Lifting / lowering device for accessory equipment in sewing machine

Abstract

The present invention address the problem of lifting and lowering accessory equipment (e.g., a device for guiding a string-like material) arranged rotatably around a needle bar, without applying a load to a cloth presser support. The lifting / lowering device is provided with: a lifting / lowering plate (91) configured to be capable of moving up and down along the axial direction of a needle bar (11); and a rotating ring (92) rotatably supported by the lifting / lowering plate (91) so as to be capable of rotating about the axis of the needle bar (11), the rotating ring (92) being configured to move up and down together with the lifting / lowering plate. Accessory equipment is mounted on the rotating ring, and the accessory equipment rotates together with the rotating ring and is lifted and lowered by the lifting / lowering plate. A drive source (93) for vertically moving the lifting / lowering plate is further provided, and the height including the uppermost position and the lowermost position of the lifting / lowering plate can be adjusted by the drive source.

Description

Lifting device for accessories in sewing machines

[0001] The present invention relates to a lifting device for an accessory device in a sewing machine, and more particularly to a lifting device suitable for lifting a material guide device that guides a string-like material, such as tape or cord, to the needle base position in a sewing machine that sews the string-like material to a workpiece using a lockstitch.

[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] For example, Patent Document 1 describes a sewing machine in which a small bobbin on which a string-like material is wound is placed around the needle bar, a guide device for guiding the string-like material pulled from the bobbin to the needle base position is rotated at an appropriate angle around the needle bar axis to supply the string-like material to the needle base, and the string-like material is sewn to the workpiece by swinging the guide device in a zigzag motion using a zigzag mechanism. In the sewing machine described therein, the guide device is attached to the presser foot support in order to raise and lower the guide device between a lower sewing position and an upper retracted position, and the guide device is raised and lowered using an up-and-down movement mechanism for the presser foot support. Furthermore, the presser foot support is provided with a vertically elongated key groove, a key member provided on the rotating body engages with the key groove, and this key engagement transmits the rotation of the rotating body to the presser foot support, and the presser foot support moves up and down independently of the rotating body.

[0004] However, in such a structure, since the guide device moves up and down together with the presser foot support that moves up and down for each stitch in cooperation with the sewing needle and rotates together with the presser foot support, the weight load applied to the presser foot support due to gravity and centrifugal force is large, and due to the influence of irregular vibrations (play), etc., the presser foot support and the key member engaged with the key groove of the presser foot support are likely to cause metal fatigue and are also likely to wear. In particular, when the key member wears, play occurs due to the gap with the key groove, and as a result, a rotational position shift occurs between the rotating body and the presser foot support. Such a rotational position shift means that the direction of the string-like material guided by the guide device is shifted with respect to the sewing direction, so that defective sewing quality may occur. In addition, since the oscillating member of the zigzag mechanism is assembled to rotate integrally with the rotating body, such a rotational position shift may cause a shift or shortage of the zigzag of the guide device, and may also cause defective zigzag sewing quality. Furthermore, as a new attempt, when installing a plurality of guide devices to facilitate the switching of the string-like material used for sewing, in the conventional structure, an even greater weight load is applied to the presser foot support, so the above problems become even more serious.

[0005] Japanese Patent Publication No. 5302728

[0006] The present invention has been made in view of the above points, and as a structure for lifting and lowering an accessory device (for example, a device for guiding a string-like material) that is rotatably arranged around the needle bar of a sewing machine, an object is to provide a lifting device having a novel structure that can solve the above various problems.

[0007] The lifting device for an accessory device in a sewing machine according to the present invention is a lifting device for an accessory device arranged around the needle bar of a sewing machine, and includes a lifting plate configured to be movable up and down along the axial direction of the needle bar, and a rotating ring rotatably supported by the lifting plate so as to be rotatable around the axis of the needle bar and configured to move up and down together with the lifting plate. The accessory device is mounted on the rotating ring, and the accessory device rotates together with the rotating ring and is lifted and lowered by the lifting plate.

