JP2006192067A - Horizontal hook for sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a horizontal hook which is easily attachable to and detachable from a sewing machine main body without removing a feed dog. <P>SOLUTION: The horizontal hook consists of: an outer hook 3 rotated horizontally by a hook shaft provided vertically at a lower part; and an inner hook 5 provided rotatably in the center of the outer hook 3. At the top of the rotation orbit of the outer hook 3, the feed dog 2 is arranged. At the outer periphery part of the outer hook 3, an avoiding part 3g for avoiding the feed dog 2 when moving the outer hook 3 up and down in a vertical direction is provided. The outer hook 3 is rotated so as to arrange the avoiding part 3g formed at the outer periphery part of the outer hook 3 at the position of the feed dog 2, and the horizontal hook is next moved in the vertical direction. Thus, the feed dog 2 arranged over the rotation orbit of the outer hook 3 can be avoided by the avoiding part 24, and the horizontal hook can easily be attached to and detached from the sewing machine main body without removing the feed dog 2 from the sewing machine main body. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a horizontal hook for a sewing machine.

In a two-needle lockstitch needle feed sewing machine, the upper thread is inserted below the needle plate with a pair of sewing needles, and the upper thread and lower thread are entangled with a pair of horizontal hooks arranged below the needle plate. Sewing is performed (see, for example, Patent Document 1). The horizontal hook captures the upper thread passed through the sewing needle to form an upper thread loop, and also functions to insert the lower thread through the upper thread loop and entangle these threads.
JP 2004-174120 A

  By the way, when it is necessary to replace the horizontal hook when removing the needle plate and maintaining the horizontal hook, the horizontal hook cannot be removed unless it is pulled up directly because of the hook shaft.

  At this time, as shown in FIG. 5, since the outer hooks 3 and 4 interfere with the feed dog 2, in order to remove the horizontal hook, the feed dog 2 must first be removed. However, since the feed dog 2 is firmly fixed to the drive mechanism with screws 2b or the like, there is a problem that it takes time to remove.

  An object of the present invention is to provide a horizontal shuttle that can be easily attached to and detached from a sewing machine body without removing a feed dog.

  In order to solve the above-mentioned problems, as shown in FIGS. 1 to 4, the invention described in claim 1 includes an outer hook 3 that is rotated horizontally by a hook shaft that is vertically provided at a lower portion, and an outer hook 3. In a sewing machine comprising a horizontal hook made up of a central hook 5 provided rotatably at the center and a feed dog 2 arranged above the rotation path of the outer hook 3, the outer hook 3 has an outer hook The sewing machine is provided with an avoidance portion (vertical surface 3g) for avoiding the feed dog 2 when the 3 is moved up and down in the vertical direction.

  According to the first aspect of the present invention, the outer hook is rotated so that the avoidance portion provided on the outer peripheral portion of the outer hook is disposed at the position of the feed dog, and then the horizontal hook is lifted vertically to rotate the hook shaft. When pulling out from the sewing machine main body, the feed dog arranged above the rotation path of the outer hook can be avoided by the avoiding part, and the horizontal hook can be removed from the sewing machine main body without removing the feed dog from the sewing machine main body. . Similarly, the horizontal hook can be attached to the sewing machine body.

  The invention according to claim 2 is the horizontal hook of the sewing machine according to claim 1, wherein the outer hook 3 protrudes toward the downstream side in the rotation direction and rotates as the outer hook 3 rotates. A sword tip 3c that captures the upper thread between the sewing needle and the sewing product, and a sword tip that is provided continuously from the sword tip 3c on the upstream side in the rotational direction and has an inclined surface from the outer peripheral portion of the outer hook toward the upper end of the inner hook. Is provided with an inclined portion 3d for guiding the portion of the upper thread captured by the sewing machine to the upper portion of the inner hook along the inclined surface, and the avoiding portion (vertical surface 3g) is downstream in the rotational direction from the sword tip 3c. And it is provided in the part of the rotation direction upstream rather than the inclination part 3d, It is characterized by the above-mentioned.

