SEWING MACHINE AND METHOD OF CONTROLLING OPERATION OF THE SAME

Abstract

A sewing machine is provided, which includes a table, support posts, upper and lower frames, a head unit, a bed unit, an X-axial head-unit-transport means and an X-axial bed-unit-transport means. An object is placed on the table. The support posts are provided on opposite sides of the table. The upper and lower frames connect the support posts to each other. The head unit is provided on the upper frame so as to be movable in an X-axis direction. The head unit has a head-unit-rotating means for rotating a sewing head. The bed unit is provided on the lower frame so as to be movable in the X-axis direction. The bed unit has a bed-unit-rotating means for rotating a sewing bed. The X-axial head-unit-transport means moves the head unit on the upper frame horizontally. The X-axial bed-unit-transport means moves the bed unit on the upper frame horizontally.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. 119(a) of Korean Patent Application Nos. 10-2010-0124830, filed on Dec. 8, 2010, 10-2011-0048013, filed on May 20, 2011, and 10-2011-0069518, filed on Jul. 13, 2011, the disclosure of each of which is incorporated by reference in its entirety for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to sewing machines and methods of controlling the operation of the sewing machines and, more particularly, to a sewing machine which is configured such that a sewing head rotates when an object, such as an airbag, a bag, a shoe, etc., is being sewn so that the sewing operation can be satisfactorily conducted without causing a hitch stitch, and in which a plurality of sewing heads may be arranged on a front surface of an upper beam in a row, so that not only the quality of the products can be enhanced but also the productivity can be markedly enhanced, and a method of controlling the operation of the sewing machine.

2. Description of the Related Art

Generally, objects, such as airbags, bags, shoes, etc., are made of comparatively thick materials and have many sewing lines, such as circular, curved, slanted lines, etc., which are difficult to sew. Thus, in the case of conventional sewing machines, hitch stitches were easily formed with respect to a correct sewing direction. Such hitch stitches make the entire stitch shape uneven, thus deteriorating the quality of the product.

FIG. 1 illustrates an embodiment of a conventional sewing machine. In the conventional sewing machine, an arm part 40 having a head unit is disposed on a table 10. A bed unit (not shown) having a hook is disposed under the table 10. A connection unit 60 connects the arm part 40 to the bed unit. An object that is supported by an object holder 50 is sewn by interaction between a needle of the head unit and the hook of the bed unit.

The sewing machine having the above construction can move the object supported by the object holder 50 in an X-axis and/or Y-axis direction, thus making it possible to form sewing stitch lines of a variety of shapes on the object.

However, in the conventional sewing machine, the object holder 50 linearly moves in the X-axis or Y-axis direction. Therefore, when the sewing machine forms a curved, circular or slanted stitch line, hitch stitches are caused in some sections.

FIGS. 2A through 2C are views showing examples of hitch stitches caused in the conventional sewing machine. In the case of a rhombic or rectangular shape, two sides of the four sides were P (Perfect stitch) sections, another side was an H/P (Hitch/Perfect stitch) section where there are normal stitches and abnormal stitches together, and the other side was an H (Hitch stitch) section.

FIG. 2C is an H-P stitch distribution chart by section after sewing. In the case of a circular stitch section, a P (Perfect stitch) section and an H (Hitch stitch) section were in a ratio of almost 1:1.

Therefore, a sewing machine which can realize perfect stitching over the entire section is required in order for the quality of the sewing to be high quality.

Furthermore, the conventional sewing machine cannot process a comparatively large object because the sewing area of the sewing machine is restrictive. To solve this problem, it is required to increase the size of the sewing machine such that its sewing area also increases. However, if the size of the sewing machine increases, the space used to install the sewing machine must also be increased. A new concept is needed for a sewing machine so that the space required to install a large sewing machine can be minimized.

In addition, the conventional sewing machine can process only one object at a time. Thus, it takes too long to process a large number of objects. Therefore, to enhance the productivity, a sewing machine which can process a plurality of objects at a time is needed.

SUMMARY OF THE INVENTION

Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a sewing machine which can realize a perfect stitch over the entirety of an object even when sewing an object such as an airbag, a bag, a shoe, etc., that are thick materials and have sewing lines which are difficult to sew, thus markedly enhancing the quality of the product.

Another object of the present invention is to provide a sewing machine which can sew an object that has a large area to be sewn despite having a small size, thus minimizing the installation space of the sewing machine.

A further object of the present invention is to provide a sewing machine which uses a single power source to transport a head unit and a bed unit, so that the size and the production cost of the sewing machine can be reduced.

Yet another object of the present invention is to provide a sewing machine which has a plurality of work areas so that the operation of sewing a plurality of objects can be continuously conducted without requiring a separate object replacing operation.

Still another object of the present invention is to provide a sewing machine which can process a plurality of objects at a time, thus markedly enhancing productivity.

Still another object of the present invention is to provide a sewing machine which is configured such that when sewing a plurality of objects, the sewing machine reads information about the objects and conducts the sewing operation according to the read information.

Still another object of the present invention is to provide a method of controlling the operation of the sewing machine in which the head unit and the bed unit are rotated while sewing so that even when sewing an object such as an airbag, a bag, a shoe, etc., a perfect stitch can be realized over the entirety of the object.

In order to accomplish the above object, the present invention provides a sewing machine, including: a table, on an upper surface of which an object to be sewn is placed; support posts provided on opposite sides of the table; upper and lower frames connecting the support posts to each other; a head unit provided on the upper frame so as to be movable in an X-axis direction, the head unit having head-unit-rotating means for rotating a sewing head within a predetermined range; a bed unit provided on the lower frame so as to be movable in the X axis direction, the bed unit having bed-unit-rotating means for rotating a sewing bed within a predetermined range; an X-axial head-unit-transport means for moving the head unit on the upper frame in a horizontal direction; and an X-axial bed-unit-transport means for moving the bed unit on the upper frame in the horizontal direction.

The X-axial head-unit-transport means may include: an X-axial head-unit-transport motor providing a drive force; a transport screw connected to a drive shaft of the X-axial head-unit-transport motor by power transmission means; a head-unit transport bracket reciprocating in the horizontal direction depending on rotation of the transport screw, with the head unit mounted to a front surface of the head unit transport bracket; and a guide rail coupled to guide couplers of the head unit transport bracket so that the head unit transport bracket is able to move horizontally on the upper frame.

The head unit may be mounted to the front surface of the head unit transport bracket. A transport box may be provided on a central portion of a rear surface of the head unit transport bracket. The transport box may be provided around the transport screw. The guide couplers may be provided on upper and lower ends of the head unit transport bracket. The guide couplers may be coupled to the guide rail.

The drive shaft of the X-axial head-unit-transport motor may be connected to the transport screw by a coupling.

