Patent Description:
Heretofore, there have been known sewing machines capable of sewing a string-shaped material, such as a tape or a cord, to a sewing workpiece by feeding the string-shaped material to a needle entry position while zigzag-swinging the string-shaped material. Patent Literatures <NUM> and <NUM> set forth below each disclose an embroidery sewing machine, according to the preamble of claim <NUM>, provided with an embroidery head capable of performing so-called zigzag stitching. In the embroidery sewing machine disclosed in Patent Literature <NUM>, a machine head includes: a needle bar that has a sewing needle provided on a lower end portion thereof and that is driven in an up-down direction; a fabric pressing member or presser foot that is driven in the up-down direction at predetermined timing in response to the up-and-down movement of the needle bar; a rotation member mounted concentrically with the needle bar and rotatable about the axis of the rotation member; and a guide member swingably mounted to the rotation member via a lever pin, and a string-shaped material supplied from a bobbin is passed through the guide member, which swings in a left-right direction (namely, in a lateral direction), to be fed to the needle entry position of the sewing needle. Further, in the embroidery sewing machine disclosed in Patent Literature <NUM>, a machine head is constructed in such a manner that a guide member is slid horizontally in a left-right direction along a guide rail via a swing member that is swingably mounted via a lever pin, and a string-shaped material supplied from a bobbin is passed through a guide member, which is moved horizontally, to be fed to a needle entry position of a sewing needle.

In the embroidery sewing machines provided with such machine heads, sewing-progressing directions relative to the sewing workpiece are calculated on the basis of predetermined sewing data and the string-shaped material is fed to the needle entry position of the sewing needle while being zigzag-swung in a predetermined pattern, by the guide member being swung in the left-right direction or horizontally moved while direction control is being performed on the rotation member in such a manner that the lever pin is always located ahead in the sewing-progressing directions. In this manner, the string-shaped material is sewn to the sewing workpiece through lock stitching with the needle bar and the presser foot driven in the up-down direction.

Further, in recent years, such sewing machines have been used for preform molding of a fiber-reinforced composite material, as well as for sewing a decorative string-shaped material to a sewing workpiece. Patent Literature <NUM> set forth below discloses an example of such preform molding. More particularly, Patent Literature <NUM> discloses a method for sewing a string-shaped material, formed of reinforcing fibers such as carbon fibers and glass fibers, to a sewing workpiece (base fabric) by use of an embroidery sewing machine constructed similarly to the aforementioned sewing machines provided with machine heads capable of performing zigzag stitching. The carbon fibers and glass fibers mainly used as the reinforcing fibers are forms of products called "tows", "rovings", and the like each formed generally as a bundle of one thousand to several tens of thousands thin single fibers that each have a diameter of a few microns and that are gathered together in a uniform direction. In the sewing machine disclosed in Patent Literature <NUM>, the tow (or roving) is wound on a small-sized bobbin pivoting around the needle bar or on a bobbin provided above the machine head, and such a tow (or roving) is passed through the guide member and then fed to the needle entry position of the sewing needle.

The conventionally known presser foot of the sewing machine functions to assist in achieving stabilized sewing by pressing an area of the sewing workpiece around a needle drop position during the sewing. Because a bottom portion of the conventionally known presser foot only has to have a size sufficient for performing the sewing-workpiece pressing function, the size of the bottom portion is not so large. However, when the string-shaped material is swung in the left-right direction by the guide member for zigzag stitching, the width over which the string-shaped material is swung leftward and rightward may exceed the size of the bottom portion of the presser foot. In such a case, the string-shaped material, swung in the left-right direction, positionally deviates from a string-shaped material covering area of the bottom portion of the presser foot in the left-right direction as viewed in plan view, and thus, the swung string-shaped material may interfere with (or catch on) the presser foot moving in the up-down direction. Normally, in a case where a stroke of the up-and-down movement of the presser foot is of an ordinary length (namely, relatively long), the guide member is swung leftward and rightward (in the lateral direction) at timing when the presser foot has been moved upward over a relatively long distance, and thus, the string-shaped material, such as a tow (long fiber bundle), leading from the guide member to the sewing workpiece (base fabric) will not interfere with (catch on) the presser foot. If the up-and-down movement stroke of the presser foot is made shorter, however, there can arise a problem of the string-shaped material interfering with (catching on) the presser foot. Namely, as the up-and-down movement stroke length of the presser foot is made shorter, the string-shaped material leading from the guide member to the base fabric may more easily positionally deviate from the bottom portion of the presser foot to go up off the bottom portion of the presser foot, and thus more easily catches on a side surface of the presser foot or an edge or the like of the bottom portion of the presser foot, when the string-shaped material is swung in the left-right direction.

