JP2008161541A - Presser foot of sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a presser foot of a sewing machine capable of making a knife excellently cut the end edges of an upper fabric and a lower fabric evenly, and capable of effectively preventing defective sewing caused by the defective cutting. <P>SOLUTION: An auxiliary guide member 6, overhanging into a guide pathway between a presser foot 13 and the other presser foot 12 in the front of a fixed knife 16 and a movable knife 17, is attached to the presser foot 13 for holding the upper fabric with a needle plate among two presser feet 12 and 13 extending from left and right sides of a needle falling position 11. The upper and lower fabrics, retained in the raised state under the restraint by the auxiliary guide member 6 and the presser foot 12, are fed to places where the fixed knife 16 and the movable knife 17 are disposed, and the upper end edges of the fabrics are cut evenly. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a presser foot for a sewing machine used for carrying out a stitching operation in which the edges of two fabrics are overlapped and sewn to a predetermined width.

  For example, for the stitching of the crotch of briefs and shorts, a sewing machine with a narrow cylindrical bed is used, and the presser foot with two fabrics stacked vertically from each edge over a predetermined width. It is carried out by a procedure in which it is held between the needle plate, sent to the needle drop position provided at the rear part of the presser foot, and stitched together by the needles that fall at the needle drop position.

  In order to obtain a high-quality sewing product in such a stitching, it is important that the overlap width of the fabric fed to the needle drop position is maintained at an appropriate width corresponding to the sewing width unique to the sewing machine. The fabric overlap width is generally adjusted at the front position of the presser foot by the manual operation of a sewing manufacturer, but there is a problem that this adjustment operation requires a great deal of skill. In order to solve this problem, conventionally, a knife (fixed knife and movable knife) for trimming and aligning the edges of the fabrics to be stitched together, and a guide means for guiding the trimmed fabrics and superimposing them vertically ( A sewing machine that does not require manual adjustment of the overlap width by using a special presser foot provided with an upper guide and a lower guide has been put into practical use (see, for example, Patent Document 1).

  FIG. 5 is a perspective view of the vicinity of the needle drop position of a sewing machine equipped with a conventional presser foot having a knife and guide means. As shown in the figure, the presser foot 1 has a pair of presser feet 12 and 13 extending in parallel to each other on the front part of the presser body 11 attached to the lower end of the presser bar 10 supported by the tip of the sewing machine arm 2. The presser bar 10 is moved downward to elastically contact the needle plate 4 on the sewing machine bed 3. The lower fabric KL and the upper fabric KU to be sewn are set in a state in which the vicinity of the respective end edges are held between the left and right presser feet 12 and 13 and the needle plate 4 and are publicly known to appear and disappear on the needle plate 4 By the action of a feed dog (not shown), the feed in the direction indicated by the white arrow in the figure is added and fed to the lower part of the presser body 11 and lowered to the needle drop position 14 at substantially the center of the presser body 11. It is sewn by the needles 5, 5.

  The left and right presser feet 12 and 13 form a guide passage 15 that opens to the front end, and a fixed knife 16 fixed to the presser foot 12 can slide in the left and right directions in the middle of the guide passage 15 A movable knife 17 attached to the presser foot 13 is arranged. As shown in the drawing, the lower fabric KL and the upper fabric KU are introduced into the guide passage 15 in a state in which the edges are raised and aligned with each other, reach the installation position of the fixed knife 16 and the movable knife 17 and move up and down. The fixed knife 16 and the movable knife 17 which are in sliding contact with each other so as to overlap each other are cut and aligned.

  At the rear position of the fixed knife 16 and the movable knife 17, an upper guide 18 lies horizontally between the upper surfaces of the left and right presser feet 12 and 13, and projects into the guide passage 15 along the lower surface of the presser foot 12. A lower guide 19 (see FIG. 6) is provided, and the lower fabric KL and the upper fabric KU whose edges are trimmed by the fixed knife 16 and the movable knife 17 are moved up and down by the action of the upper guide 18 and the lower guide 19. And is fed to the needle entry position 14.