The X-axial bed-unit-transport means may include: an X-axial bed-unit-transport motor providing a drive force; a transport screw connected to a drive shaft of the X-axial bed-unit-transport motor by power transmission means; a bed unit transport bracket reciprocating in the horizontal direction M depending on rotation of the transport screw, with the bed unit mounted to a front surface of the bed unit transport bracket; and a guide rail coupled to guide couplers of the bed unit transport bracket so that the bed unit transport bracket is able to move on the lower frame.

The bed unit may be mounted to the front surface of the bed unit transport bracket. A transport box may be provided on a central portion of a rear surface of the bed unit transport bracket. The transport box may be provided around the transport screw. The guide couplers may be provided on upper and lower ends of the bed unit transport bracket. The guide couplers may be coupled to the guide rail.

The drive shaft of the X-axial bed-unit-transport motor may be connected to the transport screw by a coupling.

The head-unit-rotating means may include: a head unit rotating motor used as a power source; a power transmission unit connected to a drive shaft of a rotating motor, the power transmission unit transmitting a drive force of the rotating motor; a driven shaft rotated by the drive force of the rotating motor transmitted by the power transmission unit; and the sewing head provided on the driven shaft, the sewing head being rotated around the driven shaft.

The power transmission unit may comprise a rotating drive gear reducing an rpm of the rotating motor and transmitting the drive force to the driven shaft at a reduced rpm.

The rotating drive gear may comprise a bevel gear configured such that the drive shaft is at a right angle to the driven shaft.

The bed-unit-rotating means may include: a bed unit rotating motor used as a power source; a power transmission unit connected to a drive shaft of a rotating motor, the power transmission unit transmitting a drive force of the rotating motor; a driven shaft rotated by the drive force of the rotating motor transmitted by the power transmission unit; and the sewing bed provided on the driven shaft.

The power transmission unit may comprise a rotating drive gear reducing an rpm of the rotating motor and transmitting the drive force to the driven shaft at a reduced rpm.

The rotating drive gear may comprise a bevel gear configured such that the drive shaft is at a right angle to the driven shaft.

A momentum of a rotating motor of the bed-unit-rotating means may be synchronized with a rotating motor of the head-unit-rotating means so that the rotating motors are operated together.

The sewing machine may further including: a head-unit-lift means provided between the X-axial head-unit-transport means and the head unit, the head-unit-lift means moving the sewing head upwards and downwards between a stand-by position and a work position.

The head-unit-lift means may include: a lift actuator installed in a main body of the sewing machine by an actuator support bracket, the lift actuator providing a drive force to move the sewing head upwards or downwards; and a lift plate coupled at a central portion of a front surface thereof to the sewing head, the lift plate being coupled on an upper end of a rear surface thereof to a head unit connection bracket connected to a drive part of the lift actuator, with guide means mounted to opposite sides of the rear surface of the lift plate.

The head-unit-lift means may further include: a support plate coupled on opposite sides of a front surface thereof to the guide means, with an actuator support bracket mounted to a central portion of a rear surface of the support plate, the actuator support bracket supporting the lift actuator thereon.

The X-axial head-unit-transport means and the X-axial bed-unit-transport means may include: an integrated X-axial transport motor provided on at least one of the support posts; an upper transport unit provided on the upper frame, the upper transport unit being connected to the head unit; a lower transport unit provided on the lower frame, the lower transport unit being connected to the bed unit; an upper guide means provided on the upper frame so that the head unit is transported along the upper frame by the upper guide means; a lower guide means provided on the lower frame so that the bed unit is transported along the lower frame by the lower guide means; and a power transmission means for transmitting a rotating force of the integrated X-axial transport motor to the upper transport unit and the lower transport unit at a same time.

The power transmission means may include: a drive pulley provided on an output shaft of the integrated X-axial transport motor; an upper driven pulley provided on an end of the upper transport unit; a lower driven pulley provided on an end of the lower transport unit; and a timing belt coupled to the drive pulley, the upper driven pulley and the lower driven pulley together so that the upper transport unit and the lower transport unit are operated at a same time by a drive force of the drive pulley.

The sewing machine may further include: a tensioner pulley for applying a tensile force to the timing belt.

Each of the upper transport unit and the lower transport unit may comprise a ball screw or a wire.

Each of the upper guide means and the lower guide means may comprise a guide rail or an LM guide.

The sewing machine may further include a Y-axial transport means for transporting a sewing frame supporting the object thereon in a Y-axis direction. The Y-axial transport means may include: a Y-axial frame extending a predetermined length in the Y-axis direction; a Y-axial linear motor provided on the Y-axial frame, the Y-axial linear motor providing a drive force to move the sewing frame in the Y-axis direction; and a support unit provided such that the sewing frame is transported in the Y-axis direction by operation of the Y-axial linear motor.

The head unit may comprise a plurality of head units arranged in a row on a front surface of the upper frame, the bed unit may comprise a plurality of bed units arranged in such a way as to correspond to the respective head units, and a plurality of objects may be held by a single sewing frame on the table so that a plurality of sewing operations are able to be conducted simultaneously.

The sewing frame holding the object may have a plurality of sewing work areas, and objects may be supported on the respective sewing work areas.

The sewing frame may include a plurality of subsidiary sewing frames provided on the single sewing frame so as to be individually removable therefrom.

An indication may be provided on the sewing frame, the indication containing information instructing about a working method. A reader for scanning the indication may be provided on the head unit. The reader may read the information contained in the indication and transmits the information to a control unit.

The indication may comprise a barcode, and the reader comprises a barcode reader.

In order to accomplish the above object, the present invention provides a method of controlling operation of a sewing machine comprising a head unit and a bed unit that are allowed to be transported in an X-axis direction and rotated around a Z-axis while sewing, the method including: (a) positioning a sewing needle of the head unit above a needle plate; (b) operating an X-axial transport motor, a Y-axial transport motor, a head unit rotating motor and a bed unit rotating motor in response to information input to a control unit; and (c) moving the sewing needle downwards by operation of an upper shaft drive motor and a lower shaft drive motor to form a stitch, and returning to (b) operating when the sewing needle is moved upwards and positioned above the needle plate, and repeating (b) operating and (c) moving.

Furthermore, an rpm of the upper shaft drive motor and an rpm of the lower shaft drive motor may be increased or reduced in proportion to rpms of the X-axial transport motor, the Y-axial transport motor, the head unit rotating motor and the bed unit rotating motor.

After the rpm of the upper shaft drive motor and the rpm of the lower shaft drive motor are reduced, the head unit rotating motor and the bed unit rotating motor may be operated.

