Sewing method, upper thread guide component, and sewing machine

Abstract

In sewing methods using a sewing machine, this makes it easier to maintain the correct tension of the upper thread. [Solution] In a sewing method using a sewing machine 10 equipped with an upper thread tension device 11, a thread guide 12 for changing the direction of the upper thread T that has passed through the upper thread tension device 11, and a balance beam 13 that can pull up the upper thread T while it is passing through the thread guide 12, the sewing machine 10 further equipped with an upper thread guide member 100 having a first guide section 120 for changing the direction of the upper thread T that has passed through the thread guide 12 and directing it back towards the thread guide 12, the upper thread T that has passed through the thread guide 12 is passed through the first guide section 120 to change its direction, passed back through the thread guide 12 before passing it through the balance beam 13, and then sewing is performed while it is passed through the balance beam 13.

Description

Technical Field

[0001] The present invention relates to a sewing method using a sewing machine. The present invention also relates to an upper thread guiding member for use by being attached to a sewing machine, and a sewing machine provided with this upper thread guiding member.

Background Art

[0002] In sewing using a sewing machine, in order to finish the seam beautifully, it is extremely important to perform sewing with an appropriate thread condition. When sewing is performed with an inappropriate thread condition, there is a risk that the thread may be tightened too much and cause sewing shrinkage (puckering), or conversely, the thread may not be tightened firmly and the seam may become loose.

[0003] In this regard, in conventional sewing machines, the thread condition was mainly adjusted by operating a thread condition device. As shown in FIG. 1, a conventional sewing machine 90 includes an upper thread condition device 91, a thread hanger 92, a balance 93, and a thread guide 900 on the front side of the sewing machine arm. As shown in FIG. 2, the thread guide 900 includes a mounting base 910 attached to the housing of the sewing machine 90, and a thread guiding portion 920 formed in a loop shape by being folded back from the left end side of the mounting base 910 to the front side. When hanging the upper thread T on this sewing machine 90, as shown in FIG. 2, the upper thread T supplied from an upper thread supply source S set on the upper side of the sewing machine arm is passed through the thread guiding portion 920 of the thread guide 900 from above, hung on the upper thread condition device 91, then hooked on the thread hanger 92 and redirected upward, passed through the thread guiding portion 920 of the thread guide 900 from below again, then hung on the balance 93, and then passed to the sewing needle 94. After hanging the upper thread T in this way, the thread condition (tension applied to the upper thread T) could be adjusted by operating the thread condition device 91.

[0004] However, since an appropriate thread condition also varies depending on the type of the sewing material, the number of layers of the sewing material, the thickness of the thread, and their combinations, etc., if one tries to achieve an appropriate thread condition only by operating the thread condition device, it may be necessary to repeat the trial sewing many times and make fine adjustments, which is often time-consuming.

[0005] In light of these circumstances, sewing machines equipped with thread guides to facilitate the proper maintenance of upper thread tension have been proposed. Examples of such thread guides include the upper thread tension adjuster 50 shown in Figure 5 of Patent Document 1. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2011-251050 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the inventors of this application found that even when sewing with a sewing machine equipped with the upper thread tension adjuster 50 described in Reference Document 1, sufficient puckering suppression could not be obtained when sewing materials that are difficult to sew (for example, relatively hard materials such as thick fabrics, or relatively soft materials).

[0008] The present invention was made to solve the above problems and provides a sewing method that makes it easier to maintain the proper tension of the upper thread. Another object of the present invention is to provide an upper thread guide member that can be used in this sewing method, and a sewing machine equipped with this upper thread guide member. [Means for solving the problem]

[0009] The above issues are, Upper thread tension device, A threading mechanism for changing the direction of the upper thread after it has passed through the upper thread tensioning device, A balance scale that can perform the action of pulling up the upper thread after the upper thread has been threaded through it, and A sewing method using a sewing machine equipped with, The aforementioned sewing machine, Upper thread guide member having a first guide section for changing the direction of the upper thread after it has passed through the thread loop and directing it back towards the thread loop. Furthermore, The upper thread, after being threaded, is passed through the first guide section to change its direction, then threaded again before passing it through the balance beam, and sewing is performed with the thread passed through the balance beam. Sewing method This is solved by providing [a solution].

[0010] This sewing method, Upper thread tension device, A threading mechanism for changing the direction of the upper thread after it has passed through the upper thread tensioning device, A balance scale that can perform the action of pulling up the upper thread after the upper thread has been threaded through it, and An upper thread guide member for use with a sewing machine equipped with the following: By having a first guide section that changes the direction of the upper thread after it has passed through the thread loop and directs it back towards the thread loop, The upper thread, after being threaded, is passed through the first guide section to change its direction, and then threaded again before passing through the balance beam, allowing sewing to be performed while the thread is on the balance beam. Upper thread guide member This can be achieved using [this method].

[0011] As a result of diligent research, the inventors of this invention have found that by ensuring a longer upper thread path from the upper thread tension device to the balance (the path the upper thread travels from immediately after passing through the upper thread tension device until it is passed through the balance), it is possible to prevent the upper thread from becoming too tight when the balance pulls up the upper thread, and to make it easier to maintain the appropriate tension of the upper thread. In the above sewing method, the upper thread that has passed through the thread loop is looped over the first guide part of the upper thread guide member to change direction, and is looped over again before being passed through the balance. Therefore, a longer upper thread path from the upper thread tension device to the balance can be ensured, making it easier to maintain the appropriate tension of the upper thread.

[0012] In some embodiments, the upper thread guide member comprises a mounting base for attaching to the front of the sewing machine, a first guide portion protruding forward from the mounting base, and a stopper portion connected to the tip of the first guide portion to prevent the thread from coming off forward from the first guide portion. By wrapping the upper thread around the outer circumference of the first guide portion, the direction of the upper thread can be changed. This allows the upper thread to be guided smoothly.

[0013] In some embodiments of this case, the upper thread guide member is further provided with a second guide member that protrudes forward from a point on the mounting base that is separated from the first guide member, and whose tip is connected to the stopper member. The gap between the first guide member and the second guide member can be used as an upper thread passage for the upper thread to pass through when the upper thread, which has passed through the thread loop, is placed on the first guide member. This makes it possible to more effectively prevent the thread from coming off the first guide member.

[0014] In some embodiments of this case, a thread release section can be provided on the outer circumference of the first guide section, on the side opposite to the side facing the second guide section, to allow for slack in the upper thread. This allows the slackened upper thread to escape into the thread release section when the balance scale lowers and slack occurs in the upper thread, making it less likely for the upper thread to get tangled.

