Material guiding device of sewing machine

Abstract

The present invention addresses the problem of easily and efficiently switching and changing a ribbon-like material to be zigzag sewn in a sewing machine capable of zigzag stitching a ribbon-like material. A material guiding device (6) comprises: a swinging part (51) that performs a swinging motion for zigzag stitching a ribbon-like material to be sewn; a guide part (61) including a plurality of guide members (61a) for guiding the ribbon-like material to the vicinity of a needle base position; and a shift mechanism (62) including a cam part (63) in which a cam path (cam groove 63a, coupling groove 63b) is formed and an engagement part (51b) that engages with the cam part and is is capable of relative motion along the cam path. The shift mechanism (62) is configured such that one guide member (61a) is associated with the swinging part (51) by moving the engagement part along the cam path, and the swinging motion of the swinging part is transmitted to the associated guide member. As an example, one of the cam part or the engagement part can move integrally with the guide part, and the other can move integrally with the swinging part.

Description

Material guide device in sewing machine

[0001] The present invention relates to a sewing machine that sews string-like materials such as tapes and cords to a workpiece by lockstitch, and more particularly to a material guiding device that enables selectively guiding one of several string-like materials to the needle position in a sewing machine capable of zigzagging the string-like material to be sewn.

[0002] Conventionally, there is a type of sewing machine known that includes a needle bar that is driven up and down, a sewing needle attached to the lower end of the needle bar, a rotating body assembled coaxially with the needle bar and freely rotating around its axis, a guide device attached to the rotating body that guides a string-like material (for example, a string-like embroidery material such as tape or cord) to the needle base position of the sewing needle, and a material supply device that supplies the string-like material to the guide device. The rotating body is rotated according to the direction of movement of the fabric based on embroidery data, and the orientation of the guide device is changed so that the direction of guidance of the string-like material to the needle base is appropriate, while sewing the string-like material to the workpiece (fabric) by lockstitch, or further, a zigzag mechanism is used to zigzag the guide device and sew the string-like material to the workpiece by zigzag stitch.

[0003] As a material supply device for this type of sewing machine, a configuration is known that uses a large bobbin on which the string-like material is wound, in order to accommodate the use of large quantities of string-like material, and that the large bobbin is actively rotated to ensure smooth dispensing of the string-like material from the bobbin (for example, Patent Document 1 or 2). Another type of material supply device is known in which a small bobbin on which the string-like material is wound is arranged around the needle bar, and the string-like material is supplied to the needle base while rotating at an appropriate angle around the needle bar axis (for example, Patent Document 3).

[0004] As shown in Patent Documents 1 to 3, generally, one bobbin is arranged corresponding to one sewing head, and a guide device for guiding a string-like material fed out from the bobbin is configured to be zigzagged (swung) by a zigzag mechanism provided corresponding to the sewing head. Therefore, when changing the type of the string-like material to be sewn, the bobbin must be replaced. Not only the bobbin replacement work, but also the replacement work of the string-like material (removal of the previous material and attachment of the next material) in the guiding path of the string-like material from the bobbin to the guide device must be performed, which causes a problem of time-consuming work. Further, since such bobbin replacement work must be performed by temporarily stopping the sewing operation of the sewing machine, it is not suitable for an automated operation of automatically changing the type of the string-like material and continuing the continuous sewing operation, and there is also a problem of inferior production efficiency.

[0005] On the other hand, Patent Document 4 below shows a configuration in which two small bobbins are arranged around a needle bar so that the string-like material to be sewn can be switched. According to this configuration, it is possible to switch the type of the string-like material to be sewn to one of the two types of string-like materials wound around the two bobbins without replacing the bobbins. However, since only one guide device capable of zigzagging is provided, if it is attempted to selectively introduce the string-like material fed out from either one of the bobbins to the guide device, the replacement work of the string-like material in the guiding path of the string-like material from the bobbin to the guide device must be performed manually, which is troublesome.

[0006] Japanese Unexamined Patent Application Publication No. 2005-144056, Japanese Unexamined Patent Application Publication No. 2007-159829, Japanese Patent No. 5302728, International Publication WO2022 / 065083

[0007] The present invention has been made in view of the above points, and an object thereof is to provide a material guiding device that can easily and efficiently switch, change, or select a string-like material to be sewn in a sewing machine capable of performing zigzag sewing (zigzag stitching) on the string-like material.

[0008] The present invention relates to a material guide device for a sewing machine, which is a material guide device for guiding a string-like material to be sewn in a sewing machine to the needle base position, and comprises: a swinging part that performs a swinging motion to swing the string-like material to be sewn in a zigzag pattern; a guide part that includes a plurality of guide members for guiding the string-like material to the vicinity of the needle base position; a cam part having a cam path formed therein, and an engaging part that engages with the cam part and is relatively movable along the cam path, and a shift mechanism configured to associate one of the guide members with the swinging part by moving the engaging part along the cam path, wherein the swinging motion of the swinging part is transmitted to the associated guide member.

[0009] According to the present invention, the guide section includes multiple guide members, so that it can guide multiple different string-like materials. Furthermore, the shift mechanism is configured to associate one guide member with the oscillating section by relatively moving the engaging section along the cam path, so that any one of the multiple guide members can be selected to associate with the oscillating section. As a result, the selected guide member is set at the needle base position, and the oscillating motion for zigzag stitching is transmitted to the guide member set at the needle base position by the oscillating section. Therefore, when switching string-like materials to be sewn, there is no need to change the string-like material to the guide device (guide member) as in the conventional technology which has only one guide device (guide member), thus saving labor. Moreover, since one oscillating section can be used for zigzag stitching of different types of string-like materials, zigzag stitching performed while switching between different types of string-like materials can be realized with a simplified configuration.

[0010] In one embodiment, one of the cam portion and the engaging portion is movable integrally with the guide portion, and the other is movable integrally with the oscillating portion. The cam path includes a plurality of main paths and connecting paths that connect each main path, and one of the guide members is associated with the oscillating portion when the engaging portion is engaged with any of the main paths. This makes it possible to associate a selected guide member with the oscillating portion with a simple engagement structure in which the engaging portion is engaged with any of the main paths. In a further embodiment, the cam portion is coupled to the guide portion, each of the main paths corresponds to a guide member, and the engaging portion is provided to oscillate together with the oscillating lever of the oscillating mechanism. This makes it possible to use one oscillating mechanism for staggered swinging of different types of string-like materials with a simple structure.

[0011] A front view of a sewing machine to which a material guide device according to one embodiment (first embodiment) of the present invention is applied. A right side view of the sewing machine shown in Figure 1. A left side view showing an enlarged portion of the sewing head of the sewing machine shown in Figure 1. A front view showing a further enlarged portion of the area surrounding the material guide device provided below the sewing head of the sewing machine shown in Figure 1. A left side view of the area surrounding the material guide device shown in Figure 4. A partial cross-sectional left side view showing a partial cross-section of the area surrounding the material guide device shown in Figure 5. A partial cross-sectional front view showing a partial removal and partial cross-section of the area surrounding the material guide device shown in Figure 4. A perspective view showing a partial removal of the area surrounding the material guide device shown in Figures 4 to 6. A perspective view of the area surrounding the material guide device seen from the opposite side of Figure 8. A schematic front view for explaining the shift operation (switching operation) performed when switching the string-like material to be sewn. A left side view of a material guide device according to another embodiment (second embodiment) of the present invention. A perspective view of the material guide device shown in Figure 11. A front view showing a part of the material guide device shown in Figure 11 cut off. A left side view showing a modified example of the material guide device shown in Figure 11. A front view of the material guide device shown in Figure 14.

[0012] Figure 1 is a front view of a sewing machine to which the material guide device 6 according to one embodiment (first embodiment) is applied, and Figure 2 is a right side view of the sewing machine. Figure 3 is a left side view showing an enlarged portion of the sewing head H of the sewing machine shown in Figure 1. This material guide device 6 is installed at the bottom of one sewing head H (near the needle base position) of a sewing machine, such as a lockstitch handle embroidery machine, and functions to guide the string-like material to be sewn in the sewing machine to the needle base position.

