Material guide device in sewing machine

Abstract

It guides the string-like material with stable tension, unaffected by differences in the rotation direction of the annular guide. [Solution] The annular guide (66), which is rotatable around the axis of the needle bar, rotates, causing the guide portion (61) to rotate as well, guiding the string-like material (L) to the needle base position. A flexible hollow member (65) is provided, and the supplied string-like material is inserted into one end (65a) of the hollow member (65) and pulled out from the other end (65b). The other end (65b) of the hollow member (65) is connected to the annular guide (66) and rotates together with the annular guide. As the hollow member (65) is pulled in in response to the rotation of the annular guide, the hollow member (65) is wrapped around the annular guide (66). When the annular guide rotates in the opposite direction, the hollow member is unwound and pushed outward, but due to the stiffness of the hollow member, it is pushed out smoothly without slackening.

Description

Technical Field

[0001] The present invention relates to a sewing machine that sews a string-like material such as a tape or a cord to a workpiece by means of a straight stitch, and particularly to a material guide device that guides the string-like material to be sewn to the position of the needle tip while rotating around the axis of the needle bar.

Background Art

[0002] Conventionally, there is known a sewing machine (for example, a straight stitch hand embroidery machine) having an upper and lower driven needle bar, a sewing needle attached to the lower end of the needle bar, a rotating body assembled coaxially with the needle bar and freely rotatable about its axis, a guide device attached to the rotating body for guiding a string-like material (for example, a string-like embroidery material such as a tape or a cord) to the position of the needle tip of the sewing needle, and a material supply device for supplying the string-like material to the guide device. The rotation of the rotating body is controlled according to the moving direction of the fabric based on embroidery data, and while changing the orientation of the guide device so that the guiding direction of the string-like material to the needle tip is appropriate, the string-like material is sewn to the workpiece (fabric) by means of a straight stitch, or the guide device is zigzagged by a zigzag mechanism and the string-like material is sewn to the workpiece by means of a zigzag stitch. As a material supply device for this type of sewing machine, in preparation for the use of a large amount of string-like material, a configuration using a large bobbin wound with the string-like material is adopted, and in order to smoothly feed out the string-like material from the bobbin, a configuration in which the large bobbin is actively rotationally driven is known (for example, Patent Document 1 or 2).

[0003] In the sewing machine described in Patent Document 1 or 2, a flexible tube through which a string-like material passes is fixed to the front of the sewing machine head via a bracket, and the tip of this tube is fixed to a holder arm fixed to the rotating body, and the string-like material pulled out from the tip is introduced into a guide device. As a result, as the rotating body rotates, the tip of the tube rotates together with the guide device according to the direction of movement of the fabric based on the embroidery data, and the string-like material passed through the tube can be appropriately guided to the needle base position of the sewing needle via the guide device. However, in such a conventional configuration, if the rotating body (and guide device) is rotated by 360 degrees or more, the tube may become entangled with related parts of the sewing machine head, so it is necessary to use embroidery pattern data that does not rotate the rotating body (and guide device) by 360 degrees or more, which has the disadvantage that the embroidery patterns that can be formed are limited.

[0004] To improve upon these shortcomings, Patent Document 3 employs a configuration that includes an annular guide that rotates with the rotating body without using a tube, and a cover member that covers the annular guide. The cover member is fixed so as not to rotate with the rotating body, and a string-like material is passed through a through-hole provided in the cover member, introducing the string-like material into the internal space between the cover member and the annular guide. Furthermore, the string-like material is pulled out from an opening provided in the annular guide and introduced into the guide device (guide tip). The annular guide is provided with a cylindrical portion that surrounds the center of rotation, and the string-like material can be wound around the cylindrical portion within the internal space. With this configuration, even if the rotating body, i.e., the guide device (guide tip), rotates 360 degrees or more, the string-like material introduced into the internal space will be wound around the cylindrical portion of the annular guide, and the string-like material will be unwound from the cylindrical portion of the annular guide as the rotation proceeds in the opposite direction to when it was wound. Therefore, it becomes possible to use embroidery pattern data that rotates the rotating body (and guide device) 360 degrees or more, thereby improving the degree of freedom in the embroidery patterns that can be formed on string-like materials. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2005-144056 [Patent Document 2] Japanese Patent Publication No. 2007-159829 [Patent Document 3] Japanese Patent No. 6049361 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] However, in the configuration shown in Patent Document 3, a problem can arise in which the tension on the string-like material differs depending on the rotation direction of the rotating body (i.e., the annular guide), resulting in unstable stitching quality. For example, when the rotation direction of the rotating body (e.g., clockwise) coincides with the direction in which the string-like material wrapped around the cylindrical part is fed out, the string-like material is fed out while being pulled by the rotating annular guide, and stitching progresses, with an amount of string-like material corresponding to the rotation angle (amount of rotation) being wrapped around the cylindrical part of the annular guide. On the other hand, when the rotating body rotates in the opposite direction (e.g., counterclockwise), the string-like material is unwound from the cylindrical part of the annular guide, but the unwound portion of the string-like material remains in the internal space of the annular guide. As a result, there is an excess of material compared to the rotation angle (amount of rotation), causing the string-like material to slacken, and the tension of the string-like material guided to the needle position becomes lower compared to stitching when rotating clockwise. This results in a difference in the tension of the string-like material guided to the needle position depending on the rotation direction of the rotating body, which negatively affects stitching quality. Furthermore, such tension differences are also influenced by the material of the string-like material. Specifically, if the string-like material is made of a material with low tension (i.e., lacking rigidity), the string-like material tends to sag and twist within the internal space of the annular guide, resulting in a more pronounced problem. On the other hand, when the rotating body rotates clockwise, tension is directly applied to the string-like material wrapped around the cylindrical part in the direction of dispensing by the cylindrical part. Therefore, if the amount of string-like material dispensed from the supply source is insufficient, the string-like material is subjected to stress, and excessive tension is likely to occur.