The rotating speed of the upper shaft drive motor and the rotating speed of the lower shaft drive motor may be controlled in response to an angle at which the head unit and the bed unit rotate.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. 1 is a perspective view showing an embodiment of a conventional sewing machine;

FIGS. 2A through 2C are views showing examples of hitch stitches caused in the conventional sewing machine;

FIG. 3 is a perspective view illustrating a head-unit-moving-bridge type sewing machine, according to a first embodiment of the present invention;

FIG. 4A is a front view illustrating the head-unit-moving-bridge type sewing machine according to the present invention;

FIG. 4B is a perspective view illustrating a structure for X-axially transporting a head unit and a bed unit of the head-unit-moving-bridge type sewing machine according to the present invention;

FIG. 5 is a perspective view illustrating an embodiment in which linear motors are used as a drive source of an X-axial head-unit-transport means and a drive source of an X-axial bed-unit-transport means according to the present invention;

FIG. 6 is a perspective view illustrating the head unit according to the present invention;

FIG. 7 is a perspective view illustrating the bed unit according to the present invention;

FIG. 8 is an exploded perspective view illustrating a head-unit-lift means according to the present invention;

FIGS. 9A and 9B are views illustrating an embodiment of a rotating drive gear unit according to the present invention;

FIG. 10 is a front view of a sewing machine, according to a second embodiment of the present invention;

FIG. 11 is a side view of the sewing machine according to the second embodiment of the present invention;

FIG. 12 illustrates a third embodiment of the present invention, showing a perspective view of a sewing machine having multi-sewing heads;

FIG. 13 is a perspective view showing an embodiment in which a linear motor is used as a drive source of a Y-axial transport means according to the present invention;

FIG. 14 is a front view of the third embodiment of the present invention;

FIG. 15 is a block diagram showing the construction of a barcode data processing device according to the second or third embodiment of the present invention; and

FIG. 16 is a flowchart of a barcode data processing method of the barcode data processing device of FIG. 15.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, embodiments of a sewing machine and a method of operating the sewing machine according to the present invention will be described in detail with reference to the attached drawings.

FIG. 3 is a perspective view illustrating a head-unit-moving-bridge type sewing machine, according to a first embodiment of the present invention. FIG. 4A is a front view illustrating the head-unit-moving-bridge type sewing machine according to the present invention. FIG. 4B is a perspective view illustrating a structure for X-axially transporting a head unit and a bed unit of the head-unit-moving-bridge type sewing machine according to the present invention.

The sewing machine according to the present invention includes a table 510 which receives an object to be sewn, support posts 502 which are provided on opposite sides of the table 510, and an upper frame 520 and a lower frame 521 which connect the support posts 502 to each other and are respectively provided on upper and lower ends of the support posts 502. The head unit 100 and the bed unit 300 are respectively provided on the upper and lower frames 520 and 521 and can be respectively moved along the upper and lower frames 520 and 521 in the X-axis direction by an X-axial head-unit-transport means 530 and an X-axial bed-unit-transport means 630.

The X-axial head-unit-transport means 530 which moves the head unit 100 along the upper frame 520 in the horizontal direction includes an X-axial head-unit-transport motor 532, a transport screw 534, a head unit transport bracket 536 and a guide rail 538. The X-axial head-unit-transport motor 532 provides drive force. The transport screw 534 is coupled to a drive shaft of the X-axial head-unit-transport motor 532 by a power transmission means such as a coupling. The head unit 100 is mounted to a front surface of the head unit transport bracket 536. The head unit transport bracket 536 is provided on the transport screw 534 and is reciprocated in the horizontal direction by the rotation of the transport screw 534. The guide rail 538 is coupled to guide couplers which are provided on upper and lower ends of the head unit transport bracket 536 so that the head unit transport bracket 536 can move along the upper frame 520 in the horizontal direction.

The head unit transport bracket 536 is coupled on the front surface thereof to the head unit 100. A transport box through which the transport screw 534 passes is provided on a central portion of a rear surface of the head unit transport bracket 536. The guide couplers which are coupled to the guide rail 538 are respectively provided on the upper and lower ends of the head unit transport bracket 536.

A well-known power transmission means, such as a coupling, is used as a structure for connecting the drive shaft of the X-axial head-unit-transport motor 532 to the transport screw 534, therefore further explanation of the connection structure will be omitted in this specification.

Preferably, a head-unit-lift means 210 is provided between the X-axial head-unit-transport means 530 and the head unit 100. The head-unit-lift means 210 moves a sewing head 109, provided with a sewing needle which reciprocates in the vertical direction, downwards to a work position or moves the sewing head 109 upwards to a stand-by position.

As shown in FIG. 8, the head-unit-lift means 210 includes a lift actuator 240 and a lift plate 230. The lift actuator 240 is installed in a main body of the sewing machine on an actuator support bracket 242 and provides a drive force used to move the sewing head 109 upwards or downwards. The sewing head 109 is coupled to a central portion of a front surface of the lift plate 230. A head unit connection bracket 244 is connected to an upper end of a rear surface of the lift plate 230. The head unit connection bracket 244 is connected to a drive part of the lift actuator 240.

Furthermore, opposite sides of the rear surface of the lift plate 230 are fastened to a guide means 250, including guide rails 252 and guide couplers 254, so that the lift plate 230 can smoothly and reliably move upwards or downwards.

The guide means 250 is provided on opposite sides of a front surface of a support plate 260 which is installed in the main body of the sewing machine. The actuator support bracket 242, by which the lift actuator 240 is installed in the main body of the sewing machine, is fastened to a central portion of a rear surface of the support plate 260.

The head-unit-lift means 210 has the following operational structure. When the drive part of the lift actuator 240 is operated, the head unit connection bracket 244 which is connected to the drive part of the lift actuator 240 is operated. Thereby, the lift plate 230 which is connected to the front end of the head unit connection bracket 244 is operated along the guide means 250. As a result, the sewing head 109 which is mounted to the front surface of the lift plate 230 is moved upwards or downwards.

Meanwhile, the X-axial bed-unit-transport means 630 which moves the bed unit 300 on the lower frame 521 in the horizontal direction includes an X-axial bed-unit-transport motor 632, a transport screw 634, a bed unit transport bracket 636 and a guide rail 638. The X-axial bed-unit-transport to motor 632 provides the drive force. The transport screw 634 is coupled to a drive shaft of the X-axial bed-unit-transport motor 632 by a power transmission means such as a coupling. The bed unit 300 is mounted to a front surface of the bed unit transport bracket 636. The bed unit transport bracket 636 is provided on the transport screw 634 and is reciprocated in the horizontal direction by the rotation of the transport screw 634. The guide rail 638 is coupled to guide couplers which are provided on upper and lower ends of the bed unit transport bracket 636 so that the bed unit transport bracket 636 can move along the lower frame 521 in the horizontal direction.

The bed unit transport bracket 636 is coupled on the front surface thereof to the bed unit 300. A transport box through which the transport screw 634 passes is provided on a central portion of a rear surface of the bed unit transport bracket 636. The guide couplers which are coupled to the guide rail 638 are respectively provided on the upper and lower ends of the bed unit transport bracket 636.

A well-known power transmission means, such as a coupling, is also used as a structure for connecting the drive shaft of the X-axial bed-unit-transport motor 632 to the transport screw 634, therefore further explanation of the connection structure will be omitted from this specification.

