JP2009072520A - Full rotation shuttle for sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reliably form stitches by reliably and smoothly entangling an needle thread loop engaged with a cone point with an under thread, regardless of the kind and thickness of the needle thread. <P>SOLUTION: The full rotation shuttle 10 is arranged in a front end part in a bed part, and connected to the front end part of a lower shaft. The full rotation shuttle 10 includes: a rotating hook 11 to be integrally rotated with the lower shaft with the vertical movement of a sewing needle; a middle hook 12 rotatably supported by the rotating hook 11; and a bobbin case 15 removably mounted on the middle hook 12. The inclination angle θA with respect to an axial center OA (an axial center O) of a thread slip inclination surface 11ea formed in the delay side part of a clockwise rotary direction R (the rotary direction) from the cone point on the outer peripheral surface of the rotating hook 11 is larger than the inclination angle θ1 of the standard rotating hook. When sewing is performed, a rear side loop thread 22ab among the needle thread loops, where the needle thread in the eye of the sewing needle is enlarged by the cone point, easily slips on the thread slip inclination surface 11ea formed by large gradient, so as to be received by the bobbin case 15. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention includes an outer hook that has a sword tip and rotates together with the lower shaft in synchronization with the vertical movement of the sewing needle, an inner hook that is rotatably supported by the outer hook, and is detachably attached to the inner hook. The present invention relates to a full rotary hook used for a sewing machine having a bobbin case.

  Conventionally, the sewing machine often uses a vertical full rotary hook with a simple hook drive mechanism. The vertical full rotary hook has an outer hook that is rotated by a lower shaft, a middle hook that is relatively rotatably attached to the outer hook, and a bobbin case that is detachably attached to the inner hook. The hook is prevented from rotating by the hook stopper.

  For example, the full rotary hook of the sewing machine described in Patent Document 1 includes an outer hook 1 connected to a rotating drive shaft, an inner hook 2 rotatably supported on the outer hook 1 while holding a bobbin case, A needle receiving member 3 fixed to the outer hook 1, and a crescent-shaped half-notch ring 4 fixed to the outer hook 1 from the rear side in order to rotatably hold the inner hook 2 to the outer hook 1, In the bobbin case, a lower thread bobbin around which a lower thread is wound is detachably stored.

  A flange portion 8 that is raised in the axial direction is formed on the outer peripheral portion of the outer hook 1, and a sliding groove 9 is formed on the inner periphery of the flange portion 8 in the circumferential direction. The outer hook 1 is integrally formed with a sword tip 6 extending in the outer hook rotating direction. The sword tip 6 has a pointed end extending in the direction of the notch 5 and a shape inclined in the direction of the connecting shaft 7. This sword tip 6 has an inclined surface 14 that increases in height as it moves from the pointed end to the root portion as a whole, and has a conical surface shape having a boundary line 16 between the outer peripheral surface 15 of the outer hook 1. The inclined surface 14 is formed with a recess 17.

  Therefore, when the sewing needle is slightly raised from the lowermost position, the upper thread 27 held by the sewing needle is loosened to form a loop. The tip of the sword tip 6 of the rotating outer hook 1 is inserted into this small loop portion, and the upper thread 27 is divided in two directions. One loop portion that engages with the front side of the sword tip 6 is hooked on the inner sword tip 13 of the inner hook 2 and wraps around the back surface 28 of the inner hook 2. The other loop portion engaged with the rear side of the sword tip 6 is restricted from moving backward by the needle receiving member 3 so as to be engaged from the inclined surface 29 of the sword tip 6 to the inclined surface 14 of the outer hook 1. become.

  That is, the loop portion engaged with the sword tip 6 responds to the clockwise rotation of the sword tip 6 integral with the outer hook 1, first along the upper surface of the thick portion 26 of the needle receiving member 3. Then, after being guided by the inclined surface 29 toward the recess 17, it slides down on the inclined surface 14, moves from the moving locus A to the moving locus B, and further moves to the front end of the inclined surface 14. To do.