  FIG. 6 is an explanatory diagram of the operation of the presser foot, in which a cross section of the presser foot 1 in a direction orthogonal to the feeding direction of the lower fabric KL and the upper fabric KU is schematically shown. FIG. 6 (b) is a cutting position by the fixed knife 16 and the movable knife 17, FIGS. 6 (c) and 6 (d) are between the cutting position and the needle drop position 14, and FIG. ) Shows the state of the lower fabric KL and the upper fabric KU at the needle drop position 14, respectively.

  As shown in FIGS. 6C and 6D, the upper guide 18 has an arch-shaped lower surface in which the presser foot 12 side is raised and the presser foot 13 side is lowered. The thickness of the presser body 11 is increased so as to be continuous with the lower surface of the presser body 11 at a position before the needle drop position 14. The lower guide 19 is a plate fixed to the lower surface of the presser foot 12, and as shown in FIGS. 6 (b) to 6 (c), the guide passage 15 immediately after the cutting position by the fixed knife 16 and the movable knife 17 is provided. A guide edge is provided that extends inward and increases in length toward the rear side and reaches the front position of the needle drop position 14.

  As shown in FIG. 6 (a), the lower fabric KL and the upper fabric KU are overlapped by appropriate widths from their respective edges, and are introduced into the guide passage 15 in a state where the mating portion is erected on the needle plate 4. Is done. In order to facilitate this introduction, an auxiliary plate P (indicated by phantom lines) is used which has an auxiliary function of standing on the upper surface of the needle plate 4 and maintaining the overlapping portion of the lower fabric KL and the upper fabric KU in an upright state.

  The lower fabric KL and the upper fabric KU introduced in this way reach the sliding contact position between the fixed knife 16 and the movable knife 17 as shown in FIG. c) and sent backward as shown in (d).

  During this time, the lower fabric KL held by the left presser foot 12 is pushed from the left side by the guide edge of the lower guide 19 protruding into the guide passage 15 and falls on the needle plate 4. On the other hand, the upper fabric KU held by the right presser foot 13 is guided by the upper guide 18 that is curved in an arch shape, falls on the lower guide 19 that overlaps with the lower guide 19, and at the end of the lower guide 19, the needle plate 4 It overlaps with the upper part of the upper lower cloth KL, is fed to the needle drop position 14 in this state, and is stitched together by the needles 5, 5... Lowered to the needle drop position 14 as shown in FIG.

In this way, the lower fabric KL and the upper fabric KU are overlapped with each other in the vicinity of their respective edges and fed into the presser foot 1 while standing on the throat plate 4, so that the ends of the lower fabric KL and the upper fabric KU are moved by the operations of the fixed knife 16 and the movable knife 17. The edges are trimmed and overlapped by the action of the upper guide 18 and the lower guide 19 and sent to the needle drop position 14, and the stitching of the lower fabric KL and the upper fabric KU with a substantially constant overlapping width is performed. This can be achieved without the need for manual adjustment of the stacking width.
Japanese Utility Model Publication No.59-34457

  Now, in the sewing machine having the presser foot 1 as described above, in order to satisfactorily perform the stitching of the lower fabric KL and the upper fabric KU, the ends of the lower fabric KL and the upper fabric KU are operated by the operation of the fixed knife 16 and the movable knife 17. The edges need to be trimmed correctly. Here, since the fixed knife 16 and the movable knife 17 act on the upper edges of the lower fabric KL and the upper fabric KU that stand up on the upper surface of the needle plate 4, the lower fabric KL and the upper fabric KU can be used to properly align the edges. It is important to stabilize the standing posture.

  As described above, the rising postures of the lower fabric KL and the upper fabric KU on the needle plate 4 are the inner surfaces of the presser feet 12 and 13 that hold each of the lower fabric KL and the upper fabric KU (the surface facing the guide passage 15). Maintained under restraint by Therefore, in order to maintain a stable rising posture, the passage width W (see FIG. 6A) of the guide passage 15 between the presser feet 12 and 13 at a position before the fixed knife 16 and the movable knife 17 is optimized. There is a need.

  However, since the appropriate value of the passage width W of the guide passage 15 varies depending on the thickness of the lower fabric KL and the upper fabric KU to be sewn, for example, a presser having a passage width W corresponding to the thick lower fabric KL and the upper fabric KU. When the gold 1 is used, when sewing the thin lower fabric KL and the upper fabric KU, in particular, the thin and soft lower fabric KL and the upper fabric KU, the lower fabric KL and the upper fabric KU in the guide passage 15 wider than the appropriate width. The upper fabric KU is bent, and the edges that are trimmed by the operations of the fixed knife 16 and the movable knife 17 are in a wavy state, and as shown in FIG. There is a possibility that a defective sewn product with the mark remaining may be obtained.