Particularly, in order to prevent poor or defective thread tightening caused by flapping of the base fabric (namely, uplifting of the base fabric caused by an upper thread at the time of thread tightening) and improve thread tightening quality without increasing tension of the upper thread, it is desirable to reduce the up-and-down movement stroke of the presser foot as short as possible. However, if the up-and-down movement stroke of the presser foot is reduced, there can arise the problem of the string-shaped material interfering with (catching on) the presser foot, as noted above. Particularly, with a sewing machine employing the construction disclosed in Patent Literature <NUM>, when tows (long fiber bundles) are sewn to a base fabric in a plurality of layers, it is necessary to adjust in advance the guide member to a relatively high position in anticipation of a layered height of the tows with a view to avoiding the guide member from interfering with the layered tows. However, in such a case, a tilt angle of the tows (long fiber bundles) leading from the guide member to the base fabric becomes large (namely, the tows take a more upright posture), and thus, the problem of the tows catching on the presser foot becomes more serious. Patent Literature <NUM> discloses a sewing machine having double needles specialized for realizing a specific embroidering effect of looping a thread back and forth transversely and stitching down the thus formed loop securely to material. Other sewing machines for embroidering applications are known from Patent Literature <NUM> and Patent Literature <NUM>.

In view of the foregoing prior art problems, it is one of the objects of the present invention to provide a sewing machine that prevents a string-shaped material, swung in a lateral direction via a guide member, from catching on a nearby component part (particularly, a presser foot) of the sewing machine.

In order to accomplish the aforementioned object, the present invention provides a sewing machine according to claim <NUM>. Advantageous embodiments may be implemented according to any of the dependent claims.

According to the present invention, the laterally elongated section of the restriction member has a length corresponding to the range of reciprocating movement of the guide member. Therefore, when the guide member is reciprocatingly moved, a portion of the string-shaped material extending from the distal end of the guide member downward to the sewing position located below the distal end of the guide member can be reliably positioned (restricted) beneath the laterally elongated section (in such a manner that unwanted upward movement of the string-shaped material can be restricted or suppressed by the laterally elongated section). Thus, when the string-shaped material is swung in the lateral (left-right) direction, the string-shaped material can be prevented from catching on a nearby component part or portion (particularly, a presser foot, or a side surface or the like of the restriction member in a case where the restriction member itself functions also as the presser foot). Namely, even where an up-and-down movement stroke of the presser foot (or an up-and-down movement stroke of the restriction member in the case where the restriction member itself functions also as the presser foot) is small, the string-shaped material can be reliably restricted to be located beneath the laterally elongated section of the restriction member without positionally deviating from a string-shaped material covering area of the laterally elongated section, and hence, the string-shaped material can be reliably prevented from catching on the presser foot (or the restriction member).

<FIG> is a front view illustrating an embodiment of a sewing machine of the present invention, which more particularly illustrates one machine head H in the sewing machine of the present invention, and <FIG> is a partly broken-away side view of the machine head H illustrated in <FIG>. A plurality of such machine heads H, rather than just one machine head H, may be provided in the inventive sewing machine. A needle bar <NUM> is provided in the machine head H in such a manner that the axis of the needle bar <NUM> extends in an up-down direction (vertical direction). The needle bar <NUM> is reciprocatingly driven in the up-down direction by rotation of a main shaft <NUM> of the sewing machine. A sewing needle <NUM> is attached to a lower end portion of the needle bar <NUM>. A support cylinder <NUM> is mounted around the outer periphery of the needle bar <NUM>, and this support cylinder <NUM> is capable of moving up and down relative to the needle bar <NUM> and rotating about the axis of the needle bar <NUM> while being guided along the inner circumferential surface of a fixed sleeve <NUM> fixed to a lower portion of the machine head H. Further, an engaging ring <NUM> is fixed to the outer circumference of an upper end portion of the support cylinder <NUM>, and a drive arm <NUM> movable in the up-down direction by being driven by a motor <NUM> is held in engagement with the engaging ring <NUM>.

A support <NUM> is fixed to the lower end of the support cylinder <NUM>. The support <NUM> has a lower end section formed in a bifurcated shape, and a key groove <NUM> extending in the up-right direction is formed in an outer side surface of one of leg portions of the bifurcated lower end section of the support <NUM>. A rotation cylinder <NUM> is mounted on the outer circumference of the fixed sleeve <NUM>. The rotation cylinder <NUM> is mounted around and concentrically with the needle bar <NUM> and only rotatable about the axis of the needle bar <NUM>. A timing pulley section <NUM> is formed on the outer circumference of an upper end portion of the rotation cylinder <NUM>, and a timing belt <NUM> is wound on and extends between the timing pulley section <NUM> and a drive pulley <NUM> fixed to a rotation shaft <NUM> of a motor <NUM>. Thus, as the motor <NUM> is driven to rotate the drive pulley <NUM>, the rotation cylinder <NUM> is rotated via the timing belt <NUM> and the timing pulley section <NUM>. A key member <NUM> engaging with the key groove <NUM> of the support <NUM> is fixed to the lower end of the rotation cylinder <NUM>. With such arrangements, the support <NUM> not only moves up and down as the support cylinder <NUM> moves up and down but also rotates about the axis of the needle bar <NUM> as the rotation cylinder <NUM> rotates.

