JP2016202750A - sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sewing machine which, while using a general-purpose needle, can reduce defects in stitch formation caused by instability in capturing of a thread loop.SOLUTION: A sewing machine 1 includes: a needle 30 through which a thread T is passed, and which is vertically moved; a hook 40 having a hook point 41 for capturing a thread loop T1 formed on the side part of the needle 30, at a capturing position to which the needle 30 is lowered; and a guide member 20 which, in such a state that the needle 30 is located at the capturing position, is provided at a position facing the hook 40 with the axis of the needle 30 interposed therebetween and is brought into contact with the thread T toward a position where the hook 40 is provided.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a sewing machine, and more particularly to a sewing machine including a guide member that assists in forming an appropriate yarn loop.

  In sewing the sewing machine, the formation of the seam becomes unstable, and the occurrence of problems such as stitch skipping, rolling, and thread breakage may become a problem. These problems are particularly likely to occur when the thickness of the sewing product changes, or when the operator has moved the sewing product significantly.

  In the conventional general sewing machine 100, during normal sewing, as shown in FIG. 5 (a), an edge portion 31 of the needle 30 is formed while the needle 30 passing through the upper thread T is lowered. A thread loop T1 is formed at the part, and a seam is formed by capturing the thread loop T1 with the sword tip 41 of the hook 40 that houses a bobbin (not shown) wound with a lower thread. However, as shown in FIGS. 5B and 6A, when the thread loop T1 is not properly formed at the position on the sword tip 41 side, such as being formed on the opposite side of the hook 40 with the needle 30 in between. Alternatively, as shown in FIG. 6B, when the needle 30 is bent and deformed and separated from the hook 40, the sword tip 41 may not be able to capture the yarn loop T1 stably. Such a situation causes problems such as skipping, whispering, and thread breakage.

  In order to avoid such troubles due to instability of thread loop capture, for example, the needle is formed thicker than before or a special coating is applied to the surface, thereby increasing the strength of the needle, bending, etc. The method of making it hard to receive the deformation | transformation of is taken. Further, as disclosed in Patent Document 1, a needle having a special shape of the edge portion in which the thread loop is formed may be used.

Japanese Patent Laid-Open No. 2004-81280

  As described above, when using special needles, even if the problems such as skipping, flapping, and thread breakage can be reduced, the needle marks are noticeable or the thread breakage occurs in the sewn product that forms the seam. If the workpiece is vibrated during the sewing operation, another problem may occur. In addition, the use of a special needle causes a decrease in the versatility of the needle itself and the sewing machine, and an increase in the cost required for the needle.

  The problem to be solved by the present invention is to provide a sewing machine using a general-purpose needle, which can reduce problems in the formation of stitches due to instability in capturing a thread loop.

  In order to solve the above problems, a sewing machine according to the present invention has a needle that passes a thread and moves up and down, and a sword that captures a thread loop formed on a side portion of the needle at a capture position where the needle is lowered. And a guide member that is provided at a position facing the hook across the needle shaft in a state where the needle is in the capturing position, and abuts against the thread in a direction in which the hook is provided. The gist is to have.

  Here, it is preferable that the sewing machine further includes a feed dog member that feeds the workpiece, and the guide member is attached to the feed dog member. In this case, it is preferable that the guide member has elasticity to push the thread toward the direction in which the hook is provided.

  Alternatively, the guide member may be attached to the shuttle.

  In the sewing machine according to the above invention, the guide member is provided at a position facing the hook across the needle shaft at the catch position where the sword tip catches the yarn loop, and the guide member faces the direction in which the hook is provided. Abut against the thread. As a result, the thread loop is easily formed at the sword tip side of the hook. Furthermore, the guide member also abuts on the needle via the thread, thereby restricting deformation such as bending of the needle. As a result, stable thread loop capture by the sword tip is promoted without the use of a special needle, and in the formation of stitches, problems such as stitch skipping, rolling, thread breakage, etc. due to unstable thread loop capture Occurrence can be suppressed.

  Here, when the sewing machine further includes a feed dog member that feeds the workpiece, and the guide member is attached to the feed dog member, using a feed dog member provided in a general sewing machine, It is possible to effectively promote the normal formation of the yarn loop and suppress the deformation of the needle in the immediate vicinity of the place where the yarn loop is formed at the capturing position.

