SEWING MACHINE WITH SEQUIN SEWING DEVICE

Abstract

In a first shifting operation for shifting a sequin sewing device from an operative position to an evacuated position or in a second shifting operation for shifting the sequin sewing device from the operative position to the evacuated position, descending movement of a needle bar is inhibited by jumping the needle bar with a sewing machine maintained in an operating condition. Also, a jump code is inserted into embroidery data at a position where a shift is to be made from sequin sewing to ordinary sewing or from ordinary sewing to sequin sewing. Alternatively, the descending movement of the needle bar may be inhibited by reducing a rotation speed of the main machine shift with the machine maintained in the operating condition.

Description

BACKGROUND OF THE INVENTION

The present invention relates generally to sewing machines equipped with a sequin sewing device for sewing a sequin onto a sewing workpiece, and more particularly an improved sewing machine capable of moving a sequin sewing device between an operative position where the sewing device can sew a sequin and an evacuated position where the sewing device can not sew a sequin.

Heretofore, there have been known sewing machines which are provided with a sequin sewing device to sew sequins (spangles) onto a sewing workpiece. Japanese Patent Application Laid-open Publication No. 2004-167097 (hereinafter referred to as “Patent Literature 1”) discloses a multi-head embroidery sewing machine equipped with a sequin sewing device and capable of performing sequin sewing and embroidery sewing in combination. According to the disclosure of Patent Literature 1, the sequin sewing device is provided on the left side surface of a needle bar case having a plurality of needle bars supported therein, and the leftmost one of the needle bars in the needle bar case is used as a sequin-sewing needle bar (hereinafter “sequin needle bar”). The sequin sewing device is vertically movable (i.e., ascendable and descendable) relative to the needle bar case; namely, when a sequin is to be sewn, the sequin sewing device is moved to a lowered position, while, when a sequin is not to be sewn, the sequin sewing device is evacuated upward to a raised position so as not to hinder ordinary embroidery sewing.

The sequin sewing device includes a sequin feed mechanism for feeding a strip of a multiplicity of continuously-connected sequins (hereinafter also referred to as “continuous sequin strip”) at a predetermined pitch. More specifically, the continuous sequin strip is played out or let out from a reel and then placed on the upper surface of a support plate, after which the continuous sequin strip is fed out at the predetermined pitch, corresponding to a size of one sequin, through feeding operation of the sequin feed mechanism. Sequin located at the leading end of the continuous sequin strip, having been fed out by the sequin feed mechanism, is sewn onto a sewing workpiece while being severed from the strip through cooperation between a fixed knife secured to the support plate and a movable blade rotatably provided on the support plate. As the sequin needle bar is moved downward, the movable blade is rotated by abutting against a needle clamp provided at the lower end of the sequin needle bar, to thereby sever the leading sequin from the strip in conjunction with the fixed knife.

When a sequin is to be sewn in the multi-head embroidery sewing machine disclosed in Patent Literature 1, the sequin needle bar is selected, and the sequin sewing device is moved downward to the lowered position. Conversely, when embroidery sewing is to be performed in the disclosed multi-head embroidery sewing machine, other needle bars than the sequin needle bar are selected, and the sequin sewing device is moved upward away from the lowered position.

In many cases, sequin sewing and embroidery sewing are performed on a sewing workpiece with a same color thread. In such cases, it is more efficient to perform the sequin sewing and embroidery sewing in a successive manner by means of the sequin needle bar with the same colored thread without switching between the needle bars. For such successive sequin sewing and embroidery sewing operations, the disclosed multi-head embroidery sewing machine is arranged to keep the sequin sewing device in the lowered position throughout the successive sewing operations; this is for the purpose of successively perform the sequin sewing and embroidery sewing operations, without the sewing machine being deactivated, to thereby reduce the necessary working time. As well known in the art, when one needle bar used for a sewing operation is to be switched to another (i.e., when so-called “thread color change” is to be effected), not only the sewing machine is deactivated, but also the thread of the needle bar having so far been used for the sewing operation is severed. When the sequin sewing device is to be vertically moved as well, the sewing machine is deactivated, because there is a possibility of the movable blade, moving together with the sequin sewing device, being damaged if the blade abuts against the needle clamp of the sequin needle bar. Thus, by performing ordinary embroidery sewing, which uses a same colored thread as in sequin sewing, by means of the sequin needle bar and keeping the sequin sewing device in the lowered position as disclosed in Patent Literature 1, it is possible to eliminate the needs for deactivating the sewing machine and selecting a different needle bar from the sequin needle bar, so that no time is required for such machine-deactivating and needle-bar-selecting operations. As a result, the necessary working time can be reduced. Of course, when ordinary embroidery sewing is performed using the sequin needle bar, the sequin feed mechanism does not feed out any sequin.

Although the sewing machine disclosed in Patent Literature 1 can reduce the necessary working time by performing ordinary embroidery sewing, which uses with the same colored thread as in sequin sewing, by means of the sequin needle bar with the sequin sewing device kept in the lowered position, the needle clamp would undesirably abut against the sequin needle bar as the sequin needle bar descends because the embroidery sewing with the sequin needle bar is performed with the sequin sewing device kept in the lowered position. Namely, the movable blade would be unnecessarily hit by the needle clamp and thus tends to be broken easily. In addition, the unnecessary abutment between the needle clamp and the movable blade would result in greater noise sound of the sewing machine.

SUMMARY OF THE INVENTION

In view of the foregoing, it is an object of the present invention to provide an improved sewing machine which, in performing ordinary sewing with a sequin needle bar, can prevent abutment between a needle clamp and a movable blade by moving a sequin sewing device to an evacuated position, and which can considerably reduce a necessary working time by allowing the sequin sewing device to move between an operative position and the evacuated position without the machine being deactivated.

In order to accomplish the above-mentioned object, the present invention provides an improved sewing machine, which comprises: a machine head including a needle bar mechanism usable for both sequin sewing and ordinary sewing, said needle bar mechanism having a vertically-movable needle bar for sewing; a sequin sewing device provided in correspondence with the needle bar mechanism and movable between an operative position where said sequin sewing device can perform sequin sewing and an evacuated position where said sewing device can not perform sequin sewing; a needle bar control section that, in a first shifting operation for shifting said sequin sewing device from the operative position to the evacuated position or in a second shifting operation for shifting said sequin sewing device from the evacuated position to the operative position, inhibits or delays descending movement of the needle bar of the needle bar mechanism while maintaining said sewing machine in an operating condition; and a movement mechanism that moves said sequin sewing device to the evacuated position in said first shifting operation but moves said sequin sewing device to the operative position in said second shifting operation while said needle bar control section inhibits or delays descending movement of the needle bar.