[0013] <Supplying the string-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 the 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 on which string-like material L is wound, 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 as an example) exist in parallel along the entire path from the material supply device 1 to the material guide device 6.

[0014] The bobbin placement device 2 includes a support plate 22 on which a plurality of bobbins 21 are arranged. A bobbin 21 is set on each of the plurality of bobbin shafts 23b erected on the support plate 22, and the bobbin 21 is fixed to the bobbin shaft 23b by a stopper 23c, so that the bobbin 21 set thereon rotates in accordance with the rotation of the bobbin shaft 23b. The stopper 23c is removable, and with the stopper 23c removed, the bobbin 21 can be attached to and detached from the tip side of the bobbin shaft 23b, thereby allowing the bobbin 21 set on the bobbin shaft 23b to be replaced. The support plate 22 is fixed to the sewing machine frame M via a pair of mounting members 4.

[0015] The above-mentioned rotary drive device (not shown) selectively rotates one bobbin shaft 23b, thereby rotating one bobbin 21 in the bobbin placement device 2 via the bobbin shaft 23b, and the string-like material L is actively fed out from the bobbin 21 as the bobbin 21 rotates. For example, each bobbin 21 is a large bobbin capable of winding a large amount of string-like material, thereby reducing the frequency of bobbin replacement due to the consumption of string-like material, and thus providing a configuration suitable for the use of large amounts of string-like material. In this case, actively rotating the bobbin 21 with the above-mentioned rotary drive device (not shown) contributes to the smooth feeding of string-like material from the large (heavy) bobbin 21.

[0016] Multiple pins 25 are erected horizontally at the lower part of the support plate 22, and the string-like material drawn from each bobbin 21 is distributed and passed through the pins 25 so that the string-like material does not interfere with each other. Multiple string-like materials (for example, 3) drawn in parallel from the material supply device 1 via the pins 25 are guided to the material guide device 6 below via the intermediate guide 7. As shown in Figure 2, the intermediate guide 7 includes a first roller 71, a reversing section 72, a second roller 73, a first guide hole 74, and a second guide hole 75. The first roller 71 consists of multiple rollers (for example, 3) corresponding to each string-like material, arranged side by side in a front view (see Figure 1), and similarly, the second roller 73 consists of multiple rollers (for example, 3) corresponding to each string-like material, arranged side by side in a front view (see Figure 1). The reversing section 72 consists of multiple holes (three, for example) corresponding to each string-like material, arranged side by side in a front view, with these holes oriented horizontally (see Figure 1). The reversing section 72 is fixed at an appropriate intermediate position on a vertically extending rail 76, and the height position at which the reversing section 72 is fixed can be appropriately changed by displacing it up or down along the rail 76.

[0017] The upper end of the rail 76 is cantilevered by a mounting member 4 and fixed to a cantilevered crossbar 77 that extends horizontally forward. A first roller 71 is attached near the base of the cantilevered crossbar 77 (towards the mounting member 4, i.e., towards the rear), and a second roller 73 is attached near the tip of the cantilevered crossbar 77 (i.e., towards the front) (see Figure 2). The first guide hole 74 is provided at the lower end of the rail 76 and consists of multiple holes (for example, 3) arranged side by side, corresponding to each string-like material, and these holes are oriented vertically (see Figures 1 and 2). Note that the multiple holes (for example, 3) of the first guide hole 74 can be seen in a plan view and are therefore not visible in Figures 1 and 2. The second guide hole 75 is provided further below the first guide hole 74 and consists of multiple holes (for example, 3) arranged side by side, corresponding to each string-like material, and these holes are oriented diagonally downward, generally pointing towards the area around the needle base position.

[0018] In the intermediate guide 7, each string-like material that has passed between the pins 25 moves downwards, touching the rear of the first roller 71, passes through the hole of the reversing section 72 from rear to front, moves upwards, is folded downwards by the second roller 73, passes through the first guide hole 74, and then passes through the second guide hole 75 to be guided to the material guide device 6 below (see Figure 2). By guiding the string-like material through the first roller 71, the reversing section 72, and the second roller 73 to the first guide hole 74 below, the movement path of the string-like material moving from top to bottom in front of the sewing head H is reliably formed in front of the sewing head H (so as not to be interfered with by the sewing head H).

[0019] A material guide device 6 is provided at the lower part of the sewing head H, around the vertically moving sewing needle 12. The material guide device 6 includes a swinging part (swinging lever 51) that performs a swinging motion to swing the string-like material to be sewn in a zigzag pattern, a guide part 61 that includes a plurality (for example, 3) of guide tubes (guide members) 61a for guiding the string-like material to the vicinity of the needle base position, and a shift mechanism 62 configured to associate one guide tube (guide member) 61a with the swinging part, and to transmit the swinging motion of the swinging part to the associated guide tube (guide member) 61a. As will be described in detail later, the shift mechanism 62 includes a cam part (cam plate 63) in which a cam path (cam groove 63a and connecting groove 63b) is formed, and an engaging part (roller 51b) that engages with the cam part (cam plate 63) and is relatively movable along the cam path, and is configured to associate one guide tube (guide member) 61a with the swinging part by moving the engaging part along the cam path. Each string-like material that passes through the second guide hole 75 of the intermediate guide 7 is inserted into the corresponding guide tube (guide member) 61a, exits the guide tube (guide member) 61a, and is guided to the needle base position. However, due to the correspondence of the guide part 61 (guide tube 61a) to the oscillating part (oscillating lever 51) by the shift mechanism 62, only one selected (associated) guide tube (guide member) 61a is set to the needle base position.

[0020] <Outline of the Sewing Head> As shown in Figure 3, the sewing head H is provided with a needle bar 11 that extends vertically in the axial direction. The needle bar 11 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 11. A support cylinder 13 is attached to the outer circumference of the needle bar 11. This support cylinder 13 is guided by the inner surface of a fixed sleeve 14 fixed to the lower part of the sewing head H, enabling relative vertical movement of the needle bar 11 and rotational movement of the needle bar 11 around its axis. In addition, an engagement ring 15 is fixed to the outer circumference of the upper end of the support cylinder 13, and a drive arm 17 that moves up and down by the drive of a motor 16 is engaged with the engagement ring 15.

[0021] A presser foot support 18 is fixed to the lower end of the support cylinder 13. The presser foot support 18 is formed in a bifurcated shape at its lower end, and a key groove 18a is formed on the outer surface of one leg, with its longitudinal direction extending vertically. A presser foot body (nipple) 19 is fixed to the other leg of the presser foot support 18. When the needle bar 11 moves up and down in accordance with the rotation of the spindle 10 to perform sewing, the drive arm 17 moves up and down in conjunction with this by the motor 16, and the presser foot body 19 moves up and down via the support cylinder 13 and presser foot support 18, 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 61a and is guided to the needle base position is sewn to the workpiece (not shown, e.g., fabric) placed on the needle plate 20 fixed to the upper surface of the sewing machine table (not shown) 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 sewing machine table in an X-Y drivable state and is driven in the X-Y direction for each stitch (sew) according to the embroidery pattern (sewing pattern) data.

[0022] A rotating cylinder (rotating body) 8 is attached to the outer circumference of the fixed sleeve 14. The rotating cylinder 8 is mounted concentrically with the needle bar 11, and is only capable of rotational movement around the axis of the needle bar 11. A timing pulley portion 80 is formed on the outer circumference of the upper end of the rotating cylinder 8, and a timing belt 83 is stretched between this timing pulley portion 80 and a drive pulley 82 fixed to the rotating shaft 81a of the direction control motor 81. As a result, when the direction control motor 81 is driven and the drive pulley 82 rotates, the rotating cylinder 8 rotates via the timing belt 83 and the timing pulley portion 80. On the other hand, a key member 84 that engages with the key groove 18a of the presser foot support 18 is fixed to the lower end of the rotating cylinder 8. Therefore, 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 13, and rotates around the axis of the needle bar 11 in accordance with the rotation of the rotating cylinder 8. As will be described later, the rotational motion of the rotating cylinder 8 is ultimately transmitted to the guide section 61 of the material guide device 6. The direction control motor 81, which is the rotational drive source for the rotating cylinder 8, is driven and controlled according to the embroidery pattern (sewing pattern) data, and rotates the guide section 61 of the material guide device 6 around the axis of the needle bar 11 so that the guide section 61 of the material guide device 6 appropriately points in the sewing direction for each stitch. As can be seen from Figure 3, the guide section 61 and the presser foot 19 are arranged facing each other (on opposite sides) with the needle bar 11 in between, and both rotate together in accordance with the rotation of the rotating cylinder 8.

