JP6698568B2 - Horizontal full rotary hook - Google Patents

Description

  TECHNICAL FIELD The present invention relates to a horizontal full-rotation rotary hook, and more particularly to a holding mechanism for holding a bobbin thread in an inner rotary hook.

  FIG. 12 is a cross-sectional view showing a typical prior art horizontal full rotary hook 69. An inner rotary hook 52 is supported by an outer rotary hook 51 of the horizontal full rotary rotary hook 69, and a bobbin 54 around which a bobbin thread 53 is wound is accommodated in the inner rotary hook 52. The outer hook 51 is fixed to a rotary shaft 56 having a vertical rotary axis L and is driven to rotate. The needle 57 reciprocates up and down as indicated by the arrow 58. The rotation axis of the bobbin 54 is in common with or parallel to the rotation axis L of the rotation shaft 56. In such a horizontal full rotary hook 69, the rail 60 formed on the outer peripheral surface 61 of the inner hook 52 is fitted into the rail groove 62 formed on the outer hook 51. The needle thread is caught by a sword tip (not shown) and slides on the bottom 66 of the inner hook 52 along with the rotation of the outer hook 51 to pass over the thread.

  Another conventional technique similar to such a conventional technique is described in Patent Document 1, for example. Patent Document 1 discloses a horizontal full-rotation rotary hook in which a latch is provided with a hole for preventing the bobbin contained in the inner hook from coming out, and the bobbin thread is held in the hole.

JP-A-8-155179

  In each of the prior arts described in FIG. 12 and Patent Document 1, in a sewing machine using a horizontal full rotary hook, when the bobbin thread is cut by a thread cutting device, an end portion of the bobbin thread pulled out from the inner hook However, it may fall into the gap between the inner and outer hook peripheral wall portions.

  When sewing is resumed, the bobbin thread is less likely to engage with the needle thread loop formed by the rotation of the outer hook, and stitch skipping may occur in which a stitch for a few stitches is not formed.

  Further, in the conventional technique described in Patent Document 1, the bobbin thread can be held on the upper surface of the inner hook by the holding section, but there is a problem that the structure of the holding section that holds the bobbin thread becomes complicated.

  An object of the present invention is to provide a horizontal full-rotation rotary hook with a simple structure and capable of reliably preventing skipping.

The present invention has a sword tip for capturing a needle thread and a cylindrical outer hook peripheral wall portion provided with the sword tip, and is rotated about a rotation axis parallel to an axis of a sewing needle through which the needle thread is inserted. Outer hook,
An inner hook that has a cylindrical inner hook peripheral wall portion and is housed in the outer hook in a manner coaxial with the rotation axis.
A bobbin stored in the inner hook,
A thread tension spring which is provided on the outer peripheral surface of the inner rotary hook peripheral wall portion and presses a bobbin thread wound around the bobbin extending from the bobbin on the outer peripheral surface of the inner rotary hook peripheral wall portion,
The inner hook is
A bobbin thread holding portion protruding radially outward from an end portion on the side facing the axis of the needle of the inner rotary hook peripheral wall portion, than the point of a sword, a person in the radial direction and the said needle A bobbin thread holding portion having a bobbin thread insertion hole through which the bobbin thread is inserted is provided on a side facing the axis from the upstream side in the rotation direction of the outer hook .
In the bobbin thread holding portion, a notch groove portion that is continuously provided in the bobbin thread insertion hole and has an opening on the downstream side of the bobbin thread holding portion in the moving direction of the needle thread is formed,
A retaining member is provided on the upper surface of the cut groove portion to cover the cut groove portion in an elastically deformed state in a state where the tip portion projects downstream of the bobbin thread holding portion in the moving direction of the needle thread. There are even horizontal full rotations.

  Further, the present invention is characterized in that the bobbin thread insertion hole is opened downstream in the moving direction of the needle thread captured by the outer hook.

Further, according to the present invention, the bobbin thread holding portion is in contact with a virtual plane including an end surface of an end portion of the inner hook peripheral wall portion on the side facing the axis of the sewing needle from the inner hook peripheral wall portion side. Characterize.

