MXPA03001442A - Bobbin case of rotary shuttle device for sewing machine. - Google Patents

Abstract

Disclosed is a bobbin case of a rotary shuttle device for a sewing machine, in which an under thread pulled out of a bobbin is continuously and stably supplied to a sewing region. The bobbin case comprises a main body integrally provided with a body, and a side portion which is bent downward at a side of the body to have a thick portion at which a fixing hole and adjusting hole is formed and a think portion at which a first and second supporting portion and a supporting piece for supporting and guiding the under thread are formed, the first and second supporting portions being divided by a boundary portion which is formed with a discharging hole for discharging the under thread pulled out of a bobbin from an inner portion of the side portion to an outside; and a guide member formed with a coupling hole and a controlling hole which is corresponding to the fixing hole and the adjusting hole and through which a fastening bolt and a controlling bolt are releasably screwed, wherein one end of the guide member is also formed with a first fixing piece and a second fixing piece which are respectively fixedly inserted into the first and second supporting hole formed at the side portion of the main body, and the second fixing piece forms a path, through which the under thread is passed, together with the supporting piece .

Description

ROTARY SHUTTER DEVICE COIL BOX FOR SEWING MACHINE Technical Field The present invention relates to a sewing machine, and more particularly, to a bobbin case of a rotary shuttle device for a sewing machine, which guides and supplies in a continuous and stable manner a lower thread extracted from the sewing machine. coil to a seam region.

Previous Technique In general, the embroidery sewing machine, domestic or industrial, as shown in FIG. 1, has a rotary shuttle device for supplying a lower thread. The rotary shuttle device comprises an external shuttle which is placed on a drive shaft 1 rotatably connected to a power generating unit, an internal shuttle 3 which is received in the external shuttle 2, a coil 4 which is received in the inner shuttle 3 and on which the lower thread is wound, and a coil box for receiving coil 4. Recently. In order to wind a large amount of lower thread in the spool 4, the spool 4 is provided with side walls 4a, 4b formed respectively at both ends thereof and a partition wall 4c formed between the side walls 4a, 4b to have a passing portion. According to a construction of the rotary shuttle device as described above, when a sewing operation is executed, the external and internal shuttles 2, 3 are rotated relatively, and at the same time, the lower thread wound on the spool 4 is removed and supplied through the bobbin case 5 and the outer shuttle 2 to a lower portion of the fabric to be sewn. Then, the lower thread is sewn into the fabric in cooperation with a lower thread supplied from the upper portion of the fabric. At that time, the bobbin case 5 guides the lower thread removed from the bobbin 4 to the outer shuttle 3 or a seam region. As shown in Figure 2, the coil box 5 is comprised of a main body 7 having a discharge hole 6 for discharging the lower thread removed from the coil 4 and a guide member 8 which is formed in the form of a type of flexible leaf spring for guiding the flexible yarn discharged through the discharge hole 6 of the main body 7 and also to prevent separation of the lower yarn. In the meantime, the main body 7 is additionally formed with a circular passage hole 7a, a rectangular support hole 7b, a fixing hole 7c and an adjustment hole 7d. Corresponding to the holes of the main body 7, at the front end of the guide member 8, a first support piece 8a inserted inside the through hole 7a of the main body 7 and a second support piece 8b inserted inside the opening of the body 7 is formed. support 7b, and also on a rear end side of the guide member 8, a coupling hole 8c is formed to secure the guide member 8 to the main body 7 and a control hole 8d formed to be adjacent to the coupling hole 8c a In order to adjust the elastic force of the guide member 8. Furthermore, between the construction portions as described above, a guide groove is formed for guiding the lower thread. Of course, a fastening bolt 9a is fastened through the coupling hole 8c within the fastening hole 7c. A control bolt 9b is also screwed into the coupling hole 8d. Then, the control bolt is tightened or loosened to adequately control the elastic force of the guide member 8. In case the bobbin is used in the embroidery sewing machine, an outlet port can be formed in a suitable location of the main body 7 so that the lower thread can be substantially extracted from the main body 7. Further, in the discharge orifice 6 of the main body 7 a groove in the shape of "·" 6a is formed to guide the lower thread towards the orifice discharge 6. According to the construction as described above, the lower thread extracted from the coil 4 leaves the discharge hole 6 of the main body 7 and passes between a side portion of the main body 7 and the guide member 8, or is then supplied through the outlet port formed in the body the main thread towards the outer shuttle 2. At that time, the lower thread comes out substantially from the outlet port (not shown) by means of a guide passage between the first support piece 8a and the second support piece 8b of the guide member.