[0007] The present invention has been made in view of the above-mentioned points, and aims to provide a sewing machine material guiding device that, in a configuration in which a string-like material is rotated in any rotational direction using an annular guide, can guide the string-like material with stable tension without being affected by differences in the rotational direction of the annular guide. [Means for solving the problem]

[0008] The sewing machine material guide device according to the present invention is a material guide device for guiding a string-like material to be sewn in a sewing machine to the needle base position, comprising: an annular guide body rotatable around the axis of the needle bar; a flexible hollow member having one end and the other end, into which a string-like material supplied from a supply source is inserted from the one end and pulled out from the other end, the other end of the hollow member configured to rotate together with the annular guide body; and a guide portion configured to rotate together with the annular guide body, for guiding the string-like material pulled out from the other end of the hollow member to the vicinity of the needle base position.

[0009] According to this, the string-like material is inserted from one end of a flexible hollow member, passes through the hollow member, is pulled out from the other end of the hollow member, is introduced into the guide section, and is guided by the guide section to the vicinity of the needle source position. Since the other end of the hollow member is configured to rotate together with the annular guide, the hollow member moves in a direction that is pulled towards the annular guide or pushed out, depending on the direction of rotation of the annular guide. Due to the flexibility (flexibility or bendability) of the hollow member, when the hollow member moves in a direction that is pulled towards the annular guide, the hollow member is easily wound up inside the annular guide along the direction of rotation of the annular guide. Also, when the hollow member moves in a direction that is pushed out from the side of the annular guide, due to the flexibility (stiffness or ease of recovery) of the hollow member, the hollow member is easily unwound from inside the annular guide, so that the excess portion of the hollow member remaining inside the annular guide is suppressed as much as possible. On the other hand, since the string-like material passes through the hollow member and is introduced into the guide section, the structure is such that the string-like material is not directly affected by the tension differences caused by the rotation direction of the annular guide. In other words, since the tension caused by the rotation of the annular guide is mostly applied to the hollow member, the tension on the string-like material that passes freely inside it is considerably suppressed. Therefore, the string-like material can be guided with stable tension without being affected by differences in the rotation direction of the annular guide, and stable sewing quality can be provided regardless of the material of the string-like material or the sewing pattern.

[0010] In one embodiment, a plurality of the hollow members are provided, and a plurality of string-like materials supplied from a supply source are inserted into one end of each hollow member and pulled out from the other end, and the other end of each hollow member is configured to rotate together with the annular guide, and the guide portion may include a plurality of guide members for guiding the string-like materials pulled out from each hollow member to the vicinity of the needle base position. This configuration allows for the selective supply of any of the plurality of string-like materials to a single sewing machine head, and since each string-like material rotates together with the annular guide while passed through its respective hollow member, the string-like materials do not interfere with or entangle with each other, and thus, excessive tension on the string-like materials due to interference or entanglement is prevented.

[0011] In one embodiment, a cover member may be further provided, positioned to form a space between itself and the annular guide, allowing the portion of the hollow member near the other end to move in and out of the space. This allows the cover member to prevent the hollow member from floating up when it is wound up or unwound within the annular guide along the rotational direction of the annular guide. Furthermore, a rotatable roller may be further provided, positioned near the entrance to the space, which can rotate in conjunction with the movement of the hollow member as it moves in and out of the space. This allows the rotation of the roller to smooth the movement of the hollow member when it comes into contact with the roller as it moves in and out of the space in response to the rotation of the annular guide, thereby assisting the rotation of the hollow member in conjunction with the annular guide. Additionally, the roller can restrict the hollow member from floating up while it moves in and out of the space, allowing the hollow member to move smoothly into and out of the space of the annular guide.

[0012] In one embodiment, a supply amount adjustment device may be provided in the supply path between the supply source and the annular guide, which adjusts the supply of the hollow member in accordance with the movement of the hollow member accompanying the clockwise or counterclockwise rotation of the annular guide. This allows the supply of the hollow member to be adjusted by the supply amount adjustment device to move the hollow member in the direction of being pushed out (i.e., to recover an appropriate amount of the hollow member) when the hollow member moves in the direction of being pushed out from the annular guide towards the inlet. Therefore, it is possible to reliably prevent any excess portion of the hollow member that is unwound from the annular guide from remaining inside the annular guide. As an example, this supply amount adjustment device may be configured to fix one end of the hollow member and hold the hollow member in a wound state that allows it to be freely wound up and unwound. With such a configuration, the hollow member can be held compactly in a wound state, so there is no risk of the movement of the hollow member during winding or unwinding irregularly contacting the surrounding parts of the sewing machine head.

[0013] For example, the supply adjustment device may include a pair of rollers, the pair of rollers configured to change the distance between their axes, the hollow member being wound around the pair of rollers, the distance between the axes of the pair of rollers being narrowed by the tension force exerted from the other end of the hollow member, and the distance between the axes of the pair of rollers being widened by the decrease in the tension force from the other end. This makes it possible to provide a more compact structure for holding the hollow member wound in a state that can be freely wound up and unwound. Furthermore, as an example, the pair of rollers may consist of an upper roller and a lower roller, and the distance between the axes of the pair of rollers may be widened by the weight of the lower roller due to the decrease in the tension force from the other end. This makes it possible to adjust the supply of the hollow member in the supply adjustment device by a simple gravitational action, and the structure can be simplified. [Brief explanation of the drawing]

[0014] [Figure 1]Front view of a sewing machine to which a material guiding device according to an embodiment of the present invention is applied. [Figure 2] Right side view of the sewing machine shown in FIG. 1. [Figure 3] Perspective view seen from obliquely above, showing an enlarged view of the main components of the material guiding device provided at the lower part of the sewing head of the sewing machine shown in FIG. 1. [Figure 4] Perspective view seen from obliquely below of the main components of the material guiding device shown in FIG. 3. [Figure 5] Exploded perspective view showing some components of the material guiding device shown in FIGS. 3 and 4 and some components of the material guide lifting mechanism related thereto, with some parts broken away. [Figure 6] Perspective view seen from obliquely above similar to FIG. 3, showing a state in which the annular guide body has rotated counterclockwise by about 90 degrees from the state shown in FIG. 3. [Figure 7] Front view of a sewing machine to which a material guiding device according to another embodiment of the present invention is applied. [Figure 8] Right side view of the sewing machine shown in FIG. 7. [Figure 9] Diagram showing an example of the winding operation of the hollow member in the embodiment shown in FIGS. 7 and 8.