According to the horizontal full rotary hook of the present invention, the bobbin thread has a simple structure in which the bobbin thread holding portion having the bobbin thread insertion hole is provided in the inner hook peripheral wall portion, and the bobbin thread is pulled from the thread tension spring of the inner hook peripheral wall portion to the tip of the blade. Also, it is stretched inward in the radial direction and over the bobbin thread insertion hole on the side of the sewing needle, thereby eliminating the problem that the bobbin thread does not engage with the needle thread loop, and it is possible to reliably prevent stitch skipping. it can. The bobbin thread can smoothly move to the bobbin thread insertion hole through the lower surface of the retaining member.

  Further, according to the horizontal full rotary hook of the present invention, since the bobbin thread insertion hole is opened on the downstream side in the moving direction of the needle thread caught by the outer hook, the needle is provided at the opening of the bobbin thread insertion hole. It is possible to prevent the yarns from coming into contact with each other or being caught, and the needle yarns can be moved smoothly.

  Further, according to the horizontal full rotary hook of the present invention, when the needle thread caught by the outer hook moves along the end surface of the inner hook, even if the needle thread comes into contact with the bobbin thread holding section, the bobbin thread holding section The needle thread can be smoothly moved on the upper surface of the inner hook.

It is the top view which notched a part of horizontal horizontal rotation hook of 1st Embodiment of this invention. It is the front view seen from the arrow A of FIG. It is sectional drawing which showed typically the state where the inner hook was accommodated in the outer hook. It is a top view which shows the positional relationship between an inner hook and an opener. It is a top view of an inner hook. It is an enlarged plan view of the bobbin thread holding portion of the inner hook. FIG. 7 is an enlarged plan view of the bobbin thread holding portion with a retaining member removed. It is sectional drawing seen from the cutting plane line BB of FIG. It is an expansion perspective view of a bobbin thread holding part. It is an expansion perspective view of the bobbin thread holding|maintenance part of 2nd Embodiment of this invention. It is an expansion perspective view of the bobbin thread holding part of 3rd Embodiment of this invention. It is sectional drawing which shows the conventional horizontal full rotation hook.

  FIG. 1 is a plan view in which a part of the horizontal full rotation rotary hook 1 of the first embodiment is cut away. FIG. 2 is a front view seen from the arrow A of FIG. FIG. 3 is a sectional view schematically showing a state where the inner rotary hook 4 is housed in the outer rotary hook 2. FIG. 4 is a plan view showing the positional relationship between the inner hook and the opener.

  The horizontal full rotary hook 1 has a cylindrical outer hook peripheral wall portion 3 and is rotated around a rotation axis L parallel to the axis of the sewing needle 50 indicated by an imaginary line through which a needle thread is inserted. An inner hook 4 having a cylindrical inner hook peripheral wall portion 5, which is housed in the outer hook 2 coaxially with the rotation axis L, a bobbin (not shown) housed in the inner hook 4, and an inner hook peripheral wall portion 5. The thread tension spring 7 is provided on the outer peripheral surface 6 and presses the bobbin thread T wound around the bobbin and wound on the bobbin on the outer peripheral surface 6 of the inner hook peripheral wall portion 5. The inner hook 4 is provided with a latch 23 for preventing the bobbin housed in the inner hook 4 from coming out.

  A rail groove 10 is formed in the outer hook 2, the rail 11 of the inner hook 4 is fitted into the rail groove 10, and the inner hook 4 is supported by the outer hook 2. The outer hook 2 is detachably attached to a rotary shaft 49 that is driven to rotate about a common axis with the rotary axis L by a screw member 13 such as a bolt. The rail groove 10 is formed on the inner peripheral surface 14 of the outer hook 2 so as to extend in the circumferential direction on an imaginary plane substantially perpendicular to the rotation axis L, and the rail 11 is formed on the outer peripheral surface 15 of the inner hook 4. There is.

