JP6069264B2 - Sewing machine rotary hook - Google Patents

Description

  The present invention relates to a rotary hook in a sewing machine.

  Conventionally, as this type of rotary hook, the inner hook is accommodated in the outer hook, the bobbin case is accommodated in the inner hook, and a rail groove is formed in the inner peripheral portion of the outer hook. A rail (for example, Patent Document 1 and Patent Document 2) in which a rail to be fitted is formed on an outer peripheral portion of the inner hook and a thread dividing portion is provided at an end of the rail is known.

  The outer hook has an outer hook sword tip that scoops the slack of the upper thread that occurs during the ascent process of the sewing needle, rotates around the fixed inner hook, and the sewing needle that pierces the fabric rises from the bottom dead center. When the upper thread begins to sag, the outer hook sword scoops and catches the upper thread sag. The captured upper thread is divided into an upper thread on the front side of the inner hook and an upper thread on the rear side at the thread dividing section (also referred to as the inner hook point), and the upper thread on the rear side is accompanied by the rotation of the outer hook. Move while touching the back of the bottom of the inner hook. Eventually, the upper thread comes off the thread dropout part, comes out of the hook, and entangles with the lower thread (not shown) to form a seam.

  In the full rotary hook having the above-described structure, the upper thread caught by the outer hook sword tip during sewing has its characteristics, i.e., the difference in the friction coefficient of the upper thread, the timing shift due to the diversification of elasticity, etc. For this reason, when the thread dividing portion cannot catch the upper thread, the upper thread enters between the sliding surfaces, i.e., the rail and the rail groove, so that the so-called thread biting occurs and the outer hook cannot rotate or the inner hook Sewing is impossible due to destruction.

  In order to prevent this, the rail is provided with 2 to 5 rail-side thread cutting grooves (cut grooves) from a position about 30 degrees away from the thread dividing portion at the tip (for example, Patent Document 3), When entering the sliding surface, the upper thread is cut by the rail-side thread cutting groove to prevent the outer hook from rotating, but depending on the conditions, the upper thread is cut by the rail-side thread cutting groove. In some cases, thread biting may occur.

Japanese Patent Laid-Open No. 2000-300883 JP 2001-204982 A Japanese Utility Model Publication No. 6-41683

  In view of the above-described problems, an object of the present invention is to provide a rotary hook for a sewing machine that can reliably cut an upper thread that has entered between a rail and a rail.

  In order to achieve the above object, the invention according to claim 1 is characterized in that an inner hook is accommodated in an outer hook, a rail groove is formed in an inner peripheral portion of the outer hook, and a rail fitted into the rail groove is provided. In the rotary hook of the sewing machine formed on the outer peripheral portion of the inner hook and having a thread dividing portion at the end of the rail, a rail-side thread cutting groove is formed on the outer peripheral surface of the rail, and the rail groove side is formed on the rail groove. A thread cutting groove is provided.

  The invention according to claim 2 is characterized in that a plurality of the rail side thread cutting grooves and the rail side thread cutting grooves are formed.

  According to the configuration of the first aspect of the present invention, the rail-side thread cutting groove cuts the upper thread fitted in the rail-side thread cutting groove and the upper thread other than the rail-side thread cutting groove, whereby the rail and the rail are cut. The upper thread that has entered between the grooves can be cut.

  Moreover, according to the structure of Claim 2 of this invention, it cut | disconnects so that an upper thread | yarn may be gradually narrowed by a some rail groove side thread cutting groove, and the upper thread of places other than a rail side thread cutting groove Can be fed to the adjacent rail-side yarn cutting groove by the rail-side yarn cutting groove, and the upper yarn can be cut in the rail-side yarn cutting groove.