Mode for Carrying Out the Invention

[0015] FIG. 1 is a front view of a sewing machine to which a material guiding device <6> according to an embodiment is applied, and FIG. 2 is a right side view of the sewing machine. This material guiding device <6> is installed at the lower part (near the needle tip position) of one sewing head <H> of a sewing machine, such as a lockstitch hand embroidery machine, and functions to guide a cord-like material to be sewn in the sewing machine to the needle tip position.

[0016] <Supply of Cord-Like Material> As an example, multiple sewing heads H can be arranged at regular intervals on the front of the sewing machine frame M, but in this embodiment, for the sake of explanation, only one sewing head H is shown. Above the sewing head H, a material supply device 1 is provided for supplying string-like material to the sewing head. As an example, the material supply device 1 includes a bobbin placement device 2 that rotatably supports multiple bobbins 21 wound with string-like material L, and a rotation drive device (not shown) that selectively imparts rotational motion to any of the bobbins 21. The figure shows an example in which three bobbins 21, each wound with a different string-like material L, are arranged in the bobbin placement device 2, and the string-like material L drawn from each bobbin 21 is supplied to the sewing head H below. As one bobbin 21, which is selectively given rotational motion by the rotation drive device (not shown), rotates, the string-like material L is actively fed out from the bobbin 21 and supplied to the sewing head H. For the sake of illustration convenience, the string-like material L is omitted from the diagram as appropriate, but multiple string-like materials L (three for example) exist in parallel along the entire path from the material supply device 1 to the material guide device 6.

[0017] The bobbin placement device 2 includes a support plate 22 on which multiple (for example, 3) bobbins 21 are placed. The bobbins 21 are set on multiple (for example, 3) bobbin shafts 23b erected on the support plate 22, and the bobbins 21 are fixed to the bobbin shafts 23b by stoppers 23c, so that the bobbins 21 set thereon rotate in accordance with the rotation of the bobbin shafts 23b. The stoppers 23c are removable, and the bobbins 21 can be attached and detached from the tip side of the bobbin shafts 23b when the stoppers 23c are removed, thereby allowing the bobbins 21 set on the bobbin shafts 23b to be replaced. The support plate 22 is fixed to the sewing machine frame M via a pair of mounting members 4.

[0018] By selectively rotating one bobbin shaft 23b with the above-described rotational drive device (not shown), one bobbin 21 in the bobbin arrangement device 2 is rotated via the bobbin shaft 23b, and a string-like material L is actively paid out from the bobbin 21 as the bobbin 21 rotates. As an example, each bobbin 21 is composed of a large bobbin capable of winding a large amount of string-like material, thereby reducing the frequency of bobbin replacement as the string-like material is consumed, and thus providing a configuration suitable for using a large amount of string-like material. In that case, actively rotating the bobbin 21 with the above-described rotational drive device (not shown) contributes to smoothly paying out the string-like material from the large (heavy) bobbin 21.

[0019] A plurality of gate pieces 25 are provided side by side at the lower part of the support plate 22. By distributing and passing the string-like materials drawn out from each bobbin 21 through each gate piece 25, the string-like materials are aligned so as not to interfere with each other. A plurality (for example, 3) of string-like materials drawn out in parallel from the material supply device 1 via each gate piece 25 are guided to the material guiding device 6 via the intermediate guide 7. As shown in FIG. 2, the intermediate guide 7 includes a first roller 71, a reversing portion 72, and a second roller 73. The first roller 71 is formed by juxtaposing a plurality (for example, 3) of rollers corresponding to each string-like material in a front view (see FIG. 1), and the second roller 73 is also formed by juxtaposing a plurality (for example, 3) of rollers corresponding to each string-like material in a front view (see FIG. 1). A plurality (for example, 3) of reversing portions 72 corresponding to each string-like material are provided, and each reversing portion 72 has a hole for passing the corresponding string-like material in the horizontal direction (see FIG. 1). A plurality (for example, 3) of vertical rails 76 corresponding to each string-like material are provided in parallel. Each reversing portion 72 is fixed at an appropriate intermediate position of each vertical rail 76, and the height position for fixing the reversing portion 72 can be appropriately changed by displacing it upward or downward along the rail 76.

[0020] Each mounting member 4 has a cantilevered crossbar 77 fixed to it, which is cantilevered and extends horizontally forward. Between the two cantilevered crossbars 77, support shafts 78 and 79 are stretched, one near the base (closer to mounting member 4, i.e., the rear) and the other near the tip (i.e., the front). A first roller 71 (three in one example) is rotatably attached to the support shaft 78 near the base (closer to mounting member 4, i.e., the rear), and a second roller 73 (three in one example) is rotatably attached to the support shaft 79 near the tip (i.e., the front) (see Figure 2). Furthermore, a mounting crossbar 75 is stretched between the two cantilevered crossbars 77, in front of the support shaft 79. One end 65a of multiple (three in one example) hollow members 65 corresponding to each string-like material is fixed to this mounting crossbar 75.

[0021] In the intermediate guide 7, each string-like material that has passed through each gate piece 25 moves downward in contact with the rear of the first roller 71, passes through the hole of the reversal section 72 from rear to front and moves upward, is folded downward by the second roller 73 and passes through the first guide hole 74, and is inserted into the hollow member 65 from one end 65a of the corresponding hollow member 65 (see Figure 2).

[0022] The hollow member 65 is made of a flexible material and has a firm yet flexible structure, extending to the lower part of the sewing head H with appropriate slack. At the lower part of the sewing head H, the main components of the material guide device 6 are provided around the vertically moving sewing needle 12. The hollow member 65 constitutes one component (material introduction part) of the material guide device 6, and the string-like material L inserted into the hollow member 65 from one end 65a passes through the hollow member 65 and is pulled out from the other end 65b (lower end) of the hollow member 65 to be introduced into the main components of the material guide device 6. The material guide device 6 includes the hollow member 65, an annular guide body 66 that can rotate around the axis of the needle bar, and a guide part 61 that is rotatable together with the annular guide body 66 and guides the string-like material L pulled out from the other end 65b of the hollow member 65 to the vicinity of the needle base position (see Figure 2). Here, the other end 65b of the hollow member 65 is configured to rotate together with the annular guide 66. As an example, the hollow member 65 can be made of a metal such as stainless steel and / or synthetic resin. For example, the hollow member 65 can be made using a stainless steel hose (or tube) that is made flexible by spiral winding or parallel winding. The guide section 61 is provided with a plurality (for example, 3) of guide tubes (guide members) 61a arranged in parallel to guide each string-like material to the vicinity of the needle source position.

