THREAD FEEDING APPARATUS FOR AN EMBROIDERING MACHINE

Abstract

The present invention relates to a thread feeding apparatus for an embroidering machine, comprising a thread tension adjuster including a thread tension adjusting body and a thread winding unit; a thread take-up unit including a thread retainer and oscillating to tense and release the upper thread; a thread take-out unit including a thread take-out lever and retaining the upper thread; a driver driving the thread winding unit to rotate and the thread take-out lever to reciprocate; a rotating motion transformer rotating the thread winding unit to wind the upper thread on the thread tension adjusting body; and a straight line motion transformer and moving the thread take-out lever to retain the upper thread on the thread retainer. Thus, a single driver is used for winding an upper thread and retaining the upper thread, thereby enhancing productivity. Further, the number of components is reduced.

Description

TECHNICAL FIELD

The present invention relates to a thread feeding apparatus for an embroidering machine, and more particularly, to a thread feeding apparatus for an embroidering machine having an improved structure.

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 threading feeding apparatus and the needle working unit.

The single needle type automatic embroidering machine includes the thread feeding apparatus that selectively supplies one of various colored upper threads from the plurality of bobbins to a single needle working unit.

The multi needle type automatic embroidering machine includes a thread feeding apparatus that supplies various colored upper threads from the plurality of bobbins to a plurality of needle working units.

Hereinafter, the thread feeding apparatus for the single needle type automatic embroidering machine will be exemplarily described.

In a conventional thread feeding apparatus for the 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, so that its tension is adjusted. Then, the upper thread is retained in a thread retainer of the thread take-up unit, moves toward the needle, and passes through an eye of the needle by a threading apparatus 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.

However, in the conventional thread feeding apparatus for the single needle type automatic embroidering machine, the foregoing operations of putting the upper thread on the thread tension adjusting boy; retaining the thread in the thread retainer of the thread take-up unit; passing the thread through the eye of the needle; etc. are individually performed by separate drivers or manually performed as necessary. Thus, the plurality of drivers causes the embroidering machine to have a complicated structure and a production cost to increase. Further, such serial operations for replacing the upper thread are not simultaneously performed, so that it takes relatively much time to replace the upper thread, thereby deteriorating productivity.

DISCLOSURE OF INVENTION

Accordingly, it is an aspect of the present invention to provide a thread feeding apparatus for an embroidering machine, in which a single driver is used for simultaneous operations of partially winding an upper thread on a thread tension adjusting boy, and retaining the upper thread in a thread retainer of a thread take-up unit, so that a time taken to replace the upper thread is reduced, thereby enhancing productivity. Further, the number of components is reduced, thereby simplifying a structure and reducing a production cost.

The foregoing and other aspects of the present invention are achieved by providing a thread feeding apparatus for an embroidering machine, comprising a thread tension adjuster that comprises a thread tension adjusting body on which an upper thread is partially wound and which makes resistance to the upper thread, and a thread winding unit provided in a predetermined rotating shaft and winding the upper thread on the thread tension adjusting body by rotating while holding the upper thread spaced apart from the rotating shaft, and adjusting the tension of the upper thread; a thread take-up unit that comprises a thread retainer on which the upper thread is retained, and oscillates within a predetermined section to tense and release the upper thread; a thread take-out unit that comprises a thread take-out lever reciprocating between a take-out position in which the upper thread is taken out from a thread transferring path and a thread retaining position on which the upper thread is retained, and retains the upper thread on the thread retainer by taking out the upper thread on the thread transferring path; a driver that drives the thread winding unit to rotate and the thread take-out lever to reciprocate; a rotating motion transformer that transforms a driving operation of the driver into a rotating motion, and rotates the thread winding unit to wind the upper thread on the thread tension adjusting body; and a straight line motion transformer that transforms the driving operation of the driver into a straight line motion, and moves the thread take-out lever to retain the upper thread on the thread retainer.

According to another aspect of the present invention, the thread feeding apparatus further comprises a lifting link connected to the driver and moves up and down by the driving operation of the driver, wherein the rotating motion transformer comprises a driving pin protruded from one side of the lifting link; a driving cam formed with a predetermined cam profile movably engaged with the driving pin, and rotatably coupled to a predetermined rotating shaft; and a power transmission unit transferring the rotation of the driving cam to the thread winding unit.