  Conversely, when the presser foot 1 having the passage width W corresponding to the thin lower fabric KL and the upper fabric KU is used, when the thick lower fabric KL and the upper fabric KU are sewn, the guide passage 15 is narrower than the appropriate width. There is a possibility that the feeding of the lower fabric KL and the upper fabric KU will be hindered and hinder the execution of sewing.

  Under such circumstances, conventionally, the presser foot 1 is appropriately replaced in accordance with the thickness of the fabric to be sewn, but at the sewing site where thin and thick materials are mixed, the presser foot 1 Replacing takes a lot of time, resulting in reduced efficiency.

  Further, when handling a fabric whose thickness changes in the direction of sewing, such as a fabric having an overlapped portion in the middle, it is impossible to replace the presser foot 1 as described above, and a high-quality sewing product is obtained. It ’s difficult.

  The present invention has been made in view of such circumstances, and makes it possible to satisfactorily align the edges of the upper and lower fabrics with a knife regardless of the type of the target fabric by adding simple parts. It is an object of the present invention to provide a presser foot for a sewing machine that can effectively prevent the occurrence of poor sewing due to imperfect alignment.

  The presser foot of the sewing machine according to the first aspect of the present invention includes two presser feet that extend substantially parallel to each other from the left and right sides of the needle drop position, and a guide passage formed between the presser feet. The guide passage in a state in which the upper fabric and the lower fabric sandwiched between the presser foot and the needle plate are raised on the needle plate together with their respective ends. In the presser foot of the sewing machine in which the edge is aligned with the knife and fed to the needle drop position while being stacked up and down, the presser foot for clamping the upper fabric is attached to the front position of the knife. An auxiliary guide member projecting inside the guide passage is provided.

  The presser foot of the sewing machine according to the second invention is characterized in that the auxiliary guide member in the first invention is attached so that the amount of protrusion into the guide passage can be changed by adjusting the position in the left-right direction.

  The presser foot of the sewing machine according to the third invention is characterized in that the auxiliary guide member in the second invention is attached by a set screw that can be operated from above the presser foot.

  Furthermore, the presser foot of the sewing machine according to the fourth invention is characterized in that the auxiliary guide member in the first to third inventions is configured to be capable of elastic displacement in the width direction of the guide passage.

  In the presser foot of the sewing machine according to the first aspect of the present invention, the auxiliary guide member that projects into the guide passage at the front position of the knife is attached to the presser foot that holds the upper fabric, Regulates the width of the guide passage, keeps the rising posture of the upper and lower fabrics stable, makes it possible to perform the edge trimming with a knife, and effectively prevents the occurrence of poor sewing due to imperfect trimming. It becomes possible to prevent.

  Further, in the presser foot of the sewing machine according to the second aspect of the invention, for example, the auxiliary guide member is attached so that the amount of overhang into the guide passage can be changed by adjusting the position in the left-right direction. The width of the passage can be optimized and the edge of the edge can be satisfactorily aligned regardless of the type of target fabric, effectively preventing the occurrence of poor sewing due to imperfect alignment. be able to.

  Further, in the presser foot of the sewing machine according to the third aspect of the present invention, the amount of extension of the auxiliary guide member can be changed by operating the set screw from above, so that the passage width can be easily optimized according to the type of the target fabric. can do.

  Further, in the presser foot of the sewing machine according to the fourth aspect of the present invention, since the auxiliary guide member capable of elastic displacement in the width direction of the guide passage is provided, the auxiliary guide member can be used even when handling a cloth whose thickness changes in the sewing advancement direction. The present invention has an excellent effect, such as being able to follow by the displacement of the belt and effectively preventing the occurrence of poor sewing due to imperfect alignment.

  Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments thereof. FIG. 1 is an exploded perspective view of a presser foot according to the present invention.

