WO2006052090A1 - Operating method of an embroidering machine - Google Patents

Abstract

The present invention relates to an operating method of an embroidering machine comprising a thread feeder, a needle working unit having a needle, a thread feeding unit forming a thread transferring path and having an upper thread feeder and a threader, a cut -thread sensor to sense whether the upper thread is cut, and a cutting unit to cut the upper thread, the operating method comprising controlling the cut -thread sensor to sense whether the upper thread is cut; stopping the needle working unit to operate; recovering the cut upper thread from the needle working unit; and driving the upper thread feeder to feed the needle working unit with a new upper thread to be threaded through the needle. Thus, it is possible to reduce time taken to feed a needle working unit with an upper thread when the upper thread is cut, thereby enhancing productivity and implementing an automation system thereof .

Description

OPERATING METHOD OF AN EMBROIDERING MACHINE

Technical Field

The present invention relates to an operating method of an embroidering machine, and more particularly, to an operating method of an embroidering machine, which senses whether a thread is cut while operating and stopping the operation when the thread is cut, thereby automatically threading a new upper thread through an eye of a needle. Background Art

In general, an automatic embroidering machine includes a head stem provided in front of a setting frame, a thread feeding apparatus mounted to the head stem and supplying various colored upper threads from a plurality of bobbins in a direction for embroidering work, and a needle working unit to perform the embroidering work by threading the supplied upper thread.

Further, the automatic embroidering machine is classified into a single needle type and a multi needle type according to the number of needles mounted to the thread feeding apparatus and the needle working unit .

The single needle type automatic embroidering machine supplies one of various colored upper threads from the plurality of bobbins to a single needle working unit to perform the embroidering work. The multi needle type automatic embroidering machine supplies various colored upper threads from the plurality of bobbins to a plurality of needle working units to perform the embroidering work. Hereinafter, the single needle type automatic embroidering machine will be exemplarily described.

In a conventional single needle type automatic embroidering machine, one upper thread selected among various colored upper threads from the plurality of bobbins passes and resists a thread tension adjusting body via a thread feeding unit, so that its tension is adjusted. Then, the upper thread is retained in a thread take-up unit, moves toward the needle, and passes through an eye of the needle by a threader having a hook capable of passing through the eye of the needle. Here, the thread take-up unit reciprocates within a predetermined section to strengthen and release the tension of the upper thread while the needle stitches.

Meanwhile, in the case where the upper thread is cut while embroidering work is normally performed, a predetermined sensor senses that the upper thread is cut and stops the embroidering machine. At this time, a user manually threads the upper thread through an eye of the needle, or manually transfers the upper thread to a standby position of a thread feeding unit in order to transfer the cut upper thread to the needle, and then restarts the embroidering machine.

However, in the conventional automatic embroidering machine, a user should manually thread the upper thread through the eye of the needle and then restarts the embroidering machine in order to feed the needle with the cut upper thread again when the upper thread is cut while the embroidering work is normally performed. Therefore, it takes relatively much time to thread a new upper thread through the eye of the needle and restart the embroidering machine, i.e., replace the cut upper thread with a new upper thread, so that the conventional embroidering machine decreases productivity and makes it difficult to implement an automation system. Disclosure of Invention

Accordingly, it is an aspect of the present invention to provide an operating method of an embroidering machine, which reduces time taken to feed a needle working unit with an upper thread when the upper thread is cut, thereby enhancing productivity and implementing an automation system thereof.

The foregoing and other aspects of the present invention are achieved by providing an operating method of an embroidering machine comprising a thread feeder, a needle working unit having a needle threaded with an upper thread supplied from the thread feeder and performing a sewing operation, a thread feeding unit forming a predetermined thread transferring path from the thread feeder to the needle working unit and having an upper thread feeder to supply the upper thread and a threader to tread the needle with the upper thread, a cut-thread sensor to sense whether the upper thread transferred along the thread transferring path is cut, and a cutting unit to cut the upper thread on the thread transferring path, the operating method comprising controlling the cut-thread sensor to sense whether the upper thread is cut; stopping the needle working unit to operate; recovering the cut upper thread from the needle working unit; and driving the upper thread feeder to feed the needle working unit with a new upper thread to be threaded through the needle.

According to another aspect of the present invention, the operating method further comprises driving the cutting unit to cut the cut upper thread after stopping the needle working unit .

According to another aspect of the present invention, the operating method further comprises driving the needle working unit to make the needle perform a sewing operation after threading the needle with a new thread. Brief Description of the Drawings FIG. 1 is a perspective view of an embroidering machine according to an embodiment of the present invention.

FIG. 2 is a schematic perspective view of a driving part of FIG. 1.

FIG. 3 is a control block diagram of the embroidering machine in FIG. 1.

FIG. 4 is a control flowchart of the embroidering machine of FIG. 1. FIG. 5 is a schematic side view of a thread tension adjuster of an embroidering machine according to an embodiment of the present invention.

FIG. 6 is a partially enlarged perspective view of the thread tension adjuster of FIG. 5. FIG. 7 is an exploded perspective view of FIG. 6.

FIGS. 8A, 8B, 9A and 9B are partially enlarged perspective views and side views showing a process of winding an upper thread on the thread tension adjuster.

FIG. 10 is an enlarged perspective view of a thread take-out unit of an embroidering machine according to an embodiment of the present invention.

FIG. 11 is a side view of FIG. 10.

FIG. 12A through 12C are plan views showing an operation between a thread take-up unit and a thread take-out lever. FIG. 13 is a partially enlarged perspective view showing a state that a thread is held by the thread take- up unit when the thread take-up unit is placed at a bottom dead point . FIG. 14 is a partially enlarged perspective view showing a state that a thread is held by the thread take- up unit when the thread take-up unit is placed at a top dead point .

FIG. 15 is an exploded perspective view of a threading unit of an embroidering machine according to an embodiment of the present invention.

FIG. 16 is a partially enlarged exploded perspective view of FIG. 15.

FIGS. 17 through 20 are perspective views illustrating a threading operation of the threading unit of FIG. 15.

FIG. 21 is an enlarged perspective view of when the threading unit of FIG. 15 completes the threading operation. FIGS. 22 and 23 are partial perspective views illustrating an operation of a thread transferring unit of the threading unit.

FIG. 24 is a partial perspective view of when the thread transferring unit of the threading unit completes the operation. FIGS. 25 through 27 are schematic side sectional view showing a process of cutting an upper thread in sequence in an embroidering machine according to an embodiment of the present invention. Best Mode for Carrying Out the Invention

Hereinbelow, embodiments of the present invention will be described with reference to accompanying drawings. As shown in FIGS. 1 through 3, an embroidering machine 1 according to the present invention includes an settling frame 5; a head stem 7 provided in front of the settling frame 5; a thread feeder 10 mounted to the head stem 7 and supplying one selected among a plurality of upper threads from a plurality of bobbins corresponding various colors to a needle 21; a needle working unit 20 having the needle 21 threaded with an upper thread 3 and performing a sewing operation of the needle 21; a thread feeding unit supplying the upper thread 3 from the thread feeder 10 to the needle working unit 20 and threading the upper thread 3 through the needle 21; a cut-thread sensor 240 sensing whether the upper thread 3 moving along a thread transferring path is cut or not; and a cutting unit 270 cutting the upper thread 3 on the thread transferring path.

The settling frame 5 is seated on a horizontal surface such as the ground, or mounted to a wall, other machinery or the like, thereby supporting the head stem 7 and the like.

The head stem 7 is preferably shaped like an approximately rectangular plate to support the thread feeder 10 and a thread feeding apparatus at the front thereof. Alternatively, the head stem may have various shapes.

The thread feeder 10 includes a thread feeding block 11 formed with a plurality of thread standby pipes 11a in which the ends of the upper threads 3 transferred from a plurality of bobbins are accommodated on standby; a plurality of connection pipes 13 placed under the thread feeding block 11 and communicating with the respective thread standby pipes 11a; a thread supporting block 15 supporting the plurality of connection pipes 13 and formed with a single thread feeding path 15a communicating with the plurality of connection pipes 13; a thread guiding block 17 provided under the thread supporting block 15 and forming a thread guiding path 17a communicating with the thread feeding path 15a; and an air supply (not shown) provided to communicate with each thread standby pipe 11a provided in the thread feeding block 11, and selectively injecting high pressure air to the thread standby pipe 11a, thereby selectively feeding the needle working unit 20 with one of the upper threads accommodated in the thread standby pipes 11a.