[0015] Incidentally, in some embodiments where a second guide section is provided and the gap between the first and second guide sections is used as a passage for the upper thread, the point where the tip of the first guide section is connected to the stopper section and the point where the tip of the second guide section is connected can be made continuous. This makes it possible to more effectively prevent the thread from coming off the first guide section. However, in this case, it is necessary to pass the upper thread through the upper thread passage from its downstream end (tip), which may make the threading process more time-consuming.

[0016] Therefore, in some other embodiments where a second guide portion is provided and the gap between the first guide portion and the second guide portion is used as the thread passage for the upper thread, a slit for dividing the stopper portion into left and right parts can be provided between the location where the tip of the first guide portion in the stopper portion is connected and the location where the tip of the second guide portion is connected. By passing the middle portion of the upper thread (any portion other than the downstream end and the upstream end of the upper thread) through this slit, the upper thread can be arranged within the thread passage for the upper thread, thus reducing the labor required for the threading operation.

Advantages of the Invention

[0017] As described above, according to the present invention, it becomes possible to provide a sewing method that can appropriately and easily maintain the thread condition of the upper thread. Further, it also becomes possible to provide an upper thread guide member that can be used in this sewing method and a sewing machine equipped with this upper thread guide member.

Brief Description of the Drawings

[0018] [Figure 1] It is a front view of a conventional sewing machine. [Figure 2] It is a view showing how to hang the upper thread on the sewing machine of FIG. 1. [Figure 3] It is a front view of a sewing machine. [Figure 4] It is a perspective view showing the periphery of the upper thread regulating device, thread hanging, and balance in the sewing machine of FIG. 3. [Figure 5] It is a view of the upper thread guide member of FIG. 4 seen from above. [Figure 6] It is a view showing an example of how to hang the upper thread on the sewing machine of FIG. 3. [Figure 7] It is a view showing another example of how to hang the upper thread on the sewing machine of FIG. 3. [Figure 8] It is a view showing another example of how to hang the upper thread on the sewing machine of FIG. 3. [Figure 9] It is a view showing another example of how to hang the upper thread on the sewing machine of FIG. 3. [Figure 10] It is a perspective view of the upper thread guide member of the first embodiment. [Figure 11] These are front view, rear view, left side view, and right side view of the upper thread guide member of the first embodiment. [Figure 12] These are a plan view and a bottom view of the upper thread guide member of the first embodiment. [Figure 13] This is a cross-sectional view of the upper thread guide member of the first embodiment. [Figure 14] This is a perspective view of the upper thread guide member of the second embodiment. [Figure 15] These are front view, rear view, left side view, and right side view of the upper thread guide member of the second embodiment. [Figure 16] These are a plan view and a bottom view of the upper thread guide member of the second embodiment. [Figure 17] This is a cross-sectional view of the upper thread guide member of the second embodiment. [Figure 18] This is a perspective view of the upper thread guide member of the third embodiment. [Figure 19] This is a photograph showing the results of a sewing experiment. [Modes for carrying out the invention]

[0019] 1. Overview Embodiments of the present invention will be described in more detail with reference to the drawings. Figure 3 is a front view of the sewing machine 10. Figure 4 is a perspective view showing the area around the upper thread tension device 11, thread guide 12, and balance wheel 13 of the sewing machine 10 in Figure 3. In Figure 4, parts of the upper thread guide member 100 that cannot be seen are indicated by dashed lines to aid in understanding the figure. Figure 5 is a view of the upper thread guide member 100 from above.

[0020] Figures 3-5 and Figures 6-9 shown later display the x, y, and z axes, and these axes are consistent across different drawings. For the sake of explanation, the positive x-axis may be referred to as "right," the negative x-axis as "left," the positive y-axis as "back" or "far," the negative y-axis as "front" or "in front," the positive z-axis as "up," and the negative z-axis as "down." Users of the sewing machine 10 typically work facing the front of the machine. That is, the positive x-axis is the "right side" from the user's perspective, and the negative x-axis is the "left side" from the user's perspective.

[0021] The sewing machine 10 shown in Figure 3 comprises a sewing machine bed 10a, a sewing machine cylinder 10b erected at the right end of the sewing machine bed 10a, and a sewing machine arm 10c extending to the left from the upper end of the sewing machine cylinder 10b. A thread stand (not shown) is provided above the sewing machine arm 10c, and the upper thread T is supplied from an upper thread supply source S (for example, a spool of thread) set on this thread stand (not shown). In other embodiments, the upper thread T can be supplied from an upper thread supply source S held by a thread stand (not shown) provided separately from the sewing machine 10.

[0022] The front side of the sewing machine arm 10c is equipped with an upper thread tension device 11, a thread guide 12, a balance wheel 13, and an upper thread guide member 100. Additionally, a needle bar 14 is mounted on the lower left end of the sewing machine arm 10c so as to be vertically movable, and a sewing needle 15 is attached to the needle bar 14.

[0023] The upper thread tensioner 11 is the part that adjusts the tension of the upper thread T supplied (pulled out) from the upper thread supply source S. The upper thread tensioner 11 in the sewing machine 10 in Figure 3 comprises a pair of tension discs 11a, a thread take-up spring 11b, and a tension dial 11c, as shown in Figure 4. The thread guide 12 is the part that changes the direction of the upper thread T by passing the upper thread T through the upper thread tensioner 11. The thread guide 12 in the sewing machine 10 in Figure 3 is formed in a hook shape, having a protruding part 12a that protrudes forward from the front side of the sewing machine arm 10c, and a curved part 12b that curves downward continuously from the tip of the protruding part 12a. This thread guide 12 is located to the left (next to) the upper thread tensioner 11. The balance wheel 13 is the part that pulls up the upper thread T while it is passed through the thread guide 12. The balance beam 13 is provided protruding from inside the sewing machine arm 10c through a balance beam opening 16 that is vertically elongated in the housing of the sewing machine arm 10c, and is capable of reciprocating (oscillating) between the top dead center and the bottom dead center within the balance beam opening 16. The tip of the balance beam 13 is provided with a thread threader 13a for passing the upper thread T through. This balance beam 13 is positioned above the thread guide 12.

[0024] The upper thread guide member 100 is a member for guiding the upper thread T. In the sewing machine 10 of Figure 3, the upper thread guide member 100 is positioned above the upper thread tension device 11. The upper thread guide member 100 attached to the sewing machine 10 in Figures 3-5 is the upper thread guide member 100 of the first embodiment. As shown in Figures 4 and 5, the upper thread guide member 100 of the first embodiment includes a mounting base 110, a first guide portion 120, a second guide portion 130, and a stopper portion 140.