[0023] A swinging lever (swinging part) 51 is attached to the outer circumference of the rotating cylinder 8 via a mounting bracket. The swinging lever 51 is pivotably mounted on the rotating cylinder 8, with a lever pin 52 as the pivot point, allowing it to swing left and right in the axial direction of the needle bar 11. This swinging lever 51 extends downward from the position of the lever pin 52 (forming a relatively long leg), and also includes a short arm 51a that extends laterally from the position of the lever pin 52 (see Figures 4 to 8). A roller 51b is provided at the lower end of the swinging lever 51, facing outwards (see Figure 7). Through this swinging lever (swinging part) 51, a swinging motion for swinging the string-like material in a zigzag pattern is applied to the guide part 61 of the material guide device 6.

[0024] Furthermore, an interlocking member 53 is fitted to the outer circumference of the rotating cylinder 8 so as to be able to move up and down and rotate. A connecting body 54 is fixed to the interlocking member 53, and one end of the connecting body 54 engages with a vertically elongated engagement groove 8a formed on the outer circumference of the rotating cylinder 8 (see Figures 5 to 9). Due to this engagement, the interlocking member 53 rotates together with the rotating cylinder 8 as the rotating cylinder 8 rotates, but can move up and down independently of the rotating cylinder 8 in the vertical direction. A roller 55 is attached to the tip of the arm portion 51a of the swinging lever 51 (see Figure 4), and an interlocking groove 54a is provided at the other end of the connecting body 54, and the roller 55 engages with the interlocking groove 54a of the connecting body 54. As a result, when the interlocking member 53 moves up and down, the engagement of the connecting groove 54a of the connecting body 54 and the roller 55, which move up and down together, causes the arm portion 51a of the swinging lever 51 to move up and down around the lever pin 52 as a pivot point, and the downward-extending swinging lever 51 (leg portion) swings laterally (left and right) like a pendulum around the lever pin 52 as a pivot point.

[0025] As shown in Figures 1 and 2, a staggered swing motor 50 is provided, which is the drive source for staggering the string-like material. Although not shown in detail, the rotational motion of this staggered swing motor 50 is converted into vertical motion and transmitted to the lifting member 56 (see Figures 4 and 7), causing the lifting member 56 to move up and down. In Figures 4 and 7, only the lower part of the lifting member 56 is shown, and the portion extending upward is not shown. A fork portion 56a is formed at the lower end of the lifting member 56, which protrudes approximately horizontally toward the needle bar 11, and this fork portion 56a engages with a groove portion 53a formed on the outer circumference of the interlocking member 53 (see Figures 3 to 7). Therefore, when the interlocking member 53 and the connecting body 54 move up and down due to the up and down movement of the lifting member 56 in response to the rotation of the staggered swing motor 50, the up and down movement of the connecting body 54 is transmitted to the arm portion 51a of the swing lever 51 via the linkage groove and roller 55, and converted into a left and right swinging motion of the swing lever 51 via the lever pin 52. This mechanism from the staggered swing motor 50 to the swing lever 51 corresponds to a swinging mechanism (staggered swing mechanism) that generates a swinging motion for swinging the string-like material to be sewn in a staggered pattern.

[0026] <Material Guiding Device> Figure 4 is a front view showing an enlarged view of the peripheral portion of the material guiding device 6 shown in Figure 1, Figure 5 is a left side view of the peripheral portion of the material guiding device 6 shown in Figure 4, and Figure 6 is a partial cross-sectional left side view showing a portion of the peripheral portion of the material guiding device 6 shown in Figure 5. Figure 7 is a partial cross-sectional front view showing a portion of the peripheral portion of the material guiding device 6 shown in Figure 4, and in particular, the guide part 61 of the material guiding device 6 has been removed so that the shift mechanism 62 can be viewed from the front. Figure 8 is a perspective view showing a portion of the peripheral portion of the material guiding device 6 shown in Figures 4 to 6 with some parts removed, and Figure 9 is a perspective view of the peripheral portion of the material guiding device 6 seen from the opposite side of Figure 8. The details of the material guiding device 6 will be described below with further reference to these figures.

[0027] The guide section 61 includes an inclined section 61b in which a plurality of guide tubes (guide members) 61a (three as an example) are arranged in parallel in the horizontal direction, tilted diagonally downward toward the needle base position, and a vertical section 61c extending vertically upward from the upper center of the inclined section 61b. 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 61c of the guide section 61 engages with the oscillating section (oscillating lever 51) via a cam plate 63, as described later, and is oscillated laterally (left and right) in conjunction with the oscillating section (oscillating lever 51). Here, the oscillating lever 51 and the cam plate 63 are located inside (need side) of the vertical section 61c of the guide section 61, and a slider 61d is fixed to the outside of the vertical section 61c. The slider 61d is slidably coupled to a guide rail 58 that extends horizontally, allowing it to slide horizontally. The guide rail 58 is fixed to the lower end of the support bracket 57, as will be described later. This sliding coupling functions to convert the pendulum-like swinging motion of the swing lever 51, which has the lever pin 52 as its pivot axis, into a horizontal swinging motion (reciprocating motion) and transmit it to the guide section 61.

[0028] The shift mechanism 62 includes a cam plate 63 as a cam section on which cam paths are formed. As shown in Figure 7, the cam paths formed in the cam plate 63 (cam section) include a plurality of main paths (cam grooves) 63a (three in one example) and connecting paths (connecting grooves) 63b that connect each main path (cam groove) 63a. Hereinafter, the main paths will simply be referred to as cam grooves, and the connecting paths as connecting grooves. In the cam plate (cam section) 63, each cam groove 63a arranged in parallel consists of a vertically elongated opening, and the connecting groove 63b consists of a roughly horizontally elongated opening formed to connect the lower parts of each cam groove 63a. Each cam groove 63a is provided corresponding to each guide cylinder (guide member) 61a. The cam plate (cam portion) 63 is positioned upright parallel to the swing surface of the swing lever 51, on the outside of the swing lever 51 (opposite the vertical axis of motion of the needle bar 11), and the roller 51b, which is provided outward at the lower end of the swing lever 51, engages with the cam plate (cam portion) 63 and is assembled to be movable along the cam groove 63a and the connecting groove 63b. This roller 51b not only transmits the swinging motion of the swing lever 51 for staggered swing to the guide portion 61, but also functions as a component (engaging portion) in the shift mechanism 62. The cam plate 63 is fixed to the inside (needle side) of the vertical portion 61c of the guide portion 61 and is movable integrally with the guide portion 61. As mentioned above, a slider 61d is fixed to the outside of the vertical portion 61c of the guide portion 61 and is linked to the support bracket 57 via the guide rail 58. This link allows the guide section 61 and cam plate 63 to move up and down together when the support bracket 57 is raised and lowered by the material guide lifting mechanism 9, which will be described later. When sewing a string-like material, the material guide lifting mechanism 9 lowers the support bracket 57 to set the guide section 61 and cam plate 63 to the lowest position (sewing position). On the other hand, when not sewing a string-like material, the material guide lifting mechanism 9 raises the support bracket 57 to set the guide section 61 and cam plate 63 to the highest position (retracted position).