Further, the thread feeder 10 preferably includes an auxiliary air supply (not shown) coupled to the thread supporting block 15 and injecting air to facilitate feeding the needle working unit 20 with the upper thread 3 transferred through one of the connection pipes 13 via the thread supporting block 15 and the thread guiding block 17.

The needle working unit 20 includes a single needle 21 reciprocatably provided placed under the head stem 7 and through which the upper thread 3 is treaded to perform an embroidering work and a presser foot (not shown) pressing an embroidering piece along a moving direction of the needle 21 while the needle 21 performs the sewing work. The needle 21 is mounted to a needle bar 25, and the needle bar 25 is reciprocated within a predetermined sewing work section by a needle bar driver 27. Here, the needle bar 25 and the needle bar driver 27 are connected to and disconnected from each other by a clutch, so that the reciprocation of the needle bar 21 is transferred to the needle bar 26 through connection of the clutch, thereby allowing the needle 21 to reciprocate within the sewing work section and perform the sewing work. The thread feeding apparatus includes an upper thread feeder forming a predetermined thread transferring path from the thread feeder 10 to the needle working unit 20 and supplying the upper thread 3; and a threader 140 threading the upper thread 3 through the needle 21. The upper thread feeder includes a thread tension adjustor 31 provided on the thread transferring path and adjusting the tension of the upper thread 3 transferred to the needle 21; a thread take-up unit 60 taking up the upper thread 3 and strengthening/releasing the tension of the upper thread 3; and a thread take-out unit 80 taking out the upper thread 3 on the thread transferring path and retaining it on the thread taking—up unit 60.

As shown in FIGS. 5 through 9, the thread tension adjustor 31 is provided between the thread supporting block 15 and the thread guiding block 17, and includes a thread tension adjusting body 32 partially winding and contacting the upper thread 3 thereon so as to adjust the tension of the upper thread 3; and a thread winding unit 35 holding the upper thread 3 holding and rotating so as to make the upper thread 3 be wound on the thread tension adjusting body 32.

The thread tension adjusting body 32 is shaped like a disk, and formed with a thread contacting part 33 recessed along the circumference thereof and on which the upper thread 3 is partially wound. The thread tension adjusting body 32 is accommodated in an accommodating groove 39 of the thread winding unit 35 (to be described later) . The thread contacting part 33 makes resistance when the upper thread 3 contacts and passes thereon, thereby adjusting the tension of the upper thread 3. Meanwhile, the thread tension adjusting body 32 is rotatably coupled to a second rotation axis 123 (to be described later) .

The thread winding unit 35 is placed under the thread supporting block 15, and integrally coupled with and rotating with the second rotation axis 123. Further, an axis line of the second rotation shaft 123 is spaced apart from a moving path of the upper thread 3 at a predetermined distance. Also, the thread winding unit 35 is penetratingly formed with a thread through hole as a holder 37 for holding the upper thread 3.

Further, the thread winding unit 35 is formed with the accommodating groove 39 to accommodate the thread tension adjusting body 32, and is rotated by a main driver 100 (to be described later) , thereby partially winding the upper thread 3 on the thread contacting part 33 of the thread tension adjusting body 32.

The thread winding unit 35 is connected to a rotating motion transformer (to be described later) , and rotates relative to the thread tension adjusting body 32, thereby allowing the upper thread 3 to be wound on the thread tension adjusting body 32.

As shown in FIGS. 10 through 14, the thread take-up unit 60 includes an arm 61 oscillating between a top dead point and a bottom dead point; a thread retainer 63 forming an opening 65 and provided in a predetermined region of the arm 61 so as to retain the upper thread 3; and an arm driver 75 to drive the arm 61 oscillate.

The arm 61 is driven by the arm driver 75 to oscillate between the top dead point and the bottom dead point in front of the thread transferring path. Here, a hydraulic cylinder, a motor, a cam device, a solenoid device or the like can be used in the arm driver 75.

The thread retainer 63 is provided in a free end of the arm 61, and oscillates between the top dead point and the bottom dead point along with the arm 61. The thread retainer 63 forms the opening 65 to retain the upper thread 3.

In addition, the thread retainer 63 includes a flap 67 to prevent the upper thread 3 retained in the opening 65 from a breakaway. Here, the flap 67 is rotatably coupled to a region adjacent to the opening 65 of the thread retainer 63, and opens and closes the opening 65. Further, the flap 67 has one side elastically supported by a flap elastic unit 69 in the thread retainer 63. The flap elastic unit 69 elastically urges the flap 67 to close the opening 65. According to the present embodiment, a coil spring is illustrated as the flap elastic unit 69, but not limited thereto. Alternatively, a flat spring, a spiral spring, etc. as well as the coil spring can be used as the flap elastic unit 69. Further, when the flap 67 is rotated by the flap elastic unit 69 and closes the opening 65, the free end of the flap 67 is stopped by a flap stopper 71 provided in an opened region of the thread retainer 63 and does not rotate any more.

Thus, the flap 67 opens the opening 65 when a thread take-out lever 81 (to be described later) is pressed, and closes the opening 65 by the flap elastic unit 69 to prevent the upper thread 3 retained in the opening 65 from a breakaway.

The thread take-out unit 80 includes the thread take-out lever 81 reciprocating between a take-out position in which the upper thread 3 is taken out from the thread transferring path and a thread retaining position in which the upper thread 3 is retained in the thread retainer 63; and a take-out lever bracket 91 rotatably supporting the thread take-out lever 81.

The thread take-out lever 81 reciprocates in a straight line along a cutting part cut at a predetermined angle to the moving path of the upper thread 3 in a predetermined region of the thread guiding block 17. The thread take-out lever 81 includes a pair of holding ends 83a and 83b opposite to and spaced apart from each other at a predetermined distance. For convenience, the holder placed in an upper side will be called an upper holding end 83a, and the holder placed in a lower side will be called a lower holding end 83b. The upper and lower holding ends 83a and 83b together with the take-out lever bracket 91 to be described later form a flap accommodating part 87 to accommodate the flap 67. Further, the upper and lower holding ends 83a and 83b are respectively formed with thread through holes 85a and 85b through which the upper thread 3 is passed, thereby holding the upper thread 3. Thus, on a plane at a predetermined angle to the thread transferring path, the thread take-out lever 81 straight moves in a straight line toward the thread retainer 63 placed at the bottom dead point, and holds the upper thread 3, thereby putting the upper thread 3 into the thread retainer 63.

The take-out lever bracket 91 is shaped like a plate, and, together with the thread take-out lever 81, presses the flap 67 to open the opening 65 of the thread take-up unit 60, thereby receiving the upper thread 3 in the opening 65. Further, a profile part 93 is provided on the surface of the take-out lever bracket 91 where the holding ends 83a and 83b of the thread take-out lever 81 are placed. Thus, the flap 67 slidably contacts the profile part 93. The profile part 93 includes a straight line moving part 93a formed in parallel with a straight line moving direction of the holding ends 83a and 83b, and allowing the flap 67 accommodated in the flap accommodating part 87 to move in a straight line,- and a transverse moving part 93b extended from the straight line moving part 93a and transversely formed at a predetermined angle to the straight line moving direction of the holding ends 83a and 83b. Further, the take-out lever bracket 91 is elastically supported by a take-out lever elastic unit (not shown) . The take-out lever elastic unit urges the take-out lever bracket 91 to elastically press the flap 67 accommodated in the flap accommodating part 87.

Thus, the thread take-out lever 81 and the take-out lever bracket 91 are connected to a straight line motion transformer (to be described later) , and reciprocates between the take-out position and the thread retaining position of the upper thread 3.