[0008] According to the present invention, the accessory is mounted on a rotating ring, and the rotating ring is rotatably supported on a lifting plate configured to move up and down along the axial direction of the needle bar, and is configured to move up and down together with the lifting plate. Therefore, the lifting and lowering of the accessory can be performed independently by the lifting plate, without relying on the presser foot support as in the conventional method. As a result, the weight load due to gravity and centrifugal force from the rotating and vertically moving accessory (e.g., a device for guiding string-like material) is not applied to the presser foot support, and the problems and inconveniences of the conventional technology described above can be solved all at once.

[0009] A front view of a sewing machine to which a lifting device according to one 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 view of the sewing head portion of the sewing machine shown in Figure 1. A front view showing an even more enlarged view of the area surrounding the lifting device and the material guide device (accessory) that are raised and lowered by the lifting device, which are located below the sewing head of the sewing machine shown in Figure 1. A left side view of the area surrounding the lifting device and material guide device shown in Figure 4. A partial cross-sectional left side view showing a partial cross-section of the area surrounding the lifting device and 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 lifting device and material guide device shown in Figure 4. A perspective view showing a partial removal of the area surrounding the lifting device and material guide device shown in Figures 4 to 6. A perspective view of the area surrounding the lifting device and material guide device as seen from the opposite side of Figure 8. A schematic front view to explain the shift operation (switching operation) performed when switching the string-like material to be sewn.

[0010] Figure 1 is a front view of a sewing machine to which a material guide lifting mechanism 9 including a lifting device according to one embodiment and a material guide device 6 as an accessory that is lifted up and down by the lifting device are 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 lifting mechanism 9 and material guide device 6 are installed below one sewing head H (near the needle position) of a sewing machine, such as a lockstitch handle embroidery machine, and function to guide the string-like material to be sewn in the sewing machine to the needle position.

[0011] <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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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.

[0016] 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).

[0017] 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.

[0018] <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.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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.

[0023] 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.

[0024] <Material Guiding Device> Figure 4 is a front view showing an enlarged view of the surrounding area of ​​the lifting device (material guide lifting mechanism 9) and material guiding device 6 shown in Figure 1. Figure 5 is a left side view of the surrounding area of ​​the lifting device and material guiding device 6 shown in Figure 4. Figure 6 is a partial cross-sectional left side view showing a partial cross-section of the surrounding area of ​​the lifting device and material guiding device 6 shown in Figure 5. Figure 7 is a partial cross-sectional front view showing a partial cross-section of the surrounding area of ​​the lifting device and material guiding device 6 shown in Figure 4. 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 partial removal of the surrounding area of ​​the lifting device and material guiding device 6 shown in Figures 4 to 6. Figure 9 is a perspective view of the surrounding area of ​​the lifting device and 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.

[0025] 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.

[0026] 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).

[0027] 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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 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 100.

[0032] 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).

[0033] 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.

[0034] 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.

[0035] 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).

[0036] 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.

[0037] 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).

[0038] 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).

[0039] 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.

[0040] <Material Guide Lifting Mechanism> As shown in Figures 1 to 9 (especially Figures 8 and 9), the material guide lifting mechanism 9, as a lifting device according to one embodiment of the present invention, comprises 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 expansion and contraction of the air cylinder 93.

[0041] 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 (rotating body) 8 positioned in the central opening of the rotating ring 91. 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 (rotating body) 8 and rotate together with the rotating cylinder (rotating body) 8.

[0042] A support bracket 57 extending downward is attached to the lower surface of the rotating ring 92. As described above, a guide rail 58 is fixed to the lower end of this support bracket 57, and a slider 61d is connected to the guide rail 58. As a result, in the material guide lifting mechanism 9, 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 the guide portion 61 and cam plate 63 move down or up together via the slider 61d connected to the guide rail 58. 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 portion 61 and cam plate 63 rotate via the support bracket 57, guide rail 58, and slider 61d. In summary, the material guide lifting mechanism 9 is configured such that a material guide device 6, including the guide section 61 and the cam plate 63, is mounted on a 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.

