SEWING MACHINE FOOT AND SEWING MACHINE

Abstract

 A sewing machine foot of the invention includes: a foot mounting portion (44) for fixing to a pressing rod (14) of a sewing machine; a pressing portion (46) for pressing a sewing object product when a sewing needle (12) pieces; and an element guide groove (46) for guiding an element row (9) of a slide fastener (8) by inserting the element row therein, the sewing machine further including: a swing arm (47) which is supported by a foot mounting portion (44) swingablly relative to the foot mounting portion (44) and swings in a vertical plane parallel to a sewing line (28) at the time of sewing; and urging means (52) disposed between the foot mounting portion (44) and the swing arm (47), for urging the swing arm (47) to the sewing object product relative to the foot mounting portion (44). Consequently, the element row (9) of the slide fastener (8) can be guided both when the sewing needle (12) pierces and when a seam is formed, so that a thick fabric (6) and a concealed slide fastener (8) which are difficult to sew together can be positioned accurately and sewed together.

Description

Technical Field

[0001] The present invention relates to a sewing machine foot to be applied to a sewing machine, the sewing machine foot including lower feed teeth provided on a lower face side of a needle plate of the sewing machine and an upper feed unit which is provided on an upper face side of the needle plate of the sewing machine and moves interlocking with the lower feed teeth, the sewing machine performing a sewing operation while feeding a sewing object product by nipping the sewing object product from above and below by the lower feed teeth and upper feed unit, and relates to the sewing machine comprising the sewing machine.

Background Art

[0002] In a sewing machine foot for sewing a concealed slide fastener known conventionally, a pair of guide grooves opposing each other across an intermediate partitioning portion formed in the longitudinal direction are formed in a central portion on a rear side of a fastener tape pressing portion, and a needle hole is provided in a relatively front end portion in the central portion of the tape pressing portion. A bottom end face of the intermediate partitioning portion is formed relatively lower than a tape pressing face on the rear face of the tape pressing portion, and the intermediate partitioning portion is projected forward from the front end of the tape pressing portion or an entrance on the front end side of the guide groove is formed widely in the form of a flare. Particularly, regarding the sewing machine foot, for example, a sewing machine foot for sewing a concealed slide fastener characterized by forming an expanded portion which is expanded in a height direction and a width direction at a front end portion of the intermediate partitioning portion has been proposed by Japanese Patent Application Laid-Open No. 54-54462 (Patent Document 1).

[0003] An upper ear portion folded back to a U- shape of a concealed slide fastener is erected with the fingers when the concealed slide fastener is sewed to a sewing object product by using the sewing machine foot described in Patent Document 1, and then inserted into a guide groove, so that the sewing operation is started. In this case, according to this patent document, the sewing operation is executed with a bottom face of the expanded portion formed at the front end portion of the intermediate partitioning portion pressing a non-sewed fastener tape. For this reason, fastener elements can be introduced into the guide groove. Further, according to this patent document, even in a space portion excluding the fastener elements or in a portion in which a top end stop formed by crushing a fastener element made of thermoplastic resin by ultrasonic processing exists, the fastener elements can be introduced into the guide groove stably.

[0004] Therefore, the sewing machine foot described in Patent Document 1 makes it possible to prevent the problems that the intermediate partitioning portion of the tape pressing portion rides on the space portion of the upper ear portion of the slide fastener or a thin upper stopper formed by crushing the fastener element at the start of sewing the concealed slide fastener, and the slide fastener is slipped out of the guide groove to thereby disturb the stability of sewing.

[0005] For example, Japanese Utility Model Application Laid-Open No. 5-74474 (patent document 2) discloses an upper feed unit of a sewing machine, comprising urging means for urging upper feed teeth toward a needle plate and pressure adjusting means for adjusting a nipping pressure between the upper and lower feed teeth by adjusting an urging force of the urging means in order to realize a secure nipping pressure and feeding force for a sewing object product.

[0006] According to the upper feed unit of the sewing machine described in Patent Document 2, the secure nipping pressure and the feeding force for the sewing object product can be applied, and changes in thickness of the sewing object product can be followed up excellently. As a consequence, an excellent quality sewed product without any faults such as sewing deflection or damage on the fabric can be obtained.

Patent Document 1: Japanese Patent Application Laid-Open No. 54-54462

Patent Document 2: Japanese Utility Model Application Laid-open No. 5-74474

Disclosure of the Invention

Problems to be Solved by the Invention

[0007] In sewing a slide fastener to a fabric, its fastener tape and sewing portion of the fabric are overlapped with each other, and the overlapped sewing object product is fed to a needle descending position to sew them together. However, if the fastener tape is sewed to a thick sewing object product such as thick fabric or leather including an automotive seat by using the sewing machine foot described in Patent Document 1, the fabric and the fastener tape cannot be fed up to the needle descending position securely because the fabric is thick, so that the positions of the fabric and fastener tape deflect. Consequently, there may occur a fault that the seam or the position of the sewing line is not stabilized, and this proposal can be inappropriate as a sewing machine foot for a thick fabric.

[0008] Particularly, when a so-called concealed slide fastener for concealing an element row of a fastener or a seam is sewed, a gap occurs between edges of right and left element attaching edge portions bent to a U-shape when the fastener elements after sewed are coupled with each other. Thus, a strict management for sewing together by narrowing an interval between the fastener element row and the sewing line as much as possible to avoid exposure of the fastener elements outside is needed. However, the sewing machine foot described in Patent Document 1 is intended for mainly a thin fabric. For this reason, strict management of the interval between the fastener element row and the sewing line may be difficult when a portion whose fabric thickness changes like in sewing of a curved portion or overlapped portion of fabrics, and this point needs to be improved in order to sew together the thick fabrics.

[0009] As a method for sewing a thick fabric, a vertical feeding method of feeding a fabric by actuating a sewing machine foot, an outside press and lower feed teeth in a composite way is available. However, in the case of the feedingmethod, the sewing machine foot, the outside press and the lower feed teeth leave fabric temporarily when feeding the fabric. For this reason, the element row of the fastener cannot be guided by the guide groove continuously, and thus, the interval between the element row of the fastener and the sewing line cannot be managed strictly.

[0010] The present invention has been achieved to solve problems possessed by the prior art, and an object of the present invention is to provide a sewing machine foot in which a fabric is pressed at a predetermined pressing force when a sewing needle pierces, and the pressing force at the time of piercing is released when a seam is formed for forming the seam by raising the sewing needle to move the fabric relatively, the sewing machine foot being capable of guiding an element row of a slide fastener securely into an element guide groove both at the time of piercing and at the time of formation of the seam even in a concealed slide fastener, and a sewing machine provided with the sewing machine foot.