In the first shifting operation for shifting the sequin sewing device from the operative position to the evacuated position or in the second shifting operation for shifting the sequin sewing device from the operative position to the evacuated position, the descending movement of the needle bar of the needle mechanism is inhibited or delayed with the sewing machine maintained in the operating condition (e.g., rotation of a main machine shaft maintained). Thus, the needle bar can be held in an upper position away from the operative position, or the time for which the needle bar is held in the upper position, can be increased, without the sewing machine being deactivated, and the sequin sewing device can be safely moved from the operative position to the evacuated position or from the evacuated position to the operative position while the needle bar is held in the upper position. Such arrangements can not only prevent unwanted hitting or abutment between the needle clamp and the movable blade, but also permits the vertical movement of the sequin sewing device and thus achieves a significant reduction of the necessary working time.

As an example, the needle bar control section is a needle jump mechanism, which inhibits the descending movement of the needle bar by placing the needle bar in a jump state.

As another example, the needle bar control section is a main machine shaft speed control device (i.e., device for controlling the operating speed of the main machine shaft), which inhibits the descending movement of the needle bar by reducing the operating speed of the main machine shaft.

According to a specific embodiment of the present invention, when an embroidery pattern comprising a mixture of a sequin-sewn portion and an ordinary embroidery portion is to be sewn, not only the needle bar control section is caused to inhibit the descending movement of the needle bar (i.e., jump the needle bar) or delays the descending movement (reduces the operating speed of the main machine shaft), but also the movement mechanism is caused to move the sequin sewing device, in correspondence with an embroidery pattern position where the first shifting operation is to be performed.

For example, when ordinary embroidery sewing (i.e., operation for sewing an ordinary embroidery portion of the embroidery pattern) is to be performed, after sequin sewing (i.e., operation for sewing a sequin-sewn portion of the embroidery pattern), by means of the same needle bar as used in the sequin sewing, the needle bar used in the sequin sewing is temporarily placed in a jump state or the operating speed of the main machine shaft is reduced, and then the sequin sewing device is moved from the operative position to the evacuated position. After that, the jump state of the needle bar is canceled or the operating speed of the main machine shaft is brought back to the normal operating speed, to thereby perform the ordinary embroidery sewing. Thus, the movable blade attached to the sequin sewing device located in the evacuated position is no longer hittable by the needle clamp of the vertically-moved needle bar. Thus, during the ordinary embroidery sewing with the same needle bar as in the sequin sewing, it is possible to prevent the movable blade from being unnecessarily hit by the needle clamp of the needle bar and thereby prevent the movable blade from being easily broken. Also, with the aforementioned arrangements, no hitting sound is produced between the movable blade and the needle bar, so that the present invention can prevent noise sound, produced by the sequin needle bar during the ordinary embroidery sewing, from becoming great. Conversely, when sequin sewing is to be performed, after ordinary embroidery sewing, with the same needle bar as used in the ordinary embroidery sewing, the descending movement of the needle bar used in the ordinary embroidery sewing is inhibited (i.e., the needle bar is jumped) or delayed (i.e., the operating speed of the main machine shaft is reduced), and then the sequin sewing device is moved from the evacuated position to the operative position. After that, the descending movement inhibition (jump state) of the needle bar is canceled or the operating speed of the main machine shaft is brought back to the normal operating speed, to thereby perform the sequin sewing. Namely, in each of the first and second shifting operations, the vertical movement of the sequin sewing device is effected with the needle bar placed in the jump state, and thus, the positional shifting of the sequin sewing device is effected without the operation of the sewing machine (rotation of the main machine shaft) being stopped. As a result, the present invention can significantly reduce a waste of the working time as compared to the conventional counterpart in which the positional shifting of the sequin sewing device is effected with the sewing machine deactivated.

As an example, the sewing machine of the present invention further comprises: an embroidery data supply section that supplies embroidery data of an embroidery pattern comprising a mixture of a sequin-sewn portion and an ordinary embroidery portion; and a data generation section that determines, on the basis of supplied embroidery data, an embroidery pattern position where the first shifting operation or the second shifting operation is to be performed and inserts a jump code instructing a needle bar jump (or main-machine-shaft speed reduction instruction instructing reduction of the operating speed of the main machine shaft) into the embroidery data in correspondence with the determined embroidery pattern position. In accordance with the jump code inserted in the embroidery data, the needle bar control section and the movement mechanism jump the needle bar (or reduce the operating speed of the main machine shaft) and move the sequin sewing device from the operative position to the evacuated position or from the evacuated position to the operative position.

As another example, the embroidery data have a jump code instructing a needle bar jump (or main-machine-shaft speed reduction instruction instructing reduction of the operating speed of the main machine shaft) inserted therein in advance in correspondence with an embroidery pattern position where the first shifting operation or the second shifting operation is to be performed, and, in accordance with the jump code (or main-machine-shaft speed reduction instruction) inserted in the embroidery data, the needle bar control section and the movement mechanism jump the needle bar (or reduce the operating speed of the main machine shaft) and move the sequin sewing device from the operative position to the evacuated position or from the evacuated position to the operative position.