It is a longitudinal cross-sectional view of the rotary hook which shows Example 1 of this invention. FIG. 3 is a cross-sectional view around the inner hook presser of the rotary hook. It is a side view of an inner hook same as the above. FIG. 3 is an enlarged side view of the yarn dividing unit. It is an AA line arrow line view of FIG. 4 same as the above. It is sectional drawing of the principal part of an outer hook same as the above. FIG. 3 is a side view of the inner hook presser as seen from the base end side of the rotary hook. It is sectional drawing of an inner hook presser same as the above. It is a perspective view of a rail groove side thread cutting groove same as the above. It is a side view of a rotary hook same as the above. It is a top view of a rotary hook same as the above. It is a perspective view of an inner hook same as the above. It is a perspective view of a bobbin case and a bobbin. It is sectional drawing of the principal part of the outer hook which shows Example 2 of this invention. It is sectional drawing of the principal part of the outer hook which shows Example 3 of this invention. It is a perspective view of a rail groove side thread cutting groove same as the above. It is sectional drawing of the rotary hook which shows Example 4 of this invention. It is an expanded sectional view of the principal part same as the above. It is a top view of the inner hook which made a part a cross section same as the above. It is a top view of a rotary hook same as the above.

  Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The embodiments described below do not limit the contents of the present invention described in the claims. In addition, all of the configurations described below are not necessarily essential requirements of the present invention. In each embodiment, an unprecedented rotary hook is obtained by adopting a new rotary hook different from the conventional one, and the rotary hook will be described.

  Hereinafter, Embodiment 1 of the rotary hook of the present invention will be described with reference to the drawings.

  As shown in FIGS. 1 to 13, the rotary hook 1 of the present embodiment is a full-rotation vertical rotary hook, and an inner hook 3 is rotatably housed in an outer hook 2 that is rotationally driven. The hook 2 has a hook shape, and a connection fixing portion 4 is provided on the base end side of the outer hook 2, and a rotation drive shaft (not shown) is fixedly fitted to the connection fixing portion 4. A shaft hole 5 to be joined is formed. In addition, a storage recess 7 is formed on the distal end side of the outer hook 2 and is enclosed by the outer peripheral wall portion 6 and stores the inner hook 3. The inner peripheral surface of the outer peripheral wall portion 6 has the inner pot 3 is formed with a rail groove 9 that fits with the rail 8 formed on the outer peripheral portion of the rail. Further, in the outer hook 2, a bottom surface portion 10 is provided on the distal end side of the connection fixing portion 4, and the base end side of the outer peripheral wall portion 6 is fixed to the bottom surface portion 10. An opening 10A that opens in the axial direction is provided. Further, the outer hook 2 is provided with an outer hook sword tip 11. In the following description, the upper and lower sides in the state of FIGS. 2 and 6 will be described as the upper side and the lower side.

  As shown in FIG. 12 and the like, the inner hook 3 has a hook shape, and the rail 8 protrudes from the outer peripheral surface 32 of the outer peripheral wall portion 31 along the circumferential direction. The inner hook 3 is accommodated in the outer hook 2 so that the inner hook 3 is not dropped by the inner hook presser 12 screwed to the outer hook 2 with the rail 8 fitted in the rail groove 9 of the outer hook 2. Has been. Thereby, the outer hook 2 and the inner hook 3 are connected rotatably.

  As shown in FIG. 3, a thread separating portion 13 is provided at one end of the rail 8, and a yarn removal portion 23 is provided at the other end. The thread dividing portion 13 is provided on the side opposite to the rotation direction R of the outer hook 2 (on the side opposite to the rotation direction). In the side view of FIG. It is formed obliquely so as to be on the rotation direction side.

  3, a plurality of rail side thread cutting grooves 14, 14... Are provided on the outer peripheral surface 8G of the rail 8 at substantially equal intervals in the circumferential direction. Further, as shown in FIG. 5, the rail side thread cutting groove 14 is obliquely provided in the thickness direction of the rail 8, and specifically, the upper side is one end side and the lower side is the other end side. It is formed obliquely and the inclination angle θ is 30 to 60 degrees, preferably 40 to 50 degrees. The inclination angle θ is an angle with respect to the thickness center of the rail side thread cutting groove 14.