However, the bobbin case constructed as indicated above causes several problems. First, since the lower thread drawn through the discharge hole 6 of the main body 7 is placed within a range of the partition wall of the coil 4 which is rotated at a high speed in the main body 7, the lower thread It is damaged and, in the worst case, is cut by the partition wall. Secondly, since the guide passage formed between the construction portions of the guide member has a broad guide region, an extension of movement and fluctuation of the lower thread is increased. Therefore, there is a problem that the lower thread is not accurately and stably delivered to the main body output port. Third, the lower thread removed from the coil 4 can not maintain adequate tension force due to the above problems. In addition, the intermittent phenomenon and the intermittent sound are generated when the lower thread is supplied, thereby reducing the amount of sewn products and also decreasing the stability in one operation of the sewing machine. Additionally, a slot for inserting the Lower thread into the discharge hole is curved. Therefore, there is another problem as it is difficult to insert the lower thread into the discharge hole.

Description of the Invention Therefore, it is an object of the present invention to provide a bobbin case of a rotary shuttle device for a sewing machine, which is capable of preventing damage or cutting of a lower thread that passes to through a main body from the coil. It is another object of the present invention to provide a bobbin case of a rotary shuttle device for a sewing machine, which is capable of deflecting the lower thread passing through a discharge opening of the main body from the range of a partition wall of a coil rotated in the main body. It is another object of the present invention to provide a bobbin case of a rotary shuttle device of a sewing machine, by which the lower thread is removed from the bobbin through an optical region of a guiding member, while that the optical tension force is maintained. It is yet another object of the present invention to provide a bobbin case of a rotary shuttle device of a sewing machine, in which the Underwire can be supplied stably and the sewing machine can be operated in a silent manner, thus increasing the quality of the sewn products. It is a further object of the present invention to provide a bobbin case of a rotary shuttle device of a sewing machine, which is capable of easily inserting one end of the lower thread wound into the bobbin within the discharge orifice. To achieve the objects and advantages above, there is provided a bobbin case of a rotary shuttle device of a sewing machine, in which a bobbin for winding a lower thread is rotatably arranged, comprising a main body provided in a manner integral with a body, and a side portion that flexes downward on one side of the body to have a thick portion in which a fixing hole and an adjustment hole are formed and a thin portion in which a first and second support portions and a support part for supporting and guiding the lower thread, the first and second support portions being divided by a boundary portion that is formed with a discharge hole for discharging the lower thread extracted from a coil from the inner portion of the lateral portion to an outer portion; and a guide member formed with a coupling hole and a control hole corresponding to the fixing hole and the adjustment hole and through which a clamping bolt and a control bolt are releasably screwed., wherein one end of the guide member is also formed with a first attachment piece and a second attachment piece that are respectively inserted in a fixed manner into the first and second support holes formed in the side portion of the main body, and the second fixing piece forms a path, through which the lower thread is passed, together with the support piece.

Brief Description of the Drawings The foregoing objects, other features and advantages of the present invention will become apparent by the description of the preferred embodiment thereof with reference to the accompanying drawings, in which: Figure 1 is an exploded perspective view of a device conventional rotary shuttle of a sewing machine; Figure 2 is an exploded perspective view of a coil box of a rotary shuttle device of a sewing machine of Figure 1; Figure 3 is an exploded perspective view of a coil box according to the present invention; Figure 4 is a partially cut-away view of a portion of a main body of the bobbin case in Figure 3; Figures 5a and 5b are partially elongated views showing a state in which a lower thread is discharged through the assembled coil box according to the present invention; Fig. 6 is a side view of a discharge orifice of the bobbin case according to another embodiment of the present invention; Figure 7 is a partially cut-away view of the main body of the bobbin case according to another embodiment of the present invention; and Figures 8a and 8b are partially elongated views showing a state in which the lower thread is discharged through the bobbin case assembled in Figure 7.