[0025] The mounting base 110 is the part that is attached to the front of the sewing machine 10 (specifically, the sewing machine arm 10c). The first guide part 120 is the part that redirects the upper thread T, which has passed through the thread guide 12, back towards the thread guide 12, and is provided projecting forward from the mounting base 110. The second guide part 130 is provided projecting forward from a point on the mounting base 110 that is spaced apart from the first guide part 120. In the sewing machine 10 of Figure 3, the second guide part 130 is located to the right of the first guide part 120. The stopper part 140 is the part that prevents the thread from coming off forward from the first guide part 120.

[0026] In the upper thread guide member 100 of the first embodiment, the tip of the first guide portion 120 and the tip of the second guide portion 130 are connected to the stopper portion 140. The gap between the first guide portion 120 and the second guide portion 130 (the area surrounded by the mounting base portion 110, the first guide portion 120, the second guide portion 130, and the stopper portion 140) serves as an upper thread passage 150 for passing the upper thread T, as shown in Figure 5.

[0027] 2.Sewing method The following describes a sewing method using the sewing machine 10 (a sewing machine 10 equipped with an upper thread guide member 100) shown in Figure 3. Figure 6 shows an example of how to thread the upper thread T onto the sewing machine 10 shown in Figure 3. In Figure 6 and Figures 7 to 9 shown later, the first guide part 120 and the second guide part 130 of the upper thread guide member 100, as well as some parts of the upper thread T that cannot be seen, are shown with dashed lines to aid in understanding the figures.

[0028] In the example shown in Figure 6, the upper thread T is threaded onto the sewing machine 10 by following the steps [1] to [7] below. [Procedure 1] The upper thread T supplied from the upper thread supply source S is passed through the upper thread passage 150 of the upper thread guide member 100 from top to bottom. [Procedure 2] The upper thread T that has passed through the upper thread passage 150 is placed between the pair of thread tension plates 11a in the upper thread tension device 11 from the right, then looped around from bottom to left along the gap between the pair of thread tension plates 11a, and then hooked onto the thread take-up spring 11b. [Step 3] The upper thread T, which has passed through the thread take-up spring 11b, is looped onto the thread guide 12 from the right and its direction is changed upwards. [Step 4] The upper thread T, which has gone through the thread loop 12 once, is passed through the upper thread passage 150 of the upper thread guide member 100 from bottom to top, and its direction is changed by looping it around the outer circumference of the first guide section 120 from the lower right, passing over to the lower left, and then directed back towards the thread loop 12. [Step 5] The upper thread T, which has passed through the first guide section 120, is looped onto the thread holder 12 from the right and its direction is changed upward. [Step 6] Pass the upper thread T, which has gone through the threading process 12 twice, through the threading section 13a of the balance beam 13 from the right. [Step 7] Pass the upper thread T, which has passed through the balance 13, through the thread hole (not shown) at the tip of the sewing needle 15.

[0029] When the sewing machine 10 is started with the upper thread T threaded through, the balance beam 13, with the upper thread T threaded through it, repeatedly moves back and forth (oscillates) between the top dead center and the bottom dead center. By moving from the top dead center to the bottom dead center, the balance beam 13 can loosen the upper thread T. This creates a loop (not shown) of the upper thread T at the tip of the sewing needle 15 that has penetrated the fabric to be sewn (not shown). By passing the lower thread supply source (not shown; for example, a bobbin) inside the bobbin case (not shown) built into the sewing machine bed 10a through this loop, the upper thread T and the lower thread (not shown) become entangled, and a stitch is formed. Subsequently, by moving from the bottom dead center to the top dead center, the balance beam 13 can pull up the upper thread T (making it taut). This tightens the stitch.

[0030] In the method of threading the upper thread T shown in Figure 6, the upper thread T, after passing through the upper thread tension device 11 and the thread guide 12, is passed over the first guide section 120 to change direction, and then passed over the thread guide 12 again before passing it through the tension lever 13 (the upper thread T is passed over the thread guide 12 twice) before passing it through the tension lever 13. Therefore, compared to the conventional example shown in Figure 2, for example, the upper thread path from the upper thread tension device 11 to the tension lever 13 (the path that the upper thread T travels from immediately after passing through the upper thread tension device 11 until it is passed through the tension lever 13) can be made longer. In this state, by performing sewing as described above, it is possible to prevent the upper thread T from becoming too tight when the tension lever 13 pulls up the upper thread T, and it is possible to maintain the appropriate thread tension of the upper thread T.

[0031] Furthermore, in the method of threading the upper thread T shown in Figure 6, when the upper thread T, which has passed through thread guide 12 once, is placed on the first guide section 120, the upper thread T is passed through the upper thread passage 150. This makes it less likely for the upper thread T, which is placed on the first guide section 120, to come off the first guide section 120 even when the balance 13 is lowered and the upper thread T is loosened.

[0032] In the example shown in Figure 6, as explained in [Step 1] to [Step 2] above, the upper thread T is passed through the upper thread passage 150 before being introduced into the upper thread tensioner 11. This prevents the upper thread T from becoming unruly and makes the stitch more stable. However, in other embodiments, the upper thread T is not passed through the upper thread passage 150 before being introduced into the upper thread tensioner 11 (the upper thread T upstream of the upper thread tensioner 11 is not guided by the upper thread guide member 100).

[0033] In the example shown in Figure 6, the upper thread T can pass through other thread guides or other thread tensioning means between the upper thread supply source S and the upper thread guide member 100 (upper thread passage 150). Furthermore, the upper thread T can pass through other thread guides or other thread tensioning means between the balance 13 and the sewing needle 15.

[0034] Figures 7-9 show other examples of how the upper thread T is threaded onto the sewing machine 10 in Figure 3. In the example in Figure 6, in step 4 above, when threading the upper thread T (the upper thread T coming out from the left side of the thread holder 12) that has passed through the thread holder 12 once around the outer circumference of the first guide section 120, the upper thread T is first passed through the upper thread passage 150 of the upper thread guide member 100, then the upper thread T is threaded from the lower right, over the top, and to the lower left of the first guide section 120, and in the subsequent step 5, the upper thread T is threaded from the right of the thread holder 12. As a result, as shown in Figure 6, the upper thread T that goes towards the first guide section 120 after passing through the thread holder 12 once and the upper thread T that goes towards the thread holder 12 again after passing through the first guide section 120 are in a state of crossing (when viewed from the front). In other words, the upper thread T, from the time it is first threaded onto the thread guide 12, through the first guide section 120, to the time it is threaded onto the thread guide 12 for the second time, was arranged to form a figure-eight shape (when viewed from the front).