By further clockwise rotation of the sword tip 6, the other upper thread 27 of the loop portion crosses from the inclined surface 14 to the right end portion of the bobbin case, and from the right end portion to the left side along the front surface of the bobbin case. Moving. That is, when the loop portion jumps from the inner hook 2 to the rope, the lower thread pulled out from the bobbin case and the upper thread loop from which the inner hook 2 jumps from the rope are entangled, so that a stitch is formed.
Utility Model Registration No. 2568825 (Page 2, FIGS. 1 and 4)

  In the full rotary hook of the sewing machine described in Patent Document 1 described above, when the stitches are formed, the upper thread to be used for sewing is sequentially nylon when sliding on the inclined surface 14 from the movement locus A to the movement locus B. In addition, when the thread thickness is very large, the movement resistance of the upper thread becomes large, and it becomes very difficult to slide off the inclined surface 14, and the loop portion is bobbed from the inclined surface 14 despite the rotation of the outer hook 1. There is a problem that the case cannot be smoothly crossed, entangled between the inner hook and the outer hook, or the seam becomes defective.

  An object of the present invention is to reliably and smoothly entangle an upper thread loop engaged with a sword regardless of the type and thickness of an upper thread so as to ensure the formation of a stitch. It is.

  The fully rotating shuttle of the sewing machine according to claim 1 has an outer hook that has a sword tip and that rotates in synchronism with the vertical movement of the sewing needle below the needle plate of the sewing machine and rotates integrally with the lower shaft, and is rotatably supported by the outer hook. And a bobbin case detachably attached to the inner hook, the upper thread loop captured by the sword tip is enlarged by rotation of the outer hook and guided to the outer surface of the bobbin case In the entire rotary hook of the sewing machine in which the slant surface for thread sliding is formed on the outer peripheral surface of the outer hook, the rotation center axis of the outer hook from the outer peripheral edge on the lower shaft side of the outer periphery of the outer hook where the inclined surface for thread slip is formed Is the distance from the outer peripheral edge on the lower shaft side of the outer periphery of the outer hook opposite to the outer peripheral face of the outer hook on which the inclined surface for thread sliding is formed with respect to the rotation central axis to the rotation central axis Is set longer.

  When sewing is started, the main shaft and the lower shaft are rotated by the rotational drive of the sewing machine motor, and the needle bar and the sewing needle attached thereto are moved up and down by the rotation of the main shaft. The outer hook of the full rotary hook connected to the lower shaft is driven to rotate in a state where the inner hook is rotationally restrained in synchronization with the vertical movement of the sewing needle. When the outer hook is rotated, the sword tip formed integrally with the outer hook is simultaneously rotated. At the timing when the sewing needle comes into contact with the hook, a small upper thread loop formed in the eye hole of the sewing needle is hooked and captured by the tip of the sword tip, and the upper thread loop is expanded according to the rotation of the sword tip.

At this time, the rear loop thread that is engaged rearward with respect to the sword tip of the upper thread loop moves to the slant surface for thread sliding on the outer peripheral surface of the outer hook by further rotation of the sword tip.
The distance from the outer peripheral edge on the lower shaft side of the outer periphery of the outer hook outer periphery on which the thread slipping inclined surface is formed to the outer periphery of the outer hook outer periphery on which the thread slipping inclined surface is formed with respect to the rotational central axis It is set longer than the distance from the outer peripheral edge on the lower shaft side of the outer periphery of the outer hook opposite to the surface to the rotation center axis. In the conventional outer hook, the distance from the lower shaft side edge of the outer periphery of the outer hook to the rotation center axis is the same.

For this reason, the inclination angle of the inclined surface for thread sliding with respect to the outer hook rotation center axis direction is formed larger than the inclination angle of the conventional outer hook. Therefore, even when the upper thread movement resistance is large and the thread thickness is very large, the rear loop thread has a large slope with the slant surface for thread sliding. The thread sliding inclined surface is easily slipped and guided to the bobbin case.

  The full rotary shuttle of the sewing machine according to claim 2 is characterized in that the upper thread loop is threaded to the outer surface side of the bobbin case from the sled surface for thread sliding on a part of the slanted surface for thread sliding. The inclination angle of the yarn crossing inclined portion with respect to the rotation center axis of the outer hook is set larger than the inclination angle of the yarn sliding inclined surface.

  A fully rotating shuttle of a sewing machine according to a third aspect is the sewing machine according to the second aspect, wherein the slanting portion for thread crossing is formed in a substantially crescent shape in a front view.