The following will describe embodiments of the present invention, but it should be appreciated that the present invention is not limited to the described embodiments and various modifications of the invention are possible without departing from the basic principles. The scope of the present invention is therefore to be determined solely by the appended claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a perspective view showing a general outer appearance of a multi-head sewing machine in accordance with a first embodiment of the present invention;

FIG. 2 is a left side view showing in enlarged scale a part of an example sequin sewing device attached to one of the machine heads in the embodiment of the present invention, which particularly shows the sequin sewing device lowered to its operative position;

FIG. 3 is a left side view of the sequin sewing device, which shows the sequin sewing device raised to its evacuated position;

FIG. 4 is a right side view showing in enlarged scale a part of a sequin feed mechanism in the embodiment of the present invention;

FIG. 5 is a block diagram showing an example control system of the embroidery sewing machine according to the embodiment of the present invention;

FIG. 6 is a flow chart showing an embodiment of processing performed in the embodiment for automatically creating needle bar jump data on the basis of embroidery data and then inserting the created needle bar jump data in the embroidery data;

FIG. 7 is a diagram showing an embroidery pattern that comprising a mixture of sequin-sewn portions and ordinary embroidery portions; and

FIG. 8 is a schematic diagram showing example formats of embroidery data corresponding to the embroidery pattern of FIG. 7, of which (a) shows original embroidery data before insertion of jump codes and (b) shows embroidery data after insertion of jump codes.

DETAILED DESCRIPTION OF EMBODIMENTS

FIG. 1 shows a four-head embroidery sewing machine equipped with four sewing machine heads and constructed in accordance with an embodiment of the present invention. Needle bar cases 2 are provided in corresponding relation to the sewing machine heads, and a needle plate 30 is disposed under each of the needle bar cases 2. Sequin sewing device 1 is attached to the left side and/or right side of each of the needle bar cases 2; in the illustrated example, the sequin sewing device 1 is attached to only the left side of the associated needle bar case 2. Each of the needle bar cases 2 comprises a multi-needle structure, and, in the case where the sequin sewing device 1 is attached to only the left side of the associated needle bar case 2 as in the illustrated example, the leftmost needle in the needle bar case 2 is used as a sequin-sewing needle bar (i.e., sequin needle bar). As conventionally known in the art, an embroidery frame 31 is driven in left-right (X) and front-rear (Y) directions in accordance with predetermined sewing data.

FIG. 2 is a left side view showing in enlarged scale one of the sequin sewing devices 1 The sequin sewing device 1 includes a mounting base 4, on which are supported a reel 5 having a continuous sequin strip 3 wound thereon and a sequin feed mechanism 6. The mounting base 4 is mounted, via two connecting arms 8, on a base 7 that is in turn fixed to the left side surface of the needle bar case 2. Each of the connecting arms 8 is pivotably connected at its opposite ends to the mounting base 4 and fixed base 7, and the mounting base 4 is vertically movable (i.e., ascendable and descendable) relative to the fixed base 7 (and hence the needle bar case 2). Air cylinder 9 is provided on the mounting base 4 and fixed to a bracket 10 that is pivotably connected to the mounting base 4. Rod of the air cylinder 9 has a distal end fixed to a bracket 11 that is pivotably connected to the fixed base 7. Through activation of the air cylinder 9, the mounting base 4 vertically moves relative to the fixed base 7, so that the entire sequin sewing device 1 vertically moves between a lowered position (i.e., operative position) where the sewing device can sew a sequin and a predetermined evacuated position (i.e., upper position shown in FIG. 3) where the sewing device is evacuated above and away from the lowered position.

FIG. 4 is a right side view showing in enlarged scale a part of the sequin feed mechanism 6. The sequin feed mechanism 6 is attached to a supporting plate 12 that is in turn mounted on a lower portion of the mounting base 4. Support plate 13 for supporting thereon sequins is horizontally attached to the lower end of the supporting plate 12, and a continuous sequin strip 3 let out from the reel 5 is led onto the upper surface of the support plate 13. Pivot arm 15, pivotable by a motor 14 fixed to the mounting base 4, is supported on the supporting plate 12. Feed lever 16 is pivotably connected to a free end portion of the pivot lever 15. The feed lever 16 is driven in a forward-rearward direction, by means of the motor 14, so as to sequentially feed the continuous sequin strip 3 at a predetermined pitch. Movable blade 17 is rotatably supported on a lower portion of the supporting plate 12, and a fixed blade 18 is formed on an end edge portion of the support plate 13 adjacent to the movable blade 17. The movable blade 17 is normally retained, by means of a torsion spring 19, in an evacuated position spaced upward from the fixed blade 18. The movable blade 17 is pressed by a needle clamp 21 provided at the lower end of a needle bar 20 as the needle bar 20 descends. As the movable blade 17 is pressed by the needle clamp 21 of the descending needle bar 20, the movable blade 17 pivots, against the biasing force of the torsion spring 19, to cooperate with the fixed blade 18 to sever the leading sequin from the fed continuous sequin strip 3. As the needle clamp 21 ascends together with the needle bar 20, the movable blade 17 returns to the evacuated position by the biasing or restoring force of the torsion spring 19. The sequin feed mechanism 6 is of the well-known type and has a construction as disclosed in Patent Literature 1 discussed above, and thus a detailed description of the sequin feed mechanism 6 is omitted here.

FIG. 5 is a block diagram showing an example control system of the embroidery sewing machine according to the instant embodiment of the present invention. Various operations performed by the embroidery sewing machine are controlled by a microcomputer that includes a CPU (Central Processing Unit) 41, ROM (Read-Only Memory) 42 and RAM (Random Access Memory) 43. Panel section 44 comprises switches and various other operators operable by a user to make various settings, selections, instructions, etc., a display and various other components. Storage section 45, which may comprise a hard disk, removable storage medium, etc., stores various control programs for carrying out the present invention, various operation control programs, embroidery-pattern sewing data corresponding to various embroidery patterns, etc. To a computer bus 46 are connected, via interfaces (I/Fs), drivers (e.g., a motor, solenoid, cylinder and the like) 47-51 for controllably driving various mechanisms of the sewing machine. For simplicity, FIG. 5 shows only the drivers 47-51.