Means for Solving the Problems

[0011] A first basic structure of the sewing machine foot of the present invention in order to achieve the above-described object is a sewing machine foot comprising: a foot mounting portion for fixing to a pressing rod of a sewing machine; a pressing portion which moves up/down together with the foot mounting portion to press a sewing object product when a sewing needle pierces; and an element guide groove which moves up/down interlocking with the foot mounting portion to guide the element row of the slide fastener with the element row inserted therein, the sewing machine foot further comprising: a swing arm which has the element guide groove and is supported by the foot mounting portion swingablly relative to the foot mounting portion so as to swing in a vertical plane parallel to a sewing line at the time of sewing; and urging means disposed between the foot mounting portion and the swing arm, for urging the swing arm to the sewing object product relative to the foot mounting portion, in order to maintain an interval between the element row and the sewing line of the slide fastener.

[0012] The sewing machine foot of the present invention is characterized in that the urging means urges the swing arm to the sewing object product, whereby part of the element guide groove guides part of the element row even if the sewing machine foot is located at any position of an upper position and a lower position.

[0013] Under such a structure, preferably, the element guide groove in the sewing machine foot is constructed to include a groove which has parallel side faces erected such that it is open to the sewing object product. Further, in case of sewing a concealed slide fastener, preferably, the opening of the element guide groove has an element inverting portion which erects an element row of the concealed slide fastener and inverts the element attaching edge formed to be bent to a U-shape up to an angle of over 90 degrees, the element inverting portion being provided at an opening end of the element guide groove.

[0014] Preferably, the pressing portion is formed in part of the swing arm, and further, the sewing machine is preferred to comprise a needle hole through which the sewing needle is to be passed, the needle hole being provided in the pressing portion, and an element escaping portion for avoiding fitting of the element row thereto, the element escaping portion being provided in the element guide groove on the rear side of a sewing portion relative to the needle hole.

[0015] With the above-described structure, preferably, the sewing machine foot of the invention further comprises a sliding face which makes contact with the surface of the sewing object product when the foot mounting portion is raised and the swing arm is rotated in the direction of the sewing object product by an operation of the urging means, the sliding face being provided in a front portion of the swing arm. Further, preferably, the sewing machine foot further comprises a tilted surface which is tilted upward relative to the bottom face of the swing arm at the front end of the sliding face, and an element inverting portion is preferred to be formed in the side face of the sliding face in the forward tilted portion. Further, the width of the sliding face is preferably set smaller than that of the pressing portion. A rearward tilted portion which executes a motion of riding on the sewing object product is preferred to be provided at the rear end of the pressing portion of the sewing machine foot. Additionally, the urging means for urging the swing arm to the sewing object product relative to the foot mounting portion may be constituted of an elastic material composed of a compression spring, a leaf spring or the like.

[0016] A second basic structure of the present invention is a sewing machine including a sewing machine foot comprising: a foot mounting portion for fixing to a pressing rod of a sewing machine; a pressing portion which moves up/down together with the foot mounting portion to press a sewing object product when a sewing needle pierces; and an element guide groove which moves up/down interlocking with the foot mounting portion to guide the element row of the slide fastener with the element row inserted therein, the sewing machine foot further comprising: a swing arm which has the element guide groove and is supported by the foot mounting portion swingablly relative to the foot mounting portion so as to swing in a vertical plane parallel to a sewing line at the time of sewing; and urging means disposed between the foot mounting portion and the swing arm, for urging the swing arm to the sewing object product relative to the foot mounting portion, in order to maintain an interval between the element row and the sewing line of the slide fastener.

Effects of the Invention

[0017] The sewing machine foot of the present invention has the first basic structure. For this reason, when a sewing needle for sewing according to the so-called synthetic feeding method of driving a sewing needle through fabric nipped by the lower feed teeth and the pressing portion of the sewing machine foot while feeding the fabric at the same time goes through the fabric, the element row is guided into the element guide groove of the sewing machine foot, so that an interval thereof relative to the sewing needle is set to drive the sewing needle through. When forming a feed portion of a seam, an operation of fixing the fabric on the sewing machine side by nipping with the outside press and the needle plate and setting the sewing needle, the lower feed teeth and the pressing portion of the sewing machine foot apart from the fabric is carried out conventionally. However, according to the present invention, the swing arm is tilted downward in a forward direction even when the mounting portion of the sewing machine foot is raised, so that at least part of the element guide groove can be kept in contact with the element row of the fastener. When the pressing rod is descended after that, a fault that the element row slips out of the element guide groove and is crushed by the pressing portion can be prevented. Therefore, even if the pressing rod is at any position, that is, raised at the time of sewing or descended, the element row of the fastener is guided still by at least part of the element guide groove to maintain the interval between the sewing line and the element row of the fastener. Thus, the element row can be guided continuously by the element guide groove even by the synthetic feeding method in which the sewing machine foot is raised and descended. Consequently, even when a fastener is sewed to a thick fabric, a place near a coupling head of the fastener element can be sewed stably, thereby preventing disturbance of sewing.

[0018] When the sewing needle is driven through in sewing according to the so-called vertical feeding method of driving a sewing needle through fabric nipped with the needle plate and the pressing portion of the sewing machine foot to fix the fabric to the sewing machine main body, a substantially entire surface of the element guide groove of the sewing machine foot makes contact with the element row of the fastener to set an interval relative to the sewing needle when the sewing needle pierces the fabric. When forming a feed portion of a seam, an operation of setting the sewing needle and the pressing portion of the sewing machine foot apart from the fabric while feeding the fabric by nipping it with the outside press and the lower feed teeth is carried out. In this case, even if the mounting portion of the sewing machine foot leaves the fabric interlocking with the sewing needle, the swing arm is tilted downward in the forward direction. Consequently, the element row can be kept to be fitted to the element guide groove. Thus, even when the feed portion of the seam is formed, the element guide groove still guides the element row, so that the element row never slips out of the element guide groove, and the interval between a sewing position and the element row can be determined. Therefore, the element row can be still guided by the element guide groove despite the vertical feeding method in which the sewing machine foot is raised and descended. Consequently, even if the fastener is sewed to a thick fabric, a place near the engaging head portion of the fastener element can be sewed stably, thereby preventing disturbance of sewing.

[0019] By forming the element guide groove having parallel side faces open to the sewing object product as an element guide groove in the sewing machine foot, the element row can be guided through the guide groove with a predetermined shape, thereby making it possible to specify the interval between a sewing position and the element row. Further, in case of a concealed slide fastener formed in a U-shape , because of provision of the element inverting portion at the opening end of the element guide groove, the element row is erected so that the element attaching edge portion of the fastener tape formed to be bent to the U-shape is inverted up to an angle of over 90 degrees. Consequently, the fastener tape of the concealed slide fastener difficult to sew together can be positioned accurately to even a thick fabric and sewed together.

[0020] The element escaping portion for avoiding fitting of the element row thereto is formed on the rear side of the sewing portion relative to the sewing needle through which the sewing needle is passed. Accordingly, the element row after sewed can be released from the element guide groove to facilitate sewing of a curved portion even if the pressing portion is formed in part of the swing arm. Therefore, even if the fastener tape is sewed to a thick fabric along the curved line, it can be sewed easily and accurately.