<FIG> is a somewhat enlarged perspective view illustrating a lower section of the machine head H of <FIG> and <FIG>. As clear also from <FIG> and <FIG>, an interlocking member <NUM> is fitted over the outer circumference of the rotation cylinder <NUM> in such a manner that the interlocking member <NUM> is movable in the up-down direction and rotatable. A connection piece <NUM> is fixed to the interlocking member <NUM> and held in engagement with an engaging groove 11a formed in the outer circumference of the rotation cylinder <NUM>. Thus, the interlocking member <NUM> is rotatable together with the rotation cylinder <NUM> as the rotation cylinder <NUM> rotates. Further, a swing lever <NUM> is mounted to the rotation cylinder <NUM> via a bracket <NUM>. The swing lever <NUM> is mounted in such a manner that the lever <NUM> is swingable, about a lever pin <NUM> mounted to an outer side surface of the bracket <NUM>, leftward and rightward of the axis of the needle bar <NUM> relative to the rotation cylinder <NUM>. The swing lever <NUM> has one arm portion 21a extending laterally from a portion adjoining the lever pin <NUM> and another arm portion 21b extending downward from the portion adjoining the lever pin <NUM>. A roller <NUM> is mounted to the distal end of the laterally extending arm portion 21a, and the roller <NUM> is held in engagement in a linking groove 19a of the connection piece <NUM>. A roller <NUM> is mounted to the distal end of the downwardly extending arm portion 21b.

A support member <NUM> having a generally U shape (or a generally U angle-like shape) as viewed in plan is fixed to the support <NUM>. The support <NUM> is coupled with one arm of the support member <NUM>, and a guide rail <NUM> is fixed to the other arm (located opposite from the one arm) of the support member <NUM>. Further, a restriction member <NUM> is mounted to a mounting portion of the support member <NUM> between the two arms, as described in detail later. A slider <NUM> is provided on the guide rail <NUM> in such a manner that the slider <NUM> is slidingly movable in the lateral direction. A guide member <NUM> is fixed to the slider <NUM> via a bracket <NUM> formed in a U shape. The guide member <NUM> is, for example, in the form of a plate spring and flexible in the up-down direction with a fixed portion of the guide member <NUM>, which is fixed to the bracket <NUM>, functioning as a flexibly bending base. The bracket <NUM> has a fitting groove <NUM> formed in its surface opposed to the swing lever <NUM>, and the roller <NUM> of the swing lever <NUM> is fitted in the fitting groove <NUM>. A guide tube 29a for passing therethrough the string-shaped material T to feed the string-shaped material T to a needle entry position (namely, a sewing position) of the sewing needle <NUM> is provided at the lower end of the guide member <NUM>. Further, a bobbin bracket <NUM> is fixed to an outer circumferential portion of the rotation cylinder <NUM> via the bracket <NUM> and an arm member <NUM>, and a bobbin <NUM> having the string-shaped material T wound thereon is rotatably supported on the bobbin bracket <NUM>. The string-shaped material T pulled out from the bobbin <NUM> is passed through the guide tube 29a to extend downward from the distal end of the guide tube 29a and is then placed on the base fabric (namely, the sewing workpiece) (not illustrated in the drawings) laid on a needle plate <NUM>.

As conventionally known, in embroidering sewing machines, an embroidery frame (not illustrated in the drawings) holding thereon a base fabric (sewing workpiece) is driven two-dimensionally per stitch in accordance with a desired sewing pattern. Thus, the base fabric (sewing workpiece) is moved relative to the machine head H. In order to sew the string-shaped material T to the base fabric (sewing workpiece) in accordance with the sewing pattern, the driving of the motor <NUM> is controlled in accordance with a sewing-progressing direction, the rotation cylinder <NUM> is rotated in response to the driving of the motor <NUM>, and the lever pin <NUM> is controlled to rotate around the needle bar <NUM> in such a manner as to be oriented in the sewing-progressing direction. Thus, the guide member <NUM> is controlled to rotate around the needle bar <NUM> in such a manner that the distal end of the guide member <NUM>, namely, the distal end of the guide tube 29a, is always oriented toward the center of the needle bar <NUM>. In this manner, the string-shaped material T extending out from the distal end of the guide member <NUM>, namely, from the distal end of the guide tube 29a, is directed or guided toward the sewing position (needle entry position). In this manner, the guide member <NUM> performs a function of guiding the string-shaped material T toward the sewing position, and the aforementioned elements <NUM>, <NUM>, <NUM>, etc. related to the string-shaped material guiding function as a device and/or a mechanism that controls a basic string-shaped material guiding direction of the guide member <NUM>.