[0035] In contrast, in the example of Figure 7, the upper thread T, which has passed through the thread guide 12 once, is first looped around the outer circumference of the first guide section 120, starting from the lower left, passing over and going to the lower right, and then passed through the upper thread passage 150 of the upper thread guide member 100, going from top to bottom. After that, as in the example of Figure 6, the upper thread T is looped onto the thread guide 12 from the right. As a result, as shown in Figure 7, the upper thread T that passes through the thread guide 12 once and goes to the first guide section 120 and the upper thread T that goes through the first guide section 120 and goes to the thread guide 12 again do not intersect. That is, the upper thread T that is looped onto the thread guide 12 once and then looped onto the thread guide 12 a second time after passing through the first guide section 120 forms a loop (when viewed from the front). In all other respects, the example of Figure 7 is the same as the example of Figure 6.

[0036] In addition, in a modified example of the example in Figure 7 (not shown), the upper thread T that has passed through the first guide section 120 can be looped onto the thread holder 12 from the left and its direction changed upward, and then the upper thread T that has come out from the right side of the thread holder 12 can be passed through the balance beam 13 from the right. In this case, the upper thread T that goes through the thread holder 12 to the first guide section 120 and the upper thread T that goes through the first guide section 120 again to the thread holder 12 will be in a state of crossing.

[0037] In the example in Figure 6, in step 6 above, the upper thread T, immediately after passing through the thread guide 12 twice, was passed directly through the balance beam 13 without passing through the upper thread guide member 100 again. In contrast, in the example in Figure 8, the upper thread T, after passing through the thread guide 12 twice, is passed through the upper thread passage 150 of the upper thread guide member 100 from bottom to top (after being placed on the right side of the first guide section 120) before being passed through the balance beam 13. In all other respects, the example in Figure 8 is the same as the example in Figure 6.

[0038] In the example in Figure 9, similar to the example in Figure 8, the upper thread T, which has passed through the thread guide 12 twice, is passed through the upper thread passage 150 and then through the balance 13. In all other respects, the example in Figure 9 is the same as the example in Figure 7. Furthermore, a modified example of the example in Figure 9 (not shown) is the same as the modified example of Figure 7 (not shown) described above, except that the upper thread T, which has passed through the thread guide 12 twice, is passed through the upper thread passage 150 and then through the balance 13.

[0039] 3. Upper thread guide member of the first embodiment The upper thread guide member 100 of the first embodiment will be described in more detail below. Figure 10 is a perspective view of the upper thread guide member 100 of the first embodiment. Figure 11 is a front view, rear view, left side view, and right side view of the upper thread guide member 100 of the first embodiment. Figure 11(a) is a front view, Figure 11(b) is a rear view, Figure 11(c) is a left side view, and Figure 11(d) is a right side view. Figure 12 is a top view and bottom view of the upper thread guide member 100 of the first embodiment. Figure 12(e) is a top view, and Figure 12(f) is a bottom view. Figure 13 is a cross-sectional view of the upper thread guide member 100 of the first embodiment. Figure 13(g) is a cross-sectional view taken along A-A' in Figure 12(e), Figure 13(h) is a cross-sectional view taken along B-B' in Figure 12(e), and Figure 13(i) is a cross-sectional view taken along C-C' in Figure 12(e).

[0040] As already mentioned, the upper thread guide member 100 of the first embodiment comprises a mounting base 110, a first guide section 120, a second guide section 130, and a stopper section 140. The base ends of the first guide section 120 and the second guide section 130 are each connected to the mounting base 110, and the tip ends of the first guide section 120 and the second guide section 130 are each connected to the stopper section 140. An upper thread passage 150 is formed in the area surrounded by the mounting base 110, the first guide section 120, the second guide section 130, and the stopper section 140.

[0041] The mounting base 110 is the part that is fixed to the housing of the sewing machine 10 with its rear surface facing the front surface of the sewing machine arm 10c of the sewing machine 10. The mounting base 110 is usually plate-shaped. In the first embodiment, as shown in Figures 11(c), (d) and 12(e), (f), the mounting base 110 is a flat plate shape with no protrusions or indentations when viewed from the side (when viewed from the left-right or up-down direction). The thickness of the mounting base 110 is not limited, but in some embodiments it is 1 mm or more and 2 mm or less.

[0042] The front view shape (shape when viewed from the front) of the mounting base 110 is not limited. In the upper thread guide member 100 of the first embodiment, as shown in Figure 10, the mounting base 110 is formed in the shape of a strip, and the end on one side (left side) in the longitudinal direction and the end on the other side in the longitudinal direction are formed in a substantially arc shape when viewed from the front. This makes it possible to make the mounting base 110 without corners, at least when viewed from the front, and makes it less likely for the upper thread T to get caught on the mounting base 110. In other embodiments, the mounting base 110 can be, for example, a strip shape with rounded corners when viewed from the front, a strip shape with chamfered corners when viewed from the front, or a strip shape with a rectangular shape when viewed from the front.

[0043] The method for fixing the mounting base 110 to the sewing machine 10 housing is not particularly limited. The mounting base 110 can be attached to the sewing machine 10 housing by means of screwing, adhesive, adhesive tape, welding, hook-and-loop fasteners, etc. Alternatively, the mounting base 110 can be fixed to the sewing machine 10 housing by fitting a part or all of the mounting base 110 to a part of the sewing machine 10 housing.

[0044] In the upper thread guide member 100 of the first embodiment, as shown in Figure 10, the mounting base 110 is provided with a mounting hole 111 that penetrates the mounting base 110 in the thickness direction. As shown in Figure 4, the mounting base 110 can be fixed to the sewing machine 10 housing by screwing a screw 200 inserted through this mounting hole 111 into the sewing machine 10 housing. As shown in Figure 10, the mounting hole 111 is formed as an elongated hole that extends along the longitudinal direction (left-right direction) of the mounting base 110. This makes it possible to adjust the mounting position of the upper thread guide member 100 on the sewing machine 10 housing (position along the longitudinal direction of the mounting base 110; position in the left-right direction).

[0045] The location of the mounting hole 111 on the mounting base 110 is not limited. In the upper thread guide member 100 of the first embodiment, as shown in Figure 10, the first guide section 120 and the second guide section 130 are connected to one longitudinal side (left side) of the mounting base 110, and the mounting hole 111 is provided on the other longitudinal side (right side) of the mounting base 110. When the upper thread guide member 100 is attached to the sewing machine 10 in the manner shown in Figures 3 to 9, the first guide section 120 and the second guide section 130 are provided on the left side of the mounting base 110, and the mounting hole 111 is provided on the right side of the mounting base 110. This makes it possible to reduce the distance between the first guide section 120 and the thread guide 12 in the left-right direction, as will be explained in detail later.