  A presser foot 1 according to the present invention is similar to the conventional presser foot 1 shown in FIG. 5, and includes a presser body 11 having a needle drop position 14 provided substantially at the center and a front portion of the presser body 11. A pair of presser feet 12 and 13 extending forward in parallel are provided. The presser body 11 has a support leg 11a erected on the rear, and an insertion hole 11b having an opening at the upper end of the support leg 11a is inserted into the lower end of the presser bar 10 indicated by a two-dot chain line in the figure. As shown in FIG. 5, it is fixedly supported at the lower end of the tip end of the sewing machine arm 2.

  As shown in FIG. 5, the presser foot 1 is lowered onto the sewing machine bed 3 together with the presser bar 10, and a presser body 11 and a pair of right and left are placed on the upper surface of the needle plate 4 horizontally mounted on the sewing machine bed 3. Use the presser foot 12 and 13 with elastic contact. Sliding plates 12a and 13a are attached to the lower surfaces of the presser feet 12 and 13, respectively. The sliding plates 12a and 13a are leaf springs that are curved into a sled shape, and the engaging portions provided by bending the front and rear ends are hooked on the front edges of the presser feet 12 and 13 and the rear edge of the presser body 11 to hold the presser foot. The front ends of the feet 12 and 13 are fixed by set screws 12b and 13b, and are attached along the entire length of the presser feet 12 and 13 and the presser body 11.

  A small presser 9 is attached to the lower part of the presser body 11 so as to be positioned between the sliding plates 12a and 13a on the rear side of the needle drop position 14. The presser foot 9 is attached by passing an integrally provided support tube 90 from below through a mounting hole (not shown) provided in the support leg 11a and urging downward by a coil spring 91 held in the support tube 90. It is. The elastic contact of the presser body 11 and the pair of left and right presser feet 12 and 13 with the needle plate 4 actually occurs via the presser foot 9 and the sliding plates 12a and 13a.

  A holding hole having a rectangular cross section that penetrates the side surface in the width direction is provided in the middle of the presser feet 12 and 13. In the holding hole of the presser foot 12 on one side (left side), a plate-shaped fixed knife 16 is cut into a guide passage 15 (see FIGS. 2 and 3) between the presser foot 13 on the other side (right side). The holding surface of the presser foot 13 on the other side (right side) faces the surface, and the blade surface facing the guide passage 15 is overlapped with the blade surface of the fixed knife 16 to the left and right. A movable knife 17 is held so as to be slidable in the direction.

  The holding hole of the presser foot 13 that holds the movable knife 17 is extended to the front part, and a holding groove 60 that is stepped down over an appropriate length is provided, and the auxiliary guide member 6 is attached to the holding groove 60. . As shown in the figure, the auxiliary guide member 6 is a member having an arcuate curved shape, and a rectangular fixed block 61 that can be fitted into the holding groove 60 is provided on the opposite side of the curved surface.

  The auxiliary guide member 6 has a fixing block 61 fitted into the holding groove 60 from the inner surface side of the presser foot 13 as shown by an arrow in the figure, and a set screw 62 is inserted from a circular hole opened on the upper surface of the presser foot 13. It is fixed by being fastened to a screw hole provided in the bottom surface of the holding groove 60 through a long hole 63 provided in the fixing block 61.

  The elongated hole 63 of the fixing block 61 is elongated to the left and right as shown in the figure, and the fixing position of the auxiliary guide member 6 is adjusted in the lateral direction within the length range of the elongated hole 63 by loosening the set screw 62. be able to. The set screw 62 can be loosened from above via a circular hole on the upper surface of the presser foot 13, and the position of the auxiliary guide member 6 is easy in a use state where the presser foot 1 is attached to the lower end of the presser bar 10. Can be adjusted to.

  In addition, a recess 70 is provided on the lower surface of the presser foot 13 at an appropriate length behind the holding hole of the movable knife 17, and a flat contact member 7 is fitted and fixed in the recess 70. is there. In the upper part of the recess 70, a notch groove 71 that opens in the upper surface and the outer surface of the presser foot 13 and extends in the left-right direction is provided.

  The abutting member 7 is a screw provided with a set screw 72 in the abutting member 7 fitted into the recess 70 from the lower position and passed through a long hole provided in the bottom surface of the notch groove 71 as indicated by an arrow in the figure. It is fixed by tightening in the hole.

