the gap between the front end of the hook stopper piece and the wall surface of the bottom wall portion in the groove, it can be surely retracted to the notch portion. Therefore, the upper thread can be easily detached from the hook stopper without being caught in the gap and causing stress such as bending and pulling.

  In the sewing machine shuttle, an inner side chamfering may be applied to an inner peripheral end portion of the notch portion with respect to the shaft, and a chamfering radius of the end portion may be larger than a radius of a thick thread used in the sewing machine. Even if the upper thread enters the notch during sewing, the chamfer radius at the end of the notch is larger than the radius of the upper thread, so that the upper thread does not get caught in the notch. Therefore, the resistance that the upper thread receives from the notch due to contact with the notch is smaller than that when the upper thread does not have a smooth contour shape. Therefore, the upper thread does not cause stress such as bending and rubbing at the edge portion of the notch, and can be easily detached from the hook stopper.

The figure which shows the hook 10 vicinity of a sewing machine. The front view of the inner pot 30. FIG. The enlarged view of the hook stop part 40 which looked at the inside of the virtual circle B of FIG. The enlarged view of the hook stop part 40 which looked at the inside of the virtual circle B of FIG. 2 from the front. The enlarged view of the hook stop part 40 cut | disconnected by the dashed-dotted line DD of FIG.

  Hereinafter, an embodiment of a sewing machine hook according to the present invention will be described with reference to the drawings. The schematic configuration of the shuttle 10 will be described with reference to FIG. As is well known, a hook 10 of a sewing machine (not shown) shown in FIG. 1 is positioned below a needle plate 2 provided in a bed portion (not shown) serving as a base of the sewing machine. The hook 10 is a vertical full rotation hook used for an industrial sewing machine as an example. The bed portion has a lower shaft (not shown) that rotates in synchronization with an upper shaft (not shown) of the sewing machine, and a shuttle shaft 3 that is linked to the lower shaft via a gear. The hook shaft 3 rotatably supports the hook 10. In the following description, the front and back direction of the paper is the axial direction of the hook shaft 3 that supports the hook 10, and the front side of the paper is the front side of the hook 10. Also, the right hand side of the page is the front side of the sewing machine, and the left hand side is the rear side of the sewing machine.

  The hook 10 includes an outer pot 20 and an inner pot 30. The outer hook 20 is connected to the hook shaft 3 and is a rotating body that rotates integrally with the hook shaft 3. The outer hook 20 rotates in synchronization with the sewing needle 1 which performs vertical movement along the alternate long and short dash line A on the needle plate 2 in synchronization with the upper shaft. The outer hook 20 of the present embodiment rotates in the counterclockwise rotation direction indicated by an arrow C when viewed from the front. The outer pot 20 has a bottomed cylindrical shape with the front side of the pot 10 being the open side. The outer hook 20 has a groove-shaped groove portion 21 that makes one round in the circumferential direction on the inner peripheral side wall. The outer hook 20 is provided with a sword tip 22 extending along the circumferential direction at its outer peripheral portion and having its tip directed forward, that is, downstream in the rotational direction C. When the sewing needle 1 moves downward, the tip of the sewing needle 1 passes through the needle through hole 5 opened in the needle plate 2 and enters the hook 10. The vertical movement of the sewing needle 1 and the rotation of the outer hook 20 are both synchronized with the upper shaft. Therefore, the outer hook 20 rotates so as to arrange the sword tip 22 at a position that does not interfere with the tip of the sewing needle 1 when the sewing needle 1 moves downward.

  The inner hook 30 is a rotating body that fits on the inner periphery of the outer hook 20 while being rotatable independently of the outer hook 20. As shown in FIG. 2, the inner hook 30 has a bottomed cylindrical shape with the front side of the hook 10 as an opening side, like the outer hook 20. The inner hook 30 has a hook-shaped hook portion 31 that substantially makes a round along the circumferential direction on the side wall on the outer peripheral side. The hook portion 31 engages with the groove portion 21 of the outer hook 20 when the inner hook 30 is fitted to the inner periphery of the outer hook 20 to prevent the inner hook 30 from coming off. The groove portion 21 guides the flange portion 31 when the inner hook 30 rotates with respect to the outer hook 20. Therefore, the inner hook 30 rotates coaxially with the outer hook 20 independently.

  The inner hook 30 includes a bobbin shaft 33 protruding at the center of the cylinder bottom 32. The inner hook 30 has a bobbin case 4 (see FIG. 1) that houses a bobbin (not shown) around which the lower thread 9 (see FIG. 4) is wound detachably attached to the inner periphery. The bobbin shaft 33 rotatably supports the bobbin in the bobbin case 4 so that the lower thread 9 can be pulled out from the bobbin according to sewing.