[0029] Thus, in the shift mechanism 62, the roller 51b (engaging part) engages with the cam plate 63 (cam part) and is movable along the cam groove 63a and the connecting groove 63b, and the cam plate 63 (cam part) is coupled to the guide part 61 and is configured to move up and down and left and right together. Here, the roller 51b (engaging part) is given left and right movement by the swing mechanism (staggered swing mechanism) via the swing lever 51, and the cam plate 63 (cam part) is given up and down movement by the material guide lifting mechanism 9 via the support bracket 57. The shift mechanism 62 displaces the cam plate 63 (cam part) and the roller 51b (engaging part) relatively in the vertical and horizontal directions by a combination of driving the cam plate 63 in the up and down direction and driving the roller 51b in the left and right (lateral) direction, thereby moving the roller 51b (engaging part) relatively along the cam groove 63a and the connecting groove 63b, and thereby moving the guide part 61 (guide cylinder 61a) in the up and down and / or lateral directions.

[0030] A specific example of the cam path (cam groove 63a and connecting groove 63b) formed in the cam portion (cam plate 63) will be further explained with reference to Figure 7. Multiple cam grooves 63a (main paths) are arranged in parallel, each extending in the vertical direction, and the connecting groove 63b (connecting path) is formed to connect the lower parts of each cam groove 63a (main path). Each cam groove 63a corresponds to each guide cylinder (guide member) 61a, and when the roller 51b (engaging part) engages with one of the cam grooves 63a (main path) and is positioned near its upper end, it is the state in which one guide cylinder (guide member) 61a corresponding to that cam groove 63a is selected, that is, the state in which the selected guide cylinder 61a is set to the needle base position (a state corresponding to the swing lever 51). In the example in Figure 7, the roller 51b is engaged with the central cam groove 63a, showing the state in which the central guide cylinder 61a is selected to be set to the needle base position. Furthermore, in the example shown in Figure 7, in order to smooth the relative lateral movement of the roller 51b along the connecting groove 63b when changing (i.e., shifting) the cam groove 63a with which the roller 51b should engage, the lengths of the left and right cam grooves 63a are made shorter than the length of the central cam groove 63a, and the connecting groove 63b that connects them is formed to consist of a combination of an inclined portion and a horizontal portion. Note that this inclined portion is not limited to a straight line and may be in the shape of a circular arc.

[0031] As shown in Figure 7, when the pivot lever 51 is in a vertical position (center position), the roller 51b is engaged with the cam groove 63a corresponding to one selected guide cylinder 61a, and the pivot lever 51 is in a vertical position, the roller 51b is not in contact with the uppermost end of the cam groove 63a, and there is empty space above the roller 51b in the cam groove 63a. This empty space takes into account that the height of the roller 51b increases somewhat when the pivot lever 51 swings from side to side like a pendulum. That is, when the cam plate 63 moves horizontally from side to side in response to the swing of the pivot lever 51, the height of the cam plate 63 (i.e., the height of the uppermost end of the cam groove 63a) does not change and remains at a constant height due to the engagement of the slider 61d and the guide rail 58, but smooth horizontal movement is ensured by allowing the somewhat elevated roller 51b to enter the empty space.

[0032] The shift mechanism 6 further includes a locking member 64 for locking the horizontal movement of the cam plate 63 (cam portion) while the roller 51b (engaging portion) is moving relative to the cam groove 63a and the connecting groove 63b. As shown in Figure 7, this locking member 64 is fixed to the rotating cylinder 8 in a state where it protrudes downward. On the other hand, a recess 63c is provided on the upper part of the cam plate 63, positioned opposite the locking member 64. When the support bracket 57 is raised by the material guide lifting mechanism 9 to set the guide portion 61 and the cam plate 63 to the uppermost position (retracted position), the locking member 64 fits into the recess 63c, locking the lateral movement of the cam plate 63.

[0033] When performing a zigzag stitch, the guide section 61 and the cam plate 63 are set to the lowest position (sewable position). For example, as shown in Figure 7, when the roller 51b is engaged with the central cam groove 63a, the central guide cylinder 61a of the guide section 61 is linked to the swing lever 51 (i.e., set to the needle base position), and stitching is performed on the string-like material guided to the needle base position by this central guide cylinder 61a. When the swing lever 51 is swung from side to side by the swing mechanism (zigzag swing mechanism) described above, the cam plate 63 moves horizontally from side to side via the roller 51b engaged with the central cam groove 63a. As a result, the guide section 61 moves horizontally from side to side around the central guide cylinder 61a engaged with the roller 51b, and zigzag stitching is performed on the string-like material guided by the central guide cylinder 61a set to the needle base position, following this horizontal movement. Furthermore, since the presser foot 19 is located on the opposite side of the guide section 61 with the needle base position in between, only the string-like material currently selected for sewing, guided by the central guide cylinder 61a set at the needle base position, is pressed against the workpiece (not shown) by the presser foot 19 as the needle 12 descends. Also, as will be described later, a material holding mechanism (material holding device) 100 is located on the opposite side of the guide section 61 with the needle base position in between, and any string-like material that has not been selected is held by a holding member 101 provided in this material holding mechanism (material holding device) 100.

[0034] Next, the shift operation (string material switching operation) performed by the shift mechanism 62 to switch the string material to be sewn will be explained with reference to Figure 10. Figure 10 is a schematic front view illustrating the shift operation (switching operation) performed by the shift mechanism 62 when switching the string material to be sewn. For convenience, only the relationship between the swing lever 51 and the cam plate 63 is shown, and the relative positional relationship of the guide part 61 is also shown in part for reference. As mentioned above, the guide part 61 moves horizontally and vertically integrally with the cam plate 63. Figure 10(a) shows the state in which the roller 51b is engaged with the central cam groove 63a, similar to Figure 7. Figure 10 shows the shift operation from the state in (a) where the central guide cylinder 61a corresponding to the central cam groove 63a is associated with the swing lever 51 (set to the needle base position), to the state in (d) where the left guide cylinder 61a corresponding to the left cam groove 63a is associated with the swing lever 51 (set to the needle base position).

[0035] First, as shown in Figure 10(b), the material guide lifting mechanism 9 raises the support bracket 57 to set the cam plate 63 (and guide portion 61) to its highest position. At this time, the cam plate 63 rises along the central cam groove 63a, guided by the roller 51b of the swing lever 51, until the roller 51b reaches the connecting groove 63b. In this state, the locking member 64 fits into the recess 63c at the top of the cam plate 63.

[0036] Next, as shown in Figure 10(c), with the cam plate 63 (and guide portion 61) set to the highest position, the swing lever 51 is swung to the left to a predetermined limit position. As a result, the roller 51b of the swing lever 51 moves to the left along the connecting groove 63b. During this leftward movement, the lateral movement of the cam plate 63 is locked by the locking member 64, preventing the cam plate 63 from moving in accordance with the lateral movement of the swing lever 51 (roller 51b), thereby allowing the roller 51b to move to the limit position to the left along the connecting groove 63b.

[0037] Next, as shown in Figure 10(d), while maintaining the leftmost limit position of the swing lever 51, the material guide lifting mechanism 9 lowers the support bracket 57 to move the cam plate 63 (and guide portion 61) to its lowest position. As the cam plate 63 descends, the lock on the cam plate 63 by the locking member 64 is released, and the cam plate 63 slides to the right along the connecting groove 63b, guided by the roller 51b, until the roller 51b engages with the left cam groove 63a. In this way, the shift operation (string material switching operation) by the shift mechanism 62 is completed, and the left guide cylinder 61a is linked to the swing lever 51 (set to the needle base position).

[0038] After the shift operation is completed, the machine enters a state where it is ready to sew onto the string-like material guided by the left-side guide cylinder 61a, which is set to the needle-start position. As described above, when the swinging lever 51 is swung from side to side by the swinging mechanism (zigzag swing mechanism), the cam plate 63 moves horizontally from side to side via the roller 51b engaged with the left-side cam groove 63a, and zigzag stitching is performed on the string-like material guided by the left-side guide cylinder 61a, which is set to the needle-start position, in accordance with this horizontal movement.