  Since the inner hook 4 has a rotational force in the same direction as the outer hook 2 due to sliding friction in the fitting portion with the outer hook 2, the engagement protrusion 4a protruding from the outer circumference of the inner hook 4 is fixed to the sewing machine bed. The engagement protrusion 46a is loosely fitted in the engagement recess 46a formed in the needle plate 46, and the engagement protrusion 4a is brought into contact with the inner surface 46a1 of the engagement recess 46a on the downstream side in the outer hook rotation direction D to rotate the inner hook 4. Is configured to prevent

  Then, the needle thread is scooped by the sword tip 47 of the outer hook 2 to form a needle thread loop, and when the needle thread loop moves around the inner hook 4, as described above, the engaging protrusion 4a and the engaging concave portion are engaged. In order to separate the inner surface 46a1 of the place 46a from the inner surface 46a1, the inner hook 4 is angularly displaced in the direction opposite to the rotation direction D of the outer hook 2 to separate the engaging protrusion 4a from the inner surface 46a1 to form a clearance. The needle thread loop passes through.

The rotating force of the inner rotary hook 4 in the opposite direction is given by the opener 45. A projecting portion 48 is provided on the end portion 18 of the inner hook peripheral wall portion 5 on the side facing the axis of the sewing needle 50 in a state of protruding from the end portion 18 to the outer side in the radial direction of the inner hook peripheral wall portion 5, The opener 45 oscillates for each needle in synchronism with a rotating shaft (not shown), and its tip end comes into contact with the protrusion 48 at a predetermined timing, and when the needle plate loop passes, the inner hook 4 is angularly displaced in the opposite direction. It is configured so that a gap is formed.

  The protruding portion 48 has an upstream guide wall portion 40 that moves to the downstream side while the needle thread captured by the outer hook 2 is in contact therewith, and a downstream guide wall portion 41 that is located on the downstream side in the needle thread movement direction. The upstream guide wall portion 40 and the downstream guide wall portion 41 are adjacent to each other via a corner portion 44. The upstream guide wall portion 40 is formed such that the distance in the radial direction from the axis of the inner hook 4 increases toward the downstream side in the rotation direction D of the outer hook 2, and the needle thread guides the upstream guide wall 40. When it moves to the corner portion 44 while being in contact with the wall portion 40 and passes through the corner portion 44, it moves away from the protruding portion 48 and moves downstream without contacting the downstream guide wall portion 41. The above-mentioned opener 45 abuts on the downstream guide wall portion 41.

  FIG. 5 is a plan view of the inner hook 4. FIG. 6 is an enlarged plan view of the bobbin thread holding portion 21 of the inner hook 4. FIG. 7 is an enlarged plan view of the bobbin thread holding portion 21 with the retaining member 27 removed. FIG. 8 is a cross-sectional view of the bobbin thread holding portion 21 of FIG. 7 taken along the section line BB. FIG. 9 is an enlarged perspective view of the bobbin thread holding portion 21.

  The inner hook 4 includes a bobbin thread holding portion 21, and the bobbin thread holding portion 21 is provided so as to face the downstream guide wall portion 41 of the protruding portion 48. The bobbin thread holding portion 21 is provided in a state of protruding from the end of the inner hook peripheral wall portion 5 on the side of the sewing needle 50 to the outer side in the radial direction of the inner hook peripheral wall portion 5, and has the bobbin thread insertion hole 22. ing. The bobbin thread insertion hole 22 is formed radially inward of the inner hook peripheral wall portion 5 and closer to the sewing needle 50 than the sword tip 47, and on the outer peripheral surface 15 of the inner hook peripheral wall portion 5 by the thread tension spring 7. The bobbin thread T that has been pressed and pulled out is held in the inserted state. The bobbin thread holding portion 21 is provided by utilizing the protruding portion 48 with which the opener 45 abuts in order to prevent the apparatus from becoming large, but the present invention is not limited to this.