Meanwhile, the embroidering machine 1 according to the present invention includes the main driver 100 to rotate the thread winding unit 35 and reciprocate the thread take-out lever 81; a lifting link 105 connected to the main driver 100 and driven by the main driver 100 to be lifted up and down; a rotating motion transformer transforming a driving operation of the main driver 100 into a rotating motion and rotating the thread winding unit 35 with respect to the thread tension adjusting body 32 so as to wind the upper thread 3 on the thread tension adjusting body 32; and the straight line motion transformer transforming the driving operation of the main driver 100 into a straight line motion and moving the thread take-out lever 81 so as to retain the upper thread 3 on the thread retainer 63.

In this embodiment, a hydraulic cylinder is used as the main driver 100. The hydraulic cylinder includes a cylinder body 101, and a cylinder rod 103 reciprocating to be extended and retracted by an operation of the cylinder body 101. The cylinder body 101 is supported by the head stem 7, and the cylinder rod 103 is spaced form and parallel with the lifting link 105. In the present invention, the hydraulic cylinder is used as the main driver 100, but not limited thereto. Alternatively, a motor or the like as well as the hydraulic cylinder can be used as the main driver 100.

The lifting link 105 stands while being spaced from and parallel with the cylinder body 101. Further, a connection link 107 is provided to connect the cylinder rod 103 with the lifting link 105. The connection link 107 is supported by the free end of the cylinder rod 103 and a first end of the lifting link 105. The rotating motion transformer includes a driving pin 111 protruding from the first end of the lifting link 105; a driving cam 113 formed with a predetermined cam profile 115 to be movably engaged with the driving pin 111 and rotatably coupled with a first rotating shaft 117; and a power transmission unit transforming the rotating motion of the driving cam 113 to the thread winding unit 35.

The driving cam 113 is coupled to the first rotating shaft 117, and the first rotating shaft 117 is rotatably provided in a supporting frame 8 supported by the head stem 7. The cam profile 115 of the driving cam 113 allows the driving cam 113 to rotate in a first direction, and includes a lifting-up profile section where the driving pin 111 is lifted up along the driving cam 113 when the lifting link 105 moves up, and a lifting-down profile section where the driving pin 111 is lifted down along the driving cam 113 when the lifting link 105 moves down. Preferably, the driving cam 113 is rotated by one turn.

The power transmission unit includes a second rotating shaft 123 spaced from the first rotating shaft 117 at a predetermined distance and coupled with the thread winding unit 35; a pair of pulleys 125 coupled to the respective rotating shafts 117 and 123; and a belt 127 connecting the pulleys 125 and transferring the rotation of the first rotating shaft 117 to the second rotating shaft 123, i.e., transferring the rotation of the driving cam 113 to the thread winding unit 35. Further, the second rotating shaft 123 is coupled with the bush 245, and rotatably installed in the supporting frame 8.

The straight line motion transformer includes a bracket 131 provided in the lifting link 105 and formed with an elongated hole 131a at a predetermined angle to a lifting direction of the lifting link 105; and a movable pin 135 provided in the thread take-out unit 80 and movably engaged with the elongated hole 141a to be moved in a straight line. Alternatively, the bracket 131 may be provided in the thread take-out unit 80, and the movable pin 135 may be provided in the lifting link 105. As shown in FIGS. 15 through 24, the threader 140 includes a needle bar lifting unit 143 to which a needle bar 25 is coupled to be lifted up and down. Therefore, the needle 21 mounted to the needle bar 25 gets out of a sewing work section and is lifted up to a threading work section for passing the upper thread 3 through the eye 21a of the needle 21.

The needle bar lifting unit 143 includes a pair of guide units 143a and 143b liftably provided in the head stem 7, partially accommodating the needle bar 25 therein, and guiding the needle bar 25 to be lifted up and down. For convenience, the guiding unit placed above the needle bar lifting unit 143 will be called an upper guiding unit 143a, and the guiding unit placed under the needle bar lifting unit 143 will be called a lower guiding unit 143b. The upper and lower guiding units 143a and 143b are coaxially aligned and spaced from each other. The upper guiding unit 143a of the needle bar lifting unit 143 is coupled to the connection link 107, and is formed with an elastic unit accommodating groove 145 to partially accommodate a needle bar elastic unit 147.

The needle bar elastic unit 147 is provided along the outer circumference of the needle bar 25, and accommodated in the elastic unit accommodating groove 145 of the upper guide unit 143a, thereby elastically connecting the needle bar 25 with the needle bar lifting unit 143. Further, the needle bar elastic unit 147 absorbs a shock from the needle bar 25 when the needle 21 sews .

Further, the threader 140 includes a thread catcher 151 that has a hook 153 for hooking the upper thread 3 and a hook body 155 supporting the hook 153, and passes the upper thread 3 through the eye 21a,- a thread catcher driver 161 reciprocating the thread catcher 151; and a thread transferring unit 181 taking up the upper thread 3 hooked by the hook 153, and moving the upper thread 3 to the hook body 155.

The thread catcher 151 includes the hook 153 for hooking the upper thread 3, and the hook body 155 for supporting the hook 153. The hook 153 is supported on the hook body 155 having a long bar shape and a relatively large cross- section.

The thread catcher driver 161 includes a main body 163; a thread catcher supporter 165 to support the thread catcher 151; a pair of supporting shafts 171 supporting the thread catcher supporter 165 to reciprocating with respect to the main body 163; and a thread catcher driving link 177 reciprocating the thread catcher supporter 165. The main body 163 is shaped like a block opened toward one side, and coupled to the settling frame 5. The main body 163 is formed with a slot 163a on a top surface thereof to prevent interference with a rotation pin 207 when the rotating pin 207 reciprocates. The thread catcher supporter 165 is shaped like a block, and provided to reciprocate on the main body 163. A first end of the thread catcher supporter 165 protrudes from the main body 163, and supports the hook 153 thereon to support the thread catcher 151, thereby allowing the hook 153 to face the eye 21a of the needle 21. Further, a pair of hook guides 167 is provided in opposite sides of the hook 153, thereby guiding the hook 153 to smoothly pass through the eye 21a of the needle 21. The hook guides 167 are supported by the thread catcher supporter 165. Also, the thread catcher supporter 165 is formed with a link accommodating groove 169 to accommodate a first end of the thread catcher driving link 177 (to be described later) .

The thread catcher supporter 165 is supported by the pair of supporting shafts 171 provided in the main body 163 and can reciprocate on the pair of supporting shafts 171. A supporting shaft elastic unit 173 is provided between an inner wall of the main body 163 and the thread catcher supporter 165. Further, the supporting shaft elastic unit 173 is provided on the outer circumference of the supporting shaft 171. Here, the supporting shaft elastic unit 173 urges the hook 153 passed through the eye 21a of the needle 21 to return to its original position from the eye 21a of the needle 21 in the state that the upper thread 3 is retained in the hook 153. The thread catcher driving link 177 is rotatably provided in the head stem 7 so as to come close to and apart from the thread catcher supporter 165. The thread catcher driving link 177 is provided with a pin sloping part 179 at an upper portion thereof. Here, the pin sloping part 179 contacts the driving pin 111 as the needle bar lifting unit 143 and the lifting link 105 are lifted up in the threading work section. The pin sloping part 179 is formed at a predetermined angle transverse to the lifting direction of the needle 21.

Thus, when the needle bar lifting unit 143 and the lifting link 105 are driven by the main driver 100 so as to lifted up within the threading work section, the driving pin 111 is lifted up while getting in contact with the pin sloping part 179 provided in the upper portion of the thread catcher driving link 177. At the same time, a lower portion of the thread catcher driver 177 is rotated toward the thread catcher supporter 165 and presses the thread catcher supporter 165, so that the thread catcher supporter 165 moves from the back to the front of the main body 163 along the supporting shaft 171, thereby allowing the hook 153 to pass through the eye 21a. The thread transferring unit 181 catches the upper thread 3 retained in the hook 153 to transfer to the hook body 155 and includes a thread transferring bracket 183 that catches the upper thread 3 passed through the eye 21a of the needle 21 and retained in the hook 153 and transfers it to the hook body 155; and a thread transferring driver 191 that drives the thread transferring bracket 183.

The thread transferring bracket 183 is disposed in parallel with a plane formed by the eye 21a of the needle 21 and the hook 153 and is rotatably installed in the main body 163. The thread transferring bracket 183 is provided with a thread catching portion 185 at a predetermined region thereof to catch the upper thread 3 retained in the hook 153 passed through the eye 21a of the needle 21. The thread transferring bracket 183 is rotatably coupled to an auxiliary supporting unit 187 coupled to the inside of the main body 163. Further, the thread transferring bracket 183 is elastically supported on the auxiliary supporting unit 187 by a thread transferring bracket elastic unit 189.