[0021] The front portion of the swing arm has the sliding face which makes contact with the surface of the sewing object product when the swing arm is rotated in a direction to the sewing object product by an operation of the urging means after the pressing force at the time when the needle is driven through is released. For this reason, sliding between the element row and the element guide groove when the feed portion of the seam is formed is improved, thereby preventing disturbance of sewing pitch and bend of the seam. Further, the tilted surface which is tilted upward relative to the bottom face of the swing arm is possessed and the forward tilted portion which executes a motion of riding on the sewing object product is provided at the front end of the sliding face. Therefore, the fabric is fed securely even if the thickness of the sewing object product is increasedhalfway, thereby preventing disturbance of sewing. Because the element inverting portion is formed, part of the element guide groove continues to guide the element guide even when the feed portion of the seam is formed, so that the element row never slips out of the element guide groove when the sewing machine foot is raised. Thereby, an interval between a sewing position and the element row is determined accurately at the time of sewing with the sewing machine foot descended. By setting the width of the sliding face smaller than the width of the pressing portion so as to avoid interference with the needle plate of the sewing machine or the lower feed teeth, the sliding face can be prevented from being damaged. Therefore, disturbance of sewing due to damage of the sliding face can be prevented.

[0022] By providing the rearward tilted portion which executes a motion of riding on the sewing object product at the rear end of the pressing portion of the sewing machine foot, the fabric can be fed to the pressing portion smoothly even if the fabric is sewed by a retracting operation. The sewing by retracting operation can be carried out without being caught even if fabrics having different thicknesses are sewed together. If an elastic material such as a compression spring or a leaf spring is adopted as urging means for urging the swing arm to the sewing object product relative to the foot mounting portion, a mechanism which fits the element guide groove to the element row can be constructed in a compact configuration.

[0023] When the sewing machine foot of the present invention having the pivot shaft which supports the swing arm including the element guide groove swingablly in a vertical plane parallel to a sewing line and the urging means for urging the element guide groove to the sewing object product is applied to the sewing machine, a substantially entire surface of the element guide groove in the sewing machine makes contact with the element row when the sewing needle pierces, so that the sewing needle can be driven through while determining an interval relative to the sewing needle. When the pressing portion of the sewing machine foot is set apart from the fabric and moved relative to the fabric in order to form the feed portion of the seam, the swing arm swings downward in the forward direction to keep the element guide groove in contact with the element row. Therefore, when the feed portion of the seam is formed, the element guide groove continues to guide the element row, thereby determining the interval between the sewing position and the element row. Thus, even when a thick fabric or fastener is sewed, disturbance of sewing can be prevented.

Brief Description of the Drawings

[0024] 

[FIG. 1] It is a perspective view of a portion near a needle descending position in a sewing machine provided with a sewing machine foot according to a first embodiment of the present invention.

[FIG. 2] It is an exploded perspective view of the sewing machine foot according to the first embodiment of the invention.

[FIG. 3] It is a sectional view of the portion near the needle descending position in a state in which a sewing needle and the sewing machine foot are descended.

[FIG. 4] It is a sectional view of the portion near the needle descending position in a state in which the sewing needle and sewing machine foot are ascended.

[FIG. 5] It is a view showing a V-V section of the section near the needle descending position shown in FIG. 3.

[FIG. 6] It is a view showing a section of the portion near the needle descending position when an ordinary slide fastener is sewed to a fabric.

[FIG. 7] It is a view showing a state in which the slide fastener shown in FIG. 6 is sewed to a thick fabric and the fabric is folded back around a sewed portion to produce another sewed portion.

[FIG. 8] It is a table showing a timing of a synthetic feeding method of feeding the fabric by actuating the sewing machine foot, an outside press, the sewing needle and lower feed teeth in a composite way.

[FIG. 9] It is a table showing a timing of a vertical feeding method of feeding the fabric by actuating the outside press and the lower feed teeth.

[FIG. 10] It is a timing chart schematically indicating vertical motion and back/forth motion of the respective components with the abscissa axis set as an angle of a spindle about the timing of the synthetic feeding method shown in FIG. 8.

[FIG. 11] It is a timing chart schematically indicating vertical motion and back/forth motion of the respective components with the abscissa axis set as an angle of a spindle about the timing of the vertical feeding method shown in FIG. 9.

[FIG. 12] It is an exploded perspective view of a sewing machine foot according to a second embodiment of the present invention, including a forward tilted portion in which the front end of the sewing machine foot is tilted upward and a rearward tilted portion in which the rear end is tilted upward.

[FIG. 13] It is a perspective view of the sewing machine foot shown in FIG. 12 as seen from below.

[FIG. 14] It is a sectional view of a portion near a sewing needle descending position in which with a foot mounting portion raised, a sliding face slides on the surface of a slide fastener to form a feed portion of a seam.

[FIG. 15] It is a view of the sewing machine foot as seen from forward of a sewing line or a view showing a section taken along XV-XV in FIG. 14.

[FIG. 16] It is a sectional view of a swing arm of the sewing machine foot taken along XVI-XVI in FIG. 14.

[FIG. 17] It is an exploded perspective view of a sewing machine foot according to a third embodiment of the present invention, including a rotatable swing head at the front end of the swing arm.

[FIG. 18] It is a side view of the sewing machine foot as seen from sideway of a sewing line, the view indicating sections of a slide fastener, fabric, needle plate and lower feed teeth. [FIG. 19] It is a perspective view showing a fourth embodiment of the present invention, including a rotatable roller head at the front end of a swing arm.

Explanation of Reference Numerals

[0025] 

6:

fabric

8,

108: slide fastener

9,

109: element row

10:

sewing unit

12:

sewing needle

14:

pressing rod

16:

outside press

22:

intermediate press

24:

upper pressing unit

26:

needle plate

28:

sewing line

40,

140, 240, 340, 440: sewing machine foot

42,

142, 242, 342, 386, 486: element guide groove

43:

mounting hole

44:

foot mounting portion

45:

mounting screw

46,

246, 346, 446: pressing portion

47,

147, 247, 347, 447: swing arm

48:

needle hole

50,

382, 482: pivot shaft

53:

bearing

54:

bearing

56:

spring seat

52:

compression spring

57:

rear stopper

58:

lower feed teeth

59:

front stopper

60,

260, 360: sliding face

128,

129: sewed portion

262:

tilted surface

263:

forward tilted portion

264:

rearward tilted portion

270:

element escaping portion

380:

swing head

383,

384: bearing

480:

roller head

B:

interval

E:

distance

H1,

H2, H3: length

L:

feeding direction of fabric

Best Mode for Carrying Out the Invention

[0026] Hereinafter, typical embodiments of a sewing machine foot according to the present invention will be described specifically with reference to the accompanying drawings. In the following embodiments, two drive systems, i.e., synthetic feed in which a sewing machine foot and a sewing needle reciprocate in a sewing direction while moving up/down and an outside press moves up/down, and up/down feed in which a sewing machine foot and a sewing needle move up/down and an outside press moves up/down while reciprocating in a sewing direction will be described as required because the structures of the sewing machine foot, sewing needle and outside press are substantially the same.