[0046] As shown in Figures 4 and 10-12, the first guide portion 120 is formed in a columnar shape that protrudes substantially vertically from the mounting base portion 110. In this case, the cross-sectional shape of the first guide portion 120 (the cross-sectional shape when cut by a plane perpendicular to the first guide portion 120; the same applies hereinafter) is not limited. At least a part of the cross-sectional shape of the first guide portion 120 can be substantially arc-shaped. That is, at least a part of the outer circumference of the first guide portion 120 can be substantially cylindrical. By attaching the upper thread guide member 100 to the sewing machine 10 so that the substantially cylindrical portion is on the upper side, the upper thread T that has passed through the thread guide 12 once can be smoothly changed direction, as shown in Figures 6-9. In the first embodiment, as shown in Figure 13, the cross-sectional shape of the first guide portion 120 is substantially circular. That is, the first guide portion 120 is substantially cylindrical, and the outer circumference of the first guide portion 120 is substantially cylindrical.

[0047] The length W1 of the first guide portion 120 (Figure 11(c)) is not limited. In some embodiments, the length W1 of the first guide portion 120 is 5 mm or more. This makes it less likely for the upper thread T to come off the first guide portion 120 and less likely for the upper thread T to get caught on the stopper portion 140, etc., even when the upper thread T is repeatedly loosened and tightened as the balance 13 moves back and forth. In some embodiments, the length W1 of the first guide portion 120 is 7 mm or more. Also, in some embodiments, the length W1 of the first guide portion 120 is 20 mm or less. This prevents the upper thread guide member 100 from becoming too large. In some embodiments, the length W1 of the first guide portion 120 is 15 mm or less.

[0048] The thickness W2 of the first guide portion 120 (if the first guide portion 120 is approximately cylindrical, this refers to the diameter of the first guide portion 120; otherwise, it refers to the maximum thickness of the first guide portion 120. The same applies hereinafter. See Figure 12(e).) is not limited. In some embodiments, the thickness W2 of the first guide portion 120 is 1 mm or more. This makes it easier to smoothly change the direction of the upper thread T. In some embodiments, the thickness W2 of the first guide portion 120 is 2 mm or more. Also, in some embodiments, the thickness W2 of the first guide portion 120 is 10 mm or less. This prevents the upper thread guide member 100 from becoming too large. In some embodiments, the thickness W2 of the first guide portion 120 is 6 mm or less.

[0049] Furthermore, the shape of the first guide portion 120 is not limited as long as at least a part of it is connected to the mounting base portion 110 and it can guide the upper thread T, which has passed through the thread loop 12 once, to change direction and return to the thread loop 12. For this reason, in other embodiments, the first guide portion 120 can be a shape other than a columnar shape. The first guide portion 120 can be, for example, a loop (annular), a plate with a guide through hole, or a rod with a guide through hole. When the first guide portion 120 is loop-shaped, the loop itself can also function as a passage for the upper thread, and when the first guide portion 120 is a plate or rod with a guide through hole, the guide through hole can also function as a passage for the upper thread.

[0050] The second guide portion 130 is provided projecting forward from a location on the mounting base 110 that is spaced apart from the first guide portion 120. In the upper thread guide member 100 of the first embodiment, as shown in Figure 10, the first guide portion 120 is connected to the end of one longitudinal side (left side) of the mounting base 110, and the second guide portion 130 is connected to a location spaced apart from the first guide portion 120 on the other longitudinal side (right side) of the mounting base 110. When the upper thread guide member 100 is attached to the sewing machine 10 in the manner shown in Figures 3 to 9, the second guide portion 130 is provided at a location on the mounting base 110 that is spaced apart to the right from the first guide portion 120.

[0051] The distance W3 between the first guide section 120 and the second guide section 130 (Figure 12(e)) is not limited. In some embodiments, the distance W3 between the first guide section 120 and the second guide section 130 is 2 mm or more. This prevents the upper thread passage 150 from becoming too narrow. In some embodiments, the distance W3 is 4 mm or more. Also, in some embodiments, the distance W3 between the first guide section 120 and the second guide section 130 is 15 mm or less. This prevents the upper thread guide member 100 from becoming too large. In some embodiments, the distance W3 is 8 mm or less.

[0052] The second guide portion 130 can also be made to protrude at an angle from the mounting base portion 110 (provided to protrude in a direction not perpendicular to the mounting base portion 110), but in the first embodiment, it is formed in a columnar shape that protrudes substantially perpendicularly from the mounting base portion 110. The cross-sectional shape of the second guide portion 130 (the cross-sectional shape when cut by a plane perpendicular to the second guide portion 130; the same applies hereinafter) is not limited. The cross-sectional shape of the second guide portion 130 can be, for example, substantially circular, substantially elliptical, or substantially polygonal (for example, substantially rectangular or substantially hexagonal). The cross-sectional shape of the second guide portion 130 can also be the same configuration as that already described for the cross-sectional shape of the first guide portion 120. In the first embodiment, as shown in Figure 13, the cross-sectional shape of the second guide portion 130 is substantially circular. That is, the second guide portion 130 is substantially cylindrical, and the outer circumference of the second guide portion 130 is substantially cylindrical.

[0053] The stopper portion 140 is not limited in its specific shape, as long as it can prevent the thread from coming off the first guide portion 120. In the first embodiment, the stopper portion 140 in the upper thread guide member 100 is formed in a plate shape that is wider (larger in a front view) than the tip surface of the first guide portion 120 (the connection surface between the first guide portion 120 and the stopper portion 140), as shown in Figure 10. More specifically, in the first embodiment, the stopper portion 140 is a flat plate shape with no uneven parts in a side view (when viewed from the left / right or up / down direction), as shown in Figures 11(c), (d) and 12(e), (f). The thickness of the stopper portion 140 is not limited, but in some embodiments, it is set to 1 mm or more and 2 mm or less.

[0054] The stopper portion 140 is connected to the tip of the first guide portion 120 in such a way that it protrudes at least upward, to the left, and to the right. This prevents the upper thread T, which is looped around the first guide portion 120, from coming off the first guide portion 120 forward by contacting the rear surface of the stopper portion 140. In the first embodiment, the stopper portion 140 also protrudes downward from the tip of the first guide portion 120. The plate-shaped stopper portion 140 can also be connected at an angle to the first guide portion 120 (in the direction of protrusion), but in the first embodiment, it is connected substantially perpendicular to the first guide portion 120 (in the direction of protrusion).