  In this case, if the guide member has elasticity to push the thread in the direction in which the hook is provided, the normal formation of the thread loop and the deformation of the needle are avoided while avoiding damage to the needle. The effect of regulation can be enhanced.

  Alternatively, when the guide member is attached to the hook, the guide member is provided on the hook itself having the sword that captures the thread loop, so that the capture of the thread loop by the sword can be effectively assisted. .

BRIEF DESCRIPTION OF THE DRAWINGS About the sewing machine concerning 1st embodiment of this invention, (a) The perspective view which shows a guide member with a feed dog member, (b) The perspective view which shows the state of the guide member vicinity during sewing. It is a front view which shows the state of the guide member vicinity during sewing about the sewing machine concerning the said embodiment, (a) is a state in which the guide member is assisting formation of a thread loop, (b) is a needle further in a guide member. The deformation | transformation of is shown. It is a front view which shows the state of the guide member vicinity during sewing about the sewing machine concerning the modification of the said embodiment. It is a figure which shows the structure of the shuttle provided with the guide member about the sewing machine concerning 2nd embodiment of this invention, (a) is a perspective view, (b) and (c) is the upper surface shown with the needle | hook and the upper thread | yarn It is a figure and a front view. It is a perspective view which shows the state of the needle front-end | tip part vicinity during a sewing about the conventional general sewing machine, (a) is the time of normal sewing, (b) has shown the state in which the thread loop is not formed normally. It is a front view which shows the state of the needle front-end | tip part vicinity during sewing about a conventional general sewing machine, (a) is a state in which the thread loop is not formed normally, (b) shows the state in which the needle is further bent. ing.

  Hereinafter, a sewing machine according to an embodiment of the present invention will be described in detail with reference to the drawings. In each figure, the yarn is shown with hatching, but it is for ease of viewing and does not show a cross section.

[First embodiment]
(Overview of sewing machine configuration)
The sewing machine 1 according to the first embodiment of the present invention has a structure as shown in FIG. 1 below a table surface (not shown) on which an operator places a workpiece and performs sewing work. ing. That is, the sewing machine 1 includes the feed dog member 10, the needle 30, and the shuttle 40. And it has the guide member 20 attached to the feed dog member 10. In this sewing machine 1, as the configuration of members other than the guide member 20 including the feed dog member 10, the needle 30, and the shuttle 40, the same ones as those of various conventional sewing machines such as general household and industrial use can be applied. it can. The detailed configuration of the guide member 20 will be described later.

  The feed dog member 10 has a top surface 11 provided on the upper side and disposed substantially parallel to the table surface. The top surface 11 is provided with a feed dog 14 that feeds the workpiece in the front-rear direction and a needle hole 15 through which the needle 30 passes. The top surface 11 extends downward from a portion opposite to the position where the hook 40 is disposed with respect to the axis of the needle 30 with respect to the width direction intersecting the front-rear direction. It has been. Further, a coupling portion 13 is provided so as to protrude from the drooping surface 12 to the opposite side of the hook 40 with respect to the width direction, and the feed dog member 10 is to be sewn at the coupling portion 13. Is coupled to a feed dog drive (not shown) that moves the feed dog 14.

  The needle 30 is a general-purpose sewing needle having an edge portion 31 that is recessed in the axial direction in the vicinity of the tip. The needle 30 passes through the needle hole 15 of the feed dog member 10 while passing the upper thread T. It is moved up and down along the axis. The needle 30 is attached to the sewing machine 1 so that the edge portion 31 faces the shuttle 40. A hook 40 that houses a bobbin (not shown) wound with a lower thread is provided on the opposite side of the feed dog member 10 from the hanging surface 12 with the shaft of the needle 30 interposed therebetween. The hook 40 is also a general-purpose hook similar to that used in a conventional general sewing machine.