FIG. 5 illustrates an embodiment in which linear motors are used as a drive source of the X-axial head-unit-transport means 530 and a drive source of the X-axial bed-unit-transport means 630 which respectively transport the head unit 100 and the bed unit 300 on the upper and lower frames 520 and 521 in the X-axis direction. In this embodiment, an X-axial head unit transport linear motor 732 is used to transport the head unit transport bracket 536 in the horizontal direction, and an X-axial bed unit transport linear motor 832 is used to transport the bed unit transport bracket 636 in the horizontal direction.

Any power generating means, as well as a rotary motor or the linear motor that is used in the embodiment of the present invention, can be used as the drive source of each of the X-axial head-unit-transport means 530 and the X-axial bed-unit-transport means 630. That is, the drive source is not limited to a special structure.

The table 510 comprises a rectangular plate. An object to be sewn is placed onto the table 510.

In the present invention, the head unit 100 and the bed unit 300 are respectively disposed at upper and lower positions of the sewing machine. The head unit 100 includes the sewing head 109, an upper shaft drive motor (not shown) and a head-unit-rotating means 103. The sewing head 109 is provided with the sewing needle which reciprocates in the vertical direction. The upper shaft drive motor operates the sewing needle. The head-unit-rotating means 103 rotates the sewing head 109 around a vertical axis.

As shown in FIG. 6, the head-unit-rotating means 103 includes a rotating motor 101 which is used as a power source, and a head side power transmission unit which is connected to a drive shaft of the rotating motor 101 and transmits drive force of the rotating motor 101 to a driven shaft that rotates the sewing head 109.

Further, the head-unit-rotating means 103 includes the driven shaft (not shown) which is rotated by the drive force of the rotating motor 101 that is transmitted by the head side power transmission unit, and the sewing head 109 which is provided on the driven shaft and is rotated around the driven shaft.

In an embodiment of the present invention, a rotating drive gear unit 102 is proposed as the head side power transmission unit. The rotating drive gear unit 102 reduces the rpm of the rotating motor 101 and then rotates the sewing head 109 at the reduced rpm. A bevel gear unit is used as the rotating drive gear unit 102.

The bevel gear unit which is used as the rotating drive gear unit 102 of the present invention is configured such that the drive shaft is at a right angle to the driven shaft. The bevel gear unit reduces the rpm of the drive shaft and then rotates the driven shaft at the reduced rpm.

In the present invention, not only the rotating drive gear unit described above but also a different kind of power transmission unit, for example, a belt unit, such as a timing belt, etc., may be used as the head side power transmission unit.

FIGS. 9A and 9B are views showing an embodiment of the rotating drive gear unit of the present invention. In the embodiment of the present invention, the drive shaft 101a of the rotating motor 101 which functions as an input shaft is at a right angle to the driven shaft 101b which functions as an output shaft. As shown in FIG. 9B, a bevel gear 102a which is provided on the drive shaft 101a engages with a bevel gear 102b which is provided on the driven shaft 101b. The bevel gears 102a and 102b are configured such that the output rpm is markedly reduced.

In an embodiment of the present invention, a rotating drive gear unit is used, which has not only a back driving function which makes it possible to rotate the input shaft (drive shaft) by rotating the output shaft (driven shaft) but also a reduction function which reduces the rpm of the input shaft and transmits the drive force to the output shaft at the reduced rpm. Due to such functions of the rotating drive gear unit, concentricity and a seam setting operation of the sewing head 109 and a sewing bed 309 can be facilitated.

As shown in FIG. 7, the bed-unit-rotating means 303 includes a rotating motor 301 which is used as a power source, and a bed side power transmission unit which is connected to a drive shaft of the rotating motor 301 and transmits the drive force of the rotating motor 301 to a driven shaft that rotates the sewing bed 309.

Further, the bed-unit-rotating means 303 includes the driven shaft (not shown) which is rotated by the drive force of the rotating motor 301 that is transmitted by the bed side power transmission unit, and the sewing bed 309 which is provided on the driven shaft and is rotated around the driven shaft.

In an embodiment of the present invention, a rotating drive gear unit 302 is proposed as the bed side power transmission unit. The rotating drive gear unit 302 reduces the rpm of the rotating motor 301 and then rotates the sewing bed 309 at the reduced rpm. A bevel gear unit is used as the rotating drive gear unit 302.

The bed side power transmission unit comprises the bevel gear unit which is configured such that the drive shaft is angled to the driven shaft at the right angle. The bed side power transmission unit has the same construction as that of the head side power transmission unit of the head-unit-rotating means, therefore its further explanation will be omitted.

In the present invention, not only the rotating drive gear unit described above but also a different kind of power transmission unit, for example, a belt unit, such as a timing belt, etc., may be used as the bed side power transmission unit.

In the drawings, the reference numerals 110 and 310 denote slip rings which are used to supply current to the corresponding rotating motors.

Furthermore, a lower shaft drive motor 305 is provided to operate a lower shaft which is installed under the sewing bed 309. The lower shaft drive motor 305 is synchronized with the upper shaft drive motor (not shown) of the head unit 100 so that they are operated at the same time. The rotating motor 301 of the bed unit 300 is synchronized in momentum with the rotating motor 101 of the head unit 100 so that they are operated together.

Meanwhile, in the sewing machine of the present invention, the head unit 100 can be moved along the upper frame 520 in the X-axis direction by the X-axial head-unit-transport means 530. Further, a sewing frame which holds thereon the object to be sewn can be moved in the Y-axis direction by a Y-axial transport means 400. Therefore, a range within which the object can be processed can be increased.

A well-known structure may be used as the Y-axial transport means 400. In an embodiment of the present invention, the Y-axial transport means 400 includes a Y-axial to frame 410, a guide rail unit 420, a support unit 440 and a Y-axial transport motor 430. The Y-axial frame 410 extends a predetermined length in the Y-axis direction. The guide rail unit 420 is provided on the Y-axial frame 410. The support unit 440 transports a sewing frame mounting unit 450 along the guide rail unit 420 in the Y-axis direction, in other words, forwards and rearwards. The Y-axial transport motor 430 provides drive force by which the support unit 440 is transported along the guide rail unit 420 in the Y-axis direction.

The guide rail unit 420 includes a guide rail (not shown), a transport member (not shown) and a drive force transmission unit (not shown). The guide rail is installed on the Y-axial frame 410 and guides the transport member (not shown), which is provided in the guide rail, so that the transport member can move forwards and rearwards (in the Y-axis direction). The transport member is provided in the guide rail (not shown) and has on a lower end thereof gear teeth which engage with a drive belt of the drive force transmission unit (not shown). An upper end of the transport member is coupled to the support unit 440. The drive force transmission unit includes a power unit comprising a plurality of pulleys which operate the drive belt that engages with the gear teeth of the transport member (not shown). Thus, the drive force transmission unit functions to transmit the drive force of the Y-axial transport motor 430 to the transport member.