  According to the first aspect of the present invention, the outer hook which has a sword tip and adjusts the vertical movement of the sewing needle under the needle plate of the sewing machine and rotates integrally with the lower shaft, and is rotatably supported by the outer hook. A slant for thread sliding that has an inner hook and a bobbin case that is detachably attached to the inner hook, expands the upper thread loop captured by the sword tip by rotating the outer hook, and guides it to the outer surface of the bobbin case For all rotary hooks of the sewing machine whose surface is formed on the outer peripheral surface of the outer hook, the distance from the outer peripheral edge on the lower shaft side of the outer periphery of the outer hook where the inclined surface for thread sliding is formed to the rotational center axis of the outer hook is Because it was set longer than the distance from the outer peripheral edge of the outer shaft outer periphery opposite to the outer peripheral surface of the outer hook on the opposite side to the outer peripheral surface of the outer hook on which the inclined surface for thread sliding was formed with respect to the rotational central shaft, The inclination angle of the slant surface for thread sliding with respect to the rotation center axis direction of the outer hook is larger than the inclination angle of the conventional outer hook. It is formed.

As a result, when the sewing starts and the timing of contact is reached, when the small upper thread loop formed in the stitch hole of the sewing needle is captured by the sword tip and expanded, it moves to the thread sliding inclined surface of the outer hook. Even when the yarn movement resistance is large and the yarn thickness is very thick, the rear loop yarn engaged on the rear side with respect to the sword tip of the upper yarn loop is a slant surface for yarn sliding with a large gradient. This makes it easier to transfer the bobbin case. Therefore, it is possible to prevent the upper thread from being wound around the entire rotary hook, and to reliably prevent the formation of stitches.

According to the second aspect of the present invention, a yarn crossing inclined portion is formed on a part of the yarn slipping inclined surface so that the upper thread loop passes from the yarn sliding inclined surface to the outer surface side of the bobbin case. The inclination angle of the thread crossing inclined portion with respect to the axial center direction of the rotation center is set to be larger than the inclination angle of the thread sliding inclined surface, so when the upper thread loop moves to the thread sliding inclined surface, The yarn slanting speed to the bobbin case can be remarkably increased by the crossing inclined portion. Therefore, even when the sewing speed is increased, it is possible to reliably prevent the upper thread from being entangled with all the rotary hooks and the formation of stitches. Other effects similar to those of the first aspect are obtained.

  According to the third aspect of the present invention, since the yarn crossing inclined portion is formed in a substantially crescent shape when viewed from the front, a part of the yarn sliding inclined surface is cut into a substantially flat shape (so-called chamfering). Thereby, the crescent-shaped inclined part for thread crossing can be formed easily. Other effects similar to those of the second aspect are achieved.

  The total rotary hook of the sewing machine of the present embodiment is configured such that the distance from the outer peripheral edge on the lower shaft side of the outer periphery of the outer hook where the slant surface for thread sliding is formed to the rotation central axis of the outer hook is relative to the rotation central axis of the outer hook. The distance from the outer peripheral edge on the lower shaft side of the outer periphery of the outer hook opposite to the outer peripheral face of the outer hook, on which the inclined surface for thread sliding is formed, was set longer than the distance from the rotation center axis of the outer hook. For this reason, the inclination angle of the slanting surface for thread sliding with respect to the rotation center axis direction of the outer hook can be formed larger than the inclination angle of the conventional outer hook, and the upper thread loop engaged with the sword is moved from the outer hook to the bobbin case. The thread crossing to a so-called bobbin case that can be guided smoothly is made smooth.

Embodiments of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the sewing machine M includes a bed portion 1, a pedestal portion 2 erected from the rear end portion of the bed portion 1, and an arm portion 3 that extends forward from the pedestal portion 2. is doing.

  Although not shown, the sewing machine M further includes a table, a cloth presser device (not shown) that presses and holds the work cloth on the feed plate (not shown) by a presser foot, and the cloth presser device and the feed plate. The cloth presser has a cloth feed device that independently moves and drives in the Y direction (front-rear direction parallel to the main shaft) and the X direction (left-right direction) orthogonal to the Y direction. By appropriately moving the apparatus, various pattern stitches such as patterns, patterns and figures are automatically sewn.

  A needle plate 5 is fixed to the upper surface of the front end portion of the bed portion 1. The bed 1 is provided with the cloth feeding device described above, and a lower shaft (pile drive shaft) 7 driven by a sewing machine motor 6 described later is disposed in the front-rear direction, and is below the sewing needle 9. Correspondingly, a full rotary hook 10 is provided at the front end of the lower shaft 7. A thread trimming mechanism (not shown) is provided between the full rotary hook 10 and the needle plate 5.