  According to the second aspect of the present invention, since the avoiding portion is provided at a portion downstream of the sword in the rotational direction and upstream of the inclined portion, the avoiding portion may hinder the movement of the upper thread. Absent.

  The invention according to claim 3 is the horizontal hook of the sewing machine according to claim 1 or 2, wherein the avoiding portion (vertical surface 3g) is one vertical surface on the outer peripheral portion of the outer hook 3 having a circular shape in plan view. The vertical surface 3g is formed parallel to the feed direction of the feed dog 2 and spaced apart from the side surface of the feed dog 2 at a predetermined rotational phase.

  According to the third aspect of the present invention, since the vertical surface is arranged in parallel to the feed direction of the feed dog and spaced apart from the side surface of the feed dog, the feed dog is located at any position in the feed direction. However, the interference between the outer hook and the feed dog can be avoided, and the horizontal hook can be easily attached to and detached from the sewing machine body without adjusting the position of the feed dog.

  According to the present invention, the outer hook is rotated so that the avoidance portion provided on the outer peripheral portion of the outer hook is disposed at the position of the feed dog, and then the horizontal hook is moved in the vertical direction, so that the rotation path of the outer hook is rotated. The feed dog disposed above can be avoided by the avoiding portion, and the horizontal hook can be easily attached to and detached from the machine body without removing the feed dog from the machine body.

  Hereinafter, embodiments of the present invention will be described. FIG. 1 is a plan view showing a schematic configuration of a sewing machine to which the present invention is applied, and FIG. 2 is an elevation view showing a horizontal shuttle of the present invention.

  The horizontal hook of the present invention includes left and right outer hooks 3 and 4 and inner hooks 5 and 6 that are supported in the outer hooks 3 and 4 while being spaced apart from each other up and down, as in the conventional horizontal hook. At the bottom of the outer hooks 3 and 4, hook shafts 3 a and 4 a arranged vertically are provided. The outer hooks 3 and 4 are rotationally driven around the hook shafts 3a and 4a. The rotation of the outer hooks 3 and 4 is interlocked with the vertical movement of the sewing needle (not shown) by connecting the hook shafts 3a and 4a to a well-known interlocking mechanism. This is twice the period of vertical movement.

  On the outer periphery of the outer hooks 3 and 4, sword tips 3c and 4c for catching the upper thread are projected outward and downstream in the rotational direction. The sword tips 3c, 4c hook and catch an upper thread stretched between the tip of a sewing needle (not shown) and a sewing product (cloth) (not shown) above the needle plate. The upper thread is pulled with the rotation of 4 to form upper thread loops 15 and 16.

  Inclined portions 3d and 4d for eliminating a step from the upper ends of the inner hooks 5 and 6 are provided continuously to the blade tips 3c and 4c on the outer peripheral portion of the outer hooks 3 and 4 upstream of the blade tips 3c and 4c in the rotation direction. ing. Of the upper thread loops 15 and 16 captured by the sword tip 3c, the portions that move along the outer peripheries of the outer hooks 3 and 4 rise while smoothly contacting the inclined portions 3d and 4d. To the top of the.

  Fitting portions 5c and 6c provided on the outer peripheral portions of the inner hooks 5 and 6, which will be described later, are constrained to the portions upstream of the inclined portions 3d and 4d in the rotational direction and downstream of the sword tips 3c and 4c. The intermediate hook pressers 3e and 4e are attached.

  In addition, protrusions 3f and 4f projecting toward the upstream side in the rotation direction are provided at the upstream ends of the inner hook pressers 3e and 4e so as to face the sword tips 3c and 4c. . The protrusions 3f and 4f guide the lower thread to the upper part of the swords 3c and 4c so that the lower thread is not captured by the swords 3c and 4c.