[0023] The material guiding device 6 further includes a shift mechanism 62 configured to associate one guide cylinder (guide member) 61a with the oscillating lever (oscillating part) 51, and to transmit the oscillating motion of the oscillating lever 51 to the associated guide cylinder (guide member) 61a. By associating the guide part 61 (guide cylinder 61a) with the oscillating lever 51 using this shift mechanism 62, only the selected (associated) one guide cylinder 61a is set to the needle base position, and the string-like material guided by the one guide cylinder 61a is sewn onto the workpiece (e.g., fabric). The shift mechanism 62 includes a cam plate 63 (Figure 5) in which a cam path (cam groove, etc.) is formed, and an engaging part (roller) that engages with the cam plate 63 and is relatively movable along the cam path, and is configured to associate one guide cylinder 1a with the oscillating lever 51 by moving the engaging part along the cam path. A detailed explanation of the shift mechanism 62 is omitted.

[0024] <Overview of the sewing head> As is well known, the sewing head H is provided with a needle bar (not shown) that is positioned to extend vertically in the axial direction. The needle bar is driven to reciprocate vertically by the rotation of the sewing machine spindle 10. A sewing needle 12 is attached to the lower end of the needle bar. A support cylinder (not shown) is attached to the outer circumference of the needle bar. This support cylinder is capable of relative vertical movement with respect to the needle bar and rotational movement around the axis of the needle bar. A presser foot support 18 is fixed to the lower end of the support cylinder, and a presser foot body (nipple) 19 is fixed to the lower end of the presser foot support 18. When the needle bar moves up and down in accordance with the rotation of the spindle 10 to perform sewing, the presser foot support 18 and the presser foot body 19 move up and down by the drive of a motor (not shown) that is linked to it, thereby performing presser foot movement synchronized with sewing. As is well known, an upper thread is passed through the sewing needle 12, and a bobbin mechanism (not shown) is provided below the needle plate 20. A string-like material that emerges from the tip of the guide tube (guide member) 61a of the guide section 61 and is guided to the needle base position is sewn to the workpiece (not shown, e.g., fabric) placed on the needle plate 20 on the table by a lockstitch using the upper and lower threads. As is well known in embroidery machines, the workpiece is stretched over an embroidery hoop (not shown), which is positioned on the table in an XY-movable state and is XY-movable for each stitch (sew) according to the embroidery pattern (sewing pattern) data.

[0025] Although not shown in Figures 1 and 2, a rotating cylinder (rotating body) 8 is mounted concentrically with the needle bar, and this rotating cylinder (rotating body) is only capable of rotational movement around the axis of the needle bar. The rotating cylinder (rotating body) 8 is rotated in accordance with the rotation of a direction control motor, which is not shown in Figures 1 and 2. A presser foot support 18 is key-engaged to the lower end of the rotating cylinder (rotating body) 8, and the presser foot support 18 (and presser foot body 19) moves up and down in accordance with the up and down movement of the support cylinder, and also rotates around the axis of the needle bar in accordance with the rotation of the rotating cylinder (rotating body) 8. The rotational motion of the rotating cylinder (rotating body) 8 is ultimately transmitted to the guide section 61 of the material guide device 6. The directional control motor, which is the rotational drive source for the rotating cylinder (rotating body) 8, is driven and controlled according to the embroidery pattern (sewing pattern) data, and rotates the guide portion 61 of the material guide device 6 around the axis of the needle bar so that the guide portion 61 appropriately points in the sewing direction for each stitch. As can be seen from Figure 2, the guide portion 61 and the presser foot 19 are arranged facing each other (on opposite sides) with the needle bar in between, and both rotate together in accordance with the rotation of the rotating cylinder (rotating body) 8. The lower end portion of the rotating cylinder (rotating body) 8 is partially shown in Figure 5, which will be described later.

[0026] A swinging lever (swinging part) 51 is attached to the outer circumference of the rotating cylinder (rotating body) 8 via a mounting bracket (Figures 2 and 5). The swinging lever 51 is swingably mounted to the rotating cylinder (rotating body) 8 in the axial direction of the needle bar. Through this swinging lever (swinging part) 51, a swinging motion for swinging the string-like material in a zigzag pattern is provided to the guide part 61 of the material guide device 6. A zigzag swing motor 50, which is the drive source for swinging the string-like material in a zigzag pattern, is provided, and the rotational motion of this zigzag swing motor 50 is converted into a left-right swinging motion of the swinging lever 51. The mechanism from the zigzag swing motor 50 to the swinging lever 51 corresponds to a swinging mechanism (zigzag swing mechanism) that generates a swinging motion for swinging the string-like material to be sewn in a zigzag pattern. Note that the configuration of the sewing head H including such a zigzag swing mechanism is publicly known, so a detailed explanation of the zigzag swing mechanism is omitted.

[0027] Figure 3 is a perspective view showing an enlarged view of the main components of the material guide device 6, viewed from diagonally above. Figure 4 is a perspective view of the main components of the material guide device 6 viewed from diagonally below. In this embodiment, a material guide lifting mechanism is used that is configured to rotate and raise / lower the material guide device 6 independently. Figures 3 and 4 also show the lifting plate 91 and the rotating ring 92, which are components of the material guide lifting mechanism. Figure 5 is an exploded perspective view showing some components of the material guide device 6 shown in Figures 3 and 4 (guide cylinder 61a, annular guide body 66, etc.) and some components of the material guide lifting mechanism related thereto (lifting plate 91, rotating ring 92), with some parts cut away.

[0028] <Material guide lifting mechanism> To briefly explain the material guide lifting mechanism, it comprises a lifting plate 91 configured to move up and down along the axial direction of the needle bar, and a rotating ring 92 rotatably supported on the lifting plate 91 so as to be able to rotate around the axis of the needle bar, and configured to move up and down together with the lifting plate 91 (Figure 5). As shown in Figure 1, an air cylinder 93 is fixed to the left side of the sewing machine head H as a drive source for moving the lifting plate 91 up and down, and a connecting rod 94 is connected to the lower end of the downwardly extending and retracting cylinder rod 93a. As shown in Figure 5, the lower end of the connecting rod 94 is connected to a predetermined location on the upper surface of the lifting plate 91, and the lifting plate 91 moves up and down in accordance with the extension and retraction of the air cylinder 93.