  The needle 30 passes through the needle hole 15 of the feed dog member 10 and descends to the lowest end of the range of vertical movement, and then rises by a part of the distance until the tip reaches the needle hole 15. This rising distance is, for example, 2 mm. In this specification, the vertical position of the needle 30 at this time is referred to as a capture position. The hook 40 and the needle 30 are positioned in the vertical direction so that the height of the sword tip 41 substantially coincides with the height of the edge portion 31 when the needle 30 is in this capture position. Note that the ascending needle 30 is not temporarily stopped at the capture position, but continues to move upward through the capture position.

  As the needle 30 rises from the lowermost position to the catching position, the tension of the upper thread T is loosened, and the upper thread T moves toward the outside of the axis of the needle 30 in the vicinity of the edge portion 31 on the side of the needle 30. A slack yarn loop T1 is formed. As shown in FIG. 1B, the needle 30 extends straight above the direction in which the axis of the needle 30 moves up and down, and the upper thread T is above the portion where the thread loop T1 is formed. In a normal state that hangs down along both side portions, the yarn loop T1 is formed outside the edge portion 31, that is, on the side where the hook 40 is disposed. At this time, the blade tip 41 of the hook 40 rotating in the direction D around the shaft 42 catches the yarn loop T1. Then, the upper thread T and the lower thread (not shown) accommodated in the hook 40 are entangled to form a seam.

(Configuration of guide member)
The guide member 20 has flexibility, such as a plate material made of stainless steel, and is made of a material that functions as a leaf spring exhibiting elasticity. The guide member 20 is attached to the surface on the side facing the needle 30 of the drooping surface 12 of the feed dog member 10. Specifically, the upper end side of the plate material cut out in a strip shape constituting the guide member 20 is fixed to the upper side of the bottom surface 12 of the feed dog member 10 by welding or the like. And the lower end side of a board | plate material is hold | maintained in the state which contacted the lower end edge 12a of the drooping surface 12. FIG. That is, the lower end portion of the guide member 20 is bent toward the hanging surface 12 substantially parallel to the lower edge 12 a of the hanging surface 12, and the bent portion is locked so as to be hung on the lower edge 12 a of the hanging surface 12.

  The length along the surface of the strip-shaped plate member constituting the guide member 20 is such that the vertical direction between the portion where the upper end portion of the guide member 20 is fixed on the hanging surface 12 of the feed dog member 10 and the lower end edge 12a. It is formed longer than the distance. And the up-and-down direction halfway part of the guide member 20 is bent so that it may protrude to the side away from the drooping surface 12, ie, the side where the hook 40 is arrange | positioned. Thus, the guide member 20 functions as a biasing member that elastically applies a force in the direction of the hook 40 to the member that is in contact with the overhanging portion 21 from the direction of the hook 40. The vertical position of the largest projecting portion of the projecting portion 21 substantially coincides with the vertical position of the sword tip 41 of the hook 40. Further, the overhang amount of the overhang portion 21 (distance from the hanging surface 12 of the guide member 20) is an upper position located on the side opposite to the hook 40 in the state where the needle 30 is in the capture position when at least the normal state described above. The thread T is determined so as to come into contact with the non-edge portion side portion T2 of the thread T from the direction in which the hanging surface 12 of the feed dog member 10 is provided in the direction in which the hook 40 is provided. Further, the force applied from the guide member 20 to the non-edge portion side portion T2 of the upper thread T and the needle 30 determined by the material and thickness of the guide member 20, the amount of overhang, and the like is at least in the normal state. It is preferable that the non-corner side portion T2 of T is large enough to be pressed against the needle 30 and small enough that the needle 30 is not substantially displaced or deformed from the normal state toward the position where the hook 40 is located. .

  As described above, in the normal state shown in FIG. 1B, the thread loop T1 of the upper thread T is formed at a portion on the shuttle 40 side where the needle 30 is provided with the edge portion 31. On the other hand, in the non-edge portion T2 located on the opposite side of the hook 40 across the shaft of the needle 30, a loop structure is not formed, and the upper thread T hangs down substantially along the side surface of the needle 30. .