  The inner hook 30 further includes a hook stopper 40 on the outer peripheral portion. As shown in FIGS. 3 and 4, the hook stopper 40 has a groove 44 extending in the radial direction with respect to the hook shaft 3. The hook stopper 7 is inserted into the groove 44 at its tip. The hook stopper 7 is fixed at the rear end side to the needle plate 2 (see FIG. 1) or the bed portion, and the tip is engaged with the groove 44, so that the inner hook 30 is driven by the outer hook 20 and rotates. Stop.

  The groove 44 includes a lower wall portion 41, an upper wall portion 42, and a bottom wall portion 43. The lower wall portion 41 is located on the downstream side in the rotation direction C of the outer hook 20 and constitutes one side wall of the groove 44. The lower wall portion 41 faces the tip end of the hook stopper piece 7 in the circumferential direction. The upper wall portion 42 is located on the upstream side in the rotation direction C and constitutes the other side wall of the groove 44. Similarly, the upper wall portion 42 faces the distal end of the hook stopper piece 7 in the circumferential direction. The bottom wall 43 has a wall surface along the circumferential direction and constitutes the bottom wall of the groove 44. The bottom wall portion 43 faces the front end of the hook stopper piece 7 in the axial direction of the hook shaft 3.

  The lower wall portion 41 has a lower thread passage 46 in which the wall surface of the bottom wall portion 43 is one side wall and the wall surface of the lower wall portion 41 is dug into a groove shape. The lower thread passage 46 functions as a passage for arranging the lower thread 9 pulled out from the bobbin and guiding it above the shuttle 10. The upper thread 8 entangles the lower thread 9 positioned in the lower thread passage 46 during sewing. The upper thread 8 raises the lower thread 9 to the position of the cloth 6 to be placed on the needle plate 2 through the needle through hole 5 to form a seam.

  The hook stopper 40 has a notch 45 formed by notching a part of the bottom wall 43 in the bottom wall 43. The notch 45 is formed by notching at least a part of the outer edge 48 of the bottom wall 43 toward the inner periphery with respect to the shaft of the shuttle shaft 3. The bottom wall portion 43 of the present embodiment is cut out with a substantially two thirds of the width of the edge 48 as a cutout portion 45. The bottom wall portion 43 is sufficiently rigid even when the notch portion 45 is formed by ensuring the width in the circumferential direction of the bottom wall portion 43 toward the inner peripheral side when forming the notch portion 45 in the bottom wall portion 43. Can be secured. Moreover, the bottom wall part 43 was able to leave the remaining part of a wall surface without notching by forming the notch part 45 in a part of wall surface. Therefore, the bottom wall portion 43 can secure a wall surface facing a distal end portion of the sewing needle 1 described later.

  As shown in FIG. 4, the width in the circumferential direction of the bottom wall 43 in the portion where the notch 45 is formed is larger in the width F on the inner peripheral side than the shaft E of the hook shaft 3 compared to the width E on the outer peripheral side. The notch 45 is a part formed by notching the bottom wall 43 wider toward the outer peripheral side when the bottom wall 43 is notched toward the inner peripheral side from the edge 48. In other words, the width of the notch 45 gradually decreases from the outer peripheral side to the inner peripheral side with respect to the shaft of the shuttle shaft 3. When the sewing machine balance (not shown) pulls the upper thread 8 onto the needle plate 2 during sewing, the upper thread 8 is likely to enter the notch 45 because the notch 45 is wider toward the outer peripheral side. The notch portion 45 guides the upper thread 8 that has entered into the end portion 49 on the inner peripheral side along the edge. Therefore, the upper thread 8 can enter the notch 45 at the end 49 located on the innermost peripheral side. Therefore, when the upper thread 8 passes through the gap between the tip of the hook stopper 7 and the wall surface of the bottom wall 43 in the groove 44, the notch The part 45 can be securely retracted. Therefore, the upper thread 8 can be easily detached from the hook stopper 40 without being caught in the gap and causing stress such as bending and pulling.

  The notch 45 has a smooth contour shape by chamfering the inner surface of the inner peripheral end 49 with respect to the shaft of the shuttle shaft 3. The chamfer radius R of the inner chamfer is larger than the radius P of the cross section G of the upper thread 8. Therefore, the upper thread 8 is not caught in the notch 45 even if the upper thread 8 enters the notch 45 during sewing. The chamfer radius R is preferably larger than the radius of the thick thread used for the sewing machine. Since the upper thread 8 has a radius P smaller than the chamfer radius R of the notch 45, the resistance received from the edge portion of the notch 45 due to contact with the notch 45 is smaller than that of the chamfer radius R or more. Therefore, the upper thread 8 can be easily detached from the hook stopper 40 without causing stress such as bending and rubbing at the edge of the notch 45.