A small-diameter drive pulley (not shown) is fitted over the drive shaft of the Y-axial transport motor 430 and is connected to a large-diameter driven pulley (not shown) by a timing belt. The driven pulley is fitted over a transport shaft 460 which transmits the drive force of the Y-axial transport motor 430 to the drive force transmission unit of the guide rail unit 420.

The drive force transmission process of the Y-axial transport means 400 is as follows. When the drive pulley connected to the drive shaft of the Y-axial transport motor rotates, the large-diameter driven pulley which is connected to the drive pulley by the timing belt is synchronized with and rotated along with the drive pulley. Then, the transport shaft 460 which is fitted through the driven pulley is rotated along with the large-diameter driven pulley.

The transport shaft 460 which is connected to the drive force transmission unit (not shown) of the guide rail unit 420 operates the power unit provided in the drive force transmission unit, thus operating the drive belt. The transport member which engages with the drive belt is operated by the operation of the drive belt. Thereby, the support unit 440 which is mounted to the transport member is operated.

Because the support unit 440 is connected to the sewing frame mounting unit 450, as the support unit 440 is transported by the transport member in the Y-axis direction, the sewing frame mounting unit 450 also moves along with the support unit 440 in the Y-axis direction.

Hereinafter, a second embodiment of the present invention will be described in detail with reference to FIGS. 10 and 11. FIG. 10 is a front view illustrating a sewing machine, according to the second embodiment of the present invention. FIG. 11 is a side view illustrating the sewing machine according to the second embodiment.

In the first embodiment of the present invention, the X-axial head-unit-transport motor (532, refer to FIG. 4A) which transports the head unit 100 in the X-axis direction is separately provided from the X-axial bed-unit-transport motor 632 which transports the bed unit 300 in the X-axis direction, although they are synchronized with each other and operated together.

However, the second embodiment of the present invention proposes a structure in which transport screws 534 and 634 of upper and lower shafts are rotated together only by a single motor.

In detail, the second embodiment of the present invention includes, as the X-axial head-unit-transport means and the X-axial bed-unit-transport means, an integrated X-axial transport motor 550, an upper transport screw 534, a lower transport screw 634, an upper guide rail 538, a lower guide rail 638 and a power transmission means. The integrated X-axial transport motor 550 is provided on one of the support posts 502. The upper transport screw 534 is installed on the upper frame 520. The head unit 100 is connected to the upper transport screw 534. The lower transport screw 634 is installed on the lower frame 521. The bed unit 300 is connected to the lower transport screw 634. The upper guide rail 538 is provided on the upper frame 520 so that the head unit 100 can be transported along the upper frame 520. The lower guide rail 638 is provided on the lower frame 521 so that the bed unit 300 can be transported along the lower frame 521. The power transmission means transmits the rotating force of the integrated X-axial transport motor 550 to the upper transport screw 534 and the lower transport screw 634 at the same time.

In this embodiment, a timing belt 552 which can reliably transmit the rotating force and make a small amount of noise is used as the power transmission means.

Furthermore, a drive pulley 551 is provided on an output shaft of the integrated X-axial transport motor 550. An upper driven pulley 535 is coupled to the corresponding end of the upper transport screw 534. A lower driven pulley 635 is coupled to the corresponding end of the lower transport screw 634.

A timing belt 552 is coupled to the drive pulley 551, the upper driven pulley 535 and the lower driven pulley 635 so that the upper transport screw 534 and the lower transport screw 634 are operated at the same time by the operation of the drive pulley 551.

The integrated X-axial transport motor 550 is installed on one of the support posts 502. Preferably, the integrated X-axial transport motor 550 is disposed at a medial position between the upper transport screw 534 and the lower transport screw 634.

In the second embodiment, although the transport screws 534 and 634 have been illustrated as being used as upper and lower transport units, the present invention is not limited to this. For example, other kinds of transport units, such as wires, gears, etc., may substitute for the transport screws 534 and 634.

Further, in the second embodiment, the guide rails 538 and 638 have been illustrated as being used as the upper and lower guide means, the present invention is not limited to this. For example, a different kind of guide means, such as LM guides, etc., may be used in place of the guide rails 538 and 638.

In addition, first and second tensioner pulleys 537 and 637 which apply tensile force to the timing belt 552 are further provided on the corresponding support post 502.

The timing belt 552 is designated by a thick dotted line in FIG. 11. The timing belt 552 connects the integrated X-axial transport motor 550, the upper and lower transport screws 534 and 634 and the first and second tensioner pulleys 537 and 637 to each other so that they operate in unison. In this embodiment, when the integrated X-axial transport motor 550 rotates, the upper and lower transport screws 534 and 634 are rotated at the same time at the same speed and in the same direction.

In the second embodiment, the timing belt 552 has been illustrated as being used as the power transmission means, but the present invention is not limited to this. For example, a different kind of power transmission means, such as a chain, a gear, etc., may substitute for the timing belt 552. A V-belt may be used unless this causes the problem of a slip.

A method of controlling the operation of the sewing machine of the present invention will be described in detail below.

After the sewing needle of the head unit 100 has been disposed above a needle plate, the X-axial head-unit-transport motor 532, 550, the Y-axial transport motor 430, the head unit rotating motor 101 and the bed unit rotating motor 301 are operated depending on data input to the control unit.

As such, to ensure the safety in use, only when the sewing needle of the head unit 100 is disposed above the needle plate can the X-axial head-unit-transport motor 532, 550, the Y-axial transport motor 430, the head unit rotating motor 101 and the bed unit rotating motor 301 be operated. For this, a needle position sensing means for detecting whether the sewing needle is disposed above the needle plate is provided. A well-known sensing means can be used as the needle position sensing means.

Thereafter, the upper shaft drive motor and the lower shaft drive motor 305 are operated to move the sewing needle downwards, thus forming a stitch. When the sewing needle moves upwards and is thus disposed above the needle plate again, the X-axial head-unit-transport motor 532, 550, the Y-axial transport motor 430, the head unit rotating motor 101 and the bed unit rotating motor 301 are operated to repeat the above process.

Here, depending on the rpm of the upper shaft drive motor which moves the sewing need upwards and downwards, the rpms of the X-axial head-unit-transport motor 532, 550, the Y-axial transport motor 430, the head unit rotating motor 101 and the bed unit rotating motor 301 can be controlled.

Typically, the rpms of these are controlled in proportion to, especially in linear proportion to, the rpm of the upper shaft drive motor.

As stated above, the lower shaft drive motor 305 is synchronized with the upper shaft drive motor and operated along with it, therefore further explanation thereof will be omitted.

Meanwhile, while stitching at high speed, if the head unit 100 and the bed unit 300 suddenly rotate, the stitching operation may not be smooth, or stress may be applied to the elements of the sewing machine.