[0027] FIG. 1 is a perspective view of a portion near a needle descending position in a sewing machine provided with a sewing machine foot according to a first embodiment of the present invention. This embodiment shows a specific example of sewing a concealed slide fastener 8 (sewing object product) to a thick fabric 6 (sewing object product) by using the sewing machine. The fabric 6 is, for example, fabric for an automobile seat or thick fabric such as leather. One end of the concealed slide fastener 8 is inverted into a U-shape, and a coil-like element row 9 is sewed to a side edge portion of the fastener tape inverted into the U-shape. In the embodiment shown in FIG. 1, representation of a sewing thread for use upon sewing is omitted.

[0028] A sewing unit 10 of the sewing machine shown in FIG. 1 comprises a pressing rod 14 which moves vertically interlocking with back/forth and up/down movements of a sewing needle 12, a sewing machine foot 40 which is fixed to the pressing rod 14 and makes contact with a sewing object product ahead of the sewing needle 12 to press the sewing object product when the sewing needle 12 pierces, and an outside press 16 which moves vertically substantially in an opposite direction to the movement of the sewing needle 12 or the sewing machine foot 40 to press the sewing object product when a seam is formed with the sewing object product not pressed by the sewing machine foot 40. As shown in FIG. 1, the pressing rod 14 and the sewing machine foot 40 constitute an intermediate press 22 which presses around a pierced portion of the sewing object product. The intermediate press 22 and the outside press 16 constitute a piercing portion which allows the sewing needle to needle by moving up and down alternately and an upper pressing unit 24 for forming a seam. A needle plate 26 which nips the sewing object product and has a hole for allowing the sewing needle 12 to pass therethrough and an opening which allows a lower feeding unit (not shown) to project out so as to nip the sewing object product from below is provided below the upper pressing unit 24.

[0029] FIG. 2 is an exploded perspective view of the sewing machine foot 40 of the present invention. As shown in FIG. 2, the sewing machine foot 40 includes: a foot mounting portion 44 for fixing the sewing machine foot 40 to the pressing rod 14 by inserting the sewingmachine foot 40 into an attachinghole 43 to the pressing rod 14 of the sewing machine and tightening a split clamp by turning a mounting screw 45; a pressing portion 46 for pressing the sewing object product with a predetermined pressing force for piercing when the sewing needle 12 pierces; an element guide groove 42 for guiding a passage of the element row 9 of the slide fastener; a pivot shaft 50 which supports a swing arm 47 vertically to the foot mounting portion 44, that is, supports the swing arm swingablly in a plane parallel to and perpendicular to a sewing line 28; and a compression spring 52 (urging means) for urging the element guide groove 42 against the sewing object product. An opening for introducing the element row 9 of the concealed fastener into the element guide groove 42 includes an element inverting portion which erects the element row 9 bent to the U-shape and inverts it up to an angle over 90 degrees. Although in the embodiment shown in FIG. 2, the element guide groove 42 is provided in the swing arm 47 while the needle hole 48 which allows the sewing needle 12 to pass therethrough and the pressing portion 46 are formed, the pressing portion 46 may be provided on the foot mounting portion 44 which does not swing.

[0030] Assuming that an upstream of the fabric feeding direction is forward and a downstream thereof is rearward, a bearing 53 and a bearing 54 for supporting the pivot shaft 50 are provided in the upper portion at the rear end of the swing arm 47 and in the lower portion at the rear end of the foot mounting portion 44, respectively. By constructing the sewing machine foot 40 in this way, the swing arm 47 can swing freely around the pivot shaft 50 relative to the foot mounting portion 44. The needle hole 48 which penetrates the swing arm 47 in a vertical direction is formed in an intermediate portion between the front end and rear end of the swing arm 47, and further, the compression spring 52 (urgingmeans) is installed in a spring seat 56 provided between the needle hole 48 and the pivot shaft 50. The compression spring 52 is disposed between the face on the bottom side of the rear end of the foot mounting portion 44 and the top face of the swing arm 47 to urge the swing arm 47 downward, so that the swing arm 47 having the element guide groove 42 is rotated around the pivot shaft 50 even if the foot mounting portion 44 is lifted up. As a consequence, the opening of the element guide groove 42 can be kept into contact with the element row 9. This can prevent the element row 9 from slipping out of the element guide groove 42 and being crushed by the pressing portion 46 when the pressing rod 14 descends. Therefore, even if the pressing rod 14 is ascended or the pressing rod 14 is descended, the element guide groove 42 continues to guide the element row 9 of the fastener to maintain an interval between a sewing position and the element row 9 of the fastener.

[0031] Although in the embodiment shown in FIG. 2, the compression spring 52 is indicated as urging means for urging the element guide groove 42 against the sewing object product, a tensile spring, leaf spring, resin and other elastic material may be used instead of the compression spring 52. By providing urging means such as the compression spring 52 in a range between the needle hole 48 and the pivot shaft 50 as shown in FIG. 2, a mechanism which continues engagement of the element row 9 with the element guide groove 42 can be constructed.

[0032] Next, movement of the sewing machine foot 40 upon sewing the fabric 6 with the concealed slide fastener 8 will be described with reference to FIGS. 3 and 4.
FIG. 3 is a sectional view of the portion near the needle descending position when the sewing needle 12 and the sewing machine foot 40 are descended. FIG. 4 is a sectional view of the portion near the needle descending position when the sewing needle 12 and the sewing machine foot 40 are ascended. The embodiments shown in FIGS. 3 and 4 concern a sewing method using a synthetic feeding method by activating the sewing machine foot 40, the outside press 16, the sewing needle 12 and lower feed teeth 58 in a composite way. The components already described in FIGS. 1 and 2 are represented with like reference numerals, and description thereof is omitted.

[0033] When the fabric 6 and the concealed slide fastener 8 are sewed together according to the synthetic feeding method using the sewingmachine as shown in FIG. 1, the concealed slide fastener 8 is set on a fabric surface F at the folded-back edge portion which is a sewing object product part of the fabric 6. With the element row 9 of the concealed slide fastener 8 passed through the element guide groove 42, sewing is started by rotating a spindle of the sewing machine. Then, at the same time when the pressing rod 14 descends to the side of a sewing object product, the lower feed teeth 58 rises, so that the sewing machine foot 40 and the lower feed teeth 58 nip the slide fastener 8 and the fabric 6 under a predetermined pressing force from above and below. Thereafter, the sewing needle 12 is descended to form a seam as shown in FIG. 3.