  The inner hooks 5 and 6 store bobbins (not shown) for supplying lower thread therein. As shown in FIG. 2, the outer portions of the outer hooks 3, 4 are arranged on the outer periphery of the inner hooks 5, 6 so that the lower portions of the inner hooks 5, 6 can be rotated while floating from the outer hooks 3, 4. Annular fitting portions 5c and 6c that are fitted to the peripheral surface are provided. The upper portions of the fitting portions 5c and 6c are restrained by the inner hook pressers 3e and 4e. Notches (not shown) for passing the upper thread under the inner hooks 5 and 6 are provided in a part of the fitting portions 5c and 6c.

At the upper part of the inner hooks 5 and 6, inner hook protrusions 5a and 6a are provided toward the outer side in the radial direction. The hook projections 5a and 6a are loosely inserted between two needle plate projections (upstream projection 1a and downstream projection 1b) that project downward from the lower surface of the needle plate 1. The needle plate protrusions are located on the upstream side and the downstream side in the rotation direction, and the inner hooks 5 and 6 receive a rotational force as the outer hooks 3 and 4 rotate, so the inner hook protrusions 5a and 6a are downstream protrusions. It will be in the state contact | abutted to 1b. For this reason, the inner hooks 5 and 6 do not rotate with the outer hooks 3 and 4.
Further, engaging protrusions 5b and 6b to be engaged with engaging claws 13 and 14 to be described later are provided on the upper side of the inner hooks 5 and 6 and upstream of the inner hook protrusions 5a and 6a in the rotation direction.

  When the outer hooks 3, 4 are rotated without rotating the inner hooks 5, 6, first, the sword tips 3 c, 4 c capture the upper thread and form upper thread loops 15, 16. At this time, the upper side (cloth side) of the upper thread is pointed inside the outer hook and the lower side (needle side) is guided outside. When the outer hook is further rotated, the upper thread (not shown) on the cloth side of the sword is guided to the lower side of the inner hooks 5 and 6 from the notch of the fitting portion.

  When the outer hooks 3 and 4 are further rotated, the upper thread on the fabric side from the sword tips 3c and 4c is passed under the middle hooks 5 and 6 from the notch, and the upper thread on the needle side from the sword tips 3c and 4c. Moves along the outer periphery of the outer hooks 3, 4, rises while smoothly contacting the inclined portions 3 d, 4 d, reaches the upper part of the inner hooks 5, 6, and moves the outer hooks 3, 4 and the inner hooks 5, 6. Pass through the top. At this time, if the inner hook protrusions 5a, 6a and the downstream protrusions 1b, 1b are kept in contact, the needle-side upper thread passes between the intermediate hook protrusions 5a, 6a and the downstream protrusions 1b, 1b. Therefore, the inner hook protrusions 5a, 6a and the downstream protrusions 1b, 1b are separated from each other by a later-described opener at a predetermined rotational phase of the outer hooks 3, 4.

  When the upper thread on the needle side exceeds the diameter of the outer hooks 3 and 4 and the outer hooks 3 and 4 are further rotated, the upper thread loops 15 and 16 are detached from the sword tips 3c and 4c. Then, the intermediate hooks 5 and 6 are passed between the upper thread on the cloth side passing through the lower part of the inner hooks 5 and 6 and the upper thread on the needle side passing through the upper part of the inner hooks 5 and 6. The lower thread supplied from the hooks 5 and 6 is entangled with the upper thread.

  When the outer hooks 3 and 4 further rotate, the upper thread loop is again captured by the sword tips 3c and 4c. By repeating the above, the upper thread and the lower thread are entangled and the sewing proceeds.

  The opener includes opener arms 7 and 8, link arms 11 and 12, and engaging claws 13 and 14. The base ends of the opener arms 7 and 8 are rotatably attached to opener shafts 9 and 10 provided in the sewing machine body. In addition, link shafts 7 a and 8 a that are connected to one ends of the link arms 11 and 12 are provided in the middle part of the opener arms 7 and 8. Further, engagement claws 13 and 14 are fixed to the tips of the opener arms 7 and 8. The engaging claws 13 and 14 engage with the engaging protrusions 5b and 6b of the inner hooks 5 and 6, respectively. Since the engaging claws 13 and 14 are fixed to the opener arms 7 and 8 by set screws 7b and 8b that are passed through elongated holes (not shown) provided in the base portion, the position can be finely adjusted.