  A sewing machine motor 6 (see FIG. 1) is fixed to the rear end portion of the arm portion 3, and a main shaft (not shown) that is driven to rotate by the drive shaft of the sewing machine motor 6 is oriented in the front-rear direction inside the arm portion 3. It is arranged. The head 4 which is the front end portion of the arm portion 3 includes a needle bar vertical drive mechanism for vertically driving a needle bar 8 with a sewing needle 9 attached to the lower end, a balance vertical drive mechanism for vertically driving a balance (not shown), and the like. The needle bar up / down drive mechanism and the balance up / down drive mechanism are driven in synchronization with the rotation of the main shaft.

  Therefore, when sewing is started, the sewing machine motor 6 is rotationally driven. Therefore, when the sewing needle 9 through which the upper thread 22 is threaded is driven by the needle bar vertical drive mechanism, the lower thread 24 is moved to the bobbin inside. When the full rotary hook 10 included in the case 15 is rotated, the stitches for each stitch are formed in order on the work cloth W by the upper thread 22 of the sewing needle 9 and the lower thread 24 of the full rotary hook 10. It has become so.

  Next, the full rotary hook 10 provided at the front end of the lower shaft 7 will be described.

  The full rotary hook 10 includes an outer hook 11 rotatably provided by the lower shaft 7, an inner hook 12 rotatably attached to the outer hook 11, and a needle receiving plate fixed to the outer hook 11 from the rear side. 13, a crescent-shaped curved ring 14 fixed to the outer hook 11 from the front side in order to rotatably hold the inner hook 12 on the outer hook 11, and a bobbin case 15 attached to the inner hook 12. Is done.

  As shown in FIG. 4, the outer hook 11 is connected to the front end portion of the lower shaft 7 via a coupling 17. An outer peripheral wall 11e is formed on the outer peripheral portion of the outer hook 11 so as to swell forward in the direction of the rotation center axis O of the outer hook, and an annular shape that slidably guides the rotation of the inner hook 12 on the inner peripheral side of the outer peripheral wall 11e. The sliding groove 11f is formed. The outer hook 11 is integrally formed with a sword tip 11a extending in the clockwise direction R (outer hook rotating direction) from the outer peripheral wall 11e. The sword tip 11a is formed in an obliquely rearward direction so that a pointed portion thereof extends to the outer peripheral side in a front view and meets the sewing needle 9 in a plan view.

  The rotational force of the sewing machine motor 6 is transmitted to the lower shaft 7. The lower shaft 7 is rotationally driven in the clockwise direction R in front view in synchronization with the main shaft, that is, in synchronization with the vertical movement of the sewing needle 9. At this time, the outer hook 11 is also rotationally driven in the clockwise direction R (see FIGS. 5 and 6). Therefore, every time the outer hook 11 rotates once in the clockwise direction R, the sword tip 11a hooks and expands the small upper thread loop 22a formed in the eye hole 9a of the sewing needle 9.

  As shown in FIGS. 5 to 7, the outer peripheral wall 11e of the outer hook 11 in the vicinity of the sword tip 11a has a sword tip inclined surface 11b that approaches the inner hook 12 side as it approaches the lower shaft 7, and a rear end of the sword tip inclined surface 11b. An outer hook inclined surface 11 c that is continuous with the lower shaft 7 and is further away from the inner hook 12 is formed. The sword tip inclined surface 11b and the outer hook inclined surface 11c form a V-shaped valley line 11d which is recessed in a V shape over a predetermined length. As shown in FIGS. 5, 6, and 8, the outer peripheral wall 11e that is continuous with the V-shaped outer peripheral wall 11e and is opposite to the sword tip 11a (the portion on the delay side in the clockwise direction R from the sword tip 11a). In addition, an inclined surface 11ea for thread sliding for guiding the upper thread loop 22a toward the bobbin case 15 is formed.