The thread transferring driver 191 includes a needle bar sloping part 193 formed in a predetermined side of the thread transferring bracket 183, and a thread unwinding bracket 195 rotating the thread transferring bracket 183 by contacting the needle bar sloping part 193 as the needle bar 25 is lifted down. Here, the needle bar sloping part 193 is cut by a predetermined width transversely to a lengthwise direction of the thread transferring bracket 183, so that an end of the thread unwinding bracket 195 (to be described later) can be lifted up and down while contacting one side of the thread transferring bracket 183.

The thread unwinding bracket 195 is coupled to a lower portion of the needle bar lifting unit 143, and has a triangle cross-section at an end thereof to be in contact with the needle bar sloping part 193. The thread unwinding bracket 195 comes apart from and in contact with the needle bar sloping part 193 formed in the thread transferring bracket 183 according as the needle bar 25 and the needle bar lifting unit 143 are lifted up and down.

Thus, both the needle bar 25 and the needle bar lifting unit 143 move down as the needle 21 moves down from the threading work section to the sewing work section, so that the thread unwinding bracket 195 is also lifted down while contacting the needle bar sloping part 193 formed in the thread transferring bracket 183. Therefore, the thread transferring bracket 183 catches the upper thread 3, which is passed through the eye 21a of the needle 21 and retained in the hook 153, and transferring the upper thread 3 to the hook body 155 while rotating toward the back of the main body 163

Meanwhile, the threader 140 further includes a thread guiding unit 111 guiding the upper thread 3 supplied from a thread feeder 10 to the plane formed by the eye 21a of the needle 21 and the hook 153, and retaining the upper thread 3 on the hook 153.

The thread guiding unit 111 includes a rotation bracket 203 formed with a predetermined thread guide sloping portion 205 in one side thereof; the rotation pin 207 moving while contacting the thread guide sloping portion 205 of the rotation bracket 203; a thread guiding bracket 209 taking up the upper thread 3 supplied from the thread feeder 10 and guiding the upper thread 3 to the plane formed by the eye 21a of the needle 21 and the hook 153; and an auxiliary link 215 connecting the rotation bracket 203 and the thread guiding bracket 209 and transferring the rotation of the rotation bracket 203 to the thread guiding bracket 209.

The rotation bracket 203 is rotatably coupled to a top surface of the main body 163. The rotation bracket 203 is formed with the thread guide sloping portion 205 in one side thereof, at a predetermined angle transversely to the lengthwise direction of the rotation bracket 203. The rotation pin 207 protrudes from a top surface of the thread catcher supporter 165 and makes the rotation bracket 203 rotate while contacting the thread guide sloping portion 205 of the rotation bracket 203 as the thread catcher supporter 165 reciprocates. Further, the rotation pin 207 reciprocates along the slot 163a of the main body 163, thereby operating without the interference with the main body 163.

The thread guiding bracket 209 includes a pair of thread guides 211 protruding from a first end thereof and leaving a predetermined space therebetween. Each thread guide 211 is formed with a thread through hole 211a through which the upper thread 3 supplied from the thread feeder 10 passes, thereby taking up the upper thread 3. Further, the thread guiding bracket 209 has a second end coupled to the auxiliary link 215.

The auxiliary link 215 connects the rotation bracket 203 with the thread guiding bracket 209, and transferring the rotation of the rotation bracket 203 to the thread guiding bracket 209, thereby rotating the thread guiding bracket 209. Here, the auxiliary link 215 transfers the rotation of the rotation bracket 203 to the thread guiding bracket 209, so that the upper thread 3 taken up by passing through the thread through hole 211a of the thread guiding bracket 209 is disposed on the plane formed by the eye 21a of the needle 21 and the hook 153. Meanwhile, the rotation bracket 203 is provided with a projection 221 extended from the end of the thread guide sloping portion 205. The projection 221 is stopped by a stopper 225 formed beneath the lifting bracket 223, thereby preventing the rotation bracket 203, which is rotated so as to make the upper thread 3 be disposed on the plane formed by the eye 21a of the needle 21 and the hook 153, from returning to its original position.

The lifting bracket 223 is provided on the rotation bracket 203, and elastically supported by a stopper elastic unit 227 urging the stopper 225 to elastically press a top portion of the main body 163. The stopper elastic unit 227 has a first end supported by the lifting bracket 223, and a second end supported by the main body 163. Meanwhile, a lifting rod 231 stands above the lifting bracket 223 while facing the stopper 225 of the lifting bracket 223. The lifting rod 231 contacts and comes apart from the lifting bracket 223 as the lifting link 105 moves up and down. Thus, the stopper 225 provided beneath the lifting bracket 223 comes apart from and contacts the projection 221.

The lifting rod 231 is shaped like a bar, and liftably coupled to an extended part 133 extend from the bracket 131. The lifting rod 231 has a bottom portion to contact and come apart from the top portion of the lifting bracket 223, and a top portion mounted with the lifting rod elastic unit 235 urging the lifting link 105 to elastically press the second end of the lifting bracket 223 when the lifting link 105 moves down within the threading work section.

When the needle bar lifting unit 143 is lifted up to the top dead point within the threading work section, the lifting rod 231 moves upward together with the needle bar lifting unit 143. At this time, the bottom portion of the lifting rod 231 comes apart from the top portion of the lifting bracket 223, so that the lifting bracket 223 is released from pressure. At the same time, the stopper 225 provided in the lifting bracket 223 presses the top surface of the rotation bracket 203 by the elasticity of the stopper elastic unit 227.

Further, when the upper thread 3 taken-up by the thread guiding bracket 209 moves to the plane formed by the eye 21a of the needle 21 and the hook 153, i.e., when the rotation bracket 203 rotates at a predetermined angle, the stopper 225 comes apart from the top surface of the rotation bracket 203 and contacts the top surface of the main body 163 by the elasticity of the stopper elastic unit 227 while contacting the projection 221 of the rotation bracket 203, thereby preventing the rotation bracket 203 from returning to its original position. Also, when the needle 21 moves down from the threading work section to the sewing work section, the lifting rod 231 moves down together with the needle bar lifting unit 143. Thus, when the bottom portion of the lifting rod 231 presses the top portion of the lifting bracket 223, the stopper 225 is spaced apart from the projection 221 while coming apart from the top portion of the main body 163, thereby allowing the rotation bracket 203 to return its original position. Meanwhile, the embroidering machine according to the present invention includes the cut-thread sensor 240 to sense whether the upper thread 3 is cut. Here, the cut- thread sensor 240 includes a shaking unit 241 retaining the upper thread 3, supported by the supporting frame 8, and shaking within a predetermined section where the upper thread 3 is tensed and released while the needle 21 stitches; and a magnetic sensor 261 magnetically interlocked with the shaking unit 241 and generating an approaching signal . The shaking unit 241 is placed under the thread winding unit 35 and coupled with the bush 245 rotatably coupled to the outer circumference of the second rotating shaft 123. The shaking unit 241 includes a direction shifter 241a to shift a transferring direction of the upper thread 3 moving toward the needle 21; a bush coupling part 241b disposed at a predetermined space from the direction shifter 241a, penetrated by the bush 245, and moving close to and apart from the magnetic sensor 261; and a connector 241c connecting one side edges of the direction shifter 241a and the bush coupling part 241b and maintaining a gap between the direction shifter 241 and the bush coupling part 241b. Further, the direction shifter 241a of the shaking unit 241 is formed with a thread retaining hole 243 to retain the upper thread 3 hung down and bent on by the direction shifter 241a.

The shaking unit 241 is driven by a shaking unit driver 247 to move the thread retaining hole 243 to the thread transferring path of the upper thread 3, thereby retaining the upper thread 3 on the thread retaining hole 243. The shaking unit driver 247 includes a shaking unit driving cam 249 formed with a cam profile 249a at a side thereof and rotatably coupled to the outer circumference of the bush 245; a cam pin 251 moving along the cam profile 249a of the shaking unit driving cam 249; a cam driver 253 rotating the shaking unit driving cam 249 by moving the cam pin 251 along the cam profile 249a of the shaking unit driving cam 249; and a cam elastic unit 255 connecting the shaking unit driving cam 249 and the head stem 7 with each other, and rotating the shaking unit driving cam 249 to return to its original position by- predetermined elasticity.