  The bobbin thread insertion hole 22 is formed in a substantially U shape in a plan view, and one side of the bobbin thread insertion hole 22 is connected to a cut groove portion 24 that is continuous with the bobbin thread insertion hole 22, and the cut groove portion 24 is It is opened to the downstream side guide wall portion 41 on the downstream side in the moving direction of the needle thread. The bobbin thread insertion hole 22 is formed in a direction oblique to the direction in which the bobbin thread T of the cut groove portion 24 is inserted, and the bobbin thread T held in the bobbin thread insertion hole 22 is located on the cut groove portion 24 side. It is difficult to move. In the present embodiment, when a 0.5 mmφ thread is used as the bobbin thread T, the width of the bobbin thread insertion hole 22 through which the bobbin thread T is inserted and the width of the cut groove portion 24 where the bobbin thread T is inserted are The bobbin thread T is approximately the same as 0.5 mm.

  Since the bobbin thread insertion hole 22 is opened to the downstream side in the moving direction C of the needle thread caught by the outer hook 2 through the cut groove section 24, the needle thread caught by the outer hook 2 is opened in the opening section 25. It is possible to prevent the needle thread that has accidentally entered from the outside or caught by the outer hook 2 from being caught in the opening 25.

  A stepped portion 26 that is recessed downward is formed on the protruding portion 48, and the bobbin thread holding portion 21 is formed on the stepped portion 26. The upper surface of the cut groove portion 24 is provided with a retaining member 27 for preventing the bobbin thread T held in the bobbin thread insertion hole 22 from coming out of the cut groove portion 24 to the outside. The retaining member 27 can be made of an elastic material such as metal or resin.

  The retaining member 27 and the fixing portion 28 located on the upstream side in the needle thread moving direction C and the regulating portion 29 that regulates the bobbin thread T inserted into the bobbin thread insertion hole 22 from coming out of the bobbin thread insertion hole 22. It has and. The fixed portion 28 is screwed to the stepped portion 26, for example. The restriction portion 29 is provided on the downstream side in the moving direction C of the needle thread with respect to the fixed portion 28, and covers the cut groove portion 24 and the opening portion 25 of the cut groove portion 24 in an elastically deformed state. The tip portion of the restriction portion 29 is chamfered to the R surface in a plan view and protrudes to the outside of the downstream guide wall portion 41 of the bobbin thread holding portion 21.

  A procedure in which the bobbin thread T pressed by the thread tension spring 7 on the outer peripheral surface 15 of the inner hook peripheral wall section 5 is held by the bobbin thread holding section 21 will be described. The bobbin thread T pressed on the outer peripheral surface 15 of the inner hook peripheral wall section 5 by the thread tension spring 7 is moved to the opening section 25 side while being in contact with the downstream guide wall section 41 of the bobbin thread holding section 21. It The corner portion 34 connecting the downstream guide wall portion 41 and the wall portion 39 of the cut groove portion 24 continuous to the downstream guide wall portion 41 is chamfered to the R surface in plan view and moved to the opening 25 side. The bobbin thread T goes under the lower surface of the restriction portion 29, moves through the opening 25 along the chamfered surface, and then is smoothly moved to the wall portion 39 side. The bobbin thread T that has moved along the wall portion 39 exits the restriction portion 29, is guided to the bobbin thread insertion hole 22, and is retained.

  In this way, the bobbin thread insertion hole 22 is formed radially inward of the inner hook peripheral wall portion 5 and closer to the sewing needle 50 than the sword tip 47, and the bobbin thread T has such a simple structure. It is possible to prevent the space from falling into the gap 31 between the inner rotary hook peripheral wall portion 5 and the outer rotary hook peripheral wall portion 3. As a result, it is possible to prevent the bobbin thread T from engaging with the needle thread captured by the outer hook 2 and preventing the seam from being formed.

  Of the peripheral wall 37 of the bobbin thread insertion hole 22, the upper end 32 of the peripheral wall 37 located on the downstream side in the needle thread moving direction C is chamfered, and the bobbin thread T engaging the needle thread is the bobbin thread insertion hole. It is possible to reduce the frictional resistance generated by the bobbin thread T and the peripheral wall 37 coming into contact with each other when the bobbin thread T extends and slides.