A type, shape, etc. of the string-shaped material T are determined appropriately in accordance with a purpose of a sewn product that is to be finished by use of the inventive sewing machine. For example, in a case where a decorative string-shaped material T is to be sewn to a sewing workpiece (not illustrated in the drawings), a tape, a string, or a cord having a color, a size, and an outer shape (flat or somewhat round outer shape) suited for a desired decoration purpose is used as the string-shaped material T. Further, in a case where a tow (long fiber bundle) that functions as reinforcing fibers for preform molding of a fiber-reinforced composite material is to be sewn to a sewing workpiece (not illustrated), the tow that functions as reinforcing fibers is used as the string-shaped material T. In such a case, the string-shaped material T is formed of carbon fibers, glass fibers, aramid fibers, boron fibers, xyron fibers, and/or the like, as the reinforcing fibers for making the preform (interim product made by pre-processing the reinforcing fibers into a shape close to a shape of a molded product), and the string-shaped material T in this case is a long belt-shaped fiber bundle called "tow", "roving" or "filament". Alternatively, the string-shaped material T may be a composite material formed by half-impregnating a reinforcing fiber bundle with a resin, a composite material formed by combining carbon fibers and resin fibers (commingled yarn), or a fiber bundle formed by roving chemical fibers and/or the like into a belt shape. Note that the guide tube 29a in the illustrated example has an elongated rectangular cross-sectional shape and is suited for a wide, flat string-shaped material T (such as a flat tow material).

As illustrated in <FIG>, a guide shaft <NUM> is disposed adjoining the needle bar <NUM> in such a manner that the axis of the shaft <NUM> extends in the up-down direction. A lifting and lowering member <NUM> is mounted on the guide shaft <NUM>. The lifting and lowering member <NUM> is movable up and down along the axis of the guide shaft <NUM> while being guided by the shaft <NUM>, by rotational driving force of a zigzag swinging motor <NUM> being transmitted to the member <NUM> via a not-illustrated drive transmission mechanism. The lifting and lowering member <NUM> has a fork portion 35a projecting substantially horizontally toward the needle bar <NUM>, and this fork portion 35a is held in engagement with a groove portion 18a formed in the outer periphery of the interlocking member <NUM>. Thus, as the interlocking member <NUM> and the connection piece <NUM> move up and down in response to the up-and-down movement of the lifting and lowering member <NUM>, the up-and-down movement of the connection piece <NUM> is converted into swinging movement of the swing lever <NUM> via the linking groove 19a and the roller <NUM>. In response to the swinging movement of the swing lever <NUM>, the roller <NUM> of the arm portion 21b fitted in the fitting groove <NUM> of the bracket <NUM> also swings, so that the bracket <NUM> and the guide member <NUM> fixed to the slider <NUM> via the bracket <NUM> reciprocatingly move straight or linearly leftward and rightward (in the lateral direction) with respect to a sewing-progressing direction as the slider <NUM> slides along the guide rail <NUM>. Although the swinging movement (reciprocating movement) of the roller <NUM> contains some vertical component as well as a horizontal component, such a vertical component of the swinging movement of the roller <NUM> is not transmitted to the bracket <NUM> because the roller <NUM> is freely movable up and down along the fitting groove <NUM>. In this manner, only the horizontal component of the swinging movement of the roller <NUM> is transmitted to the bracket <NUM>, so that the guide member <NUM> is reciprocatingly moved linearly in the horizontal direction. It should be noted that in this description, the term "lateral direction" or "left-right direction" refers to a direction of the reciprocating movement of the guide member <NUM> (direction of reciprocating movement of the horizontal component).

As well known, the zigzag swinging motor <NUM> is driven to sew the string-shaped material T to the basic fabric (sewing workpiece) through zigzag swing stitching (zigzag stitching). Namely, although the sewing-progressing direction, in which the string-shaped material T is to be sewn to the basic fabric, is controlled via the aforementioned motor <NUM>, the sewing of the string-shaped material T through the zigzag swing stitching (zigzag stitching) is controlled via the zigzag swinging motor <NUM>. The aforementioned elements <NUM>, <NUM>, <NUM>, 35a, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, etc. together function to zigzag-swing the string-shaped material T; in other words, these elements together function as a reciprocation mechanism for reciprocatingly moving the guide member <NUM> in the lateral direction.

As illustrated in <FIG>, the restriction member <NUM> is provided close to the guide member <NUM>. More specifically, the restriction member <NUM> is mounted to the mounting portion between the two arms of the support member <NUM>. <FIG> is an enlarged perspective view of the restriction member <NUM>. The restriction member <NUM> includes a fixing section 38a having an elongated hole <NUM>, and the restriction member <NUM> is fixed to the mounting portion of the support member <NUM> by a screw inserted in the elongated hole <NUM>. The restriction member <NUM> also includes a support section 38b extending leftward from a lower portion of the fixing section 38a. The restriction member <NUM> further includes a restriction section 38c extending laterally at a position lower than the support section 38b. The restriction section 38c is formed as a laterally elongated section extending in the reciprocating movement direction of the guide member <NUM> (namely, in the lateral direction). As an example, the restriction section (namely, laterally elongated section) 38c is provided at the lower end of the restriction member <NUM> and constitutes a flat surface parallel to the upper surface of the needle plate <NUM>. Of course, the flat surface of the restriction section (namely, laterally elongated section) 38c need not necessarily be precisely flat and may have appropriate, slight unevenness. Note that in the illustrated example of <FIG>, a distal end portion of the restriction section 38c is somewhat curved upward in such a manner that the distal end portion can be prevented from catching on the base fabric or the like when the restriction section 38c is lowered to its lowest position.