The shaking unit 241 moves by a shaking unit elastic unit 257 from a position where the upper thread 3 is tensed to a position where the upper thread 3 is released.

The shaking unit elastic unit 257 is provided between the shaking unit 241 and the shaking unit driver

247. The shaking unit elastic unit 257 has a first end supported by the shaking unit driving cam 249, and a second end supported by the shaking unit 241.

The magnetic sensor 261 is provided between the supporting frame 8 and the shaking unit 241, and supported by a sensor supporting bracket 263 standing on the top surface of the supporting frame 8. The top surface of the magnetic sensor 261 is spaced from the bottom surface of the shaking unit 241, i.e., the bush coupling part 241b of the shaking unit 241 at a predetermined distance. The magnetic sensor 261 is magnetically interlocked with the shaking unit 241 and generates a signal for allowing a controller 350 to determine whether the upper thread 3 is cut or not and supplies the signal to the controller 5. Here, the magnetic sensor 261 can be placed at least one position of the upper thread tensed position and the upper thread released position in the reciprocating section of the shaking unit 241. In this embodiment, the magnetic sensor 261 is disposed in the upper thread released position.

The magnetic sensor 261 can be placed at least one position of the upper thread tensed position and the upper thread released position in the reciprocating section of the shaking unit 241. In this embodiment, the magnetic sensor 261 is disposed in the upper thread released position.

Alternatively, the cut-thread sensor may be implemented by installing a rotation roller on the thread transferring path. In this case, the rotation roller can rotate in a normal state, but cannot rotate in a cut- thread state, thereby sensing whether the upper thread 3 is cut or not. Further, the cut-thread sensor may be implemented by installing a pressure sensor on the thread transferring path. In this case, the pressure sensor senses difference in tension between when the normal upper thread is fed and when the thread is cut. Also, the cut-thread sensor may be implemented by providing a device transforming the rotation of a thread tension spring during the embroidering work into an electric contact signal. In this case, a contact switch is opened in the normal embroidering work, and its rotational contact is short-circuited when the thread is cut. As shown in FIGS. 1 and 25 through 27, the cutting unit 270 includes a cutting part 271 cutting the upper thread 3 transferred from the thread feeder 10 to the needle working unit 20 along the thread transferring path; a cutting driver 281 driving the cutting part 271 to cut the upper thread 3 on the thread transferring path by a cutter 273; and a thread standby amount adjuster 311 recovering the cut upper thread 3 facing the bobbin to the thread feeder 10 so as to transfer the upper thread to the needle working unit 20 again. The cutting part 271 is placed in front of the thread feeder 10 and moves close to and apart from the thread supporting block 15 of the thread feeder 10, and includes the cutter 273 cutting the upper thread 3 and a cutter supporter 275 supporting the cutter 273. The cutter 273 has a rectangular cross-section, and is supported by the cutter supporter 275 so as to make a blade of the cutter 273 face the thread supporting block 15.

The cutting driver 281 includes a supporting shaft 283 supporting the cutter supporter 275; and an auxiliary driver 285 connected to the supporting shaft 283 and driving the cuter 273 to contact and move away from the upper thread 3, thereby allowing the cutter 273 to cut the upper thread 3 transferred along the thread transferring path. The auxiliary driver 285 includes a hydraulic cylinder 287, and a cylinder rod 289 reciprocating between extension and retraction by operation of the hydraulic cylinder 287. Meanwhile, the cylinder rod 289 is connected to the supporting shaft 283 by a cutter link 291. The cutter link 291 transfers the reciprocation of the cylinder rod 289 to the supporting shaft 283, so that the cutter supporter 275 connected to one end of the supporting shaft 283 can move toward and away from the upper thread 3 on the thread transferring path.

Further, the cutting driver 281 includes a guide 293 movably coupled to the supporting shaft 283 and guiding the upper thread 3 to move to a predetermined cutting position on the thread transferring path, and an elastic unit 301 providing predetermined elasticity to urge the cutter supporter 275 and the guide 293 to be spaced from each other.

The guide 293 is movably coupled to the supporting shaft 283 while leaving a predetermined space from the cutter supporter 275. The guide 293 is formed with a cutter through hole 295 through which the cutter 273 passes to cut the upper thread 3. Further, the guide 293 is internally mounted with a magnet 297 to attract the thread supporting block 15 of the thread feeder 10, so that the upper thread 3 on the thread transferring path is firmly attached to the circumference of a cutter accommodating groove 15b of the thread supporting block 15, and at the same time the upper thread 3 is tensed when the upper thread 3 is cut, thereby allowing the upper thread 3 to be easily cut.

Further, the guide 293 is connected to a rotating arm 299 transforming a reciprocating motion of the cylinder rod 289 into a rotating motion at a predetermined position. The rotating arm 299 has a first end coupled to the guide 293, and a second end rotatably coupled to the head stem 7.

The elastic unit 301 is provided along the outer circumference of the supporting shaft 283 between the cutter supporter 275 and the guide 293. In this embodiment, a coil spring is disclosed as the elastic unit 301, but not limited thereto. Alternatively, a flat spring, a spiral spring, etc. as well as the coil spring can be used as the elastic unit 301. Thus, the auxiliary driver 285 drives not only the guide 293 to guide the upper thread 3 on the thread transferring path to the circumference of the cutter accommodating groove 15b of the thread supporting block 15 but also the end of the cutter 273 to be accommodated in the cutter accommodating groove 15b while contacting the upper thread 3 transverse to the cutter accommodating groove 15b, thereby allowing the cutter 273 to cut the upper thread 3.

In the mean time, the thread standby amount adjustor 311 includes a thread standby amount adjusting body 313 having an accommodating space to accommodate the plurality of upper threads 3, with a predetermined length in standby, provided between the bobbin and the thread feeder 10, and a thread standby adjusting bar 321 moving the plurality of upper threads 3 to the accommodating space. Further, the thread standby amount adjuster 311 includes a thread transferring interceptor 331 provided between the bobbin and the thread standby adjusting body 313 and intercepting the plurality of upper threads 3 transferred to the thread standby amount adjusting body 313.

The thread standby amount adjusting body 313 includes a plurality of thread guides 315 to guide the plurality of upper threads 3 from the bobbin to the thread feeder 10; and a plurality of thread accommodating parts 317 communicating with each thread guide 315 and standby accommodating each upper thread 3 therein. Also, the thread standby amount adjusting body 313 further includes a guide slit 319 formed along and communicating with the thread accommodating part 317 in a direction transverse to the thread transferring direction. Preferably, the thread standby adjusting body 313 is shaped like a rectangular block.

The thread guide 315 is recessed on the top surface of the thread standby amount adjusting body 313 by a predetermined depth in the transferring direction of the upper thread 3 so as to individually accommodate the plurality of upper threads 3, respectively. Preferably, the thread guide 315 has an enough depth to prevent the upper thread 3 from breakaway while the upper thread 3 is transferred. Also, the thread guide 315 guides the upper thread cut and wound on the bobbin from the bobbin to the thread feeder 10.

The thread accommodating part 317 is recessed on the bottom surface of each thread guide 315 by a predetermined downward depth and has a predetermined width in the thread transferring direction. Further, the thread accommodating part 317 is plurally provided along the thread transferring direction. According to an embodiment of the present invention, there are three thread accommodating parts 317 along the thread transferring direction. Further, the depth of the thread accommodating part 317 is determined by the standby amount of the upper thread 3, and the standby amount of the upper thread 3 is preferably determined to make the eye 21a of the needle 21 be supplied to the needle working unit 20 and threaded with the end of the upper thread 3 accommodated in the thread standby pipe 11a of the thread feeding block 11. Further, the plurality of thread accommodating parts 317 allows the standby amount of the upper threads 3 to be distributed thereto, thereby reducing the depth of each thread accommodating part 317.