Main machine shaft driver 47 includes a main machine shaft motor. As well known in the art, a main machine shaft is rotated in accordance with a machine operation instruction, in response to which the needle bars selected in the individual machine heads are driven vertically. The rotation of the main machine shaft is stopped in accordance with a machine stop instruction. The embroidery frame driver 48 includes X-axis and Y-axis driving motors for driving the embroidery frame 31 in the X-axis and Y-axis directions. As well known in the art, the embroidery frame 31 is driven, in the X-axis and Y-axis directions, in accordance with a stitch-by-stitch sewing pattern (sewing widths and directions) corresponding to embroidery-pattern sewing data. The color change driver 49 includes motors for sliding the needle bar cases 2 of the individual machine heads. As also well known in the art, when a colored thread change is to be effected, the needle bar cases 2 of the individual machine heads are slid to select one of the needle bars which has a desired colored thread set thereon. When sequin sewing is to be performed, the needle bar 20 corresponding to the sequin sewing device 1 is selected. The needle bar jump driver 50 includes solenoids etc, for placing the needle bars 20 of the individual machine heads in a jump-sewing state. As also well known in the art, if the needle bar 20 is jumped, the needle bar 20 is held in a predetermined upper jump position and prevented from being driven vertically, even when the main machine shaft is rotating. The sequin driver 51 includes a driver (i.e., the aforementioned motor 14) for driving the sequin feed mechanism 6 of the sequin sewing device 1, and an elevating driver (i.e., the aforementioned air cylinder 9). The driver (motor 14) for driving the sequin feed mechanism 6 is controlled, by the CPU 14, in correspondence with each sequin sewing stitch during a sequin sewing operation. The elevating driver (air cylinder 9) is controlled, by the CPU 14, to move the sequin sewing device 1 to the lowered or operative position prior to the start of the sequin sewing operation and move the sequin sewing device 1 to the evacuated position after the end of the sequin sewing operation.

In this specification, an operation for shifting the sequin sewing device 1 from the operative position to the evacuated position will be referred to as “first shifting operation”, while an operation for shifting the sequin sewing device 1 from the evacuated position to the operative position will be referred to as “second shifting operation”. When the first shifting operation is to be performed may be either automatically determined by the CPU 41 in accordance with a progression of the embroidery sewing operation or automatically instructed at predetermined timing by instruction data, inserted in embroidery data, in accordance with a progression of the embroidery sewing operation, or may be instructed at appropriate timing in response to operation by a human operator of the sewing machine.

Further, during ascending/descending movement, via the sequin driver 51, of the sequin sewing device 1, i.e. during the first or second shifting operation, the CPU 41 performs needle bar control for inhibiting or delaying the descending movement of the needle bar while keeping the sewing machine in the operating condition (i.e., without the sewing machine being deactivated). First embodiment of the needle bar control comprises inhibiting the descending movement of the needle bar by means of a needle bar jump mechanism, as will be described in detail below.

According to the first embodiment of the needle bar control, the CPU 41 and needle bar jump driver 50 function as a needle bar control section, and the needle bar jump driver 50 is driven to cause the needle bar 20 to jump under the control of the CPU 41. By the jumping of the needle bar 20, undesired interference between the ascending or descending sequin sewing device 1 and the needle bar mechanism can be avoided even when the sequin sewing device 1 is caused to ascend or descend without the rotation of the main machine shaft being stopped; particularly, it is possible to prevent the needle clamp 21 from hitting the movable blade 17. Once the sequin sewing device 1 is positioned in the predetermined operative position or evacuated position after completion of the descending/ascending movement, the jump control of the needle bar 20 is terminated, after which the needle bar 20 is driven vertically in accordance with the rotation of the main machine shaft. Further, when the ordinary embroidery sewing operation is to be performed by means of the needle bar 20 corresponding to a needle bar position where the sewing device 1 is disposed, it is performed with the sequin sewing device 1 held in the upper evacuated position; thus, the needle clamp 21 of the vertically-driven (i.e., ascending and descending) needle bar 20 can be reliably prevented from hitting the movable blade 17 of the sequin sewing device 1.

The aforementioned control for causing the needle bar 20 to jump at the time of the first or second shifting operation is advantageous particularly in a case where, during sewing of one embroidery pattern, switching is performed as necessary between the sequin sewing operation and the ordinary embroidery sewing operation, using the same needle bar 20 (i.e., the same colored thread) as used in the sequin sewing operation, with the sewing machine maintained in the operating condition (i.e., without the rotation of the main machine shaft being stopped). Namely, for sewing of an embroidery pattern that comprises a mixture of sequin-sewn portions and ordinary embroidery portions, i.e. that requires a combination of sequin sewing and ordinary embroidery sewing operations using a same colored thread, the human operator can position the sequin sewing device 1 in the operative position or in the evacuated position with the sewing machine maintained in the operating state (i.e., without stopping the rotation of the main machine shaft) by performing the first or second shifting operation to vertically move the sequin sewing device 1 while jumping the needle bar 20; in this way, it is possible to smoothly perform the sequin sewing and ordinary embroidery sewing, using the same thread needle bar 20, while alternately switching between the sequin sewing and ordinary embroidery sewing operations. Further, in such a case, throughout the ordinary embroidery sewing, the needle clamp 21 of the vertically-driven (i.e., ascending and descending) needle bar 20 can be reliably prevented from hitting the movable blade 17 of the sequin sewing device 1, because the sequin sewing device 1 is held in the upper evacuated position away from the operative position.

Next, with reference to a flowchart of FIG. 6, a description will be given about processing performed in the instant embodiment for automatically creating needle bar jump data on the basis of embroidery data and then inserting the created needle bar jump data in the embroidery data. According to this embodiment, an embroidery pattern to be sewn comprises a mixture of sequin-sewn portions and ordinary embroidery portions i.e. that requires a combination of sequin sewing and ordinary embroidery sewing in such a form that, here and there in the embroidery pattern, a partial pattern change occurs from sequin sewing to ordinary embroidery sewing or from ordinary embroidery sewing to sequin sewing with a same colored thread used. It is assumed here that original embroidery data supplied from an embroidery pattern data memory (i.e., the aforementioned storage section 45) are in the conventionally-known format with no needle bar jump code set in correspondence with a partial pattern change position of the embroidery pattern. Thus, through the processing of FIG. 6, the instant embodiment automatically creates jump data and inserts the created jump data in the embroidery data at a necessary pattern change position.

By the human operator operating an operation start switch after selecting a desired embroidery pattern, the sewing machine is activated to start embroidery sewing, so that the processing of FIG. 6 is started up. Let it be assumed that, in an original stage at the start of the embroidery sewing, the sequin sewing device 1 is in the upper evacuated position. At step S1 of FIG. 6, embroidery data groups, each having n stitches (“n” represents a predetermined plural number), are sequentially pre-read from among the embroidery data stored in the embroidery pattern data memory. Namely, the stored embroidery data are sequentially pre-read per n-stitch group; more specifically, the embroidery data group of 1st to n-th stitches is first pre-read collectively, then the embroidery data group of (n+1)-th to 2n-th stitches is pre-read collectively, and so on. The number of pre-read stitches n need not always be constant and may be varied as necessary. Each pre-read embroidery data group of n stitches is stored into a working area of the RAM 43 and then used in determination operations at steps to be described below, and a “non-data jump code” etc. generated at steps to be described below are inserted in the embroidery data stored in the working area.