<FIG> is a side view illustrating a positional relationship between the restriction section (laterally elongated section) 38c of the restriction member <NUM> and the guide member <NUM>. The restriction member <NUM> is disposed close to the guide member <NUM>, without contacting the guide member <NUM>, in such a manner that a side edge 38d of the restriction section (laterally elongated section) 38c is substantially opposed to the guide member <NUM>. Namely, the restriction member <NUM> is disposed in such a manner that the restriction section (laterally elongated section) 38c is located close to the distal end of the guide member <NUM> (namely, the distal end of the guide tube 29a). Further, a portion of the string-shaped material T extending from the guide member <NUM> to the sewing position is positioned to be located beneath the restriction section (laterally elongated section) 38c of the restriction member <NUM>.

A height of the restriction section 38c relative to the support member <NUM> (namely, relative to the guide member <NUM>) can be adjusted by adjusting, via the screw, a fixed position of the fixing section 38a relative to the support member <NUM> along the elongated hole <NUM>. In this way, it is possible to adjust a height relationship between the restriction section (laterally elongated section) 38c and the distal end of the guide member <NUM> (namely, the distal end of the guide tube 29a). In this embodiment, the restriction section (laterally elongated section) 38c provided at the lower end of the restriction member <NUM> functions also as a fabric pressing member or a presser foot during a sewing operation. Namely, the driving of the aforementioned motor <NUM> (<FIG>) is controlled in synchronism with the up-and-down movement of the needle bar <NUM> during the sewing operation, in response to which the restriction member <NUM> is moved up and down via the drive arm <NUM>, the engaging ring <NUM>, the support cylinder <NUM>, the support <NUM>, and the support member <NUM> (see <FIG>, <FIG>, and the like for details of these elements), so that the restriction section (laterally elongated section) 38c provided at the lower end of the restriction member <NUM> can be caused to function as the presser foot. As illustrated in <FIG>, a needle passage hole or opening <NUM> for enabling passage therethrough of the sewing needle <NUM> is formed in the restriction section (laterally elongated section) 38c provided at the lower end of the restriction member <NUM>. In this way, the restriction section (laterally elongated section) 38c can be caused to function as the presser foot at a needle drop position of the sewing needle <NUM>. In the case where the restriction section (laterally elongated section) 38c of the restriction member <NUM> is to be caused to function also as the presser foot as noted above, the height of the restriction member <NUM> may be adjusted in such a manner that the lower surface of the restriction section (laterally elongated section) 38c is located appropriately lower than the lower surface of the guide tube 29a as illustrated in <FIG>. The aforementioned elements 38a, <NUM>, the screw, and the like together function as a position adjusting mechanism for adjusting the height position of the restriction member <NUM>. The guide member <NUM> is supported on the support member <NUM> in such a manner that the member <NUM> is slidable in the lateral direction as set forth above. Thus, as the restriction member <NUM> fixed to the support member <NUM> is moved up and down in response to the driving of the motor <NUM>, the guide member <NUM> is moved up and down together with the restriction member <NUM>. Note that in a case where the restriction section (laterally elongated section) 38c is not to be caused to function as the presser foot (namely, where an appropriate presser foot is provided separately), the restriction section (laterally elongated section) 38c need not necessarily be provided at the lower end of the restriction member <NUM>, and besides, the needle passage hole <NUM>, too, may be omitted.

The restriction section (laterally elongated section) 38c has a length corresponding to a range of the reciprocating movement of the guide member <NUM>. A specific example of such a corresponding relationship is illustrated in (a) and (b) of <FIG> of <FIG> are each an enlarged plan view illustrating a specific example of the relationship between a lateral length of the restriction section (laterally elongated section) 38c and the range of the reciprocating movement of the guide member <NUM>. More specifically, (a) of <FIG> is a plan view when the guide member <NUM> is located at the leftmost end of the reciprocating movement range, while (b) of <FIG> is a plan view when the guide member <NUM> is located at the rightmost end of the reciprocating movement range. As an example, the lateral length of the restriction section (laterally elongated section) 38c is almost equal to the reciprocating movement range of the guide member <NUM> (leftward/rightward movement range of the guide tube 29a). For example, as illustrated in (a) and (b) of <FIG>, the length of the restriction section (laterally elongated section) 38c is such a dimension that when the guide member <NUM> is located at either one of the two ends (leftmost end or rightmost end) of the reciprocating movement range of the guide member <NUM>, the entire lateral width of the string-shaped material T guided by the guide member <NUM> is covered or overlapped by the restriction section (laterally elongated section) 38c in an overlapped manner. However, the present invention is not so limited, and the length of the restriction section 38c may be such a dimension that when the guide member <NUM> is located at either one of the opposite ends (leftmost end or rightmost end) of the reciprocating movement range of the guide member <NUM>, at least part of the lateral width of the string-shaped material T guided by the guide member <NUM> is covered with the restriction section (laterally elongated section) 38c in an overlapped manner. Namely, the length of the restriction section (laterally elongated section) 38c may be a dimension somewhat smaller than the reciprocating movement range of the guide member <NUM> such that part of the width of the string-shaped material T lies outside a string-shaped-material covering area of the bottom portion of the restriction section (laterally elongated section) 38c at the leftmost end or rightmost end of the reciprocating movement range of the guide member <NUM>. As another alternative, the lateral length of the restriction section (laterally elongated section) 38c may be appropriately larger than the reciprocating movement range of the guide member <NUM> (leftward/rightward movement range of the guide tube 29a). Namely, in the present invention, examples of the aforementioned length of the restriction section (laterally elongated section) 38c corresponding to the reciprocating movement range of the guide member <NUM> include a length appropriately larger than the reciprocating movement range of the guide member <NUM>.