The guide slit 319 communicates with the thread accommodating part 317 and accommodates/guides the thread standby amount adjusting bar 321.

The thread standby adjusting bar 321 is movably accommodated in the guide slit 319, and transfers the plurality of upper threads 3 to a standby state which the upper threads 3 are accommodated in the thread accommodating part 317, from a working state which the upper threads 3 are disposed in the thread guide 315 to be supplied to the needle working unit 20. Further, the thread standby adjusting bar 321 transfers the cut upper thread 3 facing the bobbin from the thread guide 315 to the standby state, thereby recovering the ends of the plurality of upper threads 3. Preferably, thread standby adjusting bar 321 is placed above the plurality of upper threads 3. More preferably, the number of thread standby adjusting bars 321 is provided plurally corresponding to the number of guide slits 319. In this embodiment, two thread standby adjusting bars 321 are provided corresponding to two guide slits 319 in the thread transferring direction. Also, the thread standby adjusting bar 321 has a first end integrally formed with or coupled with an adjusting bar supporter 323.

The adjusting bar supporter 323 is coupled with an adjusting bar driver 325 to move the thread standby adjusting bar 321 along the guide slit 319.

The adjusting bar driver 325 is preferably implemented by a cylinder device having a first end coupled to the adjusting bar supporter 323 and allowing the adjusting bar supporter 323 to vertically reciprocate. Alternatively, the adjusting bar driver 325 may be implemented by a belt and a motor, which are connected to the adjusting bar supporter 323 and allow the adjusting bar supporter 323 to reciprocate.

Further, the thread standby amount adjuster 311 includes the thread transferring interceptor 331 provided between the bobbin and the thread standby amount adjusting body 313 and intercepting the upper thread 3 transferred from the bobbin to the thread standby amount adjusting body 313.

The thread transferring interceptor 331 is placed behind the thread standby amount adjusting body 313. The thread transferring interceptor 331 includes a supporting bracket 333 supported by the thread standby amount adjusting body 313 and formed with through holes 333a to be penetrated by the plurality of upper threads 3 transferred from the bobbin, respectively. The supporting bracket 333 is provided with an interceptor 335 thereon, which contacts and moves away from the upper threads transferred to the thread guide 315 through the through holes 333a, to intercept the plurality of upper threads 3 transferred to the thread guides 315.

The interceptor 335 is liftably coupled to the supporting bracket 333, and connected to an interceptor driver 341 by a pair or rods 337 and a connecting bar 339. The interceptor driver 341 is preferably implemented by a cylinder device having a first end connected to the connecting bar 339 and lifting the interceptor 335 toward the top surface of the supporting bracket 333, i.e., allowing the interceptor 335 to contact and move away from the plurality of upper threads 3 transferred to the thread guide 315 along the top surface of the supporting bracket 333, thereby intercepting or allowing the plurality of upper threads 3 to be transferred to the thread guide 315.

Meanwhile, the embroidering machine 1 according to the present invention includes a manipulating part 355 provided in one side of the settling frame 5 and allowing a user to manipulate the machine 1; and a controller 350 generally implemented by a microcomputer and determining whether the upper thread 3 is cut on the basis of the signal output from the manipulating part 355 and the signal output from the magnetic sensor 261. The controller 350 controls the needle bar driver 27 to drive the sewing operation of the needle 21; the arm driver 75 to drive the shaking operation of the arm 61; the main driver 100 rotating the thread winding unit 35 and reciprocating the thread take-out lever 81; the cam driver 253 rotating the shaking unit driving cam 249; the cutting driver 281 driving the cutting part 271 to make the cutter 273 to cut the upper thread 3 on the thread transferring path; the adjusting bar driver 3255 to drive the adjusting bar supporter 323 to recover the end of the cut thread 3 to the thread feeder 10; and the interceptor driver 341 to drive the interceptor 335 to intercept or allow the plurality of upper thread 3 to be transferred to the thread guide 315. Further, the controller 350 includes an embroidering program to apply a predetermined embroidering operation on an embroidering piece.

With this configuration, operation of the embroidering machine 1 according to the present invention will be described with reference to FIG. 4. A user manipulates the manipulating part 355 to make the needle 21 perform a normal sewing operation in the state that the needle 21 is normally threaded with the upper thread 3, thereby starting the embroidering part 355

At this time, when the upper thread 3 is normally transferred from the thread feeder 10 to the needle working unit 20 without being cut, the bush coupling part 241b of the shaking unit 241 periodically generates the approaching signal by magnetically interlocking with the bush coupling part 241b of the shaking unit 241 while periodically moving close to and apart from the magnetic sensor 261, thereby outputting the generated signal to the controller 350. Meanwhile, in the case where the upper thread 3 is cut, the tension of the upper thread 3 acting on the shaking unit 241 is eliminated, so that the shaking unit 241 does not shake regardless of the stitching operation of the needle 21. That is, the bush coupling part 241b of the shaking unit 241 does not periodically move close to and apart from the magnetic sensor 261, so that it continuously approaches the magnetic sensor 261. Therefore, the magnetic sensor 261 continuously generates the approaching signal and outputs the generated signal to the controller 350. At operation SlO, the controller 350 determines whether the thread is cut or not on the basis of the signal output from the magnetic sensor 261. For example, the controller 350 determines that the upper thread 3 is normally transferred from the thread feeder 10 to the needle working unit 20 without being cut when it periodically receives the signals from the magnetic sensor 261. On the other hand, the controller 350 determines that the upper thread 3 is cut when it continuously receives the signal from the magnetic sensor 261.

When the controller 350 determines that the upper thread 3 is cut, the controller 350 outputs a signal to the needle bar driver 27, and stopping the needle working unit 20 at operation S20. That is, the embroidering machine 1 stops operating.

After stopping the needle working unit 20, at operation S30 the controller 350 drives the cutting unit 270 to cut the cut upper thread 3.

Below, a process of cutting the cut upper thread 3 using the cutting unit 270 will be described schematically.

As shown in FIG. 25, in the state that the cutter 273 of the cutting part 271 is spaced apart from the thread supporting block 15, the cylinder rod 289 of the auxiliary driver 285 of the cutting driver 281 is retracted, so that the cutter 273 of the cutting part 271 is moved to the cutter accommodating groove 15b of the thread supporting block as shown in FIG. 26.

As the cylinder rod 289 of the auxiliary driver 285 is retracted, the cutter link 291 moves toward the auxiliary driver 285, and the supporting shaft 283 is disposed on the same plane as the cylinder rod 289 while being rotated by the rotating arm 299. At this time, the guide 293 is rotated toward the thread supporting block 15 as the supporting shaft 283 rotates, thereby pushing the upper thread 3 retained on the thread take-up unit 60 toward the front surface of the thread supporting block 15.

Then, as the cylinder rod 289 is retracted, the cutter supporter 275 moves toward the guide 293 in the state that the guide 293 closely contacts the front surface of the thread supporting block 15. Therefore, the end of the cutter 273 passes through the cutter through hole 295 of the guide 293, and cuts the upper thread 3 while contacting the upper thread 3 transverse the cutter accommodating groove 15b. At the same time, the elastic unit 301 interposed between the cutter supporter 275 and the guide 293 is compressed. At this time, the end of the cut upper thread 3 is cut clearly enough to easily thread the needle 21 of the needle working unit 20 with the upper thread 3.

After cutting the cut upper thread 3, at operation S40 the upper thread 3 is recovered from the needle 211 of the needle working unit 20. That is, the upper thread 3 is cut, as shown in FIG. 27, the controller 350 controls the adjusting bar driver 325 to make the thread standby amount adjusting bar 321 be lifted downward along the guide slit 319 of the thread standby amount adjusting body 313 in the state that the guide 293 closely contact the front surface of the thread supporting block 15, thereby inserting the upper thread 3 from the bobbin, on which the cut upper thread 3 is wound, by a predetermined length in the thread accommodating part 317. At this time, the thread transferring interceptor 331 is in a state for allowing the upper thread 3 to be transferred.

At the moment when the cut upper thread 3 is supplied from the bobbin to the thread accommodating part 317 by a predetermined length, the controller 350 drives the interceptor driver 341 to prevent the upper thread 3 from being transferred from the bobbin to the thread standby amount adjusting body 313.