  Since the distal end portion 33 of the restricting portion 29 of the retaining member 27 is chamfered to the R surface, the bobbin thread moved toward the opening 25 while being brought into contact with the downstream guide wall portion 41 of the bobbin thread holding portion 21. The T can move to the opening 25 without being caught by the tip 33 of the restriction portion 29.

  An upper end 38 of the downstream guide wall portion 41 connected to the opening 25 of the bobbin thread holding portion 21 is chamfered. The upper end 38 of the downstream guide wall portion 41 may be chamfered on the C surface or may be chamfered on the R surface.

  By chamfering the upper end 38 of the downstream guide wall portion 41, when the bobbin thread T moves to the opening 25 while contacting the downstream guide wall section 41, the bobbin thread T is prevented from being cut or loosened. It Further, it is possible to reduce the frictional resistance generated by the bobbin thread T coming into contact with the downstream guide wall portion 41.

The bobbin thread holding portion 21 is provided on the stepped portion 26, and the upper surface 35 of the retaining member 27 includes the virtual end surface 42 of the end portion 18 of the inner hook peripheral wall portion 5 on the side facing the axis of the sewing needle 50. The flat surface S is in contact with the inner hook peripheral wall portion 5 side. When the retaining member 27 is screwed to the bobbin thread holding portion 21 with a pan head screw 36 or the like, the head of the pan head screw 36 contacts the virtual plane S from the inner hook peripheral wall portion 5 side. ing.

  With such a structure, when the needle thread caught by the outer hook 2 moves on the virtual plane S of the inner hook 4, the needle thread is prevented from coming into contact with or getting caught in the bobbin thread holding portion 21. The needle thread can smoothly move along the virtual plane S on the surface of the inner hook 4.

  Of the wall portion 39 of the cut groove portion 24, when the bobbin thread T is inserted into the cut groove portion 24, the upper portion of the wall portion 39 on the side where the bobbin thread T contacts may be chamfered.

  With such a configuration, the bobbin thread T is prevented from being cut or loosened. Further, it is possible to reduce the frictional resistance generated by the bobbin thread T coming into contact with the wall portion 39.

  FIG. 10 is an enlarged perspective view of the bobbin thread holding portion 21 of the second embodiment. The description of the same parts as those of the first embodiment will be omitted and the same reference numerals will be used. In the present embodiment, a narrow width portion 30 narrower than the diameter of the bobbin thread T is formed in a part of the cut groove portion 24. For example, the width of the cut groove portion 24 is 0.5 mm, which is the same as the diameter of the bobbin thread T, and the width w of the narrow portion 30 is 0.3 mm.

  By providing the narrow width portion 30, it is possible to prevent the bobbin thread T held in the bobbin thread insertion hole 22 from coming out through the cut groove section 24 to the outside. When the narrow portions 30 are formed by using an elastic member, the gap between the narrow portions 30 is further reduced to further reliably prevent the bobbin thread T from coming out of the cut groove portion 24 to the outside. You can The narrow portion 30 can be formed by cutting or the like similarly to the cut groove portion 24, and the number of parts can be reduced.

  It is also possible to prevent the bobbin thread T from slipping out of the bobbin thread insertion hole 22 by forming the narrow portion 30 at a position adjacent to the bobbin thread insertion hole 22.

By providing the narrow portion 30 on the wall portion 39 of the cut groove portion 24, it is not necessary to provide the retaining member 27 protruding on the upper surface of the cut groove portion 24, and it is necessary to provide the stepped portion 26 that is concave below. Therefore, the bobbin thread holding portion 21 can easily contact the virtual plane S including the end surface 42 of the end portion 18 of the inner hook peripheral wall portion 5 on the side facing the axis of the sewing needle 50 from the inner hook peripheral wall portion 5 side. Can be

  Accordingly, when the needle thread caught by the outer hook 2 moves on the virtual plane S of the inner hook 4, the needle thread can be prevented from coming into contact with or being caught by the bobbin thread holding portion 21 with a simple configuration. it can.