According to another aspect of the present invention, the straight line motion transformer comprises a bracket provided in one of the lifting link and the thread take-out unit, and formed with an elongated hole at a predetermined angle to a lifting direction of the lifting link; and a movable pin provided in the other one of the lifting link and the thread take-out unit, and moving in a straight line while being movably engaged with the elongated hole.

According to another aspect of the present invention, the thread feeding apparatus further comprises a needle bar lifting unit to which a needle bar mounted with a needle is liftably coupled, and which is connected with the lifting link, wherein the driver drives the needle bar lifting unit to move up and down to move from a sewing work section to a predetermined threading work section.

According to another aspect of the present invention, the thread feeding apparatus further comprises a thread catcher that comprises a hook for catching the upper thread and a hook body for supporting the hook, and threads the upper thread through an eye of the needle while reciprocating to pass the hook through the eye of the needle; and a thread catcher driver that comprises a thread catcher supporter to support the thread catcher, and a thread catcher driving link formed with a pin sloping part at a predetermined angle to the lifting direction of the lifting link to contact the driving pin within the threading work section of the needle, and reciprocates the thread catcher, wherein the driver drives the driving pin to move along the pin sloping part, and allows to pass the hook through the eye of the needle by making the thread catcher driving link press and release the thread catcher supporter.

According to another aspect of the present invention, the thread feeding apparatus further comprises a thread transferring bracket that is formed with a needle bar sloping part having a predetermined angle transversely to the lifting direction of the needle bar, and is rotatably installed in a predetermined rotating shaft while being parallel with a plane formed by the eye of the needle and the hook; and a thread unwinding bracket provided in the needle bar lifting unit, and rotating the thread transferring bracket while sliding on and getting in contact with the needle bar sloping part to take up the upper thread retained in the hook and transfer the upper thread to the hook body, wherein the driver drives the lifting link to move down from the threading work position to the sewing work section and allows to rotate the thread transferring bracket by the thread unwinding bracket to thread the upper thread through the eye of the needle while the upper thread is moved to and released from the hook body.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a thread feeding apparatus for 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 side view of a thread tension adjuster of FIG. 1;

FIG. 4 is an enlarged perspective view of the thread tension adjuster of FIG. 1;

FIG. 5 is an exploded perspective view of FIG. 4;

FIGS. 6A, 6B, 7A and 7B are partially enlarged perspective views and side views showing a process of winding an upper thread on the thread tension adjuster;

FIG. 8 is an enlarged perspective view of a thread take-out unit of FIG. 1;

FIG. 9 is a side view of FIG. 8;

FIG. 10A through 10C are plan views showing an operation between a thread take-up unit and a thread take-out lever;

FIG. 11 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. 12 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. 13 is an exploded perspective view of a threading apparatus of FIG. 1;

FIG. 14 is a partially enlarged exploded perspective view of FIG. 13;

FIGS. 15 through 18 is perspective views illustrating a threading operation of the threading apparatus of FIG. 13;

FIG. 19 is an enlarged perspective view of when the threading apparatus completes the threading operation;

FIGS. 20 and 21 are partial perspective views illustrating an operation of a thread transferring unit of the threading apparatus; and

FIG. 22 is a partial perspective view of when the thread transferring unit of the threading apparatus completes the operation.

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 and 2, a thread feeding apparatus 1 for an embroidering machine 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 (not shown) 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 9; a thread tension adjuster 20 adjusting the tension of the upper thread 3 moving from the thread feeder to the needle 9; a thread take-up unit 60 taking up the upper thread 3 and strengthening/releasing the tension of the upper thread 3; a thread take-out unit 80 taking out the upper thread 3 on a thread transferring path and putting it on the thread take-up unit 60; and a threading apparatus 140 for passing the upper thread 3 through an eye 9a (refer to FIG. 19) of the needle 9.

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 and the threading apparatus 140 at the front thereof. Alternatively, the head stem may have various shapes as long as it can support the thread feeder or the like.

The thread feeder includes a thread feeding block 11 formed with a single thread feeding path 11a through which one upper thread 3 selected among the plurality of upper threads corresponding to various colors passes; and a thread guiding block 15 formed with a thread guiding path 15a that is provided under the thread feeding block 11 and communicates with the thread feeding path 11a, and guiding the thread from the thread feeder to the needle 9.

A space part 17 is provided between the thread feeding block 11 and the thread guiding block 15, leaving a predetermined space along the thread transferring path.

The space part 17 is provided with a thread tension adjustor 20 to adjust tension of the upper thread 3 transferred from the thread feeder to the needle 9.