As shown in FIG. 8, the inclination angle θA (for example, 25 °) of the thread sliding inclined surface 11ea with respect to the rotation center axis O of the outer hook 11 (in FIG. 8, the axis OA parallel to the rotation center axis 0) is 2 It is formed larger than the inclination angle θ1 (for example, 14 °) of a conventional outer hook (not shown) indicated by a dotted line. That is, as shown in FIGS. 5 and 8, the distance R0 (for example, 25 mm) from the rotation center axis O of the outer hook 11 to the edge on the lower shaft 7 side of the outer periphery where the slant surface 11ea for thread sliding is formed is Further, the distance R1 (for example, 20 mm) from the edge on the lower shaft 7 side to the rotation center axis O in the portion facing the outer peripheral edge where the slant surface 11ea for thread sliding is formed is set.
A point farthest from the tip of the sword tip 11a on the outer peripheral edge of the outer hook at the distance R0 is denoted by K in FIG.
As shown in FIG. 5, the angle between the straight line connecting the tip of the sword 11a and the rotation center axis 0 of the outer hook 11 and the straight line connecting the point K and the rotation center axis O of the outer hook 11 is approximately 150 °. Is set.
However, the inclination angle of the outer hook 11 is irrelevant after the upper thread loop 22a is guided to the bobbin case 15 side. For this reason, the point farthest from the tip of the sword 11a on the outer periphery of the outer hook at the distance R0 may be set closer to the tip of the sword 11a than the point K. A point on the tip side of the sword tip 11a from the point K is defined as K ′. As shown in FIG. 5, the angle formed between the straight line connecting the tip of the sword 11a and the rotation center axis 0 of the outer hook 11 and the straight line connecting the point K ′ and the rotation center axis O of the outer hook 11 is approximately 136 °. It becomes.
On the other hand, the point closest to the tip of the sword tip 11a on the outer periphery of the outer hook that becomes the distance R0 is represented by P in FIG. The angle between the straight line connecting the tip of the sword 11a and the rotation center axis 0 of the outer hook 11 and the straight line connecting the point P and the rotation center axis O of the outer hook 11 is set to approximately 70 °.
In the case of a conventional outer hook, the distance from the lower shaft side edge of the outer periphery of the outer hook where the slant surface for thread sliding is formed to the outer peripheral edge where the slant surface for thread sliding is formed The distance from the outer rotary shaft of the outer hook is the same. For this reason, the inclination angle of the inclined surface for thread sliding with respect to the rotation center axis direction of the outer hook is formed larger than the inclination angle of the conventional outer hook.

  Therefore, when forming the stitches, the upper thread loop 22a is engaged with the sword tip 11a, and the rear loop thread 22ab of the upper thread loop 22a reaches the thread slipping inclined surface 11ea via the V-shaped valley line 11d. At this time, the thread slipping inclined surface 11ea is easily slipped, and the bobbin case 15 is easily threaded.

  By the way, as shown in FIGS. 5, 6 and 9, an upper thread loop 22a is formed on a part of the slant surface 11ea for sliding the thread and on a part on the delay side in the clockwise direction R from the sword 11a. A thread crossing inclined portion 11g for thread crossing from the sliding inclined surface 11ea to the front side (outer surface side) of the bobbin case 15 is formed. The inclination angle θC (for example, 48 °) of the thread crossing inclined portion 11g with respect to the axial center direction of the rotation center axis O of the outer hook 11 is further greater than the inclination angle θB (for example, 20 °) of the thread sliding inclined surface 11ea. It is set large.

  The slanting portion 11g for thread crossing is a substantially flat sloping portion obtained as a result of cutting a part of the sloping surface 11ea for thread sliding substantially flat (so-called chamfering). Therefore, as shown in FIG. 5, since the outer peripheral surface of the outer peripheral wall 11e is formed in a downwardly inclined shape, the yarn crossing inclined portion 11g formed on a part of the yarn slipping inclined surface 11ea is: It is almost crescent shaped when viewed from the front.

  Although the inner hook 12 is mainly formed of a circular bottom plate portion 12b, it has an annular side wall portion 12c that rises in about a half circumference of the outer periphery of the bottom plate portion 12b. A shaft-like stud 12a that supports the bobbin case 15 is provided upright at the center of the bottom plate portion 12b. Therefore, the inner hook 12 is rotatably supported by the outer hook 11 by fitting the outer peripheral portion of the bottom plate portion 12 b into a sliding groove 11 f formed inside the outer peripheral wall 11 e of the outer hook 11.

  A block-like support body 19 is fixed to the lower side of the front end portion of the needle plate 5, and the rear end portion of the hook stopper 16 is fixed to the support body 19. The inner hook 12 is always restrained so as not to rotate with respect to the outer hook 11 by contacting a part of the side wall portion 12 c with the fork-shaped front end 16 a of the hook stopper 16.