  Further, the one side surface portion 15 and the other side surface portion 16 of the rail side thread cutting groove 14 are formed in parallel, and the bottom surface portion 17 is provided at the inner ends of the one side surface portion 15 and the other side surface portion 16, and the rail side thread cutting groove 14 is formed such that its circumferential dimension L is larger than its depth W. Furthermore, the upper edge portions 15A and 16A and the lower edge portions 15B and 16B of the one side surface portion 15 and the other side surface portion 16 are formed in a substantially radial direction of the inner hook 3. Actually, the upper edge portion 16A and the lower edge portion 15B are formed in the radial direction of the inner hook 3, and the upper edge portion 15A and the lower edge portion 16B are formed in parallel to the upper edge portion 16A and the lower edge portion 15B. ing. The upper edge portions 15A and 16A and the lower edge portions 15B and 16B are located on the upper surface portion 8U and the lower surface portion 8S of the rail 8.

  Further, in the thickness direction of the rail 8, the yarn dividing portion 13 connects the tips of the oblique lower surface portion 13S and the oblique upper surface portion 13U by the curved surface portion 13W, and the angle θ1 of the oblique lower surface portion 13S is the inclination angle θ The oblique upper surface portion 13U is smaller in angle than the oblique lower surface portion 13S.

  Further, as shown in FIG. 2, one side surface portion 18 and the other side surface portion 19 of the rail groove 9 are formed in parallel, and a bottom surface portion 20 is provided at the outer ends of the one side surface portion 18 and the other side surface portion 19. Yes. The one side surface portion 18 and the other side surface portion 19 are provided substantially orthogonal to the inner peripheral surface of the outer hook 2, and the bottom surface portion 20 is provided parallel to the inner peripheral surface of the outer hook 2.

  As shown in FIG. 2, the inner hook retainer 12 integrally includes a cylindrical portion 21 that is fixed to the outer peripheral surface 32 of the outer hook 2 and an inner flange portion 22 provided on the upper portion of the cylindrical portion 21. The one side surface portion 18 is constituted by the lower surface of the inner flange portion 22. Further, the other side surface portion 19 and the bottom surface portion 20 are formed in the outer hook 2 corresponding to the mounting location of the inner hook presser 12, and by fixing the inner hook presser 12 to the outer hook 2, FIG. As shown in FIG. The rail 8 and the rail groove 9 are formed over two thirds or more of the inner peripheral portion of the inner hook 3 and the outer peripheral portion of the outer hook 2.

  Further, as shown in FIGS. 2, 6 and 7, etc., the rail groove 9 is provided with a rail groove side yarn cutting groove 24 on each of the one side surface portion 18 and the other side surface portion 19, respectively. A plurality of cutting grooves 24 are formed at equal intervals. Further, the rail groove side thread cutting groove 24 has a front side edge 25 and a rear side edge 25A on one side surface 18 and the other side surface 19, and the front side edge 25 and the rear side edge 25A are the inner side. It intersects acutely at the end 24N. In the drawing, the front edge 25 and the rear edge 25A form 45 degrees. Further, the rear edge 25A forms the radial direction of the outer hook 2. Further, as shown in FIGS. 2 and 9, the inner end 24 </ b> N of the rail groove side thread cutting groove 24 is positioned outside the bottom surface portion 17 of the rail side thread cutting groove 14.