[0055] The upward overhang width W4 of the stopper portion 140 from the connection point with the first guide portion 120 (see Figure 11(c); hereinafter sometimes referred to as "upper overhang width W4") is not limited, but if it is too small, it may become difficult to prevent the thread from coming off, and if it is too large, the upper thread guide member 100 may become too large. For this reason, in some embodiments, the upper overhang width W4 is set to 1 mm or more and 5 mm or less, and in some embodiments, the upper overhang width W4 is set to 2 mm or more and 4 mm or less. The same configuration as described for the upper overhang width W4 can also be adopted for the leftward overhang width W5 of the stopper portion 140 from the connection point with the first guide portion 120 (see Figure 12(e); hereinafter sometimes referred to as "leftward overhang width W5").

[0056] In the upper thread guide member 100 of the first embodiment, as already described, the base end and tip of the second guide portion 130 are connected to the mounting base portion 110 and the stopper portion 140 at locations separated from the first guide portion 120, respectively, and the area surrounded by the mounting base portion 110, the first guide portion 120, the second guide portion 130, and the stopper portion 140 forms the upper thread passage 150. A slit 141 is provided between the location where the tip of the first guide portion 120 is connected to the stopper portion 140 and the location where the tip of the second guide portion 130 is connected, dividing the stopper portion 140 into left and right halves. In other words, the slit 141 divides the stopper portion 140 into a first stopper portion 140a connected to the tip of the first guide portion 120 and a second stopper portion 140b connected to the tip of the second guide portion 130. By simply passing the middle section of the upper thread T through this slit 141 from front to back, the upper thread T can be positioned within the upper thread passage. Therefore, when passing the upper thread T through the upper thread passage 150, it is no longer necessary to pass the upper thread T through the upper thread passage 150 from the downstream end, thus reducing the effort required for threading the upper thread.

[0057] The slit 141 is usually provided in a substantially straight line (without curvature) when viewed from the front. The slit 141 can also be provided substantially parallel to the vertical direction (substantially perpendicular to the line connecting the center of the connecting surface of the first guide portion 120 and the center of the connecting surface of the second guide portion 130 in the stopper portion 140), but in the first embodiment, as shown in Figure 11(a), it is provided inclined counterclockwise with respect to the vertical direction (not perpendicular to the line connecting the center of the connecting surface of the first guide portion 120 and the center of the connecting surface of the second guide portion 130 in the stopper portion 140). In other words, the slit 141 is inclined such that, on the upper side of the slit 141, the distance between the slit 141 and the first guide portion 120 is shorter than the distance between the slit 141 and the second guide portion 130, and on the lower side of the slit 141, the distance between the slit 141 and the second guide portion 130 is shorter than the distance between the slit 141 and the first guide portion 120. This makes it possible to make the angle formed on the upper side of the first stopper portion 140a obtuse (90° or more), and even when the upper thread T (Figures 6-9) wrapped around the upper side of the first guide portion 120 loosens, the upper thread T is less likely to get caught on the first stopper portion 140a.

[0058] The inclination angle θ1 of the slit 141 with respect to the vertical direction (a straight line perpendicular to the line connecting the center of the connecting surface of the first guide portion 120 and the center of the connecting surface of the second guide portion 130 in the stopper portion 140, and substantially parallel to the surface direction of the stopper portion 140) (Figure 11(a)) is not limited. In some embodiments, the inclination angle θ1 of the slit 141 is set to 10° or more. This makes it easier to obtain the above effects. In some embodiments, the inclination angle θ1 of the slit 141 is set to 15° or more. In some embodiments, the inclination angle θ1 of the slit 141 is set to 45° or less. This makes it less likely for the upper thread T, which is wrapped around the first guide portion 120, to get caught (entangled) in the slit 141 even when the upper thread T is loosened. In some embodiments, the inclination angle θ1 of the slit 141 is set to 30° or less.

[0059] The width W6 of the slit 141 (Figure 11(a)) is not limited. In some embodiments, the width W6 of the slit 141 is 2 mm or less. This makes it less likely for the upper thread T to get caught (entangled) in the slit 141 even when the upper thread T is loose. In some embodiments, the width W6 of the slit 141 is 1.5 mm or less. Also, in some embodiments, the width W6 of the slit 141 is 0.5 mm or more. This makes it easier for the upper thread T to pass through the slit 141. In some embodiments, the width W6 of the slit 141 is 0.8 mm or more.

[0060] In the upper thread guide member 100 of the first embodiment, as shown in Figure 10, the outer shape of the stopper portion 140 (the outer shape of the stopper portion 140 including the first stopper portion 140a and the second stopper portion 140b, ignoring the slit 141; the same applies hereinafter) is formed in a strip shape, and the end on one side (left side) in the longitudinal direction of the strip is formed in a substantially arc shape in front view, with the diameter widened from the cross-sectional shape of the first guide portion 120, and the end on the other side (right side) in the longitudinal direction of the strip is formed in a substantially arc shape in front view, with the diameter widened from the cross-sectional shape of the second guide portion 130. As a result, the outer shape of the stopper portion 140 can be made to be without corners, at least in front view, making it less likely for the upper thread T to get caught on the mounting base 110. In other embodiments, the outer shape of the stopper portion 140 can be, for example, a strip shape with rounded corners in front view, a strip shape with chamfered corners in front view, or a strip shape with a rectangular shape in front view.

[0061] By the way, as explained in "2. Sewing Method" above, in the sewing method using the sewing machine 10, the balance beam 13 moves back and forth between the top dead center and the bottom dead center, repeatedly loosening and tightening the upper thread T. In this regard, in the upper thread guide member 100 of the first embodiment, as shown in Figures 3-4, a thread release portion 160 for allowing the upper thread T to loosen is provided on the outer circumference of the first guide portion 120 on the side opposite to the side facing the second guide portion 130 (left side). In this thread release portion 160, the outer circumference of the first guide portion 120 is open. In other words, the left outer circumference of the first guide portion 120 is not covered by other parts of the upper thread guide member 100. As a result, when the balance beam 13 goes down and the upper thread T loosens, the looseness of the upper thread T can be released into the thread release portion 160, preventing the upper thread T from getting caught on other parts of the upper thread guide member 100. The thread relief portion 160 may be provided by opening a portion of the left outer circumference of the first guide portion 120 in the front-rear direction, but in the first embodiment, as shown in Figure 4, it is provided by opening substantially the entire left outer circumference of the first guide portion 120 in the front-rear direction. In this case, the thread relief portion 160 can also be described as an opening formed between the left end of the mounting base portion 110 and the left end of the stopper portion 140.

[0062] The material of the upper thread guide member 100 is not limited. For example, metal or resin can be used as the material of the upper thread guide member 100. In this case, examples of metals that can be used include stainless steel, steel, tool steel, high carbon steel, brass, etc. In this case, examples of resins that can be used include fluororesin (e.g., polytetrafluoroethylene resin), polyphenylene sulfide resin, polyether ether ketone resin, polyamide resin, polyacetal resin, modified polyphenylene ether resin, etc. In the first embodiment, stainless steel is used as the material of the upper thread guide member 100.