[0043] According to this embodiment, since a material guide lifting mechanism 9 is used that is configured to rotate and raise / lower the material guide device 6 independently, it is possible to provide a configuration suitable for rotating and raising / lowering the material guide device 6, which tends to become heavier when equipped with multiple guide cylinders 61a. The drive source of the material guide lifting mechanism 9 is not limited to an air cylinder 93, but may also be any other appropriate linear drive source, such as a combination of a rotary electric motor and a rotary-to-linear conversion mechanism (e.g., a ball screw), or a linear rail. Furthermore, if a drive source such as an electric motor that can arbitrarily control the stopping position is used as the drive source of the material guide lifting mechanism 9, it is advantageous because the lowest position of the guide section 61 can be variably set according to the thickness of the string-like material and / or the object to be sewn. In other words, the drive source of the material guide lifting mechanism 9 can be configured to arbitrarily adjust the height, including the highest and lowest positions of the lifting plate 91.

[0044] <Material Holding Mechanism>The material holding mechanism 100, which is arranged on the opposite side of the guide portion 61 across the vertical movement axis of the sewing needle 12, includes holding members 101 for holding respectively the string-shaped materials guided by the respective guide cylinders (guide members) 61a, in parallel in association with the respective guide cylinders (guide members) 61a (see FIGS. 5 to 9). A slider 103 is fixed to the holding member 101 via a bracket 102. As shown in FIGS. 5 and 6, a support bracket 104 extending downward is attached to the lower surface of the rotary ring 92, and a guide rail 105 is fixed to the lower end of the support bracket 104. The guide rail 105 extends horizontally in parallel with 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 slidable in the horizontal direction. 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. Therefore, the material holding mechanism 100 is adapted to move integrally (rotate, move up and down, and move horizontally) with the guide portion 61 while maintaining the correspondence between each holding member 101 and the guide cylinder (guide member) 61a.

[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. 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, 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] In a preferred embodiment, a material cutting device (not shown) is placed near the material holding mechanism 100 (for example, at the rear), and when sewing of the selected string-like material is completed, the material cutting device automatically cuts the string-like material, and the cut string-like material protruding from the tip of the corresponding guide tube (guide member) 61a is picked up by a picking mechanism attached to the material cutting device and pulled out to the position of the corresponding holding member 101, where it is held by the holding member 101. This allows the cutting and holding of the string-like material after sewing to be performed automatically. However, the invention is not limited to this, and in another embodiment, the cutting of the string-like material after sewing and the holding operation by the holding member 101 may be performed manually by an operator.

[0047] In the embodiments described above, the material supply device 1 for supplying string-like material is positioned above the sewing head H, allowing the use of a large bobbin 21. However, the lifting device according to the present invention is not limited to this configuration, and can also be applied to a configuration in which a small bobbin wound with string-like material is positioned around the needle bar, and the string-like material is supplied to the needle base while being rotated appropriately around the needle bar axis. Furthermore, the lifting device according to the present invention can be applied not only to the material guide device 6 for guiding the string-like material to the needle base position, but also to any auxiliary equipment that is rotatable and vertically movable around the needle bar of the sewing machine. Examples of auxiliary equipment to which the lifting device according to the present invention can be applied, other than the material guide device, include cutting devices, imaging devices, coloring / coating devices, and decorative material supply devices.

Claims

1. A lifting device for an accessory device arranged around the needle bar of a sewing machine, comprising: a lifting plate configured to move up and down along the axial direction of the needle bar; and a rotating ring rotatably supported on the lifting plate so as to be rotatable around the axis of the needle bar and configured to move up and down together with the lifting plate, wherein the accessory device is mounted on the rotating ring and the accessory device rotates together with the rotating ring and is raised and lowered by the lifting plate.

2. The lifting plate is capable of moving up and down independently of the presser foot of the sewing machine, the lifting device for an accessory in a sewing machine according to claim 1.

3. The lifting device for an accessory in a sewing machine according to claim 1, wherein the rotating ring is connected to a rotating body for rotating the accessory around the axis of the needle bar so as to be vertically movable and rotate integrally with the rotating body.

4. A lifting device for an accessory in a sewing machine according to any one of claims 1 to 3, further comprising a drive source for moving the lifting plate up and down.

5. A lifting device for an accessory in a sewing machine according to claim 4, wherein the drive source allows for height adjustment including the highest and lowest positions of the lifting plate.

6. The lifting device for an accessory in a sewing machine according to any one of claims 1 to 3, wherein the accessory is a material guide device capable of guiding a string-like material to be sewn in the sewing machine to the needle base position while swinging it in a zigzag pattern.

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