Further, in the state that the upper thread 3 is not transferred from the bobbin to the thread standby adjusting body 313, the cylinder rod 289 of the auxiliary driver 285 is extended so that the guide 293 is spaced apart from the thread supporting block 15. At this time, the upper thread 3 retained on the thread take-up unit 60 and the upper thread 3 from the thread take-up unit 60 to the needle working unit 20 get out of the embroidering machine 1.

Then, the thread standby adjusting bar 321 is further lifted down along the guide slit 319 of the thread standby amount adjusting body 313 so as to transfer the cut upper thread 3 extended from the cutter accommodating groove 15b to the bobbin again to the needle working unit 20. Thus, the end of the cut upper thread 3 is recovered so as to be in the standby position of the thread feeder 10, i.e., in a connection pipe 13 of the thread feeder 10.

Thus, the end of the upper thread 3 cut while performing the embroidering operation is cut clearly enough to easily thread the needle 21 of the needle working unit 20 with the upper thread 3. Further, the end of the upper thread 3 is placed in the thread standby state of the thread feeder 10, thereby completing the preparation of supplying the upper thread 3 to the needle working unit 20 again.

Then, after the cut upper thread 3 is recovered from the needle 21, the controller 350 drives the upper thread feeding unit to supply a new upper thread 3 to the needle working unit 20, thereby threading the needle 21 with the new upper thread 3 at operation S50.

Below, a process of threading the needle 21 with a new upper thread 21 will be described schematically.

First, the holder 37 of the thread winding unit 35 is placed on the thread transferring path between the thread feeding block 11 and the thread guiding block 17. At the same time, the thread through holes 85a and 85b of the respective holding ends 83a and 83b of the thread take-out lever 81 are aligned and communicated with the thread guiding path 17a of the thread guiding block 17.

Further, the controller 350 controls the cam driver 253 to be driven to move the cam pin 251 along the cam profile 249a of the shaking unit driving cam 249, so that the thread retaining hole 243 of the shaking unit 241 is coaxially aligned with the holder 37 of the thread winding unit 35. As the cam pin 251 is lifted up while moving along the cam profile 249a of the shaking unit driving cam 249, the shaking unit 241 rotates along with the shaking unit driving cam 249, so that the thread retaining hole 243 of the shaking unit 241 is aligned coaxially with and communicates with the holder 37 of the thread winding unit 35 (refer to FIGS. 8A and 8B) . Then, one upper thread 3 is selected among a plurality of standby upper threads having various colors from the thread feeding block 11, and then transferred by compressed air from the thread feeding path 15a of the thread supporting block 15 to the needle 21 via the thread guiding path 17a of the thread guiding block 17.

At this time, the upper thread 3 gets out of the thread feeding path 15a and passes through the holder 37 of the thread winding unit 35, the thread retaining hole 243 of the shaking unit 241, the thread guiding path 17a, the thread through holes 85a and 85b of the respective holding ends 83a and 83b of the thread take-out lever 81 in sequence, thereby being transferred to the needle 21 positioned in the bottom dead point of the sewing work section. Then, the controller 350 controls the main driver 100 to drive the lifting link 105 to lift up, thereby placing the needle 21 in the top dead point of the sewing work section.

At this time, as the lifting link 105 moves upward, the thread winding unit 35 rotates in a first direction by the driving cam 113, so that the upper thread 3 held by the holder 37 of the thread winding unit 35 is taken out from the thread transferring path and wound along the thread contacting part 33 of the thread tension adjusting body 32. The upper thread 3 wound on the thread contacting part 33 of the thread tension adjusting body 32 makes resistance while passing through the thread contacting part 33 of the thread tension adjusting body 32, thereby tensing the upper thread 3 moving along the thread contacting part 33.

That is, when the lifting link 105 moves upward, the driving pin 111 moves along the lifting-up profile section of the driving cam 113, thereby rotating the driving cam 113 in a first direction. As the driving cam 113 rotates, the first rotating shaft 117 rotates correspondingly, so that the rotation of the first rotating shaft 117 is transferred to the second rotating shaft 123 through each pulley 125 connected by the belt 127, thereby rotating the thread winding unit 35 in a first direction.

Meanwhile, the upper thread 3 transferred to the thread guiding block 17 through the thread tension adjusting body 32 is retained in the thread retaining hole 243 of the shaking unit 241. Then the shaking unit 241 returns to its original position by the elasticity of the cam elastic unit 255. The returned shaking unit 241 shakes by the elasticity of the shaking-unit elastic unit 257. Thus, the upper thread 3 passing through the shaking unit 241 is tensed and released by not only the tension of the upper thread 3 itself caused by the thread tension adjusting body 32 but also the shaking operation of the shaking unit 241.

At the same time, when the lifting link 105 moves upward, the thread take-out lever 81, which holds the upper thread 3 by passing through the thread through holes 85a and 85b of the respective holders 83a and 83b, goes close to the thread retainer 63 of the thread take- up unit 60 placed in the bottom dead point along with the take-out lever bracket 91 and presses the flap 67 of the thread take-up unit 60 (refer to FIG. 12A) . Then, as shown in FIG. 12B, the flap 67 blocking the opening 65 of the thread retainer 63 is rotated inwardly to open the opening 65, and then returns to its original position, i.e., a position for blocking the opening 65 by the elasticity of the elastic unit 69 when the upper thread 3 held by the thread through holes 85a and 85b of the thread take-out lever 81 approaches to a predetermined position in the opening 65.

Further, the flap 67 is accommodated in the flap accommodating part 81 formed by the thread take-out lever 81 and the take-out lever bracket 91. Also, the flap 67 gets in contact with the profile part 93 of the take-out lever bracket 91.

Then, the controller 350 controls the main driver 100 to be driven to lift up the lifting link 105 so that the needle 21 gets out of the top dead point of the sewing work section and moves toward the threading work section.

At this time, when the lifting link 105 moves upward, not only the connection link 107 but also the needle bar lifting unit 143 are lifted up.

As the needle bar lifting unit 143 is lifted up, the needle bar 25 moves up by the elasticity of the needle bar elastic unit 147. At this time, to prevent the needle bar 25 from interfering with the needle bar driver 27, the needle bar 25 is disconnected from the needle bar driver 27 by a clutch. Then, as the needle bar 25 moves upward, the needle 21 gets out of the top dead point of the sewing work section until it reaches a predetermined height, i.e., a threading alignment position where the eye 21a of the needle 21 and the hook 153 of the thread catcher 151 are aligned on the same plane (refer to FIG. 17) .

In the meantime, when the needle bar lifting unit 143 is lifted up to the threading work position after the upper thread 3 passes through the thread through hole 211a of the thread guiding bracket 209, only the needle bar lifting unit 143 is lifted up to the threading work position in the state that the needle 21 and the needle bar 25 are maintained in the thread alignment position. As shown in FIG. 18, the needle bar lifting unit 143 moves up to the threading work position, the driving pin 111 protruding from one side of the lifting link 105 moves upward while contacting the pin sloping part 179 provided in the thread catcher driving link 177, so that the lower end of the thread catcher driving link 177 rotates from the back to the front of the main body 163 and is accommodated in the link accommodating groove 169, thereby pressing the thread catcher supporter 165. At the same time, the lifting rod 231 pressing the lifting bracket 223 also moves upward, so that the lifting bracket 223 is released from the lifting rod 231.

Further, when the thread catcher supporter 165 is pressed, the thread catcher supporter 165 moves from the back to the front of the main body 163, so that the hook 153 of the thread catcher 151 placed on the same plane as the eye 21a of the needle 21 moves toward and passes through the eye 21a of the needle 21.

In the meantime, as the thread catcher supporter 165 moves from the back to the front of the main body 163, the rotation pin 207 provided in the upper portion of the thread catcher supporter 165 moves forward along the slot of the main body 163 and rotates the rotation bracket 203 while contacting the thread guide sloping portion 205 formed in the rotation bracket 203. At the same time, the stopper 225 provided in the lifting bracket 223 contacts the projection 221 formed in the rotation bracket 203, thereby preventing the rotation bracket 203 from rotating.