  The needle 30 may be bent and deformed when a step portion where the thickness of the workpiece is rapidly changed is sewn, or when an operator greatly moves the workpiece. There is a case where the tip of the needle 30 is bent and deformed in a direction away from the hook 40, that is, a direction in which the hanging surface 12 of the feed dog member 10 is disposed. In such a case, if the guide member 20 is not provided, the thread loop T1 is not stably formed in the portion of the needle 30 on the hook 40 side, as shown in FIGS. 5B and 6A. In addition, there is a possibility of being formed on the opposite side. If it becomes like this, it will become difficult to catch the upper thread T with the sword tip 41 of the hook 40, the stitches where the seam will not be partially formed, and a part of the thread constituting the twist by untwisting the upper thread T However, such troubles as thread breakage that the upper thread T is cut in the middle are likely to occur in the seam.

  However, in the sewing machine 1, the guide member 20 as described above is provided, and in the state where the needle 30 is in the capturing position, the non-edge portion side portion T2 opposite to the position where the shuttle 40 is disposed. The guide member 20 is in contact with the upper thread T in the direction in which the hook 40 is disposed. This contact eliminates the gap where the non-edge portion T2 of the upper thread T can form a yarn loop at the portion of the needle 30 opposite to the hook 40, so that the yarn loop T1 is normally provided on the edge portion 31 side. It becomes easy to be done. Further, the guide member 20 acts as a flexible leaf spring, and applies a force that elastically presses the needle thread T toward the non-edge portion side portion T2 of the upper thread T toward the shaft of the needle 30, thereby The formation of the yarn loop T1 on the side of the facing portion 31 facing the surface is further promoted. In this way, the guide member 20 promotes the formation of a stable thread loop T1 on the side of the needle 30 on which the edge portion 31 is formed facing the hook 40, so that the thread loop T1 is moved by the sword tip 41 of the hook 40. It can be captured stably and can easily form a seam normally.

  When the guide member 20 is not provided, the amount of deflection of the needle 30 increases, and when the vicinity of the tip is greatly separated from the hook 40 at the capture position, the shape is captured by the sword tip 41 as shown in FIG. Even if the possible yarn loop T1 is formed at the hook 40 side, the yarn loop T1 may not be stably captured by the sword tip 41 because the yarn loop T1 is too far from the sword tip 41. On the other hand, in the sewing machine 1, even when the needle 30 is about to be bent greatly, the bending deformation of the needle 30 can be restricted by providing the guide member 20. That is, when the guide member 20 comes into contact with the needle 30 via the non-edge portion side portion T2 of the upper thread T, the needle 30 cannot be freely bent and deformed, and the deformation amount is limited. In particular, the guide member 20 has elasticity that applies a force to the side in which the hook 40 is provided with respect to the member that is in contact with the overhanging portion 21, so that the deformed needle 30 feeds the guide member 20 to the feed dog member 10. Even if the needle member 30 is deformed so as to be pushed in the direction of the bottom surface 12, a force is applied to push back the needle 30 in the opposite direction. Thereby, the bending deformation of the needle 30 is more strongly regulated. In addition to the restriction of the bending deformation of the needle 30 as described above, the formation of the normal thread loop T1 on the side where the hook 40 is arranged is promoted as described above. It becomes easy to form the thread loop T1 having a shape suitable for catching at a position close to. The thread loop T1 is stably captured by the sword tip 41 of the hook 40, and a normal seam is easily formed.

  As described above, the guide member 20 suppresses problems caused by instability in capturing the yarn loop T1 by the sword tip 41, such as skipping, flapping, and thread breakage, and contributes to the formation of a stable seam. Such an effect is that when the needle 30 is in the capture position, the guide member 20 is located at the non-edge portion side portion of the upper thread T at the vertical position where the edge portion 31 of the needle 30 and the sword tip 41 of the shuttle 40 are disposed. Even if the guide member 20 comes into contact with the upper thread T or the needle 30 at different vertical positions, the effect is not exhibited or is limited. .

  As described above, the guide member 20 fulfilling such a function can be introduced by being attached to the feed dog member 10 provided in a conventional general sewing machine. In addition, as a member other than the guide member 20 constituting the sewing machine 1 including the needle 30, the same configuration as that of a conventional general sewing machine can be used. As described above, with a simple configuration in which the guide member 20 is attached to a conventional general sewing machine in an expanded manner, it is possible to reduce the problem of seam formation. Further, since it is not necessary to use a special member other than the guide member 20 having a simple configuration such as a specially designed needle, the cost required for the sewing machine 1 can be reduced.