Best Way to Carry Out the Invention The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. With reference to Figures 3 and 4, a coil box of a rotary shuttle device according to the present invention basically comprises a main body 10 in which a coil is rotatably mounted, and a guide member 12 for guiding a lower thread withdrawn from the spool in the main body 10. The main body 10 is integrally provided with a body portion 16 which is formed in the form of a circular plate in its entirety and has a fastening portion 14 pivotally positioned in the body portion 16, and a side portion 18 extending downward in a portion of the body portion 16 to have a desired length. In particular, the lateral portion 18 is formed with a thick portion 18a and a thin portion 18b for functionality and rigidity thereof. The thick portion 18a and the thin portion 18b are divided by a boundary portion 18c. The boundary portion 18c is formed in the form of a stepped portion due to a difference in thickness or height between the coarse portion 18a and the thin portion 18b. Meanwhile, although not shown in the figures, those skilled in the art will appreciate that an embroidery sewing machine has an exit port through which the lower thread passes. In the thick portion 18a of the side portion 18, a fixing hole 22 is formed for fixing the guide member 12 using a fastening bolt 20, and an adjustment hole 26 in which a control bolt 24 is fastened to control the elastic force of the guide member 12. Further, in the thin portion 18b of the side portion 18, a first and second support hole 28, 29 are formed to support a fastener at one end of the guide member 12. In In particular, at one end of the thin portion 18b of the side portion 18, a support part 30 is formed to support and guide the lower thread. The support piece 30 functions to guide and support the lower thread so that the lower thread withdrawn from the coil is passed between the guide member 12 and the side portion 18 and then accurately delivered to a desired sewing position. Preferably, the second support hole 29 and the support part 30 are identical with an extended line of an outer circumference of a partition wall 4c of the coil 4., and in addition the support part 30 is formed by vertical and horizontal cutting of one end of the thin portion 18b and then flexing the cut end of the thin portion 18b. Therefore, between the second fixing part of the guide member 12 and the support part 30 formed in the thin portion 18b of the thin portion 18 of the main body 10, as described below, a path of lower thread. Of course, it is preferred that both sides of the support piece 30 be rounded so that the lower thread is passed uniformly. Meanwhile, the boundary portion 18c of the side portion is formed with a discharge hole 32 through which the Underwire which is drawn from the bobbin is discharged from an inner portion of the side portion 18 to an outer portion. In particular, as shown in Figure 4, the discharge orifice 32 formed in the boundary portion 18c of the lateral portion 18 of the main body 18 is formed with two discharge openings to discharge the lower thread without damage or cutting of the lower thread. . That is, on both sides of the discharge orifice 32, a first discharge opening 34 and a second discharge opening 36 are formed which corresponds to the first discharge opening 34 so that the lower thread can selectively and essentially pass through. the same according to a position of the lower thread extracted from the coil. Preferably, each of the discharge openings 34, 36 is formed in the boundary portion 18c or the thin portion 18b adjacent to the boundary portion, and further the discharge openings 34, 36 are formed symmetrically with the boundary wall. partition 4c of coil 4 in the center. In particular, it is preferred that the discharge openings 34, 36, through which the lower thread is discharged, are formed to be deflected from a rotating range of the partition wall 4c of the coil 4 so that the lower thread 34, 36 which passes through the discharge opening 34, 36 is not in contact with the partition wall 4c of the rotating coil 4, thus preventing the Underwire from being damaged or cut by the partition wall 4c of the coil 4. Further, it is preferred that each discharge opening 34, 36 be rounded or bent so that the lower thread is discharged uniformly. Meanwhile, a guide groove 38 is communicated with the discharge hole 32 for easily inserting one end of the lower thread removed from the bobbin in the initial stage. Preferably, the guide groove 38 is molded in the shape of a diagonal or oblique line to easily and quickly insert the lower thread through the discharge slot 38 into the discharge slot 32. In this embodiment, the openings of discharge are formed to diverge from one another. However, those skilled in the art will appreciate that the discharge openings can be formed in many other ways to deviate from the rotating range of the partition wall of the coil. For example, in case a coil in which the partition wall is not formed in a central portion thereof, as shown in Figure 6, the discharge orifice 32 may be formed in the form of a linear line or an elongated hole. Referring to Figure 3, the guide member 12 is formed basically with a coupling hole 40 and a control hole 42 which are corresponding to the fixing hole 22 and the adjustment hole 26 and through which a clamping bolt 20 and a control bolt 24 are releasably screwed. At one end of the guide member 12, a first clamping piece 44 is formed which is fixedly inserted into the first support hole 28 formed in the side portion of the main body 10 and a second clamping piece 45 which is inserted in a fixed manner into the second support hole 29, thus preventing the separation of the guide member 12 from the main body 10. In addition, the first fixing part 44 restricts a range that the lower thread is removed or a part of the range