[0029] As partially shown in Figure 5, the lifting plate 91 has an annular shape, with a rotating ring 92 positioned inside it, and the rotating cylinder 8 (rotating body) positioned in the central opening of the rotating ring 92. The lifting plate 91 has three notches 91a formed on its inside at approximately equal intervals, and guide rollers (bearings) 91b are provided in each notch 91a. The guide rollers 91b are rotatably pivoted on a support member 91c which is fixed to the upper surface of the lifting plate 91 with screws. The rotating ring 92 has an outer circumferential surface that protrudes in a circular arc shape in cross-section, and its outer circumferential surface fits onto the guide rollers 91b, thereby supporting it to rotate freely inside the lifting plate 91. A connecting member 92a is fixed to the upper surface of the rotating ring 92, and this connecting member 92a is provided with an elongated engagement groove that opens inward. A vertically elongated guide body 92b, fixed to the side of the rotating cylinder 8 via a mounting bracket, is slidably engaged with the engagement groove of the connecting member 92a. As a result, the rotating ring 92 can move up and down relative to the rotating cylinder 8 (rotating body) and rotate together with the rotating cylinder 8 (rotating body). A support bracket 57 extending downward is attached to the lower surface of the rotating ring 92, and a horizontally extending guide rail 58 is fixed to the lower end of this support bracket 57. A slider 61d is coupled to the guide rail 58 and is slidable in the horizontal direction (Figure 4).

[0030] <Material Guide Device> The guide section 61 includes an inclined section 61b in which multiple guide tubes 61a are arranged in parallel in the horizontal direction, tilted diagonally downward toward the needle position, and a vertical section extending vertically upward from the upper center of the inclined section 61b (Figure 5). The inclined section 61b has holes for attaching the guide tubes 61a, and the guide tubes 61a are detachable. This allows the guide tubes 61a to be changed (replaced) depending on the thickness and cross-sectional shape of the string-like material used for sewing. The vertical section of the guide section 61 engages with the swing lever 51 via a cam plate 63 and swings laterally (left and right) in conjunction with the swing of the swing lever 51. Here, the swing lever 51 and the cam plate 63 are located inside (need side) of the vertical section of the guide section 61, and the slider 61d is fixed to the outside of the vertical section. As described above, the slider 61d is slidably coupled to the guide rail 58 that extends horizontally, allowing it to slide horizontally. This sliding coupling serves to convert or restrict the pendulum-like swinging motion of the swing lever 51, which has the lever pin 52 for staggered swing as its pivot axis, into a horizontal swinging motion (reciprocating motion) and transmit it to the guide section 61.

[0031] In the material guide lifting mechanism, extending or retracting the air cylinder 93 causes the connecting rod 94, lifting plate 91, rotating ring 92, support bracket 57, and guide rail 58 to move down or up together, and via the slider 61d connected to the guide rail 58, the guide section 61 and cam plate 63 move down or up together. On the other hand, when the rotating cylinder 8 rotates, the rotating ring 92 rotates together due to the engagement of the guide body 92b and the connecting member 92a, and consequently, the guide section 61 and cam plate 63 rotate via the support bracket 57, guide rail 58, and slider 61d. In summary, the material guide lifting mechanism is configured such that a material guide device 6, including a guide section 61 and a cam plate 63, is mounted on the rotating ring 92, and the material guide device 6 rotates together with the rotating ring 92 and is raised and lowered by the lifting plate 91.

[0032] As shown in Figures 4 and 5, the annular guide body 66 includes a large-diameter flange portion 66a and a cylindrical portion 66b extending upward from the central opening of the flange portion 66a. The assembly including the lifting plate 91, the rotating ring 92, the guide portion 61, and the shift mechanism 62 is housed within this cylindrical portion 66b. The flange portion 66a is connected to the rotating ring 92 via two connecting bridges 95 on its back side, straddling the lifting plate 91, so that the annular guide body 66 rotates integrally with the rotating ring 92 (and consequently the rotating cylinder 8). The cylindrical portion 66b is rotatably in contact with or not in contact with the lifting plate 91. As a result, the annular guide body 66 can rotate around the axis of the needle bar in conjunction with the rotation of the rotating cylinder 8, and can also move up and down together with the rotating ring 92 in conjunction with the up and down movement of the lifting plate 91.

[0033] An opening 66c is provided at a predetermined location on the flange portion 66a, and a connecting portion 66d is provided on the back side of the flange portion 66a at a position facing the opening 66c. Preferably, the opening 66c and the connecting portion 66d are provided at a location close to the guide cylinder 61a of the guide portion 61, as shown in the figure. The inlet 67 is attached to the housing of the sewing head H via a mounting bracket 67a above the annular guide body 66, and is positioned (fixed) so as not to rotate together with the annular guide body 66. As shown in Figures 1 and 2, as an example, the inlet 67 is located on the front side of the sewing machine. The portion of the hollow member 65 near the other end 65b freely passes through the inlet 67, through the opening 66c of the flange portion 66a to the connecting portion 66d, where the other end 65b of the hollow member 65 is connected to the annular guide body 66. In this way, the other end 65b of the hollow member 65 is connected so as to rotate together with the annular guide 66. The string-like material L pulled out from the other end 65b of the hollow member 65 connected to the connection part 66d is introduced into the guide cylinder 61a of the guide part 61 and is guided by the guide part 61 to the vicinity of the needle source position.

[0034] When the annular guide 66 rotates, the other end 65b of the hollow member 65 rotates together with the annular guide 66, so the lower portion of the hollow member 65 is wrapped around or unwound around the cylindrical portion 66b of the annular guide 66. Although one end 65a (upper end) of the hollow member 65 is fixed, the hollow member 65 is introduced into the inlet 67 with an appropriate amount of slack, so the hollow member 65 moves freely through the inlet 67 (is pulled in or pushed out) in response to being wrapped around or unwound around the cylindrical portion 66b.