  The guide portion 20 is attached to the feed dog member 10 that is present in the immediate vicinity of the needle 30 in the capture position, in particular, in the vicinity of the edge portion 31 that is the position where the thread loop T1 to be formed is formed. In addition, it is possible to contribute particularly effectively to the stabilization of sewing by the normal formation of the thread loop T1. The guide member 20 is made of a flexible material, so that force can be applied to the upper thread T and the needle 30 to effectively promote the formation of the normal thread loop T1, and the needle 30 Even when the guide member 20 is contacted, the needle 30 is less likely to be irreversibly deformed or damaged. Thereby, the stable sewing can be performed continuously.

(Guide member according to modification)
As another form of the guide member attached to the feed dog member 10, for example, a modification as shown in FIG. Here, the guide member 20 ′ is not made of a flexible belt-like member as described above, but is made of a block-like member having substantially no flexibility. And guide member 20 'has the taper shape which inclined so that it might protrude below in the direction in which the hook 40 is provided. The taper-shaped protrusion amount (distance from the drooping surface 12 of the feed dog member 10) is such that the guide member 20 'is located on the non-egre portion side portion of the upper thread T when the needle 30 is at the capture position at least in the normal state described above. It is determined to be in contact with T2.

  Also in this case, the guide member 20 ′ having a taper shape abuts on the non-edge portion side portion T <b> 2 of the upper thread T, so that the needle 30 on the side opposite to the hook 40 has a non-edge portion side of the upper thread T. Since there is no gap in which the portion T2 can form the yarn loop, the yarn loop T1 can be normally provided on the side of the edge portion 31 normally. Helps to form a stable yarn loop T1 on the side of the edge section 31. The guide member 20 ′ abuts on the needle 30 via the upper thread T, thereby restricting excessive bending deformation of the needle 30. As a result, problems such as stitch skipping, whirling, and thread breakage are suppressed, and formation of a stable seam is promoted.

  When the guide member 20 ′ made of a non-flexible block member is used as compared with the flexible guide member 20 described above, the yarn loop T1 is formed normally using elasticity. It is not possible to enjoy the effects of the assistance and the deformation restriction of the needle 30. However, in the case of the guide member 20 having flexibility, the elasticity of applying a force to the non-edge portion side portion T2 of the upper thread T may decrease during long-term use, and the degree of each effect may change over time. On the other hand, in the guide member 20 ′ made of a hard material that does not have flexibility, such a change with time can be suppressed to be small.

[Second Embodiment]
In the first embodiment and the modifications thereof, the guide member 20 (20 ′) that promotes the formation of a stable seam is attached to the feed dog member 10. A guide member can be attached to a member other than the feed dog member 10, and as a second embodiment, a mode in which the guide member is attached to the shuttle is shown.

  FIG. 4 shows a guide member 60 provided in the sewing machine 2 according to the second embodiment together with the shuttle 40. In the sewing machine 2 according to the present embodiment, as members other than the shuttle 40 to which the guide member 60 is attached, the same members as those constituting a conventional general sewing machine can be used. Even in comparison with the sewing machine 1 according to the first embodiment, the difference is only in that the guide member 60 is attached to the shuttle 40 and the guide member is not provided in the feed dog member. Description of is omitted.

  In the hook 40, a guide member 60 is fixed to an outer hook 43 provided with a sword tip 41. As shown in FIG. 4A, the guide member 60 moves away from the circumference of the outer hook 43 from the direction opposite to the direction in which the sword tip 41 is provided along the circumference around the shaft 42. It protrudes and is fixed. The tip side portion of the guide member 60 is located outside the tip side portion of the sword tip 41 with respect to the radial direction of the hook 40, and faces the tip side portion of the sword tip 41 along the radial direction of the hook 40, A facing portion 65 is formed as a gap between the two. The facing portion 65 is set to include a position where the needle 30 enters from above with the shuttle 40 fixed to the guide member 60 being attached to the sewing machine body. Forty sword tips 41 and the inner side surface 60 a of the guide member 60 are opposed to each other across the axis of the needle 30. 4 (b) and 4 (c), the inner surface 60a of the guide member 60 is a non-egreged portion of the upper thread T located on the opposite side of the hook 40 from the sword tip 41 with the shaft of the needle 30 interposed therebetween. The side portion T2 is in contact with the hook 40 in the direction toward the sword tip 41 side. The guide member 60 is made of a hard material that does not substantially have flexibility. For example, it is made of a metal material having a certain plate thickness similar to that constituting the outer hook 43 of the hook 40 and is formed integrally with the outer hook 43.