  The long hole on the bottom surface of the notch groove 71 is elongated in the longitudinal direction of the notch groove 71, that is, in the left-right direction. The fixing position of the contact member 7 is the length of the long hole by loosening the set screw 72. It can be adjusted in the horizontal direction within the range. The set screw 72 can be loosened from above through the opening in the upper part of the notch groove 71, and the position of the abutting member 7 is easy in the use state in which the presser foot 1 is attached to the lower end of the presser bar 10. Can be adjusted to.

  A lower guide 19 similar to that of the conventional presser foot 1 is attached to the lower surface of the presser foot 12 on the other side (left side). As described above, the lower guide 19 is provided with a guide edge that increases the protruding length into the guide passage 15 toward the rear on one edge of a rectangular fixing plate that is fastened and fixed to the lower surface of the presser foot 13 by the set screw 80. It has the shape shown in the figure.

  A leaf spring 8 is attached to the lower surface of the presser foot 12. As shown in the figure, the leaf spring 8 is connected to one edge of a fixed piece 81 having a rectangular shape corresponding to the fixed plate of the lower guide 19 and rises substantially vertically from the continuous edge of the fixed piece 81, It has an upwardly convex curved shape that decreases from the upper end to the other side and gradually decreases from the front to the rear.

  The leaf spring 8 having such a shape is integrally formed including a fixed piece 81 by a thin plate made of a metal material having rich elasticity such as a stainless steel for spring (SUS304-CSP: JIS). As shown in FIG. 6, a fixing piece 81 is placed on the upper portion of the lower guide 19 and fixed to the lower surface of the presser foot 13 by the set screw 80.

  2 is a top view of the presser foot 1 according to the present invention, and FIG. 3 is a bottom view of the presser foot 1 according to the present invention. The planar positional relationship of the auxiliary guide member 6, the abutting member 7 and the leaf spring 8 mounted as described above. It is shown. In these figures, the fixed knife 16 and the movable knife 17 are indicated by a two-dot chain line. The movable knife 17 moves forward and backward as shown by white arrows in the figure by transmission from a drive mechanism (not shown), is brought into sliding contact with the upper surface of the fixed knife 16, and is introduced into the guide passage 15 as described later. The operation of cutting the rising edges of the fabric KU and the lower fabric KL is performed.

  The auxiliary guide member 6 attached to the front end portion of the right presser foot 13 has an arcuate curved surface facing inward, and between the front end portion of the presser foot 13 and the sliding contact portion of the fixed knife 16 and the movable knife 17. , And are attached so as to project into the guide passage 15 between the presser foot 12. The position of the auxiliary guide member 6 can be adjusted in the left-right direction, and the amount of protrusion of the auxiliary guide member 6 to the inside of the guide passage 15 can be changed by this adjustment.

  As shown in FIG. 3, the contact member 7 attached to the lower surface of the presser foot 13 is located between the rear of the fixed knife 16 and the movable knife 17 and the needle drop position 14 provided on the presser body 11. . The inner edge of the presser foot 13 of the abutting member 7 protrudes to the inside of the guide passage 15 between the presser foot 12 and is positioned immediately before one side of the needle drop position 14.

  The lower guide 19 fixed to the lower surface of the left presser foot 12 includes a guide edge protruding inside the guide passage 15 between the presser foot 13 and the lower guide 19. As shown in the figure, the guide edge protrudes from the lower position of the sliding contact portion of the fixed knife 16 and the movable knife 17 to the inside of the guide passage 15 so as to increase in length toward the rear (downward in the drawing).

  As shown in FIG. 3, the leaf spring 8 fixed together with the lower guide 19 has a front end positioned above the sliding contact portion of the fixed knife 16 and the movable knife 17 and has the curved shape described above. The rear end extending rearward is attached so as to be positioned immediately before the needle drop position 14 provided in the presser body 11.

  As shown in FIG. 2, an upper guide 18 is provided on the upper part of the presser foot 1 so as to be bridged between the left and right presser feet 12 and 13 on the rear side of the sliding contact portion of the fixed knife 16 and the movable knife 17. The upper portion of the leaf spring 8 attached to the foot 12 as described above is covered with the upper guide 18. On the upper surface of the upper guide 18, a guide groove 18 a is formed that extends obliquely rearward from the front edge and continues to the outer edge on the left side of the presser body 11 (the presser foot 12 side). The guide groove 18a is provided so as to perform a guiding action for discharging the fabric end cut by the fixed knife 16 and the movable knife 17 to the left without reaching the needle drop position 14.