Thus, when the guide member <NUM> is reciprocatingly moved as noted above, the portion of the string-shaped material T extending downward from the distal end of the guide member <NUM> to the sewing position can be reliably located beneath the restriction section (laterally elongated section) 38c of the restriction member <NUM> to contact (or to be at least covered with) the covering area of the lower surface of the restriction section (laterally elongated section) 38c (and thus, unwanted upward movement of the string-shaped material T can be restricted or suppressed). In this way, when the string-shaped material T is swung laterally (in the left-right direction), it is possible to reliably prevent the string-shaped material T from catching on a nearby component part or portion (particularly, the presser foot, or an edge portion or the like of the restriction member <NUM> in the case where the restriction member <NUM> is caused to function as the presser foot). Namely, even where the up-and-down movement stroke of the presser foot (or the up-and-down movement stroke of the restriction member <NUM> if the restriction member <NUM> is constructed to function also as the presser foot as in the present embodiment) is small, the string-shaped material T can be reliably positioned to be located beneath the restriction member <NUM> without largely positionally deviating from the string-shaped material covering area of the restriction section (laterally elongated section) 38c, and hence, the string-shaped material T can be reliably prevented from catching on the presser foot (restriction member <NUM>).

Now, a description will be given about an example of a sewing operation for sewing the string-shaped material T to the base fabric (sewing workpiece) through lock stitching by the machine head H constructed in the above-described manner. First, the bobbin <NUM> having the string-shaped material T wound thereon is set on the bobbin bracket <NUM>, and the string-shaped material T is paid out from the bobbin <NUM> and passed through the guide tube 29a to be led to the needle drop position (needle entry position) of the sewing needle <NUM>. In this state, lock stitching is performed in the conventionally known manner, through the functions of the sewing needle <NUM> and a not-illustrated rotary hook, by moving the embroidery frame (not illustrated), holding the base fabric (sewing workpiece), in X-Y directions on the basis of predetermined embroidery data but also moving up and down the needle bar <NUM>. During that time, the guide member <NUM> is reciprocatingly swung, by driving of the zigzag swinging motor <NUM>, leftward and rightward between the leftmost end position illustrated in (a) of <FIG> and the rightmost end position illustrated in (b) of <FIG> at predetermined timing, so that the string-shaped material T having been led through the guide tube 29a to the drop position of the sewing needle <NUM> is swung leftward or rightward of the drop position of the sewing needle <NUM>, for example, per reciprocating movement of the needle bar <NUM> (per stitch). In this manner, the string-shaped material T is sequentially sewn to the sewing workpiece through zigzag stitching.

During the sewing operation, in response to the rotation cylinder <NUM> being rotated by the driving of the motor <NUM>, the lever pin <NUM> is controlled to be always located ahead in a relative advancing direction of the machine head H based on the movement of the embroidery frame. Further, in response to the driving of the motor <NUM>, the restriction member <NUM> is moved up and down at predetermined timing relative to the up-and-down movement of the needle bar <NUM>. During this time, the guide member <NUM> is moved up and down together with the restriction member <NUM> through the aforementioned arrangements. Note that when the sewing of the string-shaped material T has been completed (or when the sewing of the string-shaped material T is not to be carried out), the guide member <NUM> can be moved upward to a retracted position together the restriction member <NUM> by the driving of the motor <NUM>.

Height setting/control of a bottom dead point of the restriction member <NUM>, which is moved up and down by the driving of the motor <NUM>, can be performed by setting a height of the bottom dead point of the restriction member <NUM>, for example, via an operation panel in accordance with a thickness of the sewing workpiece and a type of the string-shaped material T in a manner similar to that of setting a bottom dead point of the presser foot. Further, because the guide member <NUM> is moved up and down together with the restriction member <NUM> as noted above, a height position of the guide member <NUM> is automatically changed in accordance with a change of the height of the bottom dead point of the restriction member <NUM>.