  The link arms 11 and 12 are connected at the other end to eccentric cams 3b and 4b provided integrally with the hook shafts 3a and 4a. When the hook shafts 3a and 4a rotate, the link arms 11 and 12 are given a circular motion by the eccentric cams 3b and 4b, and a swinging motion about the opener shafts 9 and 10 is given to the opener arms 7 and 8.

  When the opener arms 7 and 8 swing, the engaging claws 13 and 14 are engaged with or separated from the engaging protrusions 5b and 6b. When the engaging claws 13 and 14 are engaged with the engaging protrusions 5b and 6b, the inner hooks 5 and 6 rotate in the opposite direction to the outer hooks 3 and 4, so the inner hook protrusions 5a and 6a and the downstream protrusions 1b and 1b are rotated. Are spaced apart to create a gap through which the upper thread passes.

  When the upper thread loops 15 and 16 are caught on the sword, the upper thread needs to pass between the engaging claws 13 and 14 and the engaging protrusions 5b and 6b. At this time, the engaging claws 13 and 14 and the engaging protrusions 5b and 6b are separated from each other, and the inner hook protrusions 5a and 6a and the downstream protrusions 1b and 1b come into contact with each other. The opening and closing timing (rotation phase) between the hook projections 5a and 6a and the downstream projections 1b and 1b and the engagement claws 13 and 14 and the engagement projections 5b and 6b by the opener is determined by the eccentric cams 3b and 4b. The upper thread loops 15 and 16 are smoothly moved along the outer peripheries of the outer hooks 3 and 4, which are determined by the arrangement of the opener shafts 9 and 10 and the link shafts 7a and 8a.

  A feed dog 2 that feeds the cloth to be sewn in one direction is provided at a portion of the needle plate 1 where the sewing needle is inserted. The feed dog 2 is provided with a needle hole 2a through which a sewing needle is inserted, and has an upper surface formed in a sawtooth shape in cross section in order to increase friction when it comes into contact with the cloth.

  The feed dog 2 is driven by a drive mechanism (not shown) and advances in the cloth feed direction with the upper surface protruding upward from the upper surface of the needle plate 1, and then the upper surface is lowered below the upper surface of the needle plate 1. Repeat the reverse movement in the direction opposite to the cloth feed direction and feed the cloth. In addition, the upper direction of FIG. 1 is a front direction which sends cloth.

  The movement cycle of the drive mechanism of the feed dog 2 is synchronized with the cycle of the sewing needle, and the sewing needle is inserted into the needle hole 2, that is, the sewing needle is stuck in the cloth in the cloth feed direction together with the feed dog 2. It moves forward and retracts with the feed dog 2 in a state of coming out of the needle hole and rising above the cloth. By feeding the cloth with the feed dog 2 in a state where the sewing needle is stuck in the cloth, even a heavy cloth or a plurality of stacked cloths can be reliably fed.

  FIG. 3 is a plan view showing the horizontal hook of the present invention. The horizontal hook of the present invention is different from the conventional one in the structure of the outer hook. Hereinafter, the left horizontal hook will be described, but the same applies to the right horizontal hook.

  The outer hook 3 has an outer peripheral portion 3c, an inclined portion 3d, and an inner hook presser 3e, and the inner hook presser 3e is provided with a projection 3f. The portion provided with 3e is provided with a notch formed by a vertical surface 3g that is linear when viewed from above.