[0039] When setting the right-side guide cylinder 61a to the needle base position, the shift operation by the shift mechanism 6 can be performed in the same manner as described above (but in the reverse direction). For example, by raising the cam plate 63 (and guide portion 61) to the highest position from the state shown in Figure 10(d), the cam plate 63 slides to the left along the left-side cam groove 63a and connecting groove 63b, guided by the roller 51b, and is set to the same state as shown in Figure 10(c). Next, with the cam plate 63 (and guide portion 61) still set to the highest position, the swing lever 51 is swung to the right to a predetermined limit position, causing the roller 51b of the swing lever 51 to move relatively to the right along the connecting groove 63b. Next, while maintaining the rightward limit position of the swing lever 51, the material guide lifting mechanism 9 lowers the support bracket 57, moving the cam plate 63 (and guide portion 61) to its lowest position. As a result, the cam plate 63 slides to the left along the connecting groove 63b, guided by the roller 51b, until the roller 51b engages with the right-side cam groove 63a. In this way, the shift operation (string-like material switching operation) by the shift mechanism 62 is completed, and the right-side guide cylinder 61a, corresponding to the right-side cam groove 63a, is linked to the swing lever 51 (set to the needle base position).

[0040] To switch from a state where the left or right guide cylinder 61a is set to the needle base position to a state where the central guide cylinder 61a corresponding to the central cam groove 63a is set to the needle base position, the cam plate 63 (and guide part 61) is raised to the highest position, causing the roller 51b to descend relatively along the left or right cam groove 63a, and then move relatively to the center along the connecting groove 63b, setting it to the same state as in Figure 10(b). Then, by lowering the cam plate 63 (and guide part 61) to the lowest position, the roller 51b is engaged with the central cam groove 63a as shown in Figure 10(a). As a result, the central guide cylinder 61a corresponding to the central cam groove 63a is associated with the swing lever 51 (set to the needle base position).

[0041] In this embodiment, the guide section 61 includes a plurality of guide cylinders 61a (guide members), so that it can guide different string-like materials. Furthermore, the shift mechanism 62 is configured to associate one guide cylinder 61a (guide member) with the oscillating lever 51 (oscillating part) by relatively moving the roller 51b (engaging part) along the cam groove 63a and the connecting groove 63b (cam path). As a result, any one of the plurality of guide cylinders 61a (guide members) can be selected to associate with the oscillating lever 51 (oscillating part). By shifting the guide section 61 laterally, the selected guide cylinder 61a (guide member) is set to the needle base position, and the oscillating motion for staggered swing is transmitted to the guide cylinder 61a (guide member) set to the needle base position by the oscillating lever 51 (oscillating part). Therefore, when switching between string-like materials to be sewn, there is no need to change the string-like material to the guide device (guide member) as in conventional technology which has only one guide device (guide member), thus saving labor. Furthermore, since one oscillating mechanism (oscillating part) can be used for zigzag stitching of different types of string-like materials, zigzag stitching performed while switching between different types of string-like materials can be realized with a simplified configuration.

[0042] <Material Guide Lifting Mechanism> As shown in Figures 1 to 9 (especially Figures 8 and 9), the material guide lifting mechanism 9 includes a lifting plate 91 configured to move up and down along the axial direction of the needle bar 11, 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 11, and configured to move up and down together with the lifting plate 91. As shown in Figures 1 and 3, an air cylinder 93 is fixed to the left side of the sewing 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 a cylinder rod 93a that extends downward and retracts upward. 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.

[0043] As shown in Figures 8 and 9, 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 inwardly opening, vertically elongated engagement groove 92c (Figure 9). A vertically elongated guide body 92b, fixed to the side surface of the rotating cylinder 8 via a mounting bracket, is slidably engaged with the engagement groove 92c 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).

[0044] On the lower surface of the rotary ring 92, the support bracket 57 extending downward is attached. As described above, a guide rail 58 is fixed to the lower end of the support bracket 57, and a slider 61d is coupled to the guide rail 58. Thereby, in the material guide elevating mechanism 9, by extending or contracting the air cylinder 93, the connecting rod 94, the elevating plate 91, the rotary ring 92, the support bracket 57, and the guide rail 58 descend or ascend together, and the guide portion 61 and the cam plate 63 are descended or ascended together via the slider 61d coupled to the guide rail 58. On the other hand, when the rotary cylinder 8 rotates, the rotary ring 92 rotates together due to the engagement between the guide body 92b and the connecting member 92a. Along with this, the guide portion 61 and the cam plate 63 are rotated via the support bracket 57, the guide rail 58, and the slider 61d. In summary, the material guide elevating mechanism 9 is configured such that the material guide device 6 including the guide portion 61 and the cam plate 63 is mounted on the rotary ring 92, and the material guide device rotates together with the rotary ring 92 and is elevated and lowered by the elevating plate 91.

[0045] According to the present embodiment, since the material guide elevating mechanism 9 configured to rotate and elevate the material guide device 6 independently is used, it is possible to provide a configuration suitable for rotating and elevating the material guide device 6, which tends to increase in weight by providing a plurality of guide cylinders 61a. The drive source of the material guide elevating mechanism 9 is not limited to the air cylinder 93, and other appropriate linear drive sources, for example, a combination of a rotary electric motor and a rotation-linear conversion mechanism (for example, a ball screw), or a linear rail, etc., may be adopted as appropriate. When a drive source capable of arbitrarily variably controlling the stop position, such as an electric motor, is used as the drive source of the material guide elevating mechanism 9, it is advantageous because the lowest position of the guide portion 61 can be variably set according to the thickness of the string-like material to be sewn and / or the material to be sewn. That is, the drive source of the material guide elevating mechanism 9 can be configured such that the height adjustment including the highest position and the lowest position of the elevating plate 91 can be arbitrarily performed.

[0046] <Material Holding Mechanism> The material holding mechanism (material holding device) 100, located on the opposite side of the guide section 61 with the vertical axis of motion of the sewing needle 12 in between, is equipped with holding members 101 for holding the string-like material guided by each guide tube (guide member) 61a, arranged in parallel and corresponding to each guide tube (guide member) 61a (see Figures 5 to 9). A slider 103 is fixed to this holding member 101 via a bracket 102. As shown in Figures 5 and 6, a support bracket 104 extending downward is attached to the lower surface of the rotating ring 92, and a guide rail 105 is fixed to the lower end of this support bracket 104. The guide rail 105 extends horizontally parallel to the guide rail 58, and the slider 103 of the holding member 101 is slidably coupled to the guide rail 105 so as to be horizontally slidable. The bracket 102 of the retaining member 101 is connected to the cam plate 63 via a pair of left and right connecting members 106. Therefore, while maintaining the correspondence between each retaining member 101 and the guide cylinder (guide member) 61a, the material holding mechanism 100 moves integrally with the guide 61 (rotates, moves up and down, and moves horizontally).

[0047] 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. This structure, in which the string-like material is held on the lower side (hook-shaped fiber surface) of the holding member 101, is advantageous because it makes it easier to release the hold of the string-like material guided by the guide tube (guide member) 61a set at the needle base position. In other words, when sewing begins on a string-like material guided at the needle base position, even if the string-like material is held by the corresponding holding member 101, the hold by the holding member 101 can be automatically released when the string-like material guided at 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 (guide members) 61a that are not set at the needle base position remain held by their respective holding members 101, and since the material holding mechanism 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. 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. Furthermore, the material holding mechanism (material holding device) 100 is not limited to the illustrated example, but for example, the holding members 101 may be arranged near each guide tube (guide member) 61a and connected so that they move integrally with the guide section 61 (rotate, move up and down, and move horizontally), in which case the guide rail 105 and connecting members 106 etc. become unnecessary, resulting in a considerably simpler structure.

[0048] In a preferred embodiment, a material cutting device (not shown) is arranged near (for example, behind) the material holding mechanism (material holding device) 100. When sewing on the selected string-shaped material is completed, the string-shaped material is automatically cut by the material cutting device, and the cut string-shaped material coming out from the tip of the corresponding guide cylinder (guide member) is picked by a picking mechanism attached to the material cutting device and pulled out to the position of the corresponding holding member 101 and held by the holding member 101. This enables automatic cutting and holding of the sewn string-shaped material. However, it is not limited to this. As another embodiment, the cutting of the sewn string-shaped material and the holding operation on the holding member 101 may be manually performed by an operator.