[0034] The embodiment shown in FIG. 3 shows a sewing method by synthetic feeding, indicating a state in which the sewing needle 12 pierces with the sewing object product nipped by the sewing machine foot 40 and the lower feed teeth 58, the fabric 6 is fed by moving the sewing machine foot 40, the lower feed teeth 58 and the sewing needle 12. As shown in FIG. 3, front stoppers 59 (see FIG. 4) of the swing arm 47 come into contact with the foot mounting portion 44 to block the swing arm 47 from swinging further clockwise, so that the pressing portion 46 of the sewing machine foot 40 presses the sewing object product with a pressing force when the sewing needle pierces.

[0035] Next, when the spindle of the sewing machine is rotated by a drive source (not shown) from the state shown in FIG. 3, the sewing needle 12 rises to leave the slide fastener 8 and the fabric 6. Next, the pressing rod 14 is ascended to release the pressing force of the sewing machine foot 40. By descending the lower feed teeth 58 at the same time when the pressing rod 14 rises, the lower feed teeth 58 are set apart from the sewing object product. The outside press 16 is descended at the same time when the pressing force is released to nip the sewing object product with the needle plate 26. By forwarding the sewing machine foot 40, the lower feed teeth 58 and the sewing needle 12, set apart from the sewing object product, in a direction indicated with M, the sewing machine foot 40 and the sewing object product are moved relatively to each other so as to feed the seam. A state for forming the seam at this time is a state shown in FIG. 4.

[0036] In a state in which the sewing needle 12 is set apart from the sewing object product as shown in FIG. 4, that is, the seam is being formed, the swing arm 47 is urged against the sewing object product with a force of the compression spring 52. Because the swing arm 47 is constructed to be freely rotatable around the pivot shaft 50 relative to the foot mounting portion 44, the swing arm 47 is kept in a forward tilting state. Then, a sliding face 60 provided on a front bottom face of the swing arm 47 moves in the direction of M shown in FIG. 4 while keeping contact with the surface of the sewing object product. Since the opening of the element guide groove 42 contains an element inverting portion for erecting the element row 9 formed to be bent to the U-shape and inverting it up to an angle of over 90 degrees throughout a length H1, the element row 9 of the concealed fastener can be erected even in a state in which the swing arm 47 is tilted forward as shown in FIG. 4. Even when the pressing rod 14 is descended so that the rear end side of the swing arm 47 comes into contact with the element row 9, the element row 9 is fitted again to the rear end side of the element guide groove 42 with the front end side of the element guide groove 42 set as a criterion. Thus, such a fault that the element row 9 difficult to sew together because it is formed into the U-shape may be caught by the pressing portion 46 which moves relative to the sewing object product can be blocked.

[0037] In the state shown in FIG. 4, a swing amount of the swing arm 47 is limited because the sliding face 60 makes contact with the sewing object product. Further, even if the foot mounting portion 44 is raised, the top face of the swing arm 47 is provided with a rear stopper 57 which comes into a contact with the bottom face of the foot mounting portion 44 in order to block the swing arm 47 from rotating counterclockwise more than a predetermined swing amount.

[0038] The pressing rod 14 is descended to the side of the sewing object product again from the state shown in FIG. 4, so that the sewing machine foot 40 presses the sewing object product at a pressing force. By ascending the outside press 16, the pressing force of the outside press 16 is released, so that the condition shown in FIG. 3 is regained to form the pierced portion. By repeating the series of operations, the sewing object product is fed in the direction of L to form the sewing line 28.

[0039]  Next, a sectional shape of the element guide groove 42 will be described with reference to FIG. 5. FIG. 5 is a view showing a section of the portion near the needle descending position shown in FIG. 3 taken along the line V-V.
As shown in FIG. 5, the element guiding groove 42 which is open to the sewing object product has parallel side faces A, A' which nip the element row 9 for guide. In the embodiment shown in FIG. 5, the element guide groove 42 specifies an interval B between a bending position for the element row 9 and a sewing position in order to sew the concealed slide fastener 8 to the thick fabric 6. The element guide groove 42 guides the element row 9 by nipping to stabilize the interval B between the sewing position and the element row 9, thereby preventing disturbance of sewing.

[0040] When the concealed slide fastener 8 is sewed to the fabric 6, the interval B between the bending position for the element row 9 and the sewing position is preferred to be as small as possible in order to prevent the element row 9 after sewed from being exposed outside. Further, this interval B is preferred to be stabilized. Thus, the element guide groove 42 shown in FIG. 5 guides the element row 9 of the concealed fastener with the element row inverted up to an angle of over 90 degrees, thereby reducing the interval B. In the meantime, preferably, an angle θ of the element guide groove 42 shown in FIG. 5 is about 80 degrees.

[0041] Next, another embodiment of the sectional shape of the element guide groove 42 will be described with reference to FIG. 6. FIG. 6 is a sectional view of the portion near the needle descending position, indicating the same portion as the section shown in FIG. 5. Although FIG. 5 shows the sewing machine foot 40 for sewing the concealed slide fastener 8 to the fabric 6, FIG. 6 shows a sectional shape of a sewing machine foot 140 for sewing an ordinary slide fastener 108 to the fabric 6.

[0042] As shown in FIG. 6, an element guide groove 142 in a swing arm 147 has parallel side faces C, C' to which an element row 109 of the ordinary slide fastener 108 is fit. In the embodiment shown in FIG. 6, the element guide groove 142 specifies an interval D between the element row 109 and a sewing position in order to sew the slide fastener 108 to the thick fabric 6. Because the element guide groove 142 guides the element row 109 by nipping in this way, the interval D between the sewing position and the element row 109 can be stabilized to prevent disturbance of sewing.

[0043] FIG. 7 shows a state in which the slide fastener 108 is sewed to the thick fabric 6 by using the swing arm 147 shown in FIG. 6.
FIG. 7 shows a state in which the slide fastener 108 is sewed to the thick fabric 6 through a sewed portion 128 by using the swing arm 147 shown in FIG. 6 and the fabric 6 is folded back around the sewed portion 128 and sewed together through a sewed portion 129. A bottom face in FIG. 7 is a front surface of the fabric 6 and an upper face is a rear surface of the fabric 6. Even if the fabric 6 is thick, a distance E between an end face of the element row 109 and the folded-back line of the fabric 6 can be arranged equally by sewing the slide fastener 108 to the fabric 6 by use of the swing arm 147 having the element guide groove 142.

[0044] Next, operations of the sewingmachine foot, outside press, sewing needle, and lower feed teeth in each of the vertical feed method and synthetic feed method will be described.
FIG. 8 is a table showing a timing of the synthetic feed method of feeding a fabric by actuating the sewing machine foot, the outside press, the sewing needle and the lower feed teeth. The respective feeding directions for ascent, descent, return and feed are directions shown in FIG. 4.