together with the support piece 30. Figure 7 is a partially elongated perspective view of the main body of the coil box according to another embodiment of the present invention. The support piece 30 for supporting the lower thread is formed integrally with the first support hole 28. One end of the support piece 30 is placed at the same distance from the first and second discharge openings 34, 36. Meanwhile , the guide member 12 is in close contact with an outer face of the support piece 30 to form a space through which the lower thread is passed. In this case, it is preferred that the support part 30 is formed in a position of the first support hole 28 by a stamping process. In the following, a mode of operation of the bobbin case of the rotary shuttle device of the sewing machine according to the present invention will be fully described. For example, if a user operates the sewing machine to perform a sewing operation, the lower thread removed from the spool 4 of the rotary shuttle is discharged through the discharge hole 32 of the main body 10. At that time, the thread The lower one passing through the discharge hole 32 is discharged through the first discharge opening 34 or the second discharge opening 36 according to a position in which the lower thread is extracted from the coil 4. Therefore, the lower thread is deviated from the rotating range of the partition wall 4c in order to prevent the lower thread from coming into contact with the partition wall 4c and therefore the damage or cutting of the lower thread is completely prevented. In greater detail, in the event that the lower thread is discharged from a winding portion of the coil 4, which has a relatively large area, the Lower thread T is discharged only through the first discharge opening 34 of the discharge orifice. 32 (referring to figure 5a): Otherwise, when the lower thread is discharged from the winding portion having a relatively small area, the lower thread T is discharged only through the second discharge opening 36 of the hole of discharge 32 (referring to figure 5b). In addition, the lower thread, which is discharged through one of the discharge orifices of the discharge orifice 32, passes between the guide member 12 and the thin portion 18b of the lateral portion 18 of the main body 10 and exits through the a lower thread path formed between the second fixing part 45 of the guide member 12 and the thin portion 18b of the side portion 18 of the main body 10. At the same time, since the lower thread is discharged only through a range of the lower thread path or a range of the lower thread path defined by the fastening part and the support part, the lower thread is discharged linearly (a solid line) or discharged at an optimum inclined angle (a dotted line) to the sewing region, so that the lower thread always has a constant tension force while it is supplied. Further, since the first support hole 29 and the support part 30 are positioned to be identical with the extended line of the outer circumference of the partition wall 4c of the coil 4, and placed at the same distance from the first and second discharge openings 34, 36, the tension force applied to the lower thread is constantly maintained. Accordingly, the lower thread can move freely between the first and second discharge openings 34, 36. The tension force of the lower thread can be adjusted appropriately by controlling the elastic force of the guide member 12 using the control bolt 24 In the meantime, an operation is described in detail of the bobbin case of the rotary shuttle device of sewing machine 20 according to another embodiment of the present invention. Figures 8a and 8b are partially elongated views showing a state in which the lower thread is discharged through the bobbin case assembled in Figure 7. The lower thread T passed through the discharge opening 32 comes out in a Desired discharge angle · through a path formed between the second fixing piece 45 of the guide member 12 and the support piece 30 formed in the thin portion 18b of the side portion 18 in the engraved form. At that moment, one side of the support part 30 is identical with the extended line of the outer circumference of the partition wall 4c of the coil 4, and is positioned at the same distance from the first and second discharge openings 34, 36 to maintain always the constant tension force regardless of the position of the lower thread. In this mode, since the discharge angle is less than that of the other modes as well as a conventional coil box, the tension force applied to the lower thread T is reduced, thus preventing the lower thread T from being cut . Further, since the path of the lower thread T is tightly closed by the space formed by the thin portion 18b and the guide member 12 and the space formed by the support piece 30 and the second fixing piece 45, it is also prevented that the lower thread is separated. Therefore, the lower thread drawn from the bobbin is discharged through the bobbin case with an optimum direction and the tension force that is maintained, and then it is supplied to the seam region, thereby easily executing the operation sewing. According to the bobbin case of the rotary shuttle device of the sewing machine of the present invention, when the lower thread wound on the bobbin is unloaded, the lower thread is prevented from contacting the bobbin partition wall. and that the lower thread is damaged or cut. In addition, the lower thread is discharged through the lower thread path defined between the limited fixing part of the guide member and the support part and then always supplied in the optimum direction and the tension force. While the present invention has been described in detail, those skilled in the art will appreciate that various modifications and substitutions may be made thereto without departing from the spirit and scope of the present invention as set forth in the appended claims.