  Since the needle receiving plate 13 is not directly related to the present embodiment, the needle receiving plate 13 will be briefly described. The needle receiving plate 13 is fixed to the rear side of the outer hook 11, and is rearward of the sewing needle 9 in a predetermined period immediately before the sword tip 11 a meets the sewing needle 9. It is a guide member for exerting a guide function for guiding the contact position of the sewing needle 9 from the rear by abutting from the side. Therefore, when the sewing needle 9 is lowered, the sewing needle 9 does not collide with the sword tip 11a.

  As shown in FIGS. 4 and 10, the curved ring 14 is formed in a crescent shape in plan view, and is fixed to a part of the outer peripheral portion of the outer hook 11 by a plurality of fixing screws. Thus, the inner hook 12 is closed from the front side of the outer hook 11 by closing the outer peripheral portion of the inner hook 12 from the front side with the curved ring 14 while being fitted in the sliding groove 11 f formed in the outer peripheral wall 11 e of the outer hook 11. The outer periphery is rotatably held.

  4, 8, and 9, the bobbin case 15 is a cylindrical body whose front surface is closed, and is detachably attached to the inner hook 12 in a state in which relative rotation is prevented. Yes. The bobbin case 15 further holds a bobbin thread bobbin 18 around which a bobbin thread 24 (see FIG. 10) is detachably attached.

Next, the operation and effect of the full rotary hook 10 provided in the sewing machine M will be described.
When sewing is started, the sewing machine motor 6 is driven to rotate. When the rotational force of the sewing machine motor 6 is transmitted to the main shaft and the lower shaft 7 and further transmitted from the lower shaft 7 to the full rotary hook 10, the outer hook 11 synchronizes with the vertical movement of the sewing needle 9 to move the inner hook 12. In a state where rotation is constrained, it is rotated in the clockwise direction R when viewed from the front. When the outer hook 11 is rotated, the sword tip 11a integrally formed with the outer hook 11 simultaneously rotates in the clockwise direction R.

  When the phase angle of the main shaft when the sewing needle 9 is at the uppermost position is 0 °, the sewing needle 9 is slightly lowered from the lowermost position after the sewing needle 9 has been lowered through the work cloth W and the needle hole 5a of the needle plate 5. Only rise. When the main shaft phase angle reaches about 202 °, the pointed end of the sword tip 11a meets the eye hole 9a of the sewing needle 9, so that the small upper thread loop 22a formed in the eye hole 9a of the sewing needle 9 It is caught by the tip part and captured.

  Thereafter, since the sword tip 11a rotates in the clockwise direction R integrally with the outer hook 11, as shown in FIG. 10, the upper thread loop 22a engaged with the sword tip 11a engages the front side with respect to the sword tip 11a. In the state divided into the front loop yarn 22aa and the rear loop yarn 22ab engaged rearward with respect to the sword tip 11a, the yarn is enlarged according to the rotation of the sword tip 11a.

  That is, when the upper thread loop 22a is expanded by the sword tip 11a moving in the clockwise direction R, the front loop thread 22aa is hooked on the middle sword point (not shown) of the inner hook 12 and is shown by a dotted line in FIG. As shown, it wraps around the back side of the inner hook 12. On the other hand, since the rear loop yarn 22ab is restricted from moving backward by the needle receiving plate 13, the rear loop yarn 22ab reaches the yarn slipping inclined surface 11ea through the outer hook inclined surface 11c on the proximal end side of the sword tip 11a.

  As described above, the inclination angle θA of the slant surface 11ea for thread sliding is formed larger than the inclination angle θ1 of the conventional outer hook. Therefore, even when the movement resistance of the upper thread 22 is large and the thread thickness is very large, the rear loop thread 22ab is rotated in the clockwise direction R of the sword tip 11a by the slanting surface 11ea having a large gradient. With the movement, the thread sliding inclined surface 11ea is easily slipped and guided to the outer surface of the bobbin case 15.

  In this case, as described above, a substantially crescent-shaped slanting portion for thread crossing, in which the upper thread loop 22a is threaded from the slanting surface for thread slip 11ea to the front side of the bobbin case 15 on a part of the slanting surface for thread slip 11ea. As shown in FIG. 9, the inclination angle θC of the yarn crossing inclined portion 11g with respect to the rotation center axis O direction of the outer hook 11 is much larger than the inclination angle θB of the yarn slipping inclined surface 11ea, as shown in FIG. That is, it is set to a steep slope.