  Further, as shown in FIG. 8, the rail groove side thread cutting groove 24 has a front edge portion 26 and a rear edge portion 26A on the inner peripheral surface of the outer hook 2 and the inner peripheral surface 22F of the inner collar portion 22. The front edge 26 and the rear edge 26A intersect at an acute angle. In the drawing, the front edge 26 and the rear edge 26A form 45 degrees. Further, the rear edge 25A forms the vertical direction (center axis direction) of the outer hook 2. The front edge portions 25 and 26 are continuous with each other at the intersection angle portion 27 of the inner peripheral surface of the outer hook 2 and the one side surface portion 18 and at the intersection corner portion 27 of the inner peripheral surface of the outer hook 2 and the other side surface portion 19. The rear edge portions 25A and 26A are continuous with each other. The rail side thread cutting groove 14 and the rail groove side thread cutting groove 24 are set to have a larger interval adjacent in the circumferential direction than the width. As shown in FIGS. 2 and 8, the inner peripheral surface 22F is formed with a flat portion 29 having no rail groove side thread cutting groove 24, and the flat portion 29 has a substantially cylindrical surface shape. By leaving the flat portion 29 in this way, there is no acute angle portion on the inner peripheral surface 22F, so that the yarn is not cut by the inner peripheral surface 22F.

  Further, a needle drop hole 33 is formed in the inner hook 3 so as to be positioned on the movement locus of the outer hook sword tip 11 formed in the outer hook 2. The needle drop hole 33 is a hole for allowing the tip of a sewing needle (not shown) that moves up and down to enter, and is formed so as to penetrate the outer peripheral wall 31 of the inner hook 3 from the outer peripheral surface 32 to the inner peripheral surface. Has been.

  Further, the inner hook 3 is formed in the vicinity of the needle drop hole 33, and a non-rotating groove 34 is formed on the tip surface thereof. The anti-rotation groove 34 is for engaging with an inner hook stopper (not shown) provided on the sewing machine side to prevent the inner hook 3 from rotating.

  The inner hook 3 has a plate-like bottom surface portion 36 formed in a bridge shape on the proximal end side, and openings 36A and 36A are provided on both sides of the bottom surface portion 36, and both sides of the bottom surface portion 36 are located on the both sides. It is connected to the base end side of the outer peripheral wall portion 31. The bottom surface portion 36 has a strip shape with a substantially constant width. Further, a substantially cylindrical stud 37 serving as a bobbin shaft portion is erected at the center of the bottom surface portion 36, and the stud 37 has the central axis of the inner hook 3 as an axis. Note that the stud 37 may be provided at a position eccentric with respect to the central axis of the inner hook 3. The stud 37 is for detachably attaching a bobbin case 40 for housing the bobbin 39. In order to make the bobbin case 40 detachable, the stud 37 is provided with a stud groove 37A around its tip. ing. In addition, a pair of anti-rotation protrusions 38 are formed on the distal end side of the outer peripheral wall portion 31 of the inner hook 3 so as to be positioned in the vicinity of the needle drop hole 33.

  The bobbin case 40 has a cylindrical tubular body 41 at the center that can be fitted into a mounting hole 39B provided in the center of the bobbin 39 that winds and holds the lower thread 39A. The cylindrical body 41 is formed in a shape that allows the stud 37 of the inner hook 3 to be fitted. When the bobbin case 40 is attached to the inner hook 3, the stud 37 of the inner hook 3 is attached to the cylindrical body 41. Fit.

  The bobbin case 40 is provided with a fixing structure (the entire structure is not shown) for the inner hook 3. This fixing structure has an operation knob 42 standing upright on the top surface of the bobbin case 40. By raising the operation knob 42, the fixing knob 43 provided inside the central portion and the outer peripheral surface project. The bobbin stopper 44 provided in this manner is slidable. The operation knob 42 is biased by a coil spring (not shown) and is normally maintained in a non-standing state. The fixing claw 43 meshes with a stud groove 37 </ b> A formed in the stud 37 of the inner hook 3 in a state where the bobbin case 40 is mounted on the inner hook 3, thereby fixing the bobbin case 40 to the inner hook 3. Such a fixing claw 43 is slid in a direction to release the engagement with the stud groove 37 </ b> A by raising the operation knob 42, so that the bobbin case 40 can be attached to and detached from the inner hook 3. The bobbin stopper 44 is retracted by raising the operation knob 42 and protrudes in a normal state where the operation knob 42 is in a non-standing state.