  In the state where the needle 30 is in the capture position, the guide member 60 abuts on the non-edge portion side portion T2 of the upper thread T, so that there is no gap in which the non-edge portion side portion T2 can form the yarn loop T1. Thereby, as shown in FIG.4 (c), formation of the normal thread loop T1 in the sword tip 41 side of the shuttle 40 is accelerated | stimulated. Furthermore, even if the needle 30 is bent and deformed and enters the facing portion 65 obliquely so that the tip portion is separated from the sword tip, the guide member 60 contacts the sword tip 41 via the upper thread T, and the needle 30 is inclined. Therefore, the yarn loop T1 is prevented from being formed at a position far away from the sword tip 41. By these effects, the yarn loop T1 is stably captured by the sword tip 41 of the hook 40. As a result, it is possible to suppress problems such as skipping, flapping, and thread breakage, and to form seams stably.

  The sewing machine 2 according to the present embodiment can also be realized with a simple configuration in which the guide member 60 is provided in an extended manner in the shuttle 40 used in a conventional general sewing machine. As the members constituting the sewing machine 2 such as the needle 30, general-purpose members constituting a conventional general sewing machine can be used. In this way, it is possible to obtain the sewing machine 2 that effectively promotes the stable formation of the seam with a simple configuration and at a low cost. The hook 40 is a member itself provided with a sword tip 41 for catching the thread loop T1, and by fixing a guide member 60 for assisting the formation of the thread loop T1, there are various situations depending on the state of sewing. Even in this case, the positional relationship of the guide member 60 with respect to the sword tip 41 does not change, and the function of assisting the formation of the yarn loop T1 can be stably achieved. As described above, the guide member 60 in the present embodiment is made of a material that is substantially inflexible, unlike the guide member 20 according to the first embodiment. This is to avoid the deformation of the guide member 60 accompanying the rotation of the hook 40.

  As mentioned above, although embodiment of this invention was described in detail, this invention is not limited to the said embodiment, A various change is possible in the range which does not deviate from the summary of this invention. For example, the guide member is provided at a position facing the shuttle across the needle shaft in a state where the needle is in the capture position, and the direction in which the shuttle is provided from the direction in which the drooping surface of the feed dog member is provided. As long as it comes into contact with the upper thread toward the end, it is not limited to the feed dog member or the hook, and may be attached to another member constituting the sewing machine main body. For example, a configuration is conceivable in which a guide member is attached to a needle plate that has a needle hole through which a needle passes and a long hole that exposes a feed dog member and constitutes a part of a table surface on which a workpiece is placed.

DESCRIPTION OF SYMBOLS 1 Sewing machine 10 Feeding tooth member 11 Top surface 12 Hanging | lower surface 12a Bottom edge 14 Feeding tooth 20 Guide member 21 Overhang part 30 Needle 31 Edge part 40 Hook 41 Knife tip 43 Outer hook 60 Guide member 65 Opposite part T Upper thread T1 Yarn loop T2 Non Aegri side

Claims (4)

A needle that is threaded and moves up and down;
A hook having a sword that captures a thread loop formed on the side of the needle at the capture position where the needle is lowered;
A guide member provided at a position facing the hook across the axis of the needle in a state where the needle is in the capture position, and abutting against the thread in a direction in which the hook is provided. A sewing machine characterized by The sewing machine further includes a feed dog member that feeds a sewing product,
The sewing machine according to claim 1, wherein the guide member is attached to the feed dog member. The sewing machine according to claim 2, wherein the guide member has elasticity to push the yarn toward a direction in which the hook is provided.   The sewing machine according to claim 1, wherein the guide member is attached to the shuttle.

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