[0035] A cover member 68 is positioned above the annular guide 66. The cover member 68 is positioned to form an appropriate space with the annular guide 66, while being configured not to rotate with the annular guide 66. This space is wide enough to allow the passage of a hollow member 65 that rotates with the annular guide 66. For example, the cover member 68 is supported and fixed at the upper ends of studs (or relatively thin and short supports) provided at appropriate intervals at multiple locations (e.g., two locations) on the upper surface of the lifting plate 91, and can move up and down with the lifting plate 91 (and consequently the annular guide 66) while maintaining the height of the space. Since the studs are provided on the side of the lifting plate 91, they are located inside the cylindrical portion 66b and do not interfere with the hollow member 65 that passes through the space between the cover member 68 and the annular guide 66. The cover member 68 suppresses the flapping of the hollow member 65 when it is wound around or unwound around the cylindrical portion 66b of the annular guide 66 along the rotational direction of the annular guide 66, and also covers the hollow member 65 so that it does not protrude outwards from the annular guide 66. While providing the cover member 68 in this way is beneficial, as an alternative example, the design may be made without the cover member 68.

[0036] The cover member 68 is positioned at a lower height than the inlet 67 and does not cover the entire annular guide 66, but opens to an appropriate extent below the inlet 67. Therefore, two inlets 68a to the space are formed at the open end of the cover member 68. This allows the portion of the hollow member 65 that passes through the inlet 67 and rotates clockwise or counterclockwise together with the annular guide 66, near the other end 65b, to enter and exit the space through the inlets 68a. In the illustrated example, the inlets 68a to the space are located on the left and right sides of the inlet 67.

[0037] Near the entrance 68a to the aforementioned space, a rotatable roller 69 is provided above the annular guide 66. This roller 69 is attached to the bracket 67a and is rotatable in the direction of movement of the hollow member 65, which moves in and out of the space as the annular guide 66 rotates. The hollow member 65, which moves together with the annular guide 66, passes beneath the roller 69, and when the hollow member 65 comes into contact with the roller 69, the roller 69 rotates in conjunction with its movement, smoothing the movement of the hollow member 65. Furthermore, by being positioned near the entrance 68a to the aforementioned space, the roller 69 also serves to restrict the angle at which the hollow member 65 enters the entrance 68a from being too acute. In this way, the roller 69 can assist in the smooth movement of the hollow member 65 accompanying the annular guide 66. Furthermore, due to the stiffness of the hollow member 65, it tends to lift up, especially when being unwound from the annular guide 66. However, the roller 69 positioned above it can prevent the hollow member 65 from lifting up.

[0038] In the illustrated example, rollers 69 are positioned near each of the inlets 68a located on the left and right sides of the inlet 67 (a total of two rollers 69). However, the design is not limited to this; only one roller 69 may be provided, or none at all.

[0039] <Wrapping / unwinding operation of a hollow member around an annular guide> Figures 3 and 4 show the state where the guide cylinder 61a of the guide section 61 is positioned in front of the sewing machine, and the hollow member 65 is not wrapped around the annular guide body 66 at all. For convenience, this state will be considered as the rotation angle 0 of the rotating cylinder 8. The rotating cylinder 8 can rotate clockwise or counterclockwise at any angle including one or more rotations from this rotation angle 0 state, and the guide cylinder 61a and the annular guide body 66, etc., also rotate together clockwise or counterclockwise.

[0040] For example, when the annular guide 66 rotates counterclockwise from a rotation angle of 0, the hollow member 65, whose other end 65b rotates together with the annular guide 66, is pulled into the space of the cover member 68 from the right-side entrance 68a, while being restricted by the right-side roller 69 in Figure 3. As the rotation progresses, it is pulled by the connecting portion 66d and wraps around the cylindrical portion 66b. For reference, Figure 6 shows the state when the annular guide 66 has rotated approximately 90 degrees counterclockwise from a rotation angle of 0. With further counterclockwise rotation, the hollow member 65 can be wrapped around the cylindrical portion 66b one or more times, as long as the space below the cover member 68 allows.

[0041] When the annular guide 66 changes direction clockwise, the hollow member 65 that was wrapped around the cylindrical portion 66b is unwound clockwise towards the inlet 67. During this unwinding, the hollow member 65 moves in a direction that pushes it out from the annular guide 66 towards the inlet 67. This pushout is not hindered, and due to the flexibility (stiffness or ease of return) of the hollow member 65, the hollow member 65 is smoothly unwound from inside the annular guide 66 and smoothly pushed outward from the inlet 67. Therefore, during unwinding, almost no excess portion of the hollow member 65 remains inside the annular guide 66.

[0042] On the other hand, since the string-like material L passes through the hollow member 65 and is introduced into the guide portion 61, the structure is such that the string-like material L is not directly affected by the tension differences caused by the rotational direction of the annular guide 66. In other words, since the tension caused by the rotation of the annular guide 66 is mostly applied to the hollow member 65, the tension on the string-like material L, which passes freely inside it, is considerably suppressed. In other words, since the hollow member 65 itself is pulled and released in accordance with the rotation of the annular guide 66, direct tension load on the string-like material L can be prevented. Furthermore, even if the amount of rotation of the annular guide 66 changes, the length of the hollow member 65 (length from one end to the other end) remains constant, so the length of the string-like material L inserted inside the hollow member 65 does not change, and no extra tension is applied to the string-like material L. Therefore, the string-like material L can be guided with stable tension without being affected by differences in the rotation direction of the annular guide 66, and stable sewing quality can be provided regardless of the material of the string-like material L or the sewing pattern.

[0043] Furthermore, when the annular guide 66 rotates clockwise from a rotation angle of 0, it operates in the same manner as described above, and in accordance with the clockwise rotation, the hollow member 65 can be wound around the cylindrical portion 66b clockwise for one or more rotations, as long as the space below the cover member 68 allows. Then, when the annular guide 66 changes direction counterclockwise, the hollow member 65 that was wound around the cylindrical portion 66b is unwound counterclockwise towards the inlet 67. During this unwinding, for the same reasons as described above, the hollow member 65 is smoothly unwound from inside the annular guide 66 and smoothly pushed outward from the inlet 67, so that almost no excess portion of the hollow member 65 remains inside the annular guide 66.