Therefore, when the upper thread loop 22a moves to the yarn slipping inclined surface 11ea, the yarn slipping speed to the bobbin case 15 can be remarkably increased by the steep yarn passing inclined portion 11g.
Accordingly, even when the sewing speed is increased, it is possible to reliably prevent the upper thread 22 from being entangled with the entire rotary hook 10 and the formation of stitches.

  Thereafter, the sword tip 11a continuously circulates around the inner hook 12, and the upper thread loop 22a moves to the left along the front surface of the bobbin case 15 accordingly. Therefore, the upper thread loop 22a jumps the so-called inner hook 12 with a rope. As a result, the upper thread loop 22a extending from the eye hole 9a of the sewing needle 9 and the lower thread 24 extending from the lower thread bobbin 18 are entangled, and the upper thread loop 22a is tightened by a balance (not shown). Is formed.

Next, a modified embodiment in which the above embodiment is partially modified will be described.
1) The inclination angle θA of the inclined surface 11ea for thread sliding formed on the outer peripheral wall 11e is not limited to “25 °”, and may be an angle larger than this.

2) The distance R0 from the rotation center axis O of the outer hook 11 on which the thread slipping inclined surface 11ea is formed to the edge on the lower shaft 7 side of the outer periphery on which the thread sliding inclined surface 11ea is formed is limited to "25 mm". However, the distance may be any distance longer than the distance R1 to the rotation center axis O in the portion facing the outer peripheral edge where the slanting surface 11ea for thread sliding is formed.

3) The inclination angle θC of the yarn crossing inclined portion 11g formed on a part of the yarn slipping inclined surface 11ea is not limited to “48 °”, but other than the inclination angle θB of the yarn sliding inclined surface 11ea. Any angle may be used.

4) The yarn crossing inclined portion 11g formed on a part of the yarn slipping inclined surface 11ea has various shapes such as an oval shape and an oval shape in addition to a substantially crescent shape, depending on a cutting method (chamfering method). May be.

It is a side view of the pattern sewing machine which concerns on the Example of this invention. It is the partial expanded side view of the head and bed which provided all the rotary hooks. It is a partial enlarged plan view of a bed part. FIG. 6 is a side view of the full rotary hook with the bobbin case and lower thread bobbin removed. It is a front view of an outer pot. It is a perspective view of an outer pot. FIG. 6 is a cross-sectional view taken along line GG in FIG. 5. FIG. 6 is a cross-sectional view taken along line HH in FIG. 5. It is the II sectional view taken on the line of FIG. It is a front view of the full rotary hook in the middle of sewing.

Explanation of symbols

M Pattern sewing machine 5 Needle plate 7 Lower shaft 9 Sewing needle 10 Full rotation hook 11 Outer hook 11ea Inclined surface for thread sliding 11g Inclined surface for thread crossing 12 Middle hook 15 Bobbin case 22a Upper thread loop θ1 Inclination angle θA Inclination angle θB Inclination angle θC Inclination angle R0 Radius R1 Radius

Claims (3)

An outer hook that has a sword tip and rotates together with the lower shaft in time with the vertical movement of the sewing needle under the needle plate of the sewing machine, an inner hook that is rotatably supported by the outer hook, and an attachment / detachment to the inner hook An upper thread loop captured by the sword tip is enlarged by rotation of the outer hook, and an inclined surface for thread sliding that guides to the outer surface of the bobbin case is provided on the outer periphery of the outer hook In the full rotary hook of the sewing machine formed on the surface,
The distance from the outer peripheral edge on the lower shaft side of the outer periphery of the outer hook where the thread sliding inclined surface is formed to the rotation central axis of the outer hook is that the thread sliding inclined surface is formed with respect to the rotation central axis. The full-rotation shuttle of the sewing machine according to claim 1, wherein the total rotation shuttle of the sewing machine is set longer than the distance from the outer peripheral edge on the lower shaft side of the outer periphery of the outer casing opposite to the outer peripheral surface of the outer casing to the rotation center axis.   A part of the slanting surface for thread sliding is formed with a slanting part for thread transfer where the upper thread loop is threaded from the slanting surface for thread sliding to the outer surface side of the bobbin case. 2. The full rotary shuttle of the sewing machine according to claim 1, wherein an inclination angle of the central axis with respect to an axial direction is set larger than an inclination angle of the inclined surface for thread sliding with respect to the axial direction of the rotation central axis. .   The full rotation shuttle of the sewing machine according to claim 2, wherein the slant portion for thread crossing is formed in a substantially crescent shape when viewed from the front.