  As in the conventional case, the stitching with the sewing machine having the presser foot 1 configured as described above is performed by aligning the lower fabric KL and the upper fabric KU to be sewn with their respective end portions raised, and the left and right presser feet. This is realized by introducing into the guide passage 15 between 12 and 13, aligning the edges at the sliding contact portion between the fixed knife 16 and the movable knife 17, and feeding them to the needle drop position 14 in the vertical direction.

  FIG. 4 is an operation explanatory view of the presser foot of the sewing machine according to the present invention. This figure is a schematic cross-sectional view of the presser foot 1 in the direction orthogonal to the feeding direction of the lower fabric KL and the upper fabric KU, as in FIG. 6 in the case of the conventional presser foot, and FIG. In the vicinity of the front end of the gold 1, FIG. 4 (b) shows the vicinity of the cutting position by the fixed knife 16 and the movable knife 17, and FIGS. 4 (c) and (d) show the gap between the cutting position and the needle drop position 14. FIG. 4E shows the state of the lower fabric KL and the upper fabric KU at the needle drop position 14, respectively.

  As shown in FIGS. 4C and 4D, the lower surface of the upper guide 18 has an arch-shaped curved shape that is higher on the side of the presser foot 12 that holds the lower fabric KL and lower on the side of the presser foot 13 that holds the upper fabric KU. In addition, the height decreases toward the rear and is continuous to the front position of the needle drop position 14. The curved shape of the leaf spring 8 attached to the presser foot 12 corresponds to the shape of the lower surface of the upper guide 18 as described above, and the leaf spring 8 faces the lower surface of the upper guide 18 with an appropriate gap therebetween. So that it is positioned.

  As shown in FIG. 4 (a), the lower fabric KL and the upper fabric KU are pressed near the end portions between the presser feet 12 and 13 and the needle plate 4, and a predetermined width portion is overlapped from the end edges. The mating portion is fed into the guide passage 15 with the needle plate 4 standing. Note that P in the figure is an auxiliary plate provided to keep the overlapping portion of the lower fabric KL and the upper fabric KU in an upright state.

  In the presser foot 1 according to the present invention, at the front end of the guide passage 15. The auxiliary guide member 6 attached to the presser foot 13 that holds the upper fabric KU protrudes, and this auxiliary guide member 6 abuts on the upper fabric KU rising from the needle plate 4 and restrains the rising posture of the upper fabric KU. Together with the lower fabric KL restrained by the contact with the other presser foot 12, it acts to maintain a stable standing posture on the needle plate 4.

  The amount of protrusion of the auxiliary guide member 6 can be increased or decreased by adjusting the position in the left-right direction, and by this adjustment, the passage width W of the guide passage 15 into which the lower fabric KL and the upper fabric KU are introduced can be appropriately changed. . Therefore, by setting the appropriate passage width W according to the type of fabric to be sewn, the lower fabric KL and the upper fabric KU are sent in a stable standing posture regardless of whether they are thick, thin or soft. be able to.

  The position of the auxiliary guide member 6 can be adjusted by operating the set screw 62 from the upper part of the presser foot 13, and it is possible to respond quickly even when handling various different lower fabrics KL and upper fabrics KU. . In addition, when handling a fabric whose thickness changes in the direction of sewing, such as a fabric having an overlapping portion in the middle, if the position of the auxiliary guide member 6 is set in consideration of the thickness change, It is possible to keep the standing posture of other parts stable without hindering passage.

  Furthermore, the auxiliary guide member 6 can be constituted by, for example, a leaf spring having elasticity in the left-right direction so that the elastic displacement in the width direction of the guide passage 15 can be made. When handling a fabric whose thickness changes in the direction of travel, the leaf springs can bend at the thickness changing portion to absorb the change in thickness, and the lower fabric KL and the upper fabric KU can maintain a good standing posture. .