At step S2, a determination is made, on the basis of the pre-read embroidery data group of n stitches, as to whether or not the second shifting operation is to be performed for shifting the sequin sewing device 1 from the evacuated position to the operative position, i.e. whether the sequin sewing device should be lowered. More specifically, it is determined, at step S2, whether the sequin sewing device 1 is currently in the evacuated position and the pre-read embroidery data group of n stitches contains a sequin code (sequin feed-out instruction). The sequin code is an instruction code for instructing feed-out of a sequin per predetermined stitch. If the second shifting operation is to be performed as determined at step S2, a further determination is made, at step S3, as to which position of the embroidery data is an embroidery pattern position where the second shifting operation is to be performed. Then, in correspondence with the determined embroidery pattern position, a “sequin lowering instruction” for instructing that the second shifting operation be performed and a non-data jump code (i.e., a code instructing only a needle bar jump with zero stitch data) are generated, and the thus-generated non-data jump code is inserted in the embroidery data for an appropriate number of stitches. The number of stitches for which the non-data jump code is to be inserted is set to correspond to a time required to lower the sequin sewing device 1 from the evacuated position to the operative position, and the number is varied in accordance with the number of rotations of the main machine shaft. For example, if the non-data jump code is inserted for three stitches, the embroidery frame 31 is kept unmoved (i.e., kept in the jump state) at sewing timing of these stitches (because of the zero stitch data), during which time the sequin sewing device 1 is lowered from the evacuated position to the operative position. For example, at step S3, the i-th stitch with no sequin code set therefor and (i+1)-th stitch with a sequin code set therefor are identified, and a boundary between the i-th stitch and the 1+i)-th stitch is determined to be an embroidery pattern position where the second shifting operation is to be performed. Then, a non-data jump code for an appropriate number of stitches is inserted in the embroidery data following the i-th stitch, and a sequin lowering instruction is inserted in correspondence with the first one of the appropriate number of stitches.

At next step S4, a determination is made, on the basis of the pre-read embroidery data group of n stitches, as to whether or not the first shifting operation is to be performed for shifting the sequin sewing device 1 from the operative position to the evacuated position. In order to avoid waste of the working time resulting from frequent ascending and descending movement of the sequin sewing device, the sequin sewing device 1 in the instant embodiment is moved upward from the operative position to the evacuated position only after it has been confirmed that more than a predetermined number of stitches with no sequin code have occurred in succession, rather than being moved upward immediately upon detection of a stitch with no sequin code occurring in the embroidery data. Therefore, in the instant embodiment, it is determined, at step S4, that the first shifting operation should be performed, i.e. the sequin sewing device should be caused to ascend or raised (namely, YES determination is made at step S4), only when absence of the sequin code has been detected in succession for a predetermined number of stitches (e.g., 100 stitches) following detection of a stitch with no sequin code. Such a “predetermined number of stitches” may be variably set as desired by the human operator of the sewing machine. Let it be assumed here that, in the determination at step S4, whether or not the sequin code has not appeared (i.e., has not been detected) in succession for a predetermined number of stitches (e.g., 100 stitches) is determined regarding not only the current pre-read embroidery data of n stitches but also the last pre-read embroidery data of n stitches. All through the predetermined number of stitches (e.g., 100 stitches), the sequin sewing device 1 is maintained in the lowered position and thus the movable blade 17 is hit by the needle clamp 21 although the ordinary embroidery sewing is being performed; however, the instant embodiment accepts the hitting by the needle clamp 21 as inevitable, in order to give priority to minimization of the waste of the working time. With the sequin sewing device 1 maintained in the lowered position all through the predetermined number of stitches, the ordinary embroidery sewing is carried out with no sequin feed-out, because there is no sequin code recorded for these stitches. Needless to say, the sequin sewing device 1 may be raised immediately upon detection of when a stitch with no sequin code, without a leeway being set for the ascending movement of the sequin sewing device 1 as noted above; in this case, it is possible to completely prevent the movable blade 17 from being hit by the needle clamp 21.

With a YES determination at step S4, a “sequin raising instruction” for instructing that the first shifting operation be performed is generated, at step S5, in correspondence with an embroidery pattern position having been determined to be a position where the first shifting operation is to be performed (i.e., an embroidery pattern position the predetermined number of stitches after the detection that the stitch with no sequin code). Also, at step S5, a non-data jump code is generated and inserted in the embroidery data for an appropriate number of stitches, in a manner similar to the above-described. As also stated above, the number of stitches for which the non-data jump code is to be inserted is set to correspond to a time required to raise the sequin sewing device 1 from the operative position to the evacuated position.

At following step S6, a determination is made as to whether or not an “operation routine” of the sewing machine has already been started. If the “operation routine” has not yet been started as determined at step S6, the operation routine is started at step S7. At the “operation routine” step S7, the main machine shaft is rotated, and the embroidery data stored in the working area of the RAM 43 are sequentially read out, stitch by stitch, so that embroidery sewing (sequin sewing or ordinary embroidery sewing) is performed in accordance with the read-out embroidery data. If, on the other hand, the “operation routine” has already been started as determined at step S6, a determination is made, at step S8, as to whether or not an embroidery data group of next n stitches should be read. For example, once a quantity of unprocessed embroidery data in the working area reaches a predetermined number of stitches as the embroidery sewing progresses, a pre-read instruction is generated by the “operation routine” step S7. When generation of such a pre-read instruction has been detected, the processing returns from step S8 to step S1 in order to pre-read the embroidery data of the next n stitches. Thus, the aforementioned operations of steps S2-S5 are repeated to generate a “sequin lowering instruction” or “sequin raising instruction” and “non-data jump code” and insert the thus-generated instruction and jump code into the embroidery data of the next n stitches in question. Once the main machine shaft is rotated at the start of the embroidering, the operation of the sewing machine is performed in a continuous manner so that the “operation routine” step S7 is carried out continuously, unless a machine stop instruction is given. When a colored thread change is to be effected, for example, the sewing machine is deactivated temporarily even during the course of embroidery pattern sewing, so as to effect cutting of the sewing thread so far used and selection of and switching to the needle bar corresponding to a new colored thread. On the other hand, when a shift is to be made from the sequin sewing to the ordinary embroidery sewing, or vice versa, no machine stop instruction is generated and thus the operation of the sewing machine is continued without being stopped, unless a colored thread change is instructed. Thus, in the case where the embroidery data to be supplied from the embroidery pattern data memory (storage section 45) are in the conventional format, and when a shift is to be made from the sequin sewing to the ordinary embroidery sewing, or vice versa, with no colored thread change, any machine stop instruction inserted in the embroidery data is deleted as a jump code is inserted through the operation of step S3 or S5. Further, when the embroidery pattern sewing is to be ended, an end instruction is generated, in place of a pre-read instruction, by the “operation routine” step S7, in response to which the processing of FIG. 6 is brought to an end.