[0049] In the first embodiment described above, the material supply device 1 for supplying the string-shaped material is arranged above the sewing head H so that a large bobbin 21 can be used. However, it is not limited to this. As in the second embodiment described below, in a configuration where a small bobbin around which the string-shaped material is wound is arranged around the needle bar and the string-shaped material is supplied to the needle tip while being appropriately rotated around the needle bar axis, the material guiding device 6 according to the present invention can also be applied.

[0050] <Second Embodiment> Figure 11 is a left side view of a material guiding device 6 according to another embodiment (second embodiment) of the present invention, Figure 12 is a perspective view of the material guiding device 6 shown in Figure 11, and Figure 13 is a front view showing a part of the material guiding device 6 in a cutaway. In this embodiment, the material guide lifting mechanism 9 (a mechanism for lifting and lowering the material guiding device 6 independently) is not provided, and the material guiding device 6 is configured to move up and down together with the fabric presser support 18 in accordance with the up and down movement of the support cylinder 13. The fabric presser support 18 is fixed to the lower end of the support cylinder 13 as described above and moves up and down together with the support cylinder 13. The mechanism for moving the support cylinder 13 up and down may include a motor 16, an engagement ring 15, and a drive arm 17 (Figure 3) as described above. A fabric presser body (nipple) 19 is formed at the lower end of the fabric presser support 18, but its shape differs somewhat from that shown in the first embodiment. In Figure 11, the fabric presser body 19 is a tapered cylindrical shape integrally formed at the lower end of the fabric presser support 18. The shapes of the fabric presser support 18 and fabric presser body 19 are merely examples, and any shape or structure may be used.

[0051] As shown in Figure 11, two bobbins 26 are attached to the outer circumference of the rotating cylinder 8 so as to rotate integrally with the rotating cylinder 8 as a device for supplying string-like material. Two arm members 27 are attached to the outer circumference of the rotating cylinder 8 at approximately 180-degree intervals so as to rotate integrally with the rotating cylinder 8. Bobbin brackets 28 are fixed to the ends of each horizontally extending arm member 27, and each bobbin bracket 28 supports a bobbin 26 wound with string-like material L so as to be rotatable and detachable. The bobbins 26 attached to the outer circumference of the rotating cylinder 8 in this way are preferably small bobbins in order to reduce the load on the rotating cylinder 8. Furthermore, there is no drive means for actively feeding out the string-like material L from the bobbins 26, and the string-like material L is naturally drawn out from the rotatable bobbins 26 as sewing progresses.

[0052] Furthermore, as described above, a vertically elongated key groove 18a is provided on the side surface of the presser foot support 18, and a key member 84 fixed to the lower end of the rotating cylinder 8 engages with the key groove 18a, so that 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 13, and rotates around the axis of the needle bar 11 (Figure 3) in accordance with the rotation of the rotating cylinder 8. The mechanism for rotating the rotating cylinder 8 may be configured to include a motor 81, a drive pulley 82, a timing belt 83, and a timing pulley section 80 (Figure 3), as described above.

[0053] The oscillating mechanism (staggered swing mechanism) that generates the oscillating motion for swinging the string-like material to be sewn can also employ a configuration similar to that shown in the first embodiment. That is, although the shape of the details may differ, in the embodiment of Figure 11, as described above, an interlocking member 53 is fitted to the outer circumference of the rotating cylinder 8 so as to be able to move up and down and rotate, a connecting body 54 is fixed to the interlocking member 53, and one end of the connecting body 54 engages with a vertically elongated engagement groove 8a formed on the outer circumference of the rotating cylinder 8. In addition, a fork portion 56a formed at the lower end of the lifting member 56 (Figure 4) engages with a groove portion 53a formed on the outer circumference of the interlocking member 53, and when the interlocking member 53 and the connecting body 54 move up and down due to the up and down movement of the lifting member 56 in response to the rotation of the staggered swing motor 50 (Figure 1), the up and down movement of the connecting body 54 is transmitted to the arm portion 51a of the oscillating lever 51 via the roller 55, and converted into a left and right oscillating motion of the oscillating lever 51 via the lever pin 52. A roller 51c (engaging portion) is provided at the lower end of the swinging lever 51, facing inward.

[0054] The material guiding device 6 according to the second embodiment shown in Figures 11 to 13, similar to the first embodiment, includes a guide section 65 in which a plurality (for example, two) of guide tubes (guide members) 65a are arranged in parallel for guiding a string-like material to the vicinity of the needle base position, and a shift mechanism 66 that shifts the guide section 65 laterally to set one selected guide tube (guide member) 65a at the needle base position and engages with a swing mechanism for staggered swing so that a swinging motion for staggered swing is transmitted to the guide tube (guide member) 65a set at the needle base position. However, the specific form and structure of the guide section 65 and the shift mechanism 66 differ from those of the first embodiment.

[0055] The guide section 65 includes a vertical section 65b in which multiple guide tubes 65a (two in one example) are arranged in parallel horizontally, tilted diagonally downward toward the needle base position. Any type of guide tube 65a can be attached to this vertical section 65b by screws or the like. This allows the guide tube 65a to be changed (replaced) depending on the thickness and cross-sectional shape of the string-like material used for sewing. In the example shown in Figure 12, the material-passing holes of the guide tubes 65a are shown to be relatively small round holes, which exemplifies the case where the string-like material used for sewing is a linear material such as nichrome wire. Furthermore, the upper end of the guide tubes 65a may have a long groove into which the screws for attachment and detachment are fitted, and the height of each guide tube 65a can be individually adjusted by changing the screw tightening position. Each guide tube 65a corresponds to each bobbin 26, and the string-like material drawn from the corresponding bobbin 26 is passed through the respective material-passing holes.

[0056] The shift mechanism 66 includes a cam plate 67 as a cam section on which cam paths are formed. As shown in Figure 13, the cam paths formed in the cam plate 67 (cam section) include a plurality of main paths (cam grooves) 67a (two, for example) and connecting paths (connecting grooves) 67b that connect each main path (cam groove) 67a. Note that in Figure 13, the guide section 65 is omitted from the illustration for convenience in order to clearly show the relationship between the oscillating lever 51 (oscillating section) and the cam plate 67. As shown in Figure 11, a connecting member 65c extending inward (in the direction of the vertical axis of movement of the needle bar 11) is fixed to the lower end of the vertical portion 65b of the guide section 65, and the lower end of the cam plate (cam section) 67 is connected to the inner edge of this connecting member 65c. The cam plate 67 is positioned upright parallel to the swinging surface of the swing lever 51 and is located inside the swing lever 51 (on the side of the vertical axis of the needle bar 11). A roller 51c (engaging part) protruding inward from the lower end of the swing lever 51 engages with the cam plate 67, allowing it to move relative to the roller along the cam groove 67a and the connecting groove 67b. A stopper is provided at the tip of the roller 51c to prevent it from coming loose. A slider 65d is fixed inside the vertical portion 65b of the guide portion 65. The slider 65d is slidably coupled to a guide rail 68 that extends horizontally, allowing it to slide horizontally.

[0057] As shown in Figures 11 and 12, a support member 69 with a substantially rectangular shape is fixed to the presser foot support 18 on the side opposite to the key groove 18a, and the guide rail 68 is fixed to the support member 69 on the side opposite to the presser foot support 18. The connecting member 65c of the guide section 65 is located below the support member 69, and a cam plate 67, which is connected to the inner edge of the connecting member 65c and stands upright above, passes through the rectangular space of the support member 69. Therefore, when the presser foot support 18 moves up and down in conjunction with the up and down movement of the support cylinder 13, the guide rail 68, the guide section 65, and the cam plate 67 also move up and down together with the rectangular support member 69. When the cam plate 67 moves up and down in this way, the cam groove 67a moves relative to the roller 51c of the swing lever 51, so the swing lever 51 does not move up and down. On the other hand, when the swing lever 51 swings from side to side, the cam plate 67 moves from side to side together with it via the roller 51c that engages with the cam groove 67a, and together with the cam plate 67, the slider 65d moves horizontally along the guide rail 68, causing the guide portion 65 to reciprocate horizontally.