[0044] <Material holding device> As shown in Figure 2, the material holding device 100 is positioned on the opposite side of the guide section 61, straddling the vertical axis of movement of the sewing needle 12. As shown in Figure 4, the material holding device 100 is equipped with holding members 101 for holding the string-like material guided by each guide cylinder 61a, arranged in parallel and corresponding to each guide cylinder 61a. A slider is fixed to each holding member 101 via a bracket 102, and a guide rail 105 extending horizontally is fixed to the lower surface of the rotating ring 92. The slider of the holding member 101 is slidably coupled to the guide rail 105 so as to be slidable horizontally. The bracket 102 of the holding member 101 is connected to the cam plate 63 via a pair of left and right connecting members 106 (see Figure 5). Therefore, while maintaining the correspondence between each holding member 101 and the guide cylinder 61a, the material holding device 100 moves integrally with the guide section 61 (rotates, moves up and down, and moves horizontally).

[0045] For example, the holding member 101 has a hook-shaped fiber surface on its lower surface, and is configured to hold the corresponding string-like material by pressing it against the hook-shaped fiber surface from below, thereby entangling it with the hook-shaped fiber surface. For example, when no sewing operation is being performed, the string-like material coming out of each guide tube 61a is held below the corresponding holding member 101 (hook-shaped fiber surface). When sewing begins on a string-like material guided to the needle base position, even if the string-like material is held by the corresponding holding member 101, the holding by the holding member 101 can be automatically released when the string-like material guided to the needle base position is pushed downward by the presser foot 19 at the time of the first needle drop. On the other hand, string-like materials guided by other guide tubes 61a that are not set at the needle base position remain held by their respective holding members 101, and since the material holding device 100 moves integrally with the guide section 61 during sewing, the string-like materials that are not selected (not used) do not move irregularly and interfere with the sewing operation. Note that the holding structure of the holding member 101 is not limited to a hook-shaped fiber surface, but any other arbitrary structure can be adopted.

[0046] <Supply amount adjustment device> In the embodiments shown in Figures 1 and 2, the hollow member 65, which is fixed at one end 65a (upper end) and extends downward, is allowed to pass through the inlet 67 with an appropriate amount of slack, and the hollow member 65 moves in and out of the annular guide 66 and the inlet 67 solely by the force resulting from the other end 65b (lower end) of the hollow member 65 being pulled in or pushed out in response to the rotation of the annular guide 66. However, the invention is not limited to these embodiments, and additional means for assisting the pulling in or pushing out (especially pushing out) of the hollow member 65 may be provided. Figure 7 is a front view of a sewing machine to which a material guide device according to another embodiment of the present invention is applied, and in this embodiment, a supply amount adjustment device 110 is provided as a means for assisting the pulling in or pushing out (especially pushing out) of the hollow member 65. Figure 8 is a right side view of the sewing machine shown in Figure 7.

[0047] The supply amount adjustment device 110 is provided in the material supply path between the supply source (material supply device 1) and the annular guide 66, and is configured to adjust the supply amount of the hollow member 65 in accordance with the movement of the hollow member 65 accompanying the clockwise or counterclockwise rotation of the annular guide 66. More specifically, the supply amount adjustment device 110 is configured to fix one end 65a of the hollow member 65 and hold the hollow member 65 in a wound state that allows it to be wound up and unwound freely. More specifically, the supply amount adjustment device 110 includes a pair of rollers 111 and 112, which are configured to change the distance between their axes, and a hollow member 65 is wound around the pair of rollers 111 and 112, and the distance between the axes of the pair of rollers 111 and 112 is narrowed by the tension force exerted from the other end 65b of the hollow member 65, and widened by the decrease in the tension force from the other end 65b.

[0048] The pair of rollers 111 and 112 consist of an upper roller 111 and a lower roller 112, and are configured such that the distance between the axes of the pair of rollers 111 and 112 is widened by the weight of the lower roller 112 due to the decrease in the tensile force from the other end 65b of the hollow member 65. More specifically, when viewed from the front, a pair of vertically elongated support members 113 are suspended from the tip of the cantilever 77, and a shaft 114 is fixed to the upper part of the pair of support members 113, horizontally bridged. Multiple (for example, three) upper rollers 111 corresponding to each hollow member 65 are rotatably attached to this shaft 114. In each support member 113, a vertically elongated through groove 116 is formed in a predetermined range below the shaft 114, and a shaft 115 is horizontally bridged along this through groove 116 so as to be able to move up and down. Multiple (for example, three) lower rollers 112 corresponding to each hollow member 65 are rotatably attached to this shaft 115.

[0049] As shown in Figure 8, each hollow member 65 extending downward from one end 65a (fixed end) is wrapped around the corresponding lower roller 112 from below and extends upward, then wrapped around the corresponding upper roller 111 from above and guided downward to be introduced into the inlet 67, and the other end 65b is connected to the connection part 66d of the annular guide body 66. When the annular guide body 66 is at a rotation angle of 0, as shown in Figure 8, the lower roller 112 is positioned at the bottom of the through groove 116. Figure 9(a) is a schematic diagram showing the state of the annular guide body 66 and the lower roller 112, etc. when the annular guide body 66 is at a rotation angle of 0, with the upper part of the figure showing the state of the annular guide body 66, etc. in a plan view and the lower part showing the state of the lower roller 112, etc. in a side view.

[0050] As the hollow member 65 is wrapped around the annular guide 66, the lower roller 112 gradually rises along the through groove 116, and when it has been wrapped to its maximum rotational length, the lower roller 112 is located near the top of the through groove 116. Figure 9(b) is a schematic diagram showing the state of the annular guide 66 and the lower roller 112 when the annular guide 66 is rotated approximately 90 degrees counterclockwise, with the upper part of the figure showing the state of the annular guide 66 in a plan view and the lower part showing the state of the lower roller 112 in a side view. Figure 9(c) is a schematic diagram showing the state of the annular guide 66 and the lower roller 112 when the annular guide 66 is rotated approximately 270 degrees counterclockwise, with the upper part of the figure showing the state of the annular guide 66 in a plan view and the lower part showing the state of the lower roller 112 in a side view.

[0051] Furthermore, the length of the through groove 116 is designed with an appropriate margin to prevent the lower roller 112 from contacting the top of the through groove 116 when the maximum amount of rotation is reached. The weight of the lower roller 112 is set to be heavier than the total weight of the portion of the hollow member 65 that is located on the side of the annular guide 66 from the top of the upper roller 111 when the hollow member 65 is wrapped around the annular guide 66 by the maximum amount of rotation. Therefore, when the hollow member 65 is unwound from the annular guide 66, the weight of the lower roller 112 causes the lower roller 112 to descend by the amount it has been unwound, resulting in smooth movement of the hollow member 65 as it is pushed back from the annular guide 66 through the inlet 67, and preventing slack in the hollow member 65.