[0063] The upper thread guide member 100 is not limited in its specific mounting position, as long as it is attached to the front side of the sewing machine arm 10c in the sewing machine 10. In the sewing machine 10 of Figure 3, the upper thread guide member 100 is positioned above the upper thread tension device 11, and the thread guide 12 is positioned to the left of the upper thread tension device 11. The left-right position of the upper thread guide member 100 is not limited, but in some embodiments, the upper thread guide member 100 is mounted such that the left-right distance W7 (Figure 6) between the thread guide 12 and the first guide portion 120 of the upper thread guide member 100 is between 0 mm and 10 mm. This prevents excessive friction on the upper thread T and reduces the likelihood of excessive tension being applied to the upper thread T. In some embodiments, the distance W7 is set to be between 0 mm and 5 mm. However, the mounting base 110 of the upper thread guide member 100 should not block the balance beam opening 16.

[0064] The distance W8 (Figure 4) from the lower end of the protrusion 12a of the thread guide 12 to the upper end of the first guide portion 120 of the upper thread guide member 100 is not limited, but in some embodiments, the distance W8 is set to 1.5 cm or more. This makes it easier to secure a longer upper thread path from the upper thread tension device 11 to the balance beam 13. In some embodiments, the distance W8 is set to 2 cm or more. Also, in some embodiments, the distance W8 is set to 5 cm or less. This makes it less likely for the upper thread T to get tangled.

[0065] The orientation in which the upper thread guide member 100 is attached to the sewing machine 10 housing is not limited. In the sewing machine 10 of Figure 3, the upper thread guide member 100 is attached so that the longitudinal direction of the mounting base 110 substantially coincides with the left-right direction of the sewing machine 10. This allows the first guide portion 120 and the second guide portion 130 to be arranged side by side in the left-right direction. However, in other embodiments, for example, the upper thread guide member 100 can also be attached so that the longitudinal direction of the mounting base 110 is inclined with respect to the left-right direction of the sewing machine 10.

[0066] 4. Upper thread guide member of the second embodiment The upper thread guide member 100 of the second embodiment will be described below. In the following description, the differences between the upper thread guide member 100 of the second embodiment and the upper thread guide member 100 of the first embodiment will be the main focus. For parts not described below, the upper thread guide member 100 of the second embodiment can adopt the same configuration as that described for the upper thread guide member 100 of the first embodiment.

[0067] Figure 14 is a perspective view of the upper thread guide member 100 of the second embodiment. Figure 15 is a front view, rear view, left side view, and right side view of the upper thread guide member 100 of the second embodiment. Figure 15(a) is the front view, Figure 15(b) is the rear view, Figure 15(c) is the left side view, and Figure 15(d) is the right side view. Figure 16 is a top view and a bottom view of the upper thread guide member 100 of the second embodiment. Figure 16(e) is the top view, and Figure 16(f) is the bottom view. Figure 17 is a cross-sectional view of the upper thread guide member 100 of the second embodiment. Figure 17(g) is a cross-sectional view taken along D-D' in Figure 16(e), Figure 17(h) is a cross-sectional view taken along E-E' in Figure 16(e), and Figure 17(i) is a cross-sectional view taken along F-F' in Figure 16(e).

[0068] In the upper thread guide member 100 of the first embodiment, a slit 141 was provided between the point where the tip of the first guide portion 120 and the point where the tip of the second guide portion 130 of the stopper portion 140 were connected. In contrast, in the upper thread guide member 100 of the second embodiment, the slit 141 is not provided, and the point where the tip of the first guide portion 120 and the point where the tip of the second guide portion 130 of the stopper portion 140 are connected are continuous. This makes it more difficult for the upper thread T to come off the first guide portion 120. In addition, the stopper portion 140 can be made without corners, at least in a front view, and when the thread T loosens, it is less likely for the upper thread T to get caught on the stopper portion 140.

[0069] As a method for threading the upper thread T onto a sewing machine equipped with the upper thread guide member 100 of the second embodiment, the same method as the method for threading the upper thread T onto a sewing machine 10 (sewing machine 10 in Figure 3) equipped with the upper thread guide member 100 of the first embodiment, as described in "2. Sewing Method" above, can be adopted. Furthermore, as for the mounting position of the upper thread guide member 100 of the second embodiment onto the sewing machine 10, the same configuration as the mounting position of the upper thread guide member 100 of the first embodiment, as described in "3. Upper thread guide member of the first embodiment" above, can be adopted.

[0070] 5. Upper thread guide member of the third embodiment The upper thread guide member 100 of the third embodiment will be described below. In the following description, the differences between the upper thread guide member 100 of the third embodiment and the upper thread guide member 100 of the first embodiment will be the main focus. For parts not described below, the upper thread guide member 100 of the third embodiment can adopt the same configuration as that described for the upper thread guide member 100 of the first embodiment.

[0071] Figure 18 is a perspective view of the upper thread guide member 100 of the third embodiment. In the upper thread guide member 100 of the first embodiment, the mounting base 110 is formed in a strip shape, and an elongated mounting hole 111 extending along the longitudinal direction of the mounting base 110 is provided on the other (right) side of the mounting base 110. In contrast, in the upper thread guide member 100 of the third embodiment, as shown in Figure 18, the mounting base 110 has a shape comprising a first strip-shaped portion 110a extending from one end of the mounting base 110 to the other, and a second strip-shaped portion 110b connected to the other end of the first strip-shaped portion 110a and extending substantially perpendicular to the longitudinal direction of the first strip-shaped portion 110a. In the third embodiment, the upper end of the second strip portion 110b is connected to the other end of the first strip portion 110a, and the mounting base 110 is L-shaped in front view. However, the second strip portion 110b may also be connected to the other end of the first strip portion 110a at its longitudinal middle portion or lower end.

[0072] The first guide portion 120 and the second guide portion 130 are arranged in the first strip-shaped portion 110a, aligned along the longitudinal direction of the first strip-shaped portion 110a. The mounting hole 111 is formed in the second strip-shaped portion 110b, as an elongated hole extending along the longitudinal direction (vertical direction) of the second strip-shaped portion 110b. This allows for adjustment of the mounting position of the upper thread guide member 100 on the sewing machine 10 housing (position along the longitudinal direction of the second strip-shaped portion 110b; vertical position).