[0058] The shift mechanism 66 further includes a locking member 66a for locking the horizontal movement of the cam plate 67 (cam portion) while the roller 51c (engaging portion) is moving relative to the cam groove 67a and the connecting groove 67b (Figures 11 and 13). This locking member 66a consists of a U-shaped member (or recessed member) fixed to the rotating cylinder 8 and is positioned corresponding to the vertical position of the swing lever 51 (position of the pin 52). On the other hand, a projection 67c is provided at the upper center of the cam plate 67, opposite to the locking member 66a, so that when the guide portion 65 and the cam plate 67 are set to the uppermost position (retracted position), the locking member 66a engages with the projection 67c and the lateral movement of the cam plate 67 is locked.

[0059] When performing a zigzag stitch, the guide section 65 and the cam plate 67 are set to their lowest position (sewable position). For example, as shown in Figure 13, when the roller 51c is engaged with the left cam groove 67a, the left guide cylinder 65a of the guide section 65 is linked to the swing lever 51 (set to the needle base position), and stitching is performed on the string-like material guided to the needle base position by this left guide cylinder 65a. When the swing lever 51 is swung from side to side by the swing mechanism (zigzag swing mechanism) described above, the cam plate 67 moves horizontally from side to side via the roller 51c engaged with the left cam groove 67a. As a result, the guide section 65 moves horizontally from side to side around the left guide cylinder 65a engaged with the roller 51c, and zigzag stitching is performed on the string-like material guided by the left guide cylinder 65a set to the needle base position, following this horizontal movement.

[0060] Next, the shift operation (string material switching operation) performed by the shift mechanism 66 to switch the string material to be sewn will be described. In this description, we will assume that the shift is performed from a state in which the roller 51c is engaged with the left cam groove 67a as shown in Figure 13, to a state in which the roller 51c is engaged with the right cam groove 67a. First, when the swing lever 51 is swung to the left from the position shown in Figure 13 to the leftward limit position, the cam plate 67 also slides to the left, and the projection 67c at the upper center of the cam plate 67 is positioned directly below the locking member 66a. Then, when the cam plate 67 is raised, the roller 51c of the swing lever 51 reaches the connecting groove 67b along the left cam groove 67a. In this state, the projection 67c at the upper center of the cam plate 67 fits into the locking member 66a, and the lateral movement of the cam plate 67 is locked. Then, the swing lever 51 is swung to the right, and the roller 51c of the swing lever 51 moves to the right along the connecting groove 67b. During this rightward movement, the lateral movement of the cam plate 67 is locked by the locking member 66a, preventing the cam plate 67 from moving in accordance with the lateral movement of the swing lever 51 (roller 51c). This allows the roller 51c to be moved relatively along the connecting groove 67b to its limit position in the rightward direction.

[0061] Next, while maintaining the rightward limit position of the swing lever 51, the cam plate 67 is moved to its lowest position. As the cam plate 67 descends, the roller 51c enters the right-side cam groove 67a and engages with the right-side cam groove 67a, and the lock on the cam plate 67 by the locking member 66a is released. In this way, the roller 51c of the swing lever 51 engages with the right-side cam groove 67a, and the right-side guide cylinder 65a is aligned with the swing lever 51 (set to the needle base position), completing the shift operation (string material switching operation) by the shift mechanism 66.

[0062] After the shift operation is completed, the machine enters a state where it is ready to sew onto the string-like material guided by the right-side guide cylinder 65a, which is set to the needle-start position. As described above, when the swinging lever 51 is swung from side to side by the swinging mechanism (zigzag swing mechanism), the cam plate 67 moves horizontally from side to side via the roller 51c engaged with the right-side cam groove 67a, and a zigzag stitch is performed on the string-like material guided by the right-side guide cylinder 65a, which is set to the needle-start position, in accordance with this horizontal movement.

[0063] In Figure 11, two bobbins 26 are arranged on the outer circumference of the rotating cylinder 8 at approximately 180-degree intervals, but the arrangement is not limited to this, and the interval between them can be any degree. For example, the two bobbins 26 may be attached to the rotating cylinder 8 with the two bobbins 26 arranged side by side. In addition, a material holding mechanism similar to the material holding mechanism 100 shown in the first embodiment may also be provided in the second embodiment. For example, such a material holding mechanism can be implemented by fixing a guide rail (corresponding to the guide rail 105) extending horizontally via a mounting bracket to the fabric presser support 18 on the opposite side of the guide portion 65, sliding a slider (corresponding to the slider 103) to which a plurality of holding members (corresponding to the holding members 101) associated with each guide cylinder 65a are attached to the guide rail, and the slider is connected to the cam plate 67 via a pair of left and right connecting members (corresponding to the connecting members 106).

[0064] Next, a modified example of the material guiding device 6 (second embodiment) shown in Figure 11 will be described with reference to Figures 14 and 15. Figure 14 is a left side view showing a modified example of the material guiding device 6 shown in Figure 11, and Figure 15 is a front view of the material guiding device 6 shown in Figure 14. In this modified example as well, a plurality (for example, two) of bobbins 26 having the same configuration as shown in Figure 11 are attached to the outer circumference of the rotating cylinder 8 so as to rotate integrally with the rotating cylinder 8, but these bobbins 26 are not shown in Figures 14 and 15.

[0065] In the embodiments shown in Figures 14 and 15, the lower half of the oscillating lever 51 is configured to function as a cam plate (cam section) 110. That is, as shown in Figure 15, the lower half of the oscillating lever 51 is formed as a cam plate (cam section) 110, and the cam plate 110 has a cam path formed thereon, which includes a plurality (three as an example) of main paths (cam grooves) 110a and connecting paths (connecting grooves) 110b that connect each main path (cam groove 110a). In the cam plate (cam section) 110, each cam groove 110a consists of a vertically elongated opening that extends in the vertical direction, and the connecting groove 110b consists of a roughly horizontally elongated opening formed to connect the upper parts of each cam groove 110a. As an example, the lengths of the left and right cam grooves 110a are made shorter than the length of the central cam groove 110a, and the connecting groove 110b that connects them is formed to consist of a combination of an inclined portion and a horizontal portion.

[0066] The guide section 65 includes a plurality of guide tubes (guide members) 65e (for example, two) for guiding the string-like material to the vicinity of the needle base position, and a vertical section 65f in which these guide tubes 65e are arranged in parallel in the horizontal direction, tilted diagonally downward toward the needle base position. Any type of guide tube 65e can be attached to the vertical section 65f by screws or the like in a detachable manner, thereby allowing the guide tube 65e to be changed (replaced) depending on the thickness and cross-sectional shape of the string-like material used for sewing. A slider 65g is also fixed inside the vertical section 65f of the guide section 65. The slider 65g is slidably coupled to a guide rail 68 that extends horizontally, and is capable of sliding horizontally. As shown in Figure 15, a vertical section 65f and a slider 65g are provided individually for each guide tube 65e.

[0067] As shown in Figures 14 and 15, at the upper end of the vertical portion 65f of the guide section 65, there are rollers 65h (engaging parts) that protrude outward (in the opposite direction from the needle bar 11), corresponding to each guide cylinder 65e. The swing lever 51 is located on the outside of the vertical portion 65f of the guide section 65 (opposite side from the needle bar 11), and these rollers 65h (engaging parts) engage with the cam plate 110 of the swing lever 51, allowing them to move relative to each other along the cam groove 110a and the connecting groove 110b. When two guide cylinders (guide members) 65e are provided as shown, there are also two rollers 65h (engaging parts), and three rows of cam grooves 110a are provided. When one selected guide cylinder (guide member) 65e is associated with the swing lever 51 (set to the needle base position), the roller 65h (engaging part) corresponding to the selected guide cylinder 65e engages with the central cam groove 110a. At that time, the roller 65h corresponding to the guide tube 65e that is not selected (not set to the needle base position) is engaged with the left or right cam groove 110a. By engaging the roller 65h with the two cam grooves 110a in this way, when the swing lever 51, which has a wide cam plate 110 formed on approximately the lower half, swings from side to side, the lateral movement can be stably transmitted to the guide section 65.