[0052] In this way, by using the supply amount adjustment device 110, it is possible to reliably prevent any excess portion of the hollow member 65 that is unwound from the annular guide 66 from remaining inside the annular guide 66. Furthermore, by fixing one end 65a of the hollow member 65 and configuring it to be held in a wound state that can be freely wound up and unwound, the hollow member 65 can be held compactly in a wound state, and there is no risk of the movement of the hollow member 65 during winding or unwinding irregularly contacting the surrounding parts of the sewing head H.

[0053] Furthermore, by using a pair of rollers 111 and 112, the distance between the axes of the pair of rollers 111 and 112 is narrowed by the tension force exerted from the other end 65b of the hollow member 65 when it is wound onto the annular guide 66, and widened by the decrease in the tension force from the other end 65b when it is unwound from the annular guide 66. This configuration allows for a more compact structure to hold the hollow member 65 in a wound state that can be freely wound and unwound. Additionally, by configuring the system so that the distance between the axes of the pair of rollers 111 and 112 is widened by the weight of the lower roller 112 due to the decrease in the tension force from the other end 65b, the adjustment of the supply amount of the hollow member 65 in the supply amount adjustment device 110 can be simplified.

[0054] Furthermore, the configuration for holding the hollow member 65 in a state where it can be freely wound up and unwound is not limited to the example using the pair of rollers 111 and 112 described above, but may also use other means (for example, a winding reel). Also, the means for assisting in pushing back the hollow member 65 in the supply amount adjustment device 110 is not limited to the configuration that utilizes gravity as described above, but may also use a driving means or biasing means such as an electric motor or a spring.

[0055] In the above embodiment, multiple (for example, 3) string-like materials L are supplied in parallel, and the device is configured to selectively guide one of them to the needle base position. Using a hollow member 65 in a material guide device 6 of this type, which supplies multiple string-like materials L in this manner, also has the effect of preventing the multiple string-like materials L from interfering with each other and becoming entangled. However, the present invention is not limited to this, and can also be applied to a material guide device of the type in which only one string-like material L is supplied from the supply source and guided to the needle base position. In that case, the configuration in Figure 1 or Figure 7 can be modified to provide only one hollow member 65, and the shift mechanism 62 does not need to be provided. [Explanation of symbols]

[0056] H Sewing Head M Sewing machine frame L String-like material 1. Material supply device 6. Material guide device 61 Information Department 61a Guide tube 65 Hollow member 65a One end of the hollow member 65b Other end of hollow member 66 Circular Guide 66d Connection 67 Inlet 68 Cover component 69 Laura 110 Supply amount adjustment device 111 Upper Roller 112 Lower roller

Claims

1. A material guide device for guiding a string-like material to be sewn in a sewing machine to the needle position, A circular guide that can rotate around the axis of the needle bar, A flexible hollow member having one end and the other end, wherein a string-like material supplied from a supply source is inserted into the one end and pulled out from the other end, the other end of the hollow member being configured to rotate together with the annular guide, A guide portion is configured to be rotatable together with the annular guide body, and guides the string-like material pulled out from the other end of the hollow member to the vicinity of the needle source position. A material guide device for a sewing machine equipped with the following features.

2. The material guide device for a sewing machine according to claim 1, further comprising a cover member arranged to form a space with the annular guide body, wherein the portion of the hollow member near the other end can move in and out of the space.

3. The material guiding device for a sewing machine according to claim 2, further comprising a rotatable roller positioned near the entrance of the space, wherein the roller can rotate in conjunction with the movement of the hollow member that moves in and out of the space when it comes into contact with it.

4. The material guiding device for a sewing machine according to claim 3, wherein the entrances to the space are located on the left and right sides of the inlet, and the rollers are positioned near each entrance.

5. The material guiding device in a sewing machine according to claim 1, wherein the annular guide body includes a connecting portion for connecting the other end of the hollow member, and a string-like material pulled out from the other end connected to the connecting portion is introduced into the guide portion.

6. The material guide device for a sewing machine according to claim 5, wherein the annular guide has an opening for the other end of the hollow member to pass through, and the connecting portion is arranged to connect the other end of the hollow member that has passed through the opening.

7. The entrance to the guide section is located on the lower side of the annular guide body. The material guiding device for a sewing machine according to claim 6, wherein the connecting portion is provided on the lower surface of the annular guide body so as to face the entrance of the guide portion.

8. The material guiding device for a sewing machine according to claim 1, further comprising an inlet for passing the portion of the hollow member near the other end, wherein the inlet is positioned above the annular guide so as not to rotate together with the annular guide.

9. The material guide device for a sewing machine according to claim 1, further comprising a supply amount adjustment device provided in the supply path between the supply source and the annular guide, which adjusts the amount of the hollow member supplied in accordance with the movement of the hollow member accompanying the clockwise or counterclockwise rotation of the annular guide.

10. The material guide device for a sewing machine according to claim 9, wherein the supply amount adjustment device is configured to fix one end of the hollow member and hold the hollow member in a state in which it can be wound up and unwound.

11. The material guiding device for a sewing machine according to claim 10, wherein the supply amount adjustment device includes a pair of rollers, the pair of rollers are configured to change the distance between their axes, the hollow member is wound around the pair of rollers, the distance between the axes of the pair of rollers is narrowed by a tension force exerted from the other end of the hollow member, and the distance between the axes of the pair of rollers is widened by a decrease in the tension force from the other end.

12. The material guide device for a sewing machine according to claim 11, characterized in that the pair of rollers consists of an upper roller and a lower roller, and the distance between the axes of the pair of rollers is widened by the weight of the lower roller due to the decrease in the tension force from the other end.

13. Multiple hollow members are provided, and multiple string-like materials supplied from a supply source are inserted into one end of each hollow member and pulled out from the other end, and the other end of each hollow member is configured to rotate together with the annular guide, The material guiding device in a sewing machine according to any one of claims 1 to 12, wherein the guide section includes a plurality of guide members for guiding the string-like material drawn out from each hollow member to the vicinity of the needle base position.

14. The material guide device in a sewing machine according to claim 13, wherein the guide section is configured to select one of the guide members and associate it with the needle base position.

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