  The bobbin case 40 is formed with a guide groove 45 along its axial direction from the side wall to the top surface. The groove 45 is for positioning the circumferential direction of the bobbin case 40 when the bobbin case 40 is attached to the inner hook 3. The spacing between the anti-rotation protrusions 38 and 38 is a width that can be fitted into the groove 45 of the bobbin case 40, so that the pair of anti-rotation protrusions 38 and 38 causes the bobbin case 40 to attach to the inner hook 3. The bobbin case 40 is positioned in the circumferential direction when it is mounted on.

  In this example, the locking groove 34 is fitted with an inner hook stopper provided on the sewing machine side to keep the inner hook 3 from rotating.

  On the opposite side of the rotation-preventing groove 34, a wall cutout portion 52 is formed by cutting out the distal end side of the outer peripheral wall portion 31, and this wall cutout portion 52 is in the longitudinal direction of the rotation center of the inner hook 3. The outer peripheral wall portion 31 is formed between the vertical edge portions 53 and 54, and the outer peripheral wall portion 31 is formed with a lower outer peripheral wall portion 31 </ b> A at the vertical edge portions 53 and 54. One vertical edge portion 53 is positioned on one side edge side in the width direction of the bottom surface portion 36, and the other vertical edge portion 54 is positioned on the opening portion 36 </ b> A side on the one side in the width direction of the bottom surface portion 36. The positions 53 and 54 make an angle of about 90 degrees with respect to the center of the stud 37.

  In order to sew the cloth which is the sewing object using such a horizontal rotary hook 1, the outer hook in the state where the inner hook stopper of the sewing machine is fitted in the rotation stop groove 34 to prevent the rotation of the inner hook 3. 2 is rotated in the rotation direction R. As a result, the loop of the upper thread that occurs as the sewing needle moves up and down is caught by the outer hook sword tip 11 provided in the outer hook 2, and the upper thread that has been caught is located on the front side of the inner hook 3 at the yarn dividing portion 13. The upper thread is divided into an upper thread and an upper thread on the back side, and the upper thread on the back side moves while contacting the back surface of the bottom of the inner hook 3 as the outer hook 2 rotates. Eventually, the upper thread comes off from the thread drop-out portion 23, comes out of the hook, and entangles with the lower thread 39A drawn out from the bobbin 39, and the fabric that is to be sewn is sewn. Instead of using the bobbin 39 serving as the lower thread supply means, a bobbin formed by winding the lower thread 39A into a cylindrical shape and adhering with glue or the like may be used as the lower thread supply means. The bobbin (not shown) has the mounting hole 39B.

  By the way, normally, when the yarn dividing section 13 cannot catch the upper yarn, the upper yarn enters between the sliding surface, that is, the rail 8 and the rail groove 9 and is caught by the rail-side yarn cutting groove 14. Then, the outer hook 2 is cut by the rail side thread cutting groove 14 by the rotation of the outer hook 2.

  However, when the upper thread is not cut by the rail-side thread cutting groove 14, the upper thread fitted in the rail-side thread cutting groove 14 is rotated by the rotation of the outer hook 2 so that the rear upper edge portion 16 </ b> A and the rear lower edge portion. It will be in the state caught on 16B. In this state, when the rail-side yarn cutting groove 24 passes through the rail-side yarn cutting groove 14, the shearing action between the rear upper edge portion 16A and the rear edge portion 25A, the rear lower edge portion 16B, The upper thread is cut by the shearing action between the rear edge portions 25A. In addition, even when it does not cut | disconnect by the passage of the one rail groove side thread | yarn cutting groove 24, an upper thread | yarn is reliably cut | disconnected by the several rail groove side thread | yarn cutting groove 24 passing.