[0068] As shown in Figure 14, the guide rail 68 is fixed to the presser foot support 18 on the side opposite to the keyway 18a. Therefore, when the presser foot support 18 moves up and down in conjunction with the vertical movement of the support cylinder 13, the slider 65g and roller 65h of the guide section 65 also move up and down together with the guide rail 68. When the roller 65h of the guide section 65 moves up and down in this way, the roller 65h moves along the cam groove 110a of the cam plate 110 of the swing lever 51, so the swing lever 51 itself does not move up and down. On the other hand, when the swing lever 51 swings from side to side, the vertical portion 65f of the guide section 65 moves from side to side together via the roller 65h (engaging portion) that is engaged with the cam groove 110a, the slider 65g moves horizontally along the guide rail 68, and the guide section 65 reciprocates horizontally.

[0069] In the examples shown in Figures 14 and 15, the shift mechanism 66 has a locking member 112 for locking the horizontal movement of the guide portion 65 when the guide portion 65 is set to its uppermost position (retracted position), for example, when the roller 65h (engaging portion) is engaged with the connecting groove 110b and the swinging lever 51 (cam plate 110) is swung to the right or left. This locking member 112 consists of a U-shaped member (or recessed member) fixed to the rotating cylinder 8 and is positioned corresponding to the vertical position of the swinging lever 51 (position of the pin 52). On the other hand, a projection 66h is provided on the upper part of each vertical portion 65f of the guide portion 65, facing the locking member 112, so that when the guide portion 65 is set to its uppermost position (retracted position), the locking member 112 fits onto the projection 66h and the lateral movement of the guide portion 65 is locked.

[0070] When performing a zigzag stitch, as described above, the corresponding roller 65h corresponding to one selected guide tube 65e is engaged with the central cam groove 110a. In Figure 15, the roller 65h corresponding to the right guide tube 65e is engaged with the central cam groove 110a, and the guide section 65 is set to the lowest position (sewable position). That is, the right guide tube 65e, corresponding to the roller 65h engaged with the central cam groove 110a, is linked to the oscillating lever 51 (set to the needle base position). In this state, when the oscillating lever 51 is swung from side to side by the oscillating mechanism (zigzag swing mechanism) described above, the guide section 65 moves horizontally from side to side via the roller 65h engaged with the cam groove 110a. As a result, the right guide tube 110a, corresponding to the roller 65h engaged with the central cam groove 110a, moves horizontally from side to side at the needle base position, and zigzag stitching is performed on the string-like material guided by the right guide tube 110a according to this horizontal movement.

[0071] Next, the shift operation (string material switching operation) performed by the shift mechanism 66 to switch the string material to be sewn will be explained. In this explanation, as shown in Figure 15, the shift is performed from a state where the roller 65h corresponding to the right guide cylinder 110a is engaged with the central cam groove 110a to a state where the roller 65h corresponding to the left guide cylinder 110a engages with the central cam groove 110a. First, the presser foot support 18 is raised to the retracted position, thereby raising the guide portion 65 (roller 65h), and the two rollers 65h of the guide portion 65 are raised along the corresponding cam grooves 110a. At this time, the guide portion 65 (roller 65h) moving along the left cam groove 110a moves to the right while rising along the inclined portion of the connecting groove 110b. When the roller 65h reaches the horizontal portion of the connecting groove 110b, the projection 66h on the upper part of the guide portion 65 fits into the locking member 112, and the horizontal movement of the guide portion 65 is locked. In this state, the swing lever 51 is swung to the left, positioning the roller 65h corresponding to the left guide cylinder 110a so that it engages with the central cam groove 110a. Then, the guide part 65 (roller 65h) is lowered, causing the roller 65h corresponding to the left guide cylinder 110a to descend along the central cam groove 110a. In this way, the left guide cylinder 110a is aligned with the swing lever 51 (set to the needle base position), and the shift operation (string material switching operation) by the shift mechanism 66 is completed.

[0072] After the shift operation is completed, the machine enters a state where it is ready to sew a cord-like material guided by the left guide cylinder 110a, which is set at the needle base position. As described above, when the swing lever 51 is swung from side to side by the swing mechanism (zigzag swing mechanism), the guide part 65 moves horizontally from side to side via the roller 65h engaged with the cam groove 110a. As a result, the left guide cylinder 110a, which corresponds to the roller 65h engaged with the central cam groove 110a, moves horizontally from side to side at the needle base position, and a zigzag stitch is performed on the cord-like material guided by the left guide cylinder 110a, following this horizontal movement.

[0073] In each of the above embodiments, the cam paths formed in the cam portion (cam plates 63, 67, 110) consist of open grooves (cam grooves 63a, 67a, 110a and connecting grooves 63b, 67b, 110b). However, in implementing the present invention, the invention is not limited to these, and any structure such as a recessed groove, a protrusion, or an appropriate contour shape can be adopted as the cam path.

[0074] Furthermore, in each of the above embodiments, the shift operation by the shift mechanisms 62 and 66 to set one selected guide member to the needle base position (movement of guide members 61a, 65a, and 65e) is performed by moving the guide sections 61 and 65 together (that is, moving the multiple guide members 61a, 65a, and 65e together in the vertical and / or horizontal directions). This has the advantage of simplifying the structure of the shift mechanisms 62 and 66. However, the invention is not limited to this, and it is also possible to configure the shift mechanism to move each guide member individually (moving in the vertical and / or horizontal directions), and such embodiments are also included in the scope of the present invention.

Claims

1. A material guide device for a sewing machine, for guiding a string-like material to be sewn to the needle base position, comprising: a rocking part that performs a rocking motion to cause the string-like material to be sewn to swing in a zigzag pattern; a guide part that includes a plurality of guide members for guiding the string-like material to the vicinity of the needle base position; and a shift mechanism that includes a cam part having a cam path formed therein, and an engaging part that engages with the cam part and is relatively movable along the cam path, wherein the engaging part is moved along the cam path to associate one of the guide members with the rocking part, and the rocking motion of the rocking part is transmitted to the associated guide member.

2. A material guide device for a sewing machine according to claim 1, wherein one of the cam portion and the engaging portion is movable integrally with the guide portion, and the other is movable integrally with the oscillating portion.

3. The material guiding device for a sewing machine according to claim 1, characterized in that the cam path includes a plurality of main paths and connecting paths that connect each main path, and one of the guide members is associated with the oscillating portion when the engaging portion is engaged with any of the main paths.

4. The material guiding device in a sewing machine according to claim 3, wherein the cam portion is coupled to the guide portion, and each main path corresponds to each guide member.

5. The material guide device in a sewing machine according to claim 4, wherein the engaging portion is provided to swing together with the swinging portion.

6. A material guide device for a sewing machine according to claim 3, wherein the cam portion and the oscillating portion are integrally formed, and the engaging portion is coupled to the guide portion.

7. The material guiding device for a sewing machine according to claim 3, wherein the plurality of main paths are arranged in parallel with each other extending in the vertical direction, the connecting path is formed to connect the lower or upper parts of each main path, and the shift mechanism is configured to move the engaging portion relatively along the main path and the connecting path by displacing the cam portion and the engaging portion relatively in the vertical and horizontal directions.

8. The material guide device in a sewing machine according to claim 7, wherein the shift mechanism includes a locking member that locks the horizontal movement of one of the cam portion and the guide portion.

9. A material guide device in a sewing machine according to any one of claims 1 to 8, wherein the cam path is made of a groove.

10. A material guiding device for a sewing machine according to any one of claims 1 to 8, further comprising a material holding device having a holding member corresponding to each guide member for holding a string-like material guided by each guide member, and configured to move together with the guide section while maintaining the correspondence between the holding member and each guide member, wherein during sewing, the string-like material guided by guide members other than the guide member corresponding to the oscillating section is held by the holding member.

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