  When the sewing needle 1 (see FIG. 1) moving up and down along the alternate long and short dash line A moves downward, it carries the upper thread 8 to the needle hole 47 (see FIG. 3) provided in the back side of the hook stopper 40 of the inner hook 30. When moving upward, the upper thread 8 is left near the needle hole 47. As shown in FIG. 3, the bottom wall 43 is located on the front side of the hook 10 with respect to the needle hole 47. The bottom wall portion 43 functions as a wall surface for positioning so that the upper thread 8 remaining in the vicinity of the needle hole 47 does not protrude to the front side with respect to the bottom wall portion 43.

  As shown in FIG. 4, the notch 45 does not overlap with the alternate long and short dash line A corresponding to the trajectory of the sewing needle 1, and exists in the bottom wall 43 while being displaced in the circumferential direction. In other words, the wall surface of the bottom wall portion 43 exists at a position overlapping the position of the alternate long and short dash line A in the axial direction of the shuttle shaft 3. Therefore, the tip end portion of the sewing needle 1 reliably faces the wall surface of the bottom wall portion 43 when the sewing needle 1 moves downward. Further, the notch 45 exists in the bottom wall 43 at a position close to the upstream side in the rotation direction C of the outer hook 20. In other words, the bottom wall 43 has the notch 45 on the side closer to the upper wall 42 than the lower wall 41. Therefore, the bottom wall portion 43 can function reliably as a wall surface for positioning the upper thread 8 as described above. The locus of the sewing needle 1 may overlap with the notch 45 on the edge 48 side of the bottom wall 43. However, the bottom wall 43 can have a wall surface that faces the tip of the sewing needle 1 if the end 49 side of the notch 45 is not positioned so as to overlap the locus of the sewing needle 1 and is displaced.

  When the sewing machine balance (not shown) pulls the upper thread 8 onto the needle plate 2 during sewing, the upper thread 8 is entangled with the lower thread 9 and the tip of the hook stopper 7 located in the groove 44 of the hook stopper 40. And through the gap between the wall surfaces of the bottom wall 43. Since the upper thread 8 entangles the lower thread 9 with the rotation of the outer hook 20, the upper thread 8 is positioned at a position near the upper wall part 42 on the upstream side in the rotation direction C at the hook stopper 40 by the guidance of the outer hook 20. It is close. As shown in FIGS. 4 and 5, the upper thread 8 can be retracted into the notch 45 when passing through the gap between the tip of the hook stopper 7 and the wall surface of the bottom wall 43.

  The upper thread 8 can reduce the stress received when the bottom wall 43 has the notch 45 and passes through the gap between the tip of the hook stopper 7 and the wall surface of the bottom wall 43 during sewing. The sewing machine of the present embodiment does not cause stress such as bending and pulling due to the sewing thread being caught in the gap, even when a thicker thread is used as the sewing thread, compared with the conventional one, and the hook stopper 40 is easily provided. You can leave. Therefore, the user can save the trouble of changing to the hook according to the thickness of the thread. The conventional sewing machine does not have the notch portion 45 in the bottom wall portion 43, and uses, for example, No. 50-60 as the thickness of the sewing thread. The sewing machine of this embodiment can use the thing of No. 8, for example as thickness of a sewing thread by providing the notch part 45 in the bottom wall part 43. FIG. The chamfer radius R of the notch 45 described above is preferably larger than that of a conventional sewing thread, for example, larger than the radius P of the thick thread No. 8.

  The operation of the shuttle 10 at the time of sewing of the sewing machine including the shuttle 10 having the above configuration will be briefly described. As shown in FIG. 1, the sewing needle 1 is moved up and down by following an upper shaft (not shown), and the hook 10 is rotated counterclockwise by the outer hook 20 being driven by the hook shaft 3. The upper shaft is directly connected to a sewing machine motor (not shown) and driven, and the shuttle shaft 3 is driven in synchronization with the upper shaft via the lower shaft (not shown) as described above. The inner hook 30 does not follow even if the outer hook 20 rotates because the tip of the hook stopper 7 whose rear end is fixed to the throat plate 2 or the bed is engaged with the groove 44 of the hook stopper 40. Stop.

  When the sewing needle 1 moves downward, the sewing needle 1 penetrates the cloth 6 and enters the hook 10 through the needle through hole 5 of the needle plate 2. The sewing needle 1 reaches the needle hole 47 on the back side of the hook stopper 40 of the inner hook 30 and carries the upper thread 8 passed through the thread hole provided at the tip to the back side of the hook stopper 40. When the sewing needle 1 moves upward, the upper thread 8 does not move upward together with the sewing needle 1 due to frictional resistance with the cloth 6, remains in the vicinity of the needle hole 47, and sags to form a loop. Since the loop of the upper thread 8 does not overlap with the notch 45 as described above, the loop of the upper thread 8 abuts against the wall surface of the bottom wall 43 on the back side of the hook stopper 40 and is on the rear side with respect to the hook stopper 40. To spread.