[0045] According to the synthetic feeding method as shown in FIG. 8, at the same time when the pressing rod 14 descends to the side of the sewing object product from the state shown in FIG. 4, the lower feed teeth 58 rises, so that the sewing machine foot 40 and the lower feed teeth 58 nip the slide fastener 8 and the fabric 6 from above and below at a pressing force.
Thereafter, the sewing needle 12 descends so as to form the pierced portion for the seam as shown in FIG. 3. At this time, the sewing machine foot 40, the lower feed teeth 58 and the sewing needle 12 are moved synchronously in the direction of L shown in FIG. 3 to feed the fabric.

[0046] Next, the sewing needle 12 is raised from the state shown in FIG. 3 and set apart from the slide fastener 8 and the fabric 6. Then, the pressing rod 14 is raised to release a pressing force by which the sewing machine foot 40 presses the sewing object product. At the same time when the pressing rod 14 rises, the lower feed teeth 58 descends and leaves the sewing object product. At the same timingwhen this pressing force is released, the outside press 16 is descended, so that the sewing object product is nipped together with the needle plate 26. By returning the sewing machine foot 40, the lower feed teeth 58 and the sewing needle 12 from a state apart from the sewing object product (forwarding in the direction of M), the sewing machine foot 40 and the sewing object product are moved relatively to each other to form a feed portion of the seam. A state which forms the feed portion of the seam is the state shown in FIG. 4, in which the sliding face 60 of the sewing machine foot 40 slides on the surface of the slide fastener 8. By repeating the series of operations, the sewing object product is fed to form the sewing line 28.

[0047] Next, operations of the sewing machine foot, the outside press, the sewing needle, and the lower feed teeth in the vertical feeding method will be described.
FIG. 9 is a table showing timings of the vertical feeding method of feeding the fabric by actuating the outside press and the lower feed teeth of the sewing machine foot, the outside press, the sewing needle and the lower feed teeth. In the meantime, the respective directions for ascent, descent, return and feed shown in the table are directions indicated in FIG. 4.

[0048] In the vertical feeding method as shown in FIG. 9, the lower feed teeth 58 are raised with the outside press 16 descended as shown in FIG. 4 to nip the slide fastener 8 and the fabric 6 from above and below. Next, the sewing machine foot 40 is raised, and with that state held, the outside press 16 and the lower feed teeth 58 are fed in the direction of L (rearward) to form the feed portion of the seam. The state at this time is a state in which the sliding face 60 of the sewing machine foot 40 is sliding on the surface of the slide fastener 8 as shown in FIG. 4.

[0049]  After the operation of feeding the sewing object product ends, the sewing machine foot 40 is descended to nip the slide fastener 8 and the fabric 6 together with the needle plate 26 at a pressing force. Next, at the same time when the outside press 16 is raised, the lower feed teeth 58 are descended and an operation of forwarding and then returning for a next feeding operation is started.

[0050] Next, the sewing needle 12 is descended to form the pierce portion for the seam. After the formation of the pierced portion ends, the sewing needle 12 is raised while the outside press 16 is descended. At the same time, the lower feed teeth 58 are raised to nip the slide fastener 8 and the fabric 6 from above and below, and then, the sewing machine foot 40 is raised to start the next feeding operation. By repeating the series of operations, the sewing object product is fed successively in the direction of L to form the sewing line 28.

[0051] FIG. 10 shows a timing chart schematically indicating the vertical motion and back/forth motion of the sewing machine foot, the outside press, the sewing needle, and the lower feed teeth with the abscissa axis set as an angle of the spindle based on the table about the timing of the synthetic feeding method shown in FIG. 8. FIG. 11 shows a timing chart schematically indicating the vertical motion and back/forth motion of the sewing machine foot, the outside press, the sewing needle and the lower feed teeth with the abscissa axis of the sewing machine set as an angle of the spindle based on the table about the timing of the vertical feeding method shown in FIG. 9. Because the contents shown in FIGS. 10 and 11 are identical to those shown in FIGS. 8 and 9, description thereof is omitted.

[0052] Next, another embodiment concerning the shape of the sewing machine foot will be described.
FIG. 12 is an exploded perspective view showing a sewing machine foot 240 according to a second embodiment of the present invention, including a forward tilted portion 263 in which a front end of the sewing machine foot 240 is tilted upward and a rearward tilted portion 264 in which a rear end thereof is tilted upward. FIG. 13 is a perspective view (view taken in the direction of XIII) of the sewing machine foot 240 shown in FIG. 12 as seen from below. Components having the same function as those shown in FIG. 2 are represented with like reference numerals, and description thereof is omitted.

[0053] As shown in FIG. 12, a swing arm 247 of the sewing machine foot 240 includes: a pressing portion 246 located on the bottom face of the swing arm 247, for pressing the sewing object product at a pressing force when the sewing needle 12 pierces; the forward tilted portion 263 which has a tilted surface 262 tilted upward in a forward direction relative to the pressing face of the pressing portion 246 and rides on the sewing object product when forward sewing is carried out on the sewing object product; and the rearward tilted portion 264 which rides on the sewing object product when the sewing object product is fed in a retraction direction. Further, the forward tilted portion 263 includes: a sliding face 260 which is projected from the front end portion of the swing arm 247 in a convex shape; and a tilting element guide groove 242 which is disposed on the side face of the sliding face 260 and in which the element row 9 is passed through for guiding. In the embodiment shown in FIG. 12, the tilted surface 262 which rides on the sewing object product is formed lower than the projected sliding face 260. Although this embodiment shows an example that the pressing face of the pressing portion 246 and the tilted surface 262 are constructed of a plane, the present invention is not restricted to the plane, and at least one of the pressing portion 246, the tilted surface 262, the sliding face 360 and the rearward tilted portion 264 may be constructed of a curved face. Further, the pressing portion 246, the tilted surface 262, the sliding face 360 and the rearward tilted portion 264 may be formed in a single curved face such that all of them are continuous, and the direction and degree of the curve may be determined appropriately.

[0054] As shown in FIG. 13, an element escaping portion 270 which is expanded in its width direction is provided at a place not interfering with the needle hole 48 on a rear side of the sewing portion relative to the needle hole 48 in the pressing portion 246 so as to avoid fitting of the element row 9 therein. In the embodiments shown in FIGS. 12 and 13, a width WS of the sliding face 260 tilted and projected from the front end portion of the swing arm 247 in a convex shape is set smaller than a width WP of the pressing portion 246.

[0055] Next, the operations of the forward tilted portion 263 and the rearward tilted portion 264 will be described with reference to FIG. 14.
FIG. 14 is a sectional view of the portion near the needle descending position, indicating a state in which with the sewing needle 12 and the foot mounting portion 44 of the sewing machine foot 240 raised, the sliding face 260 provided on the forward tilted portion 263 of the swing arm 247 slides on the surface of the slide fastener 8 to form the feed portion of the seam. In the meantime, like reference numerals are attached to the components described with FIGS. 4 and 12, and description thereof is omitted.