  In addition, when the upper thread does not move between the rail 8 and the rail groove 9 except for the portion of the rail side yarn cutting groove 14, the rail side thread cutting groove 24 passes, so that one pass Or by passing through one place, the upper thread is cut little by little and cut by passing through a plurality of places. Alternatively, when the rail groove side thread cutting groove 24 passes, the upper thread moves along with the rail groove side thread cutting groove 24, and the upper thread fits into the rail side thread cutting groove 14 and cuts as described above. Is done.

  Thus, in this embodiment, corresponding to claim 1, the inner hook 3 is accommodated in the outer hook 2, and the lower thread supplying means is accommodated in the inner hook 3, so that the inner peripheral portion of the outer hook 2 is In the rotary hook of the sewing machine in which the rail groove 9 is formed, the rail 8 fitted to the rail groove 9 is formed on the outer peripheral portion of the inner hook 3, and the thread separating portion 13 is provided at the end of the rail 8, Since the rail side thread cutting groove 14 is formed in the outer peripheral surface 8G and the rail groove side thread cutting groove 24 is provided in the rail groove 9, the upper thread fitted in the rail side thread cutting groove 14 and the portions other than the rail side thread cutting groove 14 When the upper thread is cut by the rail groove side thread cutting groove 24, the upper thread that has entered between the rail 8 and the rail groove 9 can be cut.

  Thus, in this embodiment, a plurality of rail-side thread cutting grooves 14 and a plurality of rail-side thread cutting grooves 24 are formed correspondingly to the second aspect. The upper thread other than the rail-side thread cutting groove 14 is fed to the adjacent rail-side thread cutting groove 14 by the rail-side thread cutting groove 24, and the rail-side thread cutting groove 14 is cut. The upper thread can be cut at 14.

  Further, as an effect on the embodiment, the rail side thread cutting groove 14 is obliquely provided in the thickness direction of the rail 8, and the upper edge portion 16A is formed at an acute angle, so that it is caught by the upper edge portion 16A. With respect to the upper thread, the upper thread can be reliably cut by the shearing action when the radial rear edge 25A passes. Further, the upper thread sandwiched between the rail 8 and the rail groove 9 other than the rail-side yarn cutting groove 14 is sheared by the rear edge 25A in the radial direction or sent to the adjacent rail-side thread cutting groove 14. Can be. Furthermore, since the inner end 24N of the rail groove side thread cutting groove 24 is located outside the bottom surface portion 17 of the rail side thread cutting groove 14, the upper thread hooked on the upper edge portion 16A and the lower edge portion 16B is removed from the rail groove. It can be cut by the side thread cutting groove 24. Further, since the rail groove side thread cutting groove 24 has a triangular pyramid shape, the processing is easy.

  FIG. 14 shows a second embodiment of the present invention, in which the same parts as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. In this example, the rail groove side thread cutting groove 24 is provided only on the other side surface portion 19, and there are the same operations and effects as in the first embodiment. You may provide only in the one side part 18. FIG.

  15 and 16 show a third embodiment of the present invention, in which the same reference numerals are given to the same portions as those in the above-described embodiments, and detailed description thereof is omitted. In this example, the rail groove side thread cutting groove 24 forms the front edge 25 parallel to the rear edge 25A, and forms the front edge 26 parallel to the rear edge 26A. An inclined bottom surface portion 28 is provided at the bottom, and the cutting action by the rear edge portion 26A can be obtained in the same manner as in the above embodiment.

  As described above, in this embodiment, there are the same operations and effects as those of the above embodiments, and although not shown, the rail groove side thread cutting groove 24 is provided only on the other side surface portion 19, It may be provided on both of the other side surface portions 19. Further, the rail groove side thread cutting groove 24 includes an inclined bottom surface portion 28 at the bottom and has a constant circumferential length, so that the processing becomes easy. Further, as in this example, the shape of the rail groove side thread cutting groove 24 can be appropriately selected.

  FIGS. 17-20 shows Example 4 of this invention, attaches | subjects the same code | symbol to the same part as the said Example, and abbreviate | omits the detailed description. This figure shows an example in which the present invention is applied to a full rotation type horizontal rotary hook.