  FIG. 11 is an enlarged perspective view of the bobbin thread holding portion 21 of the third embodiment. The description of the same parts as those of the first and second embodiments will be omitted and the same reference numerals will be used. As a retainer member 43 for preventing the bobbin thread T held in the bobbin thread insertion hole 22 from coming out through the cut groove portion 24, a linear elastic member such as metal or resin is formed into, for example, a substantially J shape. A bent product can be used.

  By using a linear elastic member as the retaining member 43, it is possible to easily bend it into a desired shape. When the bobbin thread T abuts on the retaining member 43, the retaining member 43 acts as a cushioning material, so that the bobbin thread T abuts on the retaining member 43 and is prevented from being cut or frayed. it can. In addition, the spring constant of the retaining member 43 can be easily changed by changing the diameter of the linear member used as the retaining member 43.

DESCRIPTION OF SYMBOLS 1 Horizontal full rotation hook 2 Outer hook 3 Outer hook peripheral wall 4 Inner hook 4a Engagement protrusion 5 Inner hook peripheral wall 6,5 Outer peripheral surface 7 Thread tension spring 10 Track groove 11 Track 13 Thread member 14 Inner peripheral surface 18 End 21 Bobbin thread holding section 22 Bobbin thread insertion hole 23 Latch 24 Notch groove section 25 Opening section 26 Stepped section 27, 43 Detachment prevention member 28 Fixing section 29 Restricting section 30 Narrow section 31 Gap 32 Upper end 33 Tip section 34, 44 Corner section 35 Upper surface 36 Pan head machine screw 37 Surrounding wall 38 Upper end 39 Wall portion 40 Upstream guide wall portion 41 Downstream side guide wall portion 42 End surface 45 Opener 46 Needle plate 46a Engagement recess 46a1 One end surface 47 Blade tip 48 Projection portion 49 Rotating shaft 50 Sewing Needle T Bobbin thread S Virtual plane

Claims (3)

A sword tip that captures the needle thread, and a cylindrical outer hook peripheral wall portion provided with the sword tip, and an outer hook that is rotated around a rotation axis parallel to the axis of the sewing needle through which the needle thread is inserted,
An inner hook that has a cylindrical inner hook peripheral wall portion and is housed in the outer hook coaxially with the rotation axis.
A bobbin stored in the inner hook,
A thread tension spring which is provided on the outer peripheral surface of the inner rotary hook peripheral wall portion and presses a bobbin thread wound around the bobbin extending from the bobbin on the outer peripheral surface of the inner rotary hook peripheral wall portion,
The inner hook is
A bobbin thread holding portion protruding radially outward from an end portion on the side facing the axis of the needle of the inner rotary hook peripheral wall portion, than the point of a sword, a person in the radial direction and the said needle A bobbin thread holding portion having a bobbin thread insertion hole through which the bobbin thread is inserted is provided on a side facing the axis from the upstream side in the rotation direction of the outer hook .
In the bobbin thread holding portion, a notch groove portion that is continuously provided in the bobbin thread insertion hole and has an opening on the downstream side of the bobbin thread holding portion in the moving direction of the needle thread is formed,
A retaining member is provided on the upper surface of the cut groove portion to cover the cut groove portion in an elastically deformed state in a state where the tip portion projects downstream of the bobbin thread holding portion in the moving direction of the needle thread. Horizontal full-turn hook characterized by.   The horizontal full-rotation rotary hook according to claim 1, wherein the bobbin thread insertion hole is opened downstream in the moving direction of the needle thread caught by the outer hook. The bobbin thread holding portion is in contact with an imaginary plane including an end surface of an end portion of the inner hook peripheral wall portion on the side facing the axis of the sewing needle from the inner hook peripheral wall portion side. Alternatively, the horizontal full rotary hook described in 2.

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