[0056] When the feed portion of the seam is formed as shown in FIG. 14, the compression spring 52 urges the swing arm 247 including the element guide groove 242 against the sewing object product. Because the swing arm 247 is constructed to be freely swingable around the pivot shaft 50 relative to the foot mounting portion 44, the swing arm 247 moves in the direction of M shown in FIG. 14 such that the swing arm 247 maintains a forward tilting state with the sliding face 260 provided on the front portion of the swing arm 247 kept in contact with the surface of the sewing object product.

[0057] In the embodiment shown in FIG. 14, the forward tilted portion 263 which executes an action of riding on the sewing object product is projected forward of the swing arm 247 when the forward sewing is carried out on the sewing object product. An opening of the element guide groove 242 for guiding the element row 9 by passing the element row therethrough is formed on the side face of the sliding face 260 at the front end of the swing arm 247. The forward tilted portion 263 having the tilted surface 262 which is tilted upward in a forward direction relative to the pressing face of the pressing portion 246 is projected forward of the swing arm 247, so that a length H2 including the element guide groove 242 and its introduction portion can be set long. This enables the element row 9 inverted into the U-shape of the concealed slide fastener 8 to be erected securely by guiding through a long distance, thereby preventing a fault that the element row 9 may be caught by the pressing portion 246. Further, after the slide fastener 8 is sewed on, another fabric may be sewed together.

[0058] Provision of the rearward tilted portion 264 which executes an action of riding on the sewing object product facilitates feeding of the fabric 6 to the pressing portion 246 even when the fabric is sewed together by a retracting operation. Even in case of sewing fabrics having different thicknesses, they can be sewed together by the retracting operation without being caught.

[0059] Next, the operation of the width WS of the sliding face 260 formed smaller than the width WP of the pressing portion 246 will be described with reference to FIG. 15.
FIG. 15 is a view of the sewing machine foot 240 as seen from forward of the sewing line, or a view showing sections of the slide fastener 8, the fabric 6 and the needle plate 26 in a portion where the slide fastener 8 and the sliding face 260 make contact with each other (sectional view taken along XV-XV in FIG. 14).

[0060] As shown in FIG. 15, by setting the width WS of the projected portion of the sliding face 260 smaller than the width WP of the pressing portion 246 or smaller than a through hole WN in the needle plate 26, it is possible to prevent such a fault that the surfaces of the sliding face 260 and the needle plate 26 may be damaged because the top faces of the sliding face 260 and the needle plate 26 rub each other through a relative motion even when neither slide fastener 8 nor fabric 6 exists between the swing arm 247 and the needle plate 26 like at idle feeding time, at a stage before the slide fastener 8 and the fabric 6 are sewed together or at a stage after sewing together of the slide fastener 8 and the fabric 6 ends. Therefore, sliding between the sliding face 260/the needle plate 26 and the sewing object product can be maintained in an excellent state in a long period to prevent disturbance of sewing.

[0061] Next, an operation of a case where the pressing portion 246 is formed in part of the swing arm 347 while the element escaping portion 270 is provided in the element guide groove 242 on the rear side of the sewing portion relative to the needle hole 48 in the pressing portion 246 will be described with reference to FIG. 16.
FIG. 16 is a sectional view of the swing arm 247 of the sewing machine foot 240 taken along the line XVI-XVI shown in FIG. 14.
As shown in FIG. 16, the element row 9 after sewed can be bent in the right and left direction by providing an element escaping portion 270 for avoiding fitting of the element row 9 thereto on the rear side of the sewing portion relative to the needle hole 48 through which the sewing needle 12 is passed. Even if the slide fastener 8 is sewed to the thick fabric 6 and further a curved section is sewed, a fault that the element row 9 may slip out of the element guide groove 42 can be blocked while sewing of the curved portion can be carried out easily. The element guide groove 42 having substantially the same width as that of the element row 9 is formed between the element escaping portion 270 and the needle hole 48 to block a direct interference between the needle hole 48 and the element escaping portion 270. With such a structure, stabilized sewing without deflection of a descending needle can be executed, and at the same time, the curved section can be sewed together by bending the element row 9 after sewing in the right and left direction.

[0062] Next, another embodiment of the swing arm of the sewing machine foot will be described with reference to FIG. 17. FIG. 17 is an exploded perspective view showing a third embodiment of the present invention in which a swing head 380 capable of rotating is further provided at the front end of the swing arm 347 constituting the sewing machine foot 340.
As shown in FIG. 17, the sewing machine foot 340 comprises: a foot mounting portion 44 for fixing to the pressing rod 14 of the sewing machine; a pressing portion 346 for pressing a sewing object product at a predetermined pressing force when the sewing needle 12 pierces; element guide grooves 342, 386 for guiding the element row 9 by passing the element row therethrough; a pivot shaft 50 which supports the swing arm 347 freely swingablly in a vertical plane parallel to the sewing line relative to the foot mounting portion 44; and a pivot shaft 382 which supports the swing head 380 freely swingablly in a vertical plane parallel to the sewing line relative to the swing arm 347. A bearing 383 and a bearing 384 which support the pivot shaft 382 are provided in the front end of the swing arm 347 and the rear end of the swing head 380, respectively. Like the embodiment shown in FIG. 2, a compression spring (not shown) which functions as urging means for urging the element guide groove 342 against the sewing object product is provided behind the needle hole 48 in the swing arm 347 and in front of the pivot shaft 50.

[0063] With such a structure of the sewing machine foot 340, the swing arm 347 can swing around the pivot shaft 50 relative to the foot mounting portion 44, and the swing head 380 can swing around the pivot shaft 382 relative to the swing arm 347.

[0064] Next, an operation of the sewing machine foot 340 provided with the rotatable swing head 380 at the front end of the swing arm 347 will be described with reference to FIG. 18.
FIG. 18 is a view of the sewing machine foot 340 as seen from sideway of the sewing line, or a side view with sectional views of the slide fastener 8, the fabric 6, the needle plate 26 and the lower feed teeth 58.
As shown in FIG. 18, element guide grooves 386, 342 for guiding the element row 9 by passing the element row therethrough are formed in the sliding face 360 of the swing head 380 and part of the swing arm 347.

[0065] When the feed portion of the seam is formed with the foot mounting portion 44 raised, the swing arm 347 is urged by a compression spring (not shown) in the direction of the sewing object product. Because the swing arm 347 is constructed to be swingable around the pivot shaft 50 relative to the foot mounting portion 44, the swing arm 347 is moved in the direction of M shown in FIG. 18 while maintaining the forward tilted state.