Claims (8)

1. A bobbin case of a rotary shuttle device of a sewing machine, in which a bobbin for winding a lower thread is rotatably mounted, comprising: a main body 10 integrally provided with a body 16, and a side portion 18 which flexes downward on one side of the body 16 to have a thick portion 18a in which a fixing hole 22 and adjustment hole 26 and a thin portion 18b are formed in which a first and second portions of support 28, 29 and a support part for supporting and guiding the lower thread, the first and second portions which are divided by a boundary portion 18c which is formed with a discharge hole 32 for unloading the lower thread removed from the coil from a Internal portion of lateral portion 18 towards an external portion; and a guide member 12 formed with a coupling hole 40 and a control hole 42 which is corresponding to the fixing hole 22 and the adjustment hole 26 and through which a fastening bolt 20 and a control bolt 24 are releasably screw, wherein one end of the guide member 12 is also formed with a first clamping piece 44 and a second clamping piece 45 which are fixedly inserted respectively into the first and second support holes 28, 29 formed in the lateral portion 18 of the main body 10, and the second fixing part 45 forms a path, through which the lower thread is passed, together with the support piece 30.

2. The coil box in accordawith the rei indication 1, wherein the discharge orifice 32 is formed with a first discharge opening 34 and a second discharge opening 36 through which the lower thread withdrawn from the spool is passed from Selectively adjust according to a position of the lower thread. The bobbin case according to claim 2, wherein the discharge openings 34, 36 of the discharge orifice 32 are formed in the boundary portion 18c of the lateral portion 18, while maintaining a distafrom the member. guide 12. The bobbin case according to claim 2, wherein each of the discharge openings 34, 36 is positioned to be deflected from a rotating range of the partition wall 4c if the coil 4 is positioned. in the main body 10 and has the partition wall 4c. The coil box according to claim 1, wherein the discharge orifice 32 is connected to a guide slot 38 which is formed diagonally from one side of the coarse portion 18a to a central portion of the discharge orifice 32. for inserting one end of the lower thread into the discharge hole 32 at an initial stage. The coil box according to claim 1, wherein the discharge orifice 32 is formed in the form of an elongated hole. The bobbin case according to one of claims 1 to 6, wherein the support part 30 is integrally formed with the first support hole 28, and in close contact with one side of the guiding member 12. The coil box according to claim 7, wherein a side end of the support piece 30, through which the lower thread is passed, is positioned at the same distafrom the first and second discharge openings. , 36