The following paragraphs describe a specific example of the sewing operation performed in the instant embodiment, in relation to a case where an embroidery pattern to be sewn is of a type comprising a mixture of sequin-sewn portions and ordinary embroidery portions, i.e. requiring a combination of sequin sewing and ordinary embroidery sewing as illustrated in FIG. 7. In FIG. 7, A1-A3 indicate ordinary embroidery sewing (ordinary embroidery portions), and B1 and B2 indicate sequin sewing (sequin-sewn portions). Let it be assumed here that the ordinary embroidery sewing A1-A3 and the sequin sewing B1 and B2 are performed with a same colored thread and in the order of “embroidery sewing A1→sequin sewing B1→embroidery sewing A2→sequin sewing B2→embroidery sewing A3. Also assume that each of the ordinary embroidery sewing A1 and A3 requires 100 stitches or more while the ordinary embroidery sewing A2 requires less than 100 stitches.

In a case where embroidery data of an embroidery pattern as illustrated in FIG. 7 are stored in an external memory, the stored embroidery data are read out from the external memory into the sewing machine and then stored into the embroidery pattern data memory (storage section 45) that is, for example, in the form of a hard disk. Then, for how many switches a non-data jump code is to be generated at the time of raising/lowering the sequin sewing device 1 is set, and at which one of successive stitches of the ordinary embroidery sewing following the sequin sewing the sequin sewing device 1 is to be evacuated upward, i.e. how many stitches of the ordinary embroidery sewing have to be counted before the sequin sewing device 1 is evacuated upward (namely, the predetermined number of stitches noted above in relation to step S4 of FIG. 6) is set. Here, it is assumed that a non-data jump code is generated for three stitches and the sequin sewing device 1 is evacuated when 100 stitches or over of the ordinary embroidery sewing have occurred following the sequin sewing. As noted above, these numbers of stitches may be preset or variably set by the human operator. Further, the number of stitches for which a non-data jump code is to be generated may be determined in accordance with the current number of rotations of the sewing machine, or may be set individually or separately for the upward evacuating movement and for the lowering movement.

Once sewing is started by activation of the sewing machine, a desired sequin needle bar is selected in accordance with colored thread data. At an initial stage of the sewing, the sequin sewing device 1 is still kept in the upper evacuated position because no sequin code has been detected yet from the pre-read embroidery data. Through execution of the operation routine S7 of FIG. 6, the ordinary embroidery sewing A1 is performed using the sequin needle bar. Then, once the data of the sequin sewing B1 are pre-read in accordance with a progression of the ordinary embroidery sewing A1, not only a non-data jump code is generated and inserted, along with a “sequin lowering instruction”, in a predetermined embroidery pattern position, where a stitch with no sequin code set therefor switches to a stitch with a sequin code set therefor, for three stitches immediately before the stitch with a sequin code. For reference purposes, a format of original embroidery data is schematically shown in (a) of FIG. 8, and a format of embroidery data having the “sequin lowering instruction”, “sequin raising instruction” and “non-data jump code” inserted therein is schematically shown in (b) of FIG. 8. Thus, when the ordinary embroidery sewing A1 has been completed through the execution of the operation routine step S7 of FIG. 6, the sequin needle bar is placed in the jump state for three stitches and the sequin sewing device 1 is lowered to the operative position while the sequin needle bar is placed in the jump state, in accordance with the “sequin lowering instruction” and “non-data jump code” inserted as data for the next stitch; throughout such a period, the rotation of the main machine shaft is maintained.

Then, once the sewing has progressed to a stitch with a “sequin code” following the sewing of the stitches of the “non-data jump code” through the execution of the operation routine step S7 of FIG. 6, the jump state of the sequin needle bar is canceled so that sewing responsive to the vertical movement of the needle bar is permitted, the sequin feed mechanism 6 is activated, in accordance with the “sequin codes”, to feed a continuous sequin strip 3, and thus, the sequin sewing B1 is performed. Then, once the data of the ordinary embroidery sewing A2 are pre-read in accordance with a progression of the sequin sewing B1, a determination is made, at step S4 of FIG. 6 and in an embroidery pattern position where a shift is made to the ordinary embroidery sewing, as to whether the first shifting operation is to be performed for shifting the sequin sewing device 1 from the operative position to the evacuated position. More specifically, at step S4 of FIG. 6, a determination is made as to whether or not the ordinary embroidery sewing A2 has lasted for 100 stitches or more following the sequin sewing B1. In the illustrated example, where the ordinary embroidery sewing A2 is less than 100 stitches, a NO determination is made at step S4, so that the operation of step S5 of FIG. 6 is skipped; thus, the sequin sewing device 1 is not evacuated and no non-data jump code is generated either. In this case, the sequin sewing device 1 is still kept in the lowered position when the ordinary embroidery sewing A2 is to be performed, through the operation routine, following the sequin sewing B1; however, because of absence of the “sequin code”, the continuous sequin strip 3 is not fed so that the ordinary embroidery sewing A2 can be performed safely.