  The horizontal rotary hook 61 includes an outer hook 62, an inner hook 63, a bobbin (not shown), and the like. Note that the top and bottom in FIG. 17 are the top and bottom of the horizontal rotary hook 61. In this example, a bobbin (not shown) is directly stored in the inner hook 63 without using a bobbin case. Alternatively, the bobbin may be stored directly in the inner hook 63. In this example, the inner end 24N of the rail groove side thread cutting groove 24 is located inside the bottom surface portion 17 of the rail side thread cutting groove 14.

  In the outer hook 62, a storage chamber 64 for storing the inner hook 63, a fitting shaft 65 fitted to a rotation drive shaft (not shown) extending in the vertical direction, and an upper thread along with the rotation operation The outer hook sword tip 11 for hooking the loop portion, the rail groove 9 and the inner hook presser 12 are provided.

  Further, a bobbin support 66 is erected at the center of the bottom surface portion 36 of the inner hook 63, and the bobbin around which the lower thread is wound is stored in the inner hook 63 with the bobbin support 66 inserted therethrough. The bobbin holding member 67 provided on the top of the bobbin support 66 prevents the pop-up from the inner hook 63. In the figure, 68 is a needle.

  Then, when the rotational force is transmitted to the outer hook 62 of the horizontal rotary hook 61, the outer hook 62 is rotationally driven. On the other hand, the inner hook 63 is fitted in a recess formed in the machine body of the sewing machine (not shown) with the inner hook stopper convex portion 69, and prevents rotation against the rotational action caused by the frictional force caused by the rotation of the outer hook 62. Is done. In synchronism with the rotation of the outer hook 62, an upper thread (not shown) is supplied to the passage path of the outer hook blade tip 11 by the needle 68. The upper hook sword tip 11 is caught, and the upper thread is caught by the yarn dividing section 13 and divided into an upper thread on the front side of the inner hook 63 and an upper thread on the rear side. , The thread is passed over and a seam is formed.

  At this time, the upper thread that has entered between the rail 8 and the rail groove 9 can be cut by the rail side yarn cutting groove 14 and the rail groove side yarn cutting groove 24. In addition, the arrangement | positioning and shape of the rail groove side thread | yarn cutting groove 24 can apply the thing of the said Examples 1-3. In this example, the inner end 24N of the rail groove side thread cutting groove 24 is located outside the bottom surface portion 17 of the rail side thread cutting groove 14.

  As described above, in this embodiment, the same operations and effects as the above-described embodiments are obtained.

  Further, as an effect of the embodiment, since the other side surface portion 19 is on the lower side in the horizontal rotary hook 61, it is preferable to provide the rail groove side yarn cutting groove 24 at least on the other side surface portion 19.

  The present invention is not limited to this embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, the shape and number of the rail side thread cutting grooves and the rail groove side thread cutting grooves can be appropriately selected. Further, the present invention can be applied to a rotary hook of various sewing machines other than the embodiment.

DESCRIPTION OF SYMBOLS 1 Rotary hook 2 Outer hook 3 Inner hook 8 Rail 9 Rail groove 11 Outer hook sword tip 12 Inner hook presser 13 Thread separation part 14 Rail side thread cutting groove 24 Rail groove side thread cutting groove 61 Rotating hook 62 Outer hook 63 Inner hook

Claims (2)

The inner hook is housed in the outer hook, and a rail groove is formed on the inner peripheral portion of the outer hook, and a rail that fits into the rail groove is formed on the outer peripheral portion of the inner hook, and at the end of the rail. A sewing machine rotary hook provided with a thread dividing portion, wherein a rail side thread cutting groove is formed on an outer peripheral surface of the rail, and a rail groove side thread cutting groove is provided in the rail groove. The rotary hook for a sewing machine according to claim 1, wherein a plurality of said rail side thread cutting grooves and a plurality of said rail side thread cutting grooves are formed.

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