Further, as the rotation bracket 203 rotates, the auxiliary link 215 rotates. Thus, the thread guiding bracket 209 rotates at an angle of about 90 degrees, so that the upper thread 3 passing through the thread through hole 211a of the thread guiding bracket 209 is guided to the plane formed by the eye 21a of the needle 21 and the hook 153, and is at the same time retained on the thread catcher 151 (refer to FIG. 19) . At this time, the thread catcher 151 and the hook guide 167 are placed between the pair of thread guides 211 of the thread guiding bracket 209. Then, the main driver 100 drives the lifting link 105 to lift down, thereby moving the needle bar lifting unit 143 from the threading work position to the threading alignment position (refer to FIG. 20) .

At this time, as the needle bar lifting unit 143 moves down, the lifting rod 231 spaced from the lifting bracket 223 is also lifted down. Also, as the needle bar lifting unit 143 moves down, the driving pin 111 protruding from one side of the lifting link 105 moves down while contacting the pin sloping part 179 provided in the thread catcher driving link 177, so that the lower end of the thread catcher driving link 177 rotates toward the back of the main body 163 and releasing the thread catcher supporter 165 from pressure.

When the thread catcher supporter 165 is released from the thread catcher driving link 177, the thread catcher supporter 165 moves toward the back of the main body 163 by the elasticity of the supporting shaft elastic unit 173. Thus, the thread catcher 151 supported by the thread catcher supporter 165 also moves toward the back of the main body 163, so that the hook 153 of the thread catcher 151 gets out of the eye 21a of the needle 21 while catching the upper thread 3, and is then disposed at a predetermined space from the needle 21. At this time, the upper thread 3 is still remained to be retained on the hook 153 even though it passes through the eye 21a of the needle 21.

Then, the main driver 100 drives the needle bar lifting unit 143 to move down, thereby moving the needle 21 from the threading work section to the sewing work section. When the needle bar lifting unit 143 moves down, the needle 21 and the needle bar 25 are also lifted down. At the same time, the lifting rod 231 is also lifted down and presses one side of the lifting bracket 223, so that the stopper 225 of the lifting bracket 223 comes apart from the top surface of the main body 163 and releases the projection 221 of the rotation bracket 203, thereby allowing the rotation bracket 203 to rotate in a second direction and return to its original position. Further, when the rotation bracket 203 is rotated to return to its original position, the auxiliary link 215 rotates in the second direction, so that the thread guiding bracket 209 also returns to its original position.

As shown in FIG. 22, the thread unwinding bracket 195, provided in the needle bar lifting unit 143 and spaced from the thread transferring bracket 183 at a predetermined distance, moves down along the needle bar sloping part 193 formed in the thread transferring bracket 183 as shown in FIG. 23 when the needle bar 25 and the needle bar lifting unit 143 are lifted down, thereby rotating the thread transferring bracket 183 in the first direction. At this time, the tread catching portion 185 of the thread transferring bracket 183 passes through the eye 21a of the needle 21 and catches the upper thread 3 retained on the hook body 155, thereby moving it toward the hook body 155.

Then, the main driver 100 drives the needle lifting link 105 to lift down, thereby moving needle 21 from the threading work section to the bottom dead point of the sewing work section. When the lifting link 105 is lifted down, the driving pin 111 moves along the lifting-down profile section of the driving cam 113, so that the thread winding unit 35 winds the upper thread 3 on the thread tension adjusting body 32 as shown in FIGS. 9A and 9B while rotating in the first direction. Thus, the holder 37 of the thread winding unit 35 returns to its original position where it communicates with the thread feeding path 15a of the thread supporting block 15.

At the same time, when the lifting link 105 is lifted down, the thread take-out lever 81 moves backward from the thread retaining position to the take-out position of the upper thread 3, and the flap 67 of the thread retainer 63 slides in a straight line along the straight line moving part 93a of the profile part 93 of the take-out lever bracket 91 in the state that the flap 67 blocks the opening 65, thereby reaching the transverse moving part 93b of the profile part 93. Further, the flap 67 slides along the transverse moving part 93b, so that the free end of the take-out lever bracket 91 gradually comes apart from the thread take-out lever 81, and the flap accommodating part 87 opens, thereby allowing the flap 67 to get out of the flap accommodating part 87 of the thread take-out unit 80.

At the moment when the flap 67 gets out of the flap accommodating part 87 of the thread take-out unit 80, the take-out lever bracket 91 rotates toward the lateral side of the thread take-out lever 81 by the elasticity of the take-out lever elastic unit and returns to its original position. Further, to make the thread guiding path 17a of the thread guiding block 17 communicate with the thread through holes 85a and 85b of the respective holding ends 83a and 83b, the thread take-out lever 81 returns to its original position as shown in FIG. 13. At this time, as shown in FIGS. 12C and 13, the upper thread 3 passes through the thread guiding path 17a of the upper thread guiding block 17 and the thread through hole 85a of the upper holding end 83a, and its direction is changed in the flap 67. Then, the upper thread 3 passes through the thread through hole 85b of the lower holding end 83b and the thread guiding path 17a of the lower thread guiding block 17, thereby being transferred to the needle 21.

Then, as shown in FIG. 14, when the arm driver 75 drives the thread retainer 63 of the thread take-up unit 60 to be positioned in the top dead point, the upper thread 3 retained on the thread retainer 63 is tensed. Thus, the upper thread 3 retained on the thread retainer 63 is alternately tensed and released while oscillating between the bottom dead point and the top dead point by the oscillation of the arm driver 75.

Further, when the lifting link 105 moves down, the needle bar 25 and the needle bar lifting unit 143 are lifted down from the threading work section to the sewing work section, so that the upper thread 3 retained on the hook body 155 of the thread catcher 151 is naturally released from the hook body 155 and threaded through the eye 21a of the needle 21, thereby completing the threading work as shown in FIGS. 21 and 24. After threading the needle 21 with the new upper thread 3, the controller 350 drives the needle bar driver 27 again so as to perform the remaining embroidering operation according to a predetermined embroidering program at operation S60. Further, the controller 350 determines whether the embroidering program is finished or not at operation S70. When the embroidering program is finished, the controller 350 stops the needle bar driver 27 from operating, thereby completing the embroidering work. Thus, when it is sensed that the upper thread is cut on the way of normally performing the embroidering operation, the operation of the needle working unit is automatically stopped, and then the needle is automatically threaded with a new upper thread, so that a time taken to feed the needle with a new upper thread is reduced, thereby enhancing productivity and implementing an automation system thereof.

In the foregoing embodiment, the cut upper thread is cut by driving a cutting unit after stopping the needle working unit. Alternatively, the operation of cutting the cut upper thread may be selectively performed.

Also, in the foregoing embodiment, the cut upper thread is cut by the cutting unit with the cutter.

Alternatively, a laser beam, a hot wire and the like may be used instead of the cutter for cutting the cut upper thread.

Meanwhile, it will be appreciated by those skilled in the art that the present invention can be applied to various sewing apparatuses such as the single needle automatic embroidering machine, a multi needle automatic embroidering machine, a sewing machine, etc.

As described above, the present invention provides an operating method of an embroidering machine, which reduces time taken to feed a needle working unit with an upper thread when the upper thread is cut, thereby enhancing productivity and implementing an automation system thereof.

Claims

ClaimsWhat is claimed is:

1. An operating method of an embroidering machine comprising a thread feeder, a needle working unit having a needle threaded with an upper thread supplied from the thread feeder and performing a sewing operation, a thread feeding unit forming a predetermined thread transferring path from the thread feeder to the needle working unit and having an upper thread feeder to supply the upper thread and a threader to tread the needle with the upper thread, a cut-thread sensor to sense whether the upper thread transferred along the thread transferring path is cut, and a cutting unit to cut the upper thread on the thread transferring path, the operating method comprising: controlling the cut-thread sensor to sense whether the upper thread is cut; stopping the needle working unit to operate; recovering the cut upper thread from the needle working unit; and driving the upper thread feeder to feed the needle working unit with a new upper thread to be threaded through the needle.

2. The operating method according to claim 1, further comprising driving the cutting unit to cut the cut upper thread after stopping the needle working unit .

3. The operating method according to claim 1 or 2, further comprising driving the needle working unit to make the needle perform a sewing operation after threading the needle with a new thread.