  The vertical surface 3g is preferably provided at a position that does not hinder the movement of the upper thread loop 15 that moves along the outer periphery of the outer hook 3. Therefore, the position where the vertical surface 3g can be provided is a portion where there is no sword tip 3c for catching the upper thread loop 15 or the inclined portion 3d where the upper thread loop 15 contacts, and the downstream side in the rotational direction from the sword tip 3c and the inclined portion. It is a portion on the upstream side in the rotational direction from 3d, that is, a portion to which the inner hook presser 3e is attached.

  Here, as shown in FIG. 4, the vertical surface 3 g is parallel to the feed direction of the feed dog 2 when the outer hook 3 is arranged in a predetermined rotational phase with the horizontal hook attached to the sewing machine body. And it arrange | positions apart from the side surface of the feed dog 2 to the side. For this reason, interference between the outer hook 3 and the feed dog 2 can be avoided, and the horizontal hook can be attached to and detached from the sewing machine main body without removing the feed dog 2 from the sewing machine main body.

  Moreover, in the state which has arrange | positioned the vertical surface 3g in this way, even if the feed dog 2 exists in any position of a feed direction, interference with the outer hook 3 and the feed dog 2 can be avoided. For this reason, the horizontal shuttle can be attached to and detached from the sewing machine body without adjusting the position of the feed dog 2.

  In the above embodiment, the outer peripheral portion of the outer hook 3 is provided with a notch by the vertical surface 3g to avoid interference between the outer hook 3 and the feed dog 2. However, the shape of the notch is not limited to this. Any shape that can avoid interference with the feed dog 2 and that does not impair the function of the outer hook 3 is optional.

  Further, when the horizontal hook is removed, the outer hooks 5 and 6 are connected to the hook shafts 3a and 4a and the known interlocking mechanism. It can rotate freely regardless of. For this reason, the formation position of the vertical surfaces 3g and 4g on the circumference of the outer hook 3 is not limited to the above-mentioned position, and is arbitrary as long as the function of the horizontal hook is not hindered. Other specific detailed structures can be changed as appropriate.

It is a top view which shows schematic structure of the sewing machine with which this invention is applied. It is an elevational view showing a horizontal shuttle of the sewing machine of the present invention. It is a top view which shows the horizontal shuttle of the sewing machine of this invention. It is a top view which shows arrangement | positioning of the horizontal shuttle and feed dog of the sewing machine of this invention. It is a top view which shows the arrangement | positioning of the horizontal shuttle and feed dog of the conventional sewing machine.

Explanation of symbols

2 Feed dog 3, 4 Outer hook 3c, 4c Blade tip 3d, 4d Inclined part 3g, 4g Vertical surface (avoidance part)
5 and 6

Claims (3)

A horizontal hook composed of an outer hook that is rotated horizontally by a hook shaft provided vertically at the bottom, and an inner hook that is rotatably provided at the center of the outer hook;
In a sewing machine provided with a feed dog arranged above the rotation path of the outer hook,
A horizontal hook for a sewing machine, characterized in that an outer periphery of the outer hook is provided with an avoiding portion for avoiding a feed dog when the outer hook is moved up and down in the vertical direction.   The outer edge of the outer hook protrudes toward the downstream side in the rotation direction, and the outer hook rotates to capture the upper thread between the sewing needle and the sewing product. An inclined portion that has an inclined surface that extends from the outer peripheral portion of the outer hook toward the upper end of the inner hook, and guides the upper thread sewing needle side portion of the upper thread captured by the sword tip to the upper portion of the inner hook along the inclined surface 2. The horizontal hook for a sewing machine according to claim 1, wherein the avoiding portion is provided at a portion downstream of the sword in the rotational direction and upstream of the inclined portion in the rotational direction.   The avoiding portion is formed as a notch by a single vertical surface in the outer peripheral portion of the outer hook having a circular shape in plan view, and the vertical surface is parallel to the feed direction of the feed dog and more than the side surface of the feed dog at a predetermined rotational phase. The horizontal hook of the sewing machine according to claim 1 or 2, wherein the horizontal hook of the sewing machine is spaced apart from the side.

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