Therefore, the sewing machine is preferably configured such that the rpm of the upper shaft drive motor is reduced to a predetermined range before the head unit 100 and the bed unit 300 rotate, for example, before 5 to 10 stitches prior to when they begin to rotate.

As necessary, the upper shaft drive motor may temporarily stop.

Furthermore, the rpm of the upper shaft drive motor may be controlled in response to the angle at which the head unit 100 and the bed unit 300 rotate. As the rpm of the upper shaft drive motor increases, the time for which the rotating motors 101 and 301 can move to a predetermined angle is reduced. Thus, preferably, the angle at which the head unit 100 and the bed unit 300 rotate is inversely proportional to the rpm of the upper shaft drive motor.

For instance, if the angle at which the head unit 100 and the bed unit 300 rotate is 30° or more, the rpm of the upper shaft drive motor is lowered to a range from 0 rpm to 100 rpm before the rotating motors 101 and 301 are operated. If the rotating motor 101 and 301 are not in operation or rotate to a predetermined angle or less, the rpm of the upper shaft drive motor automatically returns to the normal level.

The operation of the sewing machine of the present invention having the above-mentioned construction will be explained below.

To start sewing, a sewing start switch (not snow) is turned on. Then, the head unit 100 moves downwards, and the upper shaft drive motor (not shown) of the head unit is operated. The lower shaft drive motor 305 of the bed unit 300 which is synchronized with the upper shaft drive motor of the head unit 100 is operated along with the upper shaft drive motor.

To sew the object in a circular, curved or slant line, when the head unit rotating motor 101 is operated, the sewing head 109 is rotated by drive force which is transmitted from the head unit rotating motor 101 by the head side power transmission unit.

Here, because the bed unit rotating motor 301 is synchronized in momentum with the head unit rotating motor 101, the sewing bed 309 is also rotated.

As such, the sewing head 109 and the sewing bed 309 rotate together while sewing the object. Therefore, the quality of sewing relative to the variation in the rotation angle can be made better.

That is, because the head unit 100 and the bed unit 300 are completely rotated by the head unit rotating motor 101 and the bed unit rotating motor 301 before the upper shaft drive motor and the lower shaft drive motor 305 are operated, the orientation of a sewn thread can be maintained constant. Hence, even when sewing an object, such as an airbag, a bag, a shoe, etc., the perfect stitch can be realized over the entirety of the object.

FIG. 12 illustrates a third embodiment of the present invention, showing a perspective view of a sewing machine having multi-sewing heads. FIG. 13 is a perspective view showing an embodiment in which a linear motor is used as a drive source of a Y-axial transport means according to the present invention. FIG. 14 is a front view of the third embodiment of the present invention.

In the third embodiment of the present invention, the head unit 100 comprises a plurality of head units 100 which are arranged in a row on the upper frame 520. The bed unit also comprises a plurality of bed units which are arranged to correspond to the respective head units 100. A plurality of objects are held by a single sewing frame 50 on the table 510. Thus, the sewing machine of the third embodiment can sew the objects at the same time.

The sewing frame 50 is separated into individual areas so that the objects can be respectively supported on the individual areas of the sewing frame 50. The sewing frame 50 can be moved in the Y-axis direction by the Y-axial transport means.

The method of placing the objects on the sewing frame 50 is as follows. Subsidiary sewing frames may be individually removably provided at positions corresponding to the respective head units 100. Alternatively, as shown in the drawings, object support members which are individually partitioned from each other may be provided on the single sewing frame 50, so that the objects are respectively held on the object support members.

In other words, the sewing frame 50 may be configured such that the subsidiary sewing frames are individually removably provided on the single large sewing frame 50. Alternatively, the object support members may be provided on the sewing frame 50 in such a way that the sewing frame 50 is partitioned only into several work sections by the object support members, so that only the objects can be removable from the sewing frame 50. However, the present invention is not limited only to these structures.

Furthermore, not only the rotary type Y-axial transport motor 430 can be used as the Y-axial transport means, as shown in FIGS. 13, but also a Y-axial linear motor 910 can be used.

The Y-axial linear motor 910 is installed on the Y-axial frame 410 and provides the drive force that moves the sewing frame 50 in the X-axis direction. As well as the rotating motor or the linear motor which was stated in the description of the first embodiment of the present invention, a ball screw structure can be used as a drive source of the Y-axial transport means. In addition, any other power generating means can be used as the drive source. In the present invention, the drive source is not limited to any special structure.

Meanwhile, each of the sewing heads which are arranged in a row on the upper frame 520 is rotatably configured. Here, the sewing heads are operated in the same direction at the same time by sewing data (pattern data) which is input by a worker so that the objects which are placed on the table 510 can be sewn at the same time in the same shape.

Because such a multi-head structure can process a plurality of objects at the same time, the productivity of the sewing machine can be markedly enhanced.

Moreover, different colors of threads (yarns) may be used to sew the objects which are placed on the sewing frame 50. In this case, although the objects are sewn in the same shape, they can be sewn in different colors. Therefore, the optimum colors of the threads (yarns) suitable for the sewing design can be easily selectively used.

(Method of Improving the Productivity/Workability Using Barcodes)

Referring to FIGS. 12 and 14, a plurality of work sections are arranged in a row in the X-axis direction.

In this embodiment of the present invention, the object support members, each of which individually supports a single object that is a single work unit, are provided on the sewing frame 50. Thus, the sewing frame 50 has a plurality of work sections.

An indication 53, which contains information about a sewing pattern, sewing information and a working method, is formed on a predetermined portion of the sewing frame 50. A reader 54 which scans the indication 53 is provided on the head unit.

The reader 54 reads the information contained in the indication 53 and sends it to the control unit. The nub of the information contained in the indication 53 includes which pattern to sew or which way to sew.

A great variety of information, as well as the sewing pattern and sewing work information, can be contained in the indication 53.

Examples of the great variety of information may include how much work is left to do, how many objects can be sewn in the same pattern from now on without scanning the indication, by how much to reduce the stitching speed when the objects are tough or thick, etc.

As such, because the indication 53 and the reader 54 are used, each object can be sewn in the pattern P that is desired by the worker.

Furthermore, using the indication and reader is advantageous in that the working error can be detected in advance as follows.

Before the sewing operation begins, the worker inputs, using an input means or wire/wireless communication means, information about a sewing pattern and the sewing work to the control unit of the sewing machine. The reader reads information contained in the indication, and the sewing unit begins the sewing operation when the information about the sewing pattern and the sewing work that was input to the control unit before the sewing operation matches with the information that the reader read. If the two kinds of information differ from each other, an error indicator generates an error signal to let the worker recognize this.