In a case where string-shaped materials T in the form of bundles of long reinforcing fibers, such as carbon fibers and glass fibers, are to be sewn to a sewing workpiece (base fabric) in a plurality of layers, a height of the reinforcing fibers sewn increases each time a layer of the string-shaped material T is superimposed on the sewing workpiece (base fabric). In order to deal with such a height change, a new height of the bottom dead point of the restriction member <NUM> may be set via the operation panel per layer sewing step. In this manner, per layer sewing step, the height position of the guide member <NUM> is changed automatically in response to the height setting of the restriction member <NUM>.

In the above-described embodiment of <FIG>, the reciprocation mechanism for reciprocatingly moving the guide member <NUM> in the lateral direction is constructed to reciprocatingly move the guide member <NUM> straight or linearly in the lateral direction. However, the present invention is not so limited, and the reciprocation mechanism may be constructed to swing the guide member <NUM> in the lateral direction. <FIG> is a front view illustrating a lower section of the machine head H, which more particularly illustrates another embodiment of the present invention that employs the reciprocation mechanism constructed to swing the guide member in the lateral direction, and <FIG> is a side view of the lower section of the machine head H illustrated in <FIG>. In <FIG>, same reference characters as in <FIG> denote elements of the same functions as the elements illustrated in <FIG> and thus will not be described here to avoid unnecessary duplication. Further, elements and arrangements related to the reciprocation mechanism for swinging the guide member in the lateral direction are mainly illustrated in <FIG>, and other elements and arrangements not illustrated in <FIG> are substantially similar to the elements and arrangements illustrated in <FIG>, <FIG>, and the like.

In <FIG>, the interlocking member <NUM> is moved up and down via the lifting and lowering member <NUM> in response to the driving of the zigzag swinging motor <NUM> (<FIG>) and is rotated together with the rotation cylinder <NUM>, as set forth above. A swing lever <NUM> is mounted to the rotation cylinder <NUM> via the bracket <NUM>. The swing lever <NUM> is mounted to the rotation cylinder <NUM> in such a manner that the lever <NUM> is swingable, relative to the rotation cylinder <NUM>, leftward and rightward of the axis of the needle bar <NUM> about the lever pin <NUM> mounted to an outer side surface of the bracket <NUM>. The swing lever <NUM> has one arm portion 51a extending laterally from a position adjoining the lever pin <NUM> and another arm portion 51b extending downward from a position adjoining the lever pin <NUM>. The roller <NUM> is mounted to the distal end of the laterally extending arm portion 51a, and the roller <NUM> is held in engagement in the linking groove 19a of the connection piece <NUM>.

The arm portion 51b of the swing lever <NUM> is connected to a guide member <NUM> via a connection member <NUM>. A guide tube 50a for guiding the string-shaped material to the sewing position is mounted to the distal end of the guide member <NUM>. Note that the guide member <NUM> in the illustrated example of <FIG> has a generally round cross-sectional shape and hence is suited for string-shaped materials of a generally round cross-sectional shape or a small width. By adjusting a mounted position of the guide member <NUM> via an elongated hole 52a formed in the connection member <NUM>, it is possible to adjust a height of the distal end of the guide member <NUM> (guide tube 50a) from the needle plate <NUM>. Further, when the sewing of the string-shaped material is not to be carried out, the connection member <NUM> and the guide member <NUM> can be moved upward to a retracted position, by loosening a screw <NUM> fastening the connection member <NUM> to the arm portion 51b of the swing lever <NUM> and then causing the connection member <NUM> and the guide member <NUM> to pivot upward.

As the interlocking member <NUM> and the connection piece <NUM> is moved up and down in response to the driving of the zigzag swinging motor <NUM> (<FIG>), the up-and-down movement of the connection piece <NUM> is converted into swinging movement of the swing lever <NUM> via the linking groove 19a and the roller <NUM>. In response to the pivoting movement of the swing lever <NUM>, the guide member <NUM> connected to the arm portion 51b of the lever <NUM> is swung in the left-right (lateral) direction. In this manner, the string-shaped material (not illustrated in <FIG>) passed through the guide tube 50a is swung in the lateral direction.