Then, once the data of the sequin sewing B2 are pre-read in accordance with a progression of the ordinary embroidery sewing A2, a determination is made, at step S2 of FIG. 6 and on the basis of recognition of a sequin code, as to whether the second shifting operation is to be performed for shifting the sequin sewing device 1 from the evacuated position to the operative position. Because the sequin sewing device 1 is still kept in the lowered position at this stage, there is no need to perform the second shifting operation, and thus, a NO determination is made at step S2. Thus, generation and insertion of a “sequin lowering instruction” and “non-data jump code” is not executed at step S3 of FIG. 6. Upon completion of the ordinary embroidery sewing A2 through the execution of the operation routine, a shift is made to the sequin sewing B2. Because the sequin sewing device 1 is still kept in the lowered position at this stage and because “sequin codes” are included in the stitch data, the sequin feed mechanism 6 is operated, in accordance with the sequin codes, to feed the continuous sequin strip 3, so that the sequin sewing B2 is performed.

Then, once the data of the ordinary embroidery sewing A3 are pre-read in accordance with a progression of the sequin sewing B2, a determination is made, at step S4 of FIG. 6 and in an embroidery pattern position where a shift is made to the ordinary embroidery sewing, as to whether the first shifting operation is to be performed for shifting the sequin sewing device 1 from the operative position to the evacuated position. Because, in this case, the ordinary embroidery sewing A3 lasts for 100 stitches or more, a YES determination is made at step S4 of FIG. 6, so that the processing goes to step S5. At step S5, not only a “non-data jump code” for three stitches is generated and inserted, along with a “sequin raising instruction”, between the last stitch of the sequin sewing B2 and the first stitch of the ordinary embroidery sewing A3. Upon completion of the sequin sewing B2 through the execution of the operation routine, the feeding of the continuous sequin strip 3 is stopped and the sequin needle bar is placed in the jump state for three stitches, during which time the sequin sewing device 1 is moved upward from the operative position to the evacuated position. Throughout such a period, the rotation of the main machine shaft is maintained. Immediately after that, the jump state of the sequin needle bar is canceled, so that the ordinary embroidery sewing A3 is performed on the basis of the embroidery data of the embroidery sewing A3. At this stage, the sequin sewing device 1 is still kept in the evacuated position, and thus, the movable blade 17 of the sequin sewing device 1 is not hit by the needle clamp 21 of the vertically-moving needle bar 20. After completion of the ordinary embroidery sewing A3, the sewing machine is deactivated.

As described above, the instant embodiment is arranged in such a manner that, when embroidery sewing is to be performed using the sequin needle bar before or after sequin sewing, the raising/lowering of the sequin sewing device 1 is effected, with the sequin needle bar placed in the jump state, without the sewing machine being deactivated. Thus, the instant embodiment can reliably prevent the movable blade 17 from being unnecessarily hit by the needle clamp 21 and thereby prevent the movable blade 17 from being easily broken. Also, because no hitting sound is produced between the movable blade 17 and the needle bar 21, the instant embodiment can prevent noise sound, produced by the sequin needle bar during embroidering, from becoming great. Further, because the raising/lowering of the sequin sewing device 1 is effected with the sequin needle bar placed in the jump state, the embodiment can significantly reduce a waste of the working time as compared to the conventional counterpart in which the raising/lowering of the sequin sewing device is effected with the sewing machine deactivated. Furthermore, in a case where the number of embroidering stitches is relatively small and thus the operating efficiency may be lowered if the sequin sewing device is raised and lowered, the raising/lowering of the sequin sewing device may be omitted.

Next, a description will be given a second embodiment of the needle bar control, where, at the time of the aforementioned first shifting operation or second shifting operation, control is performed for delaying the descending movement of the needle bar with the sewing machine maintained in the operating condition. In the second embodiment, the CPU 41 functions as a needle bar control section, which delays the descending movement of the needle bar 20 by reducing the moving speed of the needle bar 20. Because, normally, the needle bar 20 is driven vertically in interlocked relation to the rotation of the main machine shaft, the speed reduction of the needle bar 20 can be achieved by reducing the rotation speed of the main machine shaft. Raising/lowering of the sequin sewing device 1, similar to the aforementioned raising/lowering (i.e., the aforementioned first shifting operation or second shifting operation), is effected while the descending movement of the needle bar 20 is being delayed.

In order to carry out the second embodiment, it is only necessary to insert a “main-machine-shaft speed reduction instruction” in embroidery data, in place of the “non-data jump code” that is inserted in the first embodiment for instructing the raising/lowering of the sequin sewing device 1 (i.e., the aforementioned first shifting operation or second shifting operation). Thus, once the “main-machine-shaft speed reduction instruction” is given during an embroidery sewing operation, the rotation speed of the main machine shaft is reduced in response to the main-machine-shaft speed reduction instruction, and thus, the vertically-driven speed of the needle bar 20 is reduced in a predetermined portion of its stroke so that the descending movement, from a raised position, of the needle bar 20 is delayed. Therefore, the raising/lowering of the sequin sewing device 1 (i.e., the aforementioned first shifting operation or second shifting operation) can be effected during a leeway period before the start of the descending movement, from the raised position, of the needle bar 20. Note that the number of rotations of the main machine shaft at the time of the speed reduction may be preset or variably set as desired by the human operator of the sewing machine.

Therefore, in this second embodiment too, when embroidery sewing is to be performed using the sequin needle bar before or after sequin sewing, the raising/lowering of the sequin sewing device 1 can be effected without the sewing machine being deactivated. Further, because the descending movement of the needle bar is delayed, the second embodiment can prevent the movable blade 17 from being unnecessarily hit by the needle clamp 21 and thereby prevent the movable blade 17 from being easily broken. Also, because no hitting sound is produced between the movable blade 17 and the needle bar 21, the second embodiment can prevent noise sound, produced by the sequin needle bar during embroidering, from becoming great. Further, the second embodiment can significantly reduce a waste of the working time as compared to the conventional counterpart in which the raising/lowering of the sequin sewing device is effected with the sewing machine deactivated.