  As shown in FIG. 4B, the lower fabric KL and the upper fabric KU fed in this way reach the sliding contact position between the fixed knife 16 and the movable knife 17, and the upper edges thereof are trimmed. Since the auxiliary guide member 6 is extended just before the fixed knife 16 and the movable knife 17, the edges of the lower fabric KL and the upper fabric KU are trimmed while maintaining a stable rising posture. As shown in FIG. 7, there is a possibility that a defective sewing form in which the wavy portion A due to inadequate cutting is left on the edge of the upper fabric KU and stitched to the lower fabric KL as shown in FIG. It can be avoided.

  The front end of the leaf spring 8 is located near the rear upper part of the fixed knife 16 and the movable knife 17 as described above, and the front part of the lower guide 19 is located at the lower part. The guide edge of the lower guide 19 comes into contact with the lower portion of the lower fabric KL cut by the above, and the leaf spring 8 elastically contacts the upper portion of the upper fabric KU. Note that the cut end of the fabric is guided and discharged to the guide groove 18a on the upper surface of the upper guide 18 as described above.

  The lower fabric KL and the upper fabric KU, the upper edges of which are trimmed by the fixed knife 16 and the movable knife 17, are further moved to the needle drop position 14 as shown in FIGS. 4 (c) to (d). Get closer. During this time, the lower fabric KL is pushed from the left side by the guide edge of the lower guide 19 that increases the length of projection into the guide passage 15 and falls on the lower needle plate 4. The upper fabric KU is pushed downward by the leaf spring 8 that elastically contacts the upper portion. The leaf spring 8 has a curved shape in which the side of the presser foot 13 that holds the upper fabric KU is low and lower toward the rear, and the upper fabric KU is pushed downward by the action of the leaf spring 8 and is lowered. It falls on the guide 19 and overlaps the upper surface of the lower fabric KL at the feeding position in FIG. 4D beyond the rear end of the lower guide 19.

  The lower fabric KL and the upper fabric KU reach the front position of the needle drop position 14 as shown in FIG. The lower guide 19 does not exist at this position, and the upper fabric KU directly overlaps the upper surface of the lower fabric KL. The contact member 7 attached to the lower surface of the presser foot 13 protrudes at the front position of the needle drop position 14, and this protrusion presses the upper fabric KU toward the overlapping portion with the lower fabric KL. The upper fabric KU overlaps the upper surface of the lower fabric KL without looseness, and is fed into the needle drop position 14 in this state and is stitched together by the needles 5, 5.

It is a disassembled perspective view of the presser foot concerning the present invention. It is a top view of the presser foot concerning the present invention. It is a bottom view of the presser foot concerning the present invention. It is operation | movement explanatory drawing of the presser foot of the sewing machine which concerns on this invention. It is a perspective view of the vicinity of the needle drop position of a sewing machine equipped with a conventional presser foot. It is operation | movement explanatory drawing of the conventional presser foot. It is a figure which shows the bad sewing form obtained when the conventional presser foot is used.

Explanation of symbols

1 Presser foot 4 Needle plate 6 Auxiliary guide member
12 Presser foot
13 Presser foot
14 Needle entry position
15 Guide passage
16 Fixed knife
17 Movable knife
62 Set screw
KL under fabric
KU top fabric

Claims (4)

Each of the presser foot includes two presser feet that extend substantially parallel to each other from the left and right sides of the needle drop position, and a knife disposed in the middle of the guide passage formed between the presser feet. The upper fabric and the lower fabric sandwiched between the needle plate and the needle plate are fed to the guide passage in a state where the respective end portions are raised on the needle plate, and the edges are cut and aligned by the knife. In the presser foot of the sewing machine that is repeatedly fed to the needle drop position,
A presser foot for a sewing machine, comprising an auxiliary guide member that is attached to a position in front of the knife of the presser foot that sandwiches the upper fabric and that projects to the inside of the guide passage.   The presser foot of a sewing machine according to claim 1, wherein the auxiliary guide member is attached so that a protruding amount into the guide passage can be changed by adjusting a position in a left-right direction.   The presser foot of the sewing machine according to claim 2, wherein the auxiliary guide member is attached by a set screw that can be operated from above the presser foot.   The presser foot of the sewing machine according to any one of claims 1 to 3, wherein the auxiliary guide member is configured to be capable of elastic displacement in the width direction of the guide passage.

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