  The sword tip 22 of the outer hook 20 captures the loop of the upper thread 8 on the back side of the hook stopper 40 as the outer hook 20 rotates. The upper thread 8 captured by the sword tip 22 forms a new loop on the front side of the hook 10 along a guide groove (not shown) on the outer periphery of the outer hook 20 as the outer hook 20 further rotates. The new loop of the upper thread 8 surrounds the outer periphery of the lower thread 9 drawn out from the bobbin (not shown) in the bobbin case 4 attached to the inner hook 30. The upper thread 8 is guided to the outer hook 20 and approaches the side close to the upper wall 42 in the groove 44 of the hook stopper 40 of the inner hook 30.

  A balance (not shown) pulls the upper thread 8 onto the needle plate 2. The upper thread 8 passes through the gap between the front end of the hook stopper 7 and the wall surface of the bottom wall portion 43 to reduce the loop formed on the front side of the hook 10. As shown in FIG. 5, the upper thread 8 can be retracted to the notch 45 of the bottom wall 43 without forcibly passing the gap even if the gap between the hook stopper 7 and the bottom wall 43 is narrow. Therefore, the upper thread 8 does not cause stress such as bending and pulling. The notch 45 has a smooth contour line shape with a chamfered inner surface. Therefore, when the upper thread 8 is retracted into the notch 45, even if it comes into contact with the notch 45, the contact resistance is relatively small and no stress is caused. The balance further pulls up the upper thread 8. The upper thread 8 winds the lower thread 9 around the loop that has become smaller. Similarly, the lower thread 9 is also retracted to the notch 45, and the clearance between the hook stopper 7 and the bottom wall 43 is removed without stress. The lower thread 9 passes through the needle passage hole 5 and reaches the cloth 6, and forms a seam on the cloth 6 together with the upper thread 8.

  The present invention is not limited to the above embodiment. The present invention can be variously modified. Although the notch 45 is formed by notching the bottom wall 43, the bottom wall 43 may be provided with a recess or a groove that does not penetrate the wall so that the upper thread 8 can be retracted. The cutout 45 may be chamfered at the corner of the edge portion. In the present embodiment, the shape of the notch 45 is tapered from the outer peripheral side to the inner peripheral side, but the bottom wall 43 may be cut into a square, for example. The cutout 45 is cut out from at least a part of the edge 48 on the outer peripheral side of the bottom wall 43, but may be formed by cutting out the whole. Even when the bottom wall portion 43 is formed by cutting out the entire edge 48 to form the cutout portion 45, it is only necessary to secure a wall surface that faces the tip portion of the sewing needle 1 when the sewing needle 1 moves downward.

DESCRIPTION OF SYMBOLS 1 Sewing needle 2 Needle plate 3 Hook shaft 7 Hook stop piece 8 Upper thread 9 Lower thread 10 Hook 20 Outer hook 21 Groove part 30 Inner hook 40 Hook part 41 Lower wall part 42 Upper wall part 43 Bottom wall part 44 Groove 45 Notch part 48 Edge 49 Edge

Claims (5)

An outer hook supported by a shaft provided under the needle plate of the sewing machine and rotating integrally with the shaft according to the vertical movement of the sewing needle, and supported by the outer hook and rotatable independently of the outer hook. And a hook for a sewing machine having a hook stop portion to which a hook stopper piece attached to the sewing machine is engaged, and an inner hook whose rotation to be driven by the outer hook is restricted by the hook stopper piece,
The hook stop is
A lower wall portion provided at a position facing the hook stopper on the downstream side in the rotation direction when the outer hook rotates in the forward direction;
An upper wall portion provided at a position facing the hook stopper on the upstream side in the rotational direction of the outer hook;
The lower wall portion and the upper wall portion are connected by a wall surface along the rotational direction to form a groove with which the hook stopper piece engages with the lower wall portion and the upper wall portion, and with respect to the shaft A sewing machine hook comprising: a bottom wall portion having a notch portion formed by notching at least a part of an outer peripheral edge toward an inner periphery side.   2. The sewing machine hook according to claim 1, wherein a width in the rotation direction of the bottom wall portion in a portion where the notch portion is formed is larger on an inner peripheral side than the outer peripheral side with respect to the shaft.   The cutout portion is formed in the bottom wall portion at a position shifted from a position where the tip of the sewing needle faces the bottom wall portion when the sewing needle moves up and down. The sewing machine pot as described in 1.   The sewing machine hook according to any one of claims 1 to 3, wherein the notch portion is formed on the bottom wall portion closer to the upper wall portion than the lower wall portion.   5. An inner side chamfer is applied to an inner peripheral end of the notch with respect to the shaft, and a chamfer radius of the end is larger than a radius of a thick thread used in the sewing machine. The sewing machine pot according to any one of the above.

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