As described above, each of the embodiments is arranged in such a manner that embroidery data are pre-read per predetermined number of stitches and the “non-data jump code” or “main-machine-shaft speed reduction instruction”, intended to shift the sequin sewing device 1 vertically between the evacuated position and the operative position, is generated and inserted substantially concurrently with (or slightly ahead of the sewing operation. However, the present invention is not so limited and may be arranged in such a manner that, when embroidery data of a desired embroidery pattern have been read from an external memory to the sewing machine before the operation of the sewing machine is started, all of the embroidery data of the embroidery pattern are checked, then all “sequin lowering instructions”, “sequin raising instructions” and “non-data jump codes” (or “main-machine-shaft speed reduction instructions”) to be inserted are generated and inserted into the embroidery data and then the operation of the sewing machine is started. In another alternative, “sequin lowering instructions”, “sequin raising instructions” and “non-data jump codes” (or “main-machine-shaft speed reduction instructions”) may be inserted in advance in embroidery data of a desired embroidery pattern, and such embroidery data having the jump codes (or “main-machine-shaft speed reduction instructions”) inserted therein may be read from an external memory or the like into the sewing machine.

Further, arrangements may be made such that the sequin sewing device 1 can be held in an intermediate position (hereinafter referred to as “lower evacuated position”) between the operative position and the aforementioned evacuated position (hereinafter referred to as “upper evacuated position”). If the sequin sewing device 1 is caused to vertically move only between the operative position and the lower evacuated position at the time of switching between sequin sewing and ordinary embroidery sewing using the sequin needle bar, it is possible to reduce the time required for the vertical movement of the sequin sewing device 1. In such a case, it is better to evacuate the sequin sewing device 1 to the upper evacuated position when the sewing machine has been deactivated. Namely, the evacuated position used may be any one of two or more predetermined evacuated positions, rather than just one, as long as it is a position where the sequin sewing device 1 can not perform sequin sewing (i.e., where the movable blade 17 is not hit by the needle clamp 21).

The drive means for vertically moving the sequin sewing device 1 is not limited to the air cylinder 9 and may be an electric motor or other actuator.

Further, whereas the embodiments of the present invention have been described above in relation to the multi-head, multi-needle sewing machine equipped with the sequin sewing device 1, the present invention may be applied to sewing machines of various other types equipped with a sequin sewing device.

Claims

1. A sewing machine comprising:

a machine head including a needle bar mechanism usable for both sequin sewing and ordinary sewing, said needle bar mechanism having a vertically-movable needle bar for sewing;

a sequin sewing device provided in correspondence with the needle bar mechanism and movable between an operative position where said sequin sewing device can perform sequin sewing and an evacuated position where said sewing device can not perform sequin sewing;

a needle bar control section that, in a first shifting operation for shifting said sequin sewing device from the operative position to the evacuated position or in a second shifting operation for shifting said sequin sewing device from the evacuated position to the operative position, inhibits or delays descending movement of the needle bar of the needle bar mechanism while maintaining said sewing machine in an operating condition; and

a movement mechanism that moves said sequin sewing device to the evacuated position in said first shifting operation but moves said sequin sewing device to the operative position in said second shifting operation while said needle bar control section inhibits or delays descending movement of the needle bar.

2. A sewing machine as claimed in claim 1 wherein, when an embroidery pattern comprising a mixture of a sequin-sewn portion and an ordinary embroidery portion is to be sewn, not only said needle bar control section is caused to inhibit or delay the descending movement of the needle bar but also said movement mechanism is caused to move said sequin sewing device, in correspondence with an embroidery pattern position where said first shifting operation or said second shifting operation is to be performed.

3. A sewing machine as claimed in claim 1 wherein said needle bar control section inhibits the descending movement of the needle bar by jumping the needle bar.

4. A sewing machine as claimed in claim 3 which further comprises:

an embroidery data supply section that supplies embroidery data of an embroidery pattern comprising a mixture of a sequin-sewn portion and an ordinary embroidery portion; and

a data generation section that determines, on the basis of supplied embroidery data, an embroidery pattern position where said first shifting operation or said second shifting operation is to be performed and inserts a jump code, instructing a needle bar jump, into the embroidery data in correspondence with the determined embroidery pattern position, and

wherein, in accordance with the jump code inserted in the embroidery data, said needle bar control section and said movement mechanism jump the needle bar and move said sequin sewing device from the operative position to the evacuated position or from the evacuated position to the operative position.

5. A sewing machine as claimed in claim 3 which performs embroidery sewing on the basis of embroidery data of an embroidery pattern comprising a mixture of a sequin-sewn portion and an ordinary embroidery portion, and

wherein the embroidery data have a jump code, instructing a needle bar jump, inserted therein in advance in correspondence with an embroidery pattern position where said first shifting operation or said second shifting operation is to be performed, and

wherein, in accordance with the jump code inserted in the embroidery data, said needle bar control section and said movement mechanism jump the needle bar and move said sequin sewing device from the operative position to the evacuated position or from the evacuated position to the operative position.

6. A sewing machine as claimed in claim 1 wherein said needle bar control section delays the descending movement of the needle bar by reducing an operating speed of a main machine shaft.

7. A sewing machine as claimed in claim 6 which further comprises:

an embroidery data supply section that supplies embroidery data of an embroidery pattern comprising a mixture of a sequin-sewn portion and an ordinary embroidery portion; and

a data generation section that determines, on the basis of supplied embroidery data, an embroidery pattern position where said first shifting operation or said second shifting operation is to be performed and inserts a main-machine-shaft speed reduction instruction, instructing reduction of the operating speed of the main machine shaft, in the embroidery data in correspondence with the determined embroidery pattern position, and

wherein, in accordance with the main-machine-shaft speed reduction instruction inserted in the embroidery data, said needle bar control section and said movement mechanism reduces the operating speed of the main machine shaft and move said sequin sewing device from the operative position to the evacuated position or from the evacuated position to the operative position.

8. A sewing machine as claimed in claim 6 which performs embroidery sewing on the basis of embroidery data of an embroidery pattern comprising a mixture of a sequin-sewn portion and an ordinary embroidery portion, and

wherein the embroidery data have a main-machine-shaft speed reduction instruction inserted therein in advance in correspondence with an embroidery pattern position where said first shifting operation or said second shifting operation is to be performed, and

wherein, in accordance with the main-machine-shaft speed reduction instruction inserted in the embroidery data, said needle bar control section and said movement mechanism jump the needle bar and move said sequin sewing device from the operative position to the evacuated position or from the evacuated position to the operative position.