In <FIG>, the support <NUM> not only moves up and down as the support cylinder <NUM> moves up and down but also rotates about the axis of the needle bar as the rotation cylinder <NUM> rotates, in the same manner as set forth above. A restriction member <NUM> is mounted to one of the lower end portions (namely, the lower end portion which the key member <NUM> is not engaged with) of the bifurcated support <NUM>. <FIG> is an enlarged perspective view of the restriction member <NUM>. The lower end of the restriction member <NUM> is formed as a laterally elongated restriction section (namely, a laterally elongated section) 60c. In this embodiment, a fixing section 60a extends upward from a substantially middle portion of a side edge 60b of the restriction section (laterally elongated section) 60c, and the restriction member <NUM> is screwed to the support <NUM> via the fixing section 60a. Like the aforementioned restriction section (laterally elongated section) 38c, the restriction section (laterally elongated section) 60c of the restriction member <NUM> has a length corresponding to a range of reciprocating movement of the guide member <NUM>. Further, like the aforementioned restriction section (laterally elongated section) 38c, the restriction section (laterally elongated section) 60c of the restriction member <NUM> constitutes a flat surface parallel to the needle plate <NUM>. Note that two distal end portions extending from the laterally opposite ends of the restriction section 60c are somewhat bent upward in such a manner that the distal end portions can be prevented from catching on the base fabric and/or the like when the restriction section 60c is lowered to its lowest position. Furthermore, the needle passage hole (opening) <NUM> for enabling passage therethrough of the sewing needle <NUM> is formed in the restriction section (laterally elongated section) 60c, and the restriction member <NUM> can function also as the presser foot. Note that a portion of the string-shaped material (not illustrated) extending from the guide member <NUM> to the sewing position is positioned to be located beneath the restriction section (laterally elongated section) 60c of the restriction member <NUM>.

<FIG> illustrates a state where the guide member <NUM> has been swung to the leftmost end of the reciprocating movement (swinging movement) range of the member <NUM>. It can be seen from <FIG> that when the guide member <NUM> is located at the leftmost end of the reciprocating movement (swinging movement) range, the entire width or part of the width of the sting-shaped material guided by the guide member <NUM> is covered or overlapped by the restriction section (laterally elongated section) 50c. It can also be seen from <FIG> that when the guide member <NUM> is located at the rightmost end of the reciprocating movement (swinging movement) range, too, the entire width or part of the width of the sting-shaped material guided by the guide member <NUM> is covered or overlapped by the restriction section (laterally elongated section) 50c. Namely, the lateral length of the restriction section (laterally elongated section) 60c is substantially equal to the length of the horizontal component of the reciprocating movement (swinging movement) range of the guide member <NUM> (swinging movement range of the guide tube 50a). Note that the lateral length of the restriction section (laterally elongated section) 60c of the restriction section <NUM> need not necessarily be precisely equal to the length of the horizontal component of the reciprocating movement (swinging movement) range of the guide member <NUM> (swinging movement range of the guide tube 50a) and may be appropriately longer or shorter than the latter.

With such arrangements, as the guide member <NUM> is reciprocatingly moved (swung), the portion of the string-shaped material (not illustrated) extending from the distal end of the guide member <NUM> downward to the sewing position below the guide member <NUM> can be reliably positioned beneath the restriction section (laterally elongated section) 60c in such a manner as to contact (or at least to be covered by) the lower surface of the restriction section (laterally elongated section) 60c (namely, in such a manner that unwanted upward movement of the string-shaped material can be restricted or suppressed by the lower surface of the restriction section 60c). In this way, when the string-shaped material is swung laterally (in the left-right direction), it is possible to reliably prevent the string-shaped material from catching on a nearby component part or portion (particularly, the presser foot, or a side surface of the restriction member <NUM> in this embodiment). Namely, even where the up-and-down movement stroke of the presser foot (or up-and-down movement stroke of the restriction member <NUM> in the case where the restriction member <NUM> itself functions also as the presser foot as in this embodiment) is small, the string-shaped material can be reliably restricted to be located beneath the restriction section 60c without positionally deviating from the string-shaped material covering area of the restriction section (laterally elongated section) 60c, and thus, the string-shaped material can be reliably prevented from catching on the presser foot (or the restriction member <NUM>).

In the embodiment illustrated in <FIG>, although the guide member <NUM> and the restriction member <NUM> are rotated together about the axis of the needle bar in response to the rotation of the rotation cylinder <NUM>, the guide member <NUM> is not moved up and down when the restriction member <NUM> is moved up and down in response to the up-and-down movement of the support <NUM>. <FIG> illustrate the restriction member <NUM> when the member <NUM> is, for example, at its top dead point, and the restriction member <NUM> is moved up and down between the top dead point and the bottom dead point lower than the top dead point.

Claim 1:
A sewing machine capable of sewing a string-shaped material to a sewing workpiece through zigzag stitching, the sewing machine comprising:
a guide member (<NUM>) for guiding the string-shaped material (T) toward a sewing position, the guide member (<NUM>) having a distal end from which the string-shaped material (T) extends out; and
a reciprocation mechanism (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) for reciprocatingly moving the guide member (<NUM>) in a lateral direction,
characterized in that the sewing machine further comprises:
a restriction member (<NUM>) disposed close to the guide member (<NUM>) and having a laterally elongated section (38c), the laterally elongated section (38c) extending in a reciprocating movement direction of the guide member (<NUM>) in such a manner that a portion of the string-shaped material (T) extending out from the distal end of the guide member (<NUM>) to the sewing position is restricted to be located beneath the laterally elongated section (38c), the laterally elongated section (38c) having a length corresponding to a range of reciprocating movement of the distal end of the guide member (<NUM>),
wherein the guide member (<NUM>) is reciprocatingly movable relative to the restriction member (<NUM>).