[0073] As a method for threading the upper thread T onto a sewing machine equipped with the upper thread guide member 100 of the third embodiment, the same method as the method for threading the upper thread T onto a sewing machine 10 (sewing machine 10 in Figure 3) equipped with the upper thread guide member 100 of the first embodiment, as described in "2. Sewing Method" above, can be adopted. Furthermore, regarding the mounting position of the upper thread guide member 100 of the third embodiment onto the sewing machine 10, the same configuration as the mounting position of the upper thread guide member 100 of the first embodiment, as described in "3. Upper Thread Guide Member of the First Embodiment" above, can be adopted. Moreover, although the orientation in which the upper thread guide member 100 of the third embodiment is attached to the sewing machine 10 is not limited, in some embodiments, it can be attached so that the longitudinal direction of the first strip-shaped portion 110a substantially coincides with the left-right direction on the sewing machine 10. This allows the first guide portion 120 and the second guide portion 130 to be arranged side by side in the left-right direction.

[0074] 6. Sewing machine The sewing machine 10 is not limited in type, as long as it is equipped with an upper thread tensioner 11, a thread guide 12, and a balance wheel 13. For example, the sewing machine 10 can be a professional sewing machine, an industrial sewing machine, or a household sewing machine. For example, a lockstitch sewing machine (a sewing machine for straight stitching only) can be used as a professional or industrial sewing machine. The control mechanism of the sewing machine 10 is also not limited. For example, the sewing machine 10 can be an electric sewing machine, an electronically controlled sewing machine, or a computerized sewing machine.

[0075] In Figure 3, the thread guide 12 in the sewing machine 10 was formed in a hook shape. However, the specific shape of the thread guide 12 is not limited as long as it can be used to change the direction of the upper thread T. Other examples of the shape of the thread guide 12 include, for example, a loop shape (ring shape), a plate shape with a guide through hole, or a rod shape with a guide through hole. The thread guide 12 may be fixed (not movable) to the sewing machine arm 10c, or it may be movable relative to the sewing machine arm 10c (for example, it may be able to move up and down in synchronization with the sewing operation of the sewing machine 10). [Examples]

[0076] The sewing experiment was conducted according to the following procedure.

[0077] (Experiment 1) Using the sewing machine 10 shown in Figure 3, which has the upper thread guide member 100 attached, a straight stitch was made through two layers of truck sheet tarpaulin with the upper thread T threaded in the manner shown in Figure 8. Sun-S Bond #10 (manufactured by Sun-S Co., Ltd.) was used for both the upper thread T and the lower thread.

[0078] (Experiment 2) The upper thread guide member 100 was removed from the sewing machine 10 used in Experiment 1, and the conventional thread guide 900 shown in Figure 2 was installed in its place. Sewing was then performed with the upper thread T threaded in the manner shown in Figure 2. All other conditions were the same as in Experiment 1.

[0079] (result) Figure 19 shows photographs illustrating the results of sewing experiments. Figure 19(a) shows the results of Experiment 1, and Figure 19(b) shows the results of Experiment 2. Generally, it is said that puckering (shrinkage during sewing) is likely to occur with stiff fabrics that have little elasticity, such as tarpaulin. In this regard, as shown in Figure 19(a), in Experiment 1, which used a sewing machine 10 equipped with an upper thread guide member 100, almost no puckering was observed, and there was little fabric warping. In contrast, as shown in Figure 19(b), in Experiment 2, which used a sewing machine 10 equipped with a conventional thread guide 900, puckering occurred, and the fabric became warped. [Explanation of symbols]

[0080] 10 Sewing Machines 10a Sewing machine bed 10b Sewing machine stand section 10cm sewing machine arm 11. Upper thread tensioner 11a Thread tension disc 11b Thread retraction spring 11c Thread Tension Dial 12 Threading 12a Protrusion 12b Curved section 13 Balance 13a Threading section 14 needle bars 15 sewing needles 16 Opening for balance 90 Conventional sewing machines 91 Upper thread tensioner 92 Threading 93 Balance 94 sewing needles 100 Upper thread guide member 110 Mounting base 110a First strip portion 110b Second band-shaped section 111 Mounting holes 120 First Information Department 130 Second Information Department 140 Stopper part 140a First stopper section 140b Second stopper section 141 Slit 150 Needle thread passage 160 Thread release section 200 screws 900 thread guide (conventional thread guide) 910 Mounting base 920 Thread guide section S Needle thread supply source T Needle thread

Claims

1. Upper thread tension device, A threading mechanism for changing the direction of the upper thread after it has passed through the upper thread tensioning device, A balance scale that can perform the action of pulling up the upper thread after the upper thread has been threaded through it, and A sewing method using a sewing machine equipped with, The aforementioned sewing machine, Upper thread guide member having a first guide section for changing the direction of the upper thread after it has passed through the thread loop and directing it back towards the thread loop. Furthermore, The upper thread, after being threaded, is passed through the first guide section to change its direction, then threaded again before passing it through the balance beam, and sewing is performed with the thread passed through the balance beam. Sewing method.

2. The upper thread guide member is A mounting base for attaching to the front of the sewing machine, A first guide portion is provided that protrudes forward from the mounting base, A stopper section is connected to the tip of the first guide section to prevent the thread from coming off forward from the first guide section. It is said to be equipped with By looping the upper thread around the outer circumference of the first guide section, it became possible to change the direction of the upper thread. The sewing method according to claim 1.

3. The upper thread guide member is A second guide portion is provided on the mounting base, protruding forward from a point separated from the first guide portion, and its tip is connected to the stopper portion. Furthermore, The gap between the first guide section and the second guide section serves as a passage for the upper thread, allowing the upper thread, after being threaded, to pass through when it is placed on the first guide section. The sewing method according to claim 2.

4. The sewing method according to claim 3, wherein a thread release portion for allowing the upper thread to loosen is provided on the outer circumference of the first guide portion, on the side opposite to the side facing the second guide portion.

5. The sewing method according to claim 3 or 4, wherein a slit is provided between the point where the tip of the first guide portion is connected and the point where the tip of the second guide portion is connected in the stopper portion, thereby dividing the stopper portion into left and right halves.

6. The sewing method according to claim 3 or 4, wherein the portion where the tip of the first guide portion is connected in the stopper portion and the portion where the tip of the second guide portion is connected are continuous.

7. Upper thread tension device, A threading mechanism for changing the direction of the upper thread after it has passed through the upper thread tensioning device, A balance scale that can perform the action of pulling up the upper thread after the upper thread has been threaded through it, and An upper thread guide member for use with a sewing machine equipped with the following: By having a first guide section that changes the direction of the upper thread after it has passed through the thread loop and directs it back towards the thread loop, The upper thread, after being threaded, is passed through the first guide section to change its direction, and then threaded again before passing through the balance beam, allowing sewing to be performed while the thread is on the balance beam. Upper thread guide component.

8. A sewing machine comprising the upper thread guide member according to claim 7.

Images