[0066] Because the swing head 380 constructed to be rotatable around the pivot shaft 382 is provided at the front end of the swing arm 347, the sliding face 360 of the swing arm 380 is moved in the direction of M shown in FIG. 18 while keeping contact with the surface of the sewing object product. The element inverting portion which erects the element row 9 formed to be bent into the U-shape and inverts it up to an angle of over 90 degrees is provided throughout a length H3 in the opening of the element guide groove 386 formed in the sliding face 360 of the swing head 380. Consequently, even if the swing arm 347 is tilted forward as shown in FIG/ 18, the element row 9 of the concealed fastener can be erected effectively. Thus, the element row 9 formed into the U-shape can be erected effectively, thereby preventing such a fault that the element row 9 may be caught by the pressing portion 346 which moves relatively to the sewing object product. Then, even when the pressing rod 14 is descended, it is possible to prevent a fault that the element row may slip out of the element guide groove 342 and crushed by the pressing portion. Therefore, even if the concealed slide fastener 8 is sewed to the thick fabric 6, disturbance of sewing can be prevented.

[0067] Next, another embodiment of the swing arm of the sewing machine foot will be described with reference to FIG. 19. FIG. 19 is a perspective view showing a fourth embodiment of the present invention in which a rotatable roller head 480 is provided at the front end of the swing arm 447 constituting the sewing machine foot 440.

[0068] As shown in FIG. 19, the sewing machine foot 440 comprises: the foot mounting portion 44 for fixing to the pressing rod 14 of the sewing machine; a pressing portion 446 which presses a sewing object product at a predetermined pressing force when the sewing needle 12 pierces; an element guide groove 486 for guiding the element row of the slide fastener by passing the element row therethrough; the pivot shaft 50 which supports the swing arm 47 swingablly in a plane parallel to the sewing line relative to the foot mounting portion 44; and a pivot shaft 482 which supports the roller head 480 rotatably in a plane parallel to the sewing line relative to the swing arm 447. Like the embodiment shown in FIG. 2, a compression spring (not shown) which functions as urging means for urging the element guide groove 486 against the sewing object product is provided behind the needle hole 48 in the swing arm 447 and in front of the pivot shaft 50.

[0069] With such a structure of the sewing machine foot 440, the swing arm 447 can swing around the pivot shaft 50 relative to the foot mounting portion 44, and the roller head 480 can be rotated relative to the swing arm 447.

[0070] Next, an operation of the embodiment having the rotatable roller head 480 at the front end of the swing arm 447 will be described.
The circumferential face of the roller head 480 shown in FIG. 19 always makes contact with the fastener tape surface of the slide fastener 8 before sewing, so that when the feed portion of the seam is formed, the roller head 480 rolls on the slide fastener 8. The element guide groove 486 is formed in the circumferential face of the roller head 480, and the element guide groove 486 erects and inverts the element row 9 formed to be bent into the U-shape. Consequently, even if the swing arm 447 is tilted forward or the sewing object product is pressed at the pressing force, the element row 9 of the concealed fastener can be erected.

[0071] In the meantime, the present invention is not limited to the above-described embodiments but needless to say, may be modified in various ways within the scope of the claims of the invention. For example, the element escaping portion 270 may be formed in the element guide groove 42 of the first embodiment, or the tilted surface 262 may be formed entirely flat.

Industrial Applicability

[0072] By using a sewing machine foot of the present invention, a concealed slide fastener can be sewed to a thick material such as fabric and leather.

Claims

1. A sewing machine foot (40) comprising:

a foot mounting portion (44) for fixing to a pressing rod (14) of a sewing machine;

a pressing portion (46) which moves up/down together with the foot mounting portion (44) to press a sewing object product when a sewing needle (12) pierces; and

an element guide groove (42) which moves up/down interlocking with the foot mounting portion (44) to guide an element row (9) of a slide fastener (8) with the element row inserted therein, the sewing machine foot characterized by further comprising:

a swing arm (47) which has the element guide groove (42) and is supported by the foot mounting portion (44) swingablly relative to the foot mounting portion (44) to swing in a vertical plane parallel to a sewing line (28) at the time of sewing; and

urging means (52) disposed between the foot mounting portion (44) and the swing arm (47), for urging the swing arm (47) to the sewing object product relative to the foot mounting portion (44).

2. The sewing machine foot according to claim 1, characterized in that the urging means (52) urges the swing arm (47) to the sewing object product, whereby part of the element guide groove (42) guides part of the element row (9) even if the sewing machine foot (40) is located at any position of an upper position and a lower position.

3. The sewing machine foot according to claim 1, characterized in that the element guide groove (42) has parallel side faces open to the sewing object product.

4. The sewing machine foot according to claim 3, characterized in that an opening of the element guide groove (42) has an element inverting portion which erects an element attaching edge portion of a concealed fastener formed to be bent to a U-shape and inverts the element attaching edge portion up to an angle of over 90 degrees.

5. The sewing machine foot according to any one of claims 1 to 4, characterized in that the pressing portion (46) is formed in part of the swing arm (47).

6. The sewing machine foot according to claim 5, characterized by further comprising:

a needle hole (48) through which the sewing needle (12) is to be passed, the needle hole being provided in the pressing portion, and

an element escaping portion (270) for avoiding fitting of the element row (9) thereto is provided in the element guide groove (242) on a rear side of a sewing portion relative to the needle hole (48).

7. The sewing machine foot according to any one of claims 1 to 4, characterized by further comprising:

a tilted surface (262) which is tilted upward relative to a bottom face of the swing arm (47) at the front end of the swing arm (47); and

a forward tilted portion (263) which executes a motion of riding on the sewing object product.

8. The sewing machine foot according to claim 7, characterized in that
a sliding face (60), which makes contact with the surface of the sewing object product when the foot mounting portion (44) is raised and the swing arm (47) is rotated in a direction of the sewing object product by an operation of the urging means (52), is provided in a front portion of the swing arm (47), and
the width of the sliding face (260) is set smaller than the width of the pressing portion (246).

9. The sewing machine foot according to any one of claims 1 to 4, characterized in that
a rearward tilted portion (264) which executes a motion of riding on the sewing object product is provided at a rear end of the pressing portion (246).

10. The sewing machine foot according to any one of claims 1 to 4, characterized by further comprising an elastic material composed of a compression spring (52), a leaf spring or the like as the urging means (52).

11. A sewing machine characterized by including a sewing machine foot (40) comprising:

a foot mounting portion (44) for fixing to a pressing rod (14) of a sewing machine;

a pressing portion (46) which moves up/down together with the foot mounting portion (44) to press a sewing object product when a sewing needle (12) pierces;

an element guide groove (42) which moves up/down interlocking with the foot mounting portion (44) to guide an element row (9) of a slide fastener (8) with the element row inserted therein;

a swing arm (47) which has the element guide groove (42) and is supported by the foot mounting portion (44) swingablly relative to the foot mounting portion (44) to swing in a vertical plane parallel to a sewing line (28) at the time of sewing; and

urging means (52) disposed between the foot mounting portion (44) and the swing arm (47), for urging the swing arm (47) to the sewing object product relative to the foot mounting portion (44).

Drawing