For example, after the worker inputs information about the sewing pattern and the sewing work to the control unit of the sewing machine using the input means or wire/wireless communication means and stores it in the control unit before the sewing operation begins, if the sewing work information that has been stored in the control unit of the sewing machine differs from the current information that is contained in the indication of the sewing frame, an error signal is generated to let the worker know the difference, and the sewing operation is stopped.

Such an operation of the sewing machine of the present invention can prevent a problem in which expensive fabric may be destroyed by carrying out work that is incorrect and not desired by the worker.

In the present invention, one selected from among a variety of styles, such as numerals, colors, a punch card, a barcode and an RFID card, etc., can be selectively used as the indication.

In an embodiment of the present invention, a barcode which is inexpensive but is able to contain a lot of information is used. In this case, the reader comprises a barcode reader.

Furthermore, in another embodiment of the present invention, a sewing frame position sensing means may be further provided, which determines whether the subsidiary sewing frames are disposed on the sewing frame at the correct positions.

A proximity sensor, a resistance sensor or the like can be selectively used as the sewing frame position sensing means.

As described above, in a sewing machine according to the present invention, a head unit and a bed unit can rotate while sewing. Thus, the orientation of a sewn thread can be maintained constant. Therefore, even when sewing an object, such as an airbag, a bag, a shoe, etc., a perfect stitch can be realized over the entirety of the object.

Furthermore, unlike the conventional sewing machine in which an arm part is connected to a bed unit by a connection unit, the head unit is provided on a bridge supported by a support post, so that the sewing machine can be designed in an arch shape without a vertical connection structure being required to connect the head unit to the bed unit. Hence, a sewing work area with respect to a Y-axis (longitudinal) direction of the sewing machine can be markedly increased.

In addition, the head unit and the bed unit are provided on the upper and lower bridges so as to be movable in an X-axis direction along the upper and lower bridges. Therefore, a sewing work area with respect to the X-axis (lateral) direction of the sewing machine can also be markedly increased.

Further, in the case of the structure in which the head unit is provided on the bridge, because vibrations which are generated when the head unit and the bed unit rotate are markedly reduced, the sewing operation can be more rapidly carried out.

Moreover, placing an object on the head unit or removing it therefrom is facilitated because the head unit is movable vertically. Unlike the conventional technique which can sew only a thin object, the sewing machine of the present invention can sew objects of different thicknesses including comparatively thick objects as well as thin objects.

Furthermore, in the conventional sewing machine, the upper and lower shafts are connected to a single motor by timing belts or the like. Thus, an excessive load is applied to the motor. However, in the present invention, an upper shaft drive motor and a lower shaft drive motor are separately provided and operated, thus avoiding the conventional problem of the excessive load, and making it possible to increase the speed of the sewing operation.

Further, an integrated X-axial transport motor and a timing belt may be used to transport the head unit and the bed unit in the X-axial direction. In this case, the size of the sewing machine and the production cost thereof can be reduced.

Moreover, a plurality of objects to be sewn can be processed at the same time. Thus, the productivity of the sewing machine can be markedly enhanced.

In addition, the sewing machine of the present invention is operated such that a reader reads information about an object to be sewn and the object is sewn in accordance with the read information, thus preventing working errors in advance.

Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.

Claims

1. A sewing machine comprising:

a table, on an upper surface of which an object to be sewn is placed;

support posts provided on opposite sides of the table;

upper and lower frames connecting the support posts to each other;

a head unit provided on the upper frame so as to be movable in an X-axis direction, the head unit having head-unit-rotating means for rotating a sewing head within a predetermined range;

a bed unit provided on the lower frame so as to be movable in the X-axis direction, the bed unit having bed-unit-rotating means for rotating a sewing bed within a predetermined range;

X-axial head-unit-transport means for moving the head unit on the upper frame in a horizontal direction; and

X-axial bed-unit-transport means for moving the bed unit on the upper frame in the horizontal direction.

2. The sewing machine as set forth in claim 1, wherein the X-axial head-unit-transport means comprises:

an X-axial head-unit-transport motor providing a drive force;

a transport screw connected to a drive shaft of the X-axial head-unit-transport motor by power transmission means;

a head unit transport bracket reciprocating in the horizontal direction depending on rotation of the transport screw, with the head unit mounted to a front surface of the head unit transport bracket; and

a guide rail coupled to guide couplers of the head unit transport bracket so that the head unit transport bracket is able to move horizontally on the upper frame.

3. The sewing machine as set forth in claim 2, wherein the head unit is mounted to the front surface of the head unit transport bracket; a transport box is provided on a central portion of a rear surface of the head unit transport bracket, the transport box being provided around the transport screw; and the guide couplers are provided on upper and lower ends of the head unit transport bracket, the guide couplers being coupled to the guide rail.

4. The sewing machine as set forth in claim 2, wherein the drive shaft of the X-axial head-unit-transport motor is connected to the transport screw by a coupling.

5. The sewing machine as set forth in claim 1, wherein a drive source of the X-axial head-unit-transport means comprises a rotating motor.

6. The sewing machine as set forth in claim 1, wherein a drive source of the X-axial head-unit-transport means comprises a linear motor.

7. The sewing machine as set forth in claim 1, wherein the X-axial bed-unit-transport means comprises:

an X-axial bed-unit-transport motor providing a drive force;

a transport screw connected to a drive shaft of the X-axial bed-unit-transport motor by power transmission means;

a bed unit transport bracket reciprocating in the horizontal direction depending on rotation of the transport screw, with the bed unit mounted to a front surface of the bed unit transport bracket; and

a guide rail coupled to guide couplers of the bed unit transport bracket so that the bed unit transport bracket is able to move on the lower frame.

8. The sewing machine as set forth in claim 7, wherein the bed unit is mounted to the front surface of the bed unit transport bracket; a transport box is provided on a central portion of a rear surface of the bed unit transport bracket, the transport box being provided around the transport screw; and the guide couplers are provided on upper and lower ends of the bed unit transport bracket, the guide couplers being coupled to the guide rail.

9. The sewing machine as set forth in claim 7, wherein the drive shaft of the X-axial bed-unit-transport motor is connected to the transport screw by a coupling.

10. The sewing machine as set forth in claim 1, wherein a drive source of the X-axial bed-unit-transport means comprises a rotating motor.

11. The sewing machine as set forth in claim 1, wherein a drive source of the X-axial bed-unit-transport means comprises a linear motor.

12. The sewing machine as set forth in claim 1, wherein the head-unit-rotating means comprises:

a head unit rotating motor used as a power source;

a power transmission unit connected to a drive shaft of a rotating motor, the power transmission unit transmitting a drive force of the rotating motor;

a driven shaft rotated by the drive force of the rotating motor transmitted by the power transmission unit; and

the sewing head provided on the driven shaft, the sewing head being rotated around the driven shaft.

13. The sewing machine as set forth in claim 12, wherein the power transmission unit comprises a rotating drive gear reducing an rpm of the rotating motor and transmitting the drive force to the driven shaft at a reduced rpm.

14. The sewing machine as set forth in claim 13, wherein the rotating drive gear comprises a bevel gear configured such that the drive shaft is at a right angle to the driven shaft.

15. The sewing machine as set forth in claim 12, wherein the power transmission unit comprises a timing belt.

16. The sewing machine as set forth in claim 1, wherein the bed-unit-rotating means comprises:

a bed unit rotating motor used as a power source;

a power transmission unit connected to a drive shaft of a rotating motor, the power transmission unit transmitting a drive force of the rotating motor;

a driven shaft rotated by the drive force of the rotating motor transmitted by the power transmission unit; and

the sewing bed provided on the driven shaft.

17. The sewing machine as set forth in claim 16, wherein the power transmission unit comprises a rotating drive gear reducing an rpm of the rotating motor and transmitting the drive force to the driven shaft at a reduced rpm.

18. The sewing machine as set forth in claim 17, wherein the rotating drive gear comprises a bevel gear configured such that the drive shaft is at a right angle to the driven shaft.

19. The sewing machine as set forth in claim 16, wherein the power transmission unit comprises a timing belt.

20. The sewing machine as set forth in claim 1, wherein a momentum of a rotating motor of the bed-unit-rotating means is synchronized with a rotating motor of the head-unit-rotating means so that the rotating motors are operated together.

21. The sewing machine as set forth in claim 1, further comprising:

head-unit-lift means provided between the X-axial head-unit-transport means and the head unit, the head-unit-lift means moving the sewing head upwards and downwards between a stand-by position and a work position.

22. The sewing machine as set forth in claim 21, wherein the head-unit-lift means comprises:

a lift actuator installed in a main body of the sewing machine by an actuator support bracket, the lift actuator providing a drive force to move the sewing head upwards or downwards; and

a lift plate coupled at a central portion of a front surface thereof to the sewing head, the lift plate being coupled on an upper end of a rear surface thereof to a head unit connection bracket connected to a drive part of the lift actuator, with guide means mounted to opposite sides of the rear surface of the lift plate.

23. The sewing machine as set forth in claim 21, wherein the head-unit-lift means further comprises:

a support plate coupled on opposite sides of a front surface thereof to the guide means, with an actuator support bracket mounted to a central portion of a rear surface of the support plate, the actuator support bracket supporting the lift actuator thereon.

24. The sewing machine as set forth in claim 1, wherein the X-axial head-unit-transport means and the X-axial bed-unit-transport means comprises:

an integrated X-axial transport motor provided on at least one of the support posts;

an upper transport unit provided on the upper frame, the upper transport unit being connected to the head unit;

a lower transport unit provided on the lower frame, the lower transport unit being connected to the bed unit;

upper guide means provided on the upper frame so that the head unit is transported along the upper frame by the upper guide means;

lower guide means provided on the lower frame so that the bed unit is transported along the lower frame by the lower guide means; and

power transmission means for transmitting a rotating force of the integrated X-axial transport motor to the upper transport unit and the lower transport unit at a same time.

25. The sewing machine as set forth in claim 24, wherein the power transmission means comprises:

a drive pulley provided on an output shaft of the integrated X-axial transport motor;

an upper driven pulley provided on an end of the upper transport unit;

a lower driven pulley provided on an end of the lower transport unit; and

a timing belt coupled to the drive pulley, the upper driven pulley and the lower driven pulley together so that the upper transport unit and the lower transport unit are operated at a same time by a drive force of the drive pulley.

26. The sewing machine as set forth in claim 25, further comprising:

a tensioner pulley for applying a tensile force to the timing belt.

27. The sewing machine as set forth in claim 24, wherein each of the upper transport unit and the lower transport unit comprises a ball screw.

28. The sewing machine as set forth in claim 24, wherein each of the upper transport unit and the lower transport unit comprises a wire.

29. The sewing machine as set forth in claim 24, wherein each of the upper guide means and the lower guide means comprises a guide rail.

30. The sewing machine as set forth in claim 24, wherein each of the upper guide means and the lower guide means comprises an LM guide.

31. The sewing machine as set forth in claim 1, further comprising:

Y-axial transport means for transporting a sewing frame supporting the object thereon in a Y-axis direction.

32. The sewing machine as set forth in claim 31, wherein the Y-axial transport means comprises:

a Y-axial frame extending a predetermined length in the Y-axis direction;

a Y-axial linear motor provided on the Y-axial frame, the Y-axial linear motor providing a drive force to move the sewing frame in the Y-axis direction; and

a support unit provided such that the sewing frame is transported in the Y-axis direction by operation of the Y-axial linear motor.

33. The sewing machine as set forth in claim 1,

wherein the head unit comprises a plurality of head units arranged in a row on a front surface of the upper frame,

the bed unit comprises a plurality of bed units arranged in such a way as to correspond to the respective head units, and

a plurality of objects are held by a single sewing frame on the table so that a plurality of sewing operations are able to be conducted simultaneously.

34. The sewing machine as set forth in claim 1, wherein a sewing frame holding the object comprises a plurality of sewing work areas, and objects are supported on the respective sewing work areas.

35. The sewing machine as set forth in claim 34, wherein the sewing frame comprises a plurality of subsidiary sewing frames provided on the single sewing frame so as to be individually removable therefrom.

36. The sewing machine as set forth in claim 34, wherein an indication is provided on the sewing frame, the indication containing information instructing about a working method, and a reader for scanning the indication is provided on the head unit,

wherein the reader reads the information contained in the indication and transmits the information to a control unit.

37. The sewing machine as set forth in claim 36, wherein the indication comprises a barcode, and the reader comprises a barcode reader.

38. A method of controlling operation of a sewing machine comprising a head unit and a bed unit that are allowed to be transported in an X-axis direction and rotated around a Z-axis while sewing, the method comprising:

(a) positioning a sewing needle of the head unit above a needle plate;

(b) operating an X-axial transport motor, a Y-axial transport motor, a head unit rotating motor and a bed unit rotating motor in response to information input to a control unit; and

(c) moving the sewing needle downwards by operation of an upper shaft drive motor and a lower shaft drive motor to form a stitch, and returning to (b) operating when the sewing needle is moved upwards and positioned above the needle plate, and repeating (b) operating and (c) moving.

39. The method as set forth in claim 38, wherein an rpm of the upper shaft drive motor and an rpm of the lower shaft drive motor are increased or reduced in proportion to rpms of the X-axial transport motor, the Y-axial transport motor, the head unit rotating motor and the bed unit rotating motor.

40. The method as set forth in claim 38, wherein after the rpm of the upper shaft drive motor and the rpm of the lower shaft drive motor are reduced, the head unit rotating motor and the bed unit rotating motor are operated.

41. The method as set forth in claim 38, wherein the rotating speed of the upper shaft drive motor and the rotating speed of the lower shaft drive motor are controlled in response to an angle at which the head unit and the bed unit rotate.