As shown in FIGS. 3 through 7, the thread tension adjuster 20 includes a thread tension adjusting body 21 winding and contacting the upper thread 3 passing through the space part 17 thereon so as to adjust the tension of the upper thread 3; and a thread winding unit 25 holding the upper thread 3 passing through the space part 17 and rotating so as to make the upper thread 3 be wound on the thread tension adjusting body 21.

The thread tension adjusting body 21 is shaped like a disk, and formed with a thread contacting part 23 recessed along the circumference thereof and on which the upper thread 3 is partially wound. The thread tension adjusting body 21 is accommodated in an accommodating groove 29 of the thread winding unit 25 (to be described later). The thread contacting part 23 makes resistance when the upper thread 3 contacts and passes thereon, thereby adjusting the tension of the upper thread 3. Meanwhile, the thread tension adjuster 21 is rotatably coupled to a second rotation axis 123 (to be described later).

The thread winding unit 25 is placed under the thread feeding block 11, 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 passing through the space part 17 at a predetermined distance. Also, the thread winding unit 25 is penetratingly formed with a thread through hole as a holder 27 for holding the upper thread 3 passing through the space part 17.

Further, the thread winding unit 25 is formed with the accommodating groove 29 to accommodate the thread tension adjusting body 21, and is rotated by the driver 100 (to be described later), thereby partially winding the upper thread 3 on the thread contacting part 23 of the thread tension adjusting body 21.

The thread winding unit 25 is connected to a rotating motion transformer (to be described later), and rotates relative to the thread tension adjusting body 21, thereby allowing the upper thread 3 to be wound on the thread tension adjusting body 21.

Meanwhile, a shaking unit 31 is provided under the thread winding unit 25, and holds the upper thread 3. The shaking unit 31 shakes within a predetermined section where the tension of the upper thread 3 is alternately strengthened and released as the needle 9 stitches.

The shaking unit 31 is coupled to a bush 35 rotatably coupled to the outer circumference of the second rotation axis 123. The shaking unit 31 includes a direction changer 31a to change a moving direction of the upper thread 3 toward the needle 9; a bush coupling part 31b penetratingly coupled with the bush 35 at a predetermined distance from the direction changer 31a and moving close to and apart from a magnetic sensor (not shown) to sense the shakes of the shaking unit 31; and a connector 31c connecting the direction changer 31a with the bush coupling part 31b at their one sides and maintaining a gap between the direction changer 31a and the bush coupling part 31b. The direction changer 31a of the shaking unit 31 is formed with a thread retaining hole 33 to curvedly hold the upper thread 3 changed in its direction by the direction changer 31a.

The shaking unit 31 is driven by a shaking unit driver 41 to move the thread retaining hole 33 to the moving path of the upper thread 3, thereby allowing the thread retaining hole 33 to hold the upper thread 3. The shaking unit driver 41 includes a shaking unit driving cam 43 formed with a predetermined cam profile 43a on a lateral surface and rotatably coupled to the outer circumference of the bush 35; a cam pin 45 moving along the cam profile 43a of the shaking unit driving cam 43; a cam driver (not shown) rotating the shaking unit driving cam 43 by moving the cam pin 45 along the cam profile 43a of the shaking unit driving cam 43; and a cam elastic unit 49 connecting the shaking unit driving cam 43 with the head stem 7 and rotating the shaking unit driving cam 43 by predetermined elasticity so as to return the shaking unit driving cam 43 to its original position.

Meanwhile, the shaking unit 31 moves the upper thread 3 from a tensed position to a released position by a shaking-unit elastic unit 51 having predetermined elasticity.

The shaking-unit elastic unit 51 is placed between the shaking unit 31 and the shaking unit driver 41. The shaking-unit elastic unit 51 has a first end supported by the shaking unit driving cam 43 (to be described later), and a second end supported by the shaking unit 31.

As shown in FIGS. 8 through 12, a 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 with 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 19 cut at a predetermined angle to the moving path of the upper thread 3 in a predetermined region of the thread guiding block 15. 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 of the space part 17, 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 passing through the space part 17, 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 between the holding ends 83a and 83b of the thread take-out lever 81. 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 liner 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 threading feeding apparatus 1 for the embroidering machine according to the present invention includes a driver 100 to rotate the thread winding unit 25 and reciprocate the thread take-out lever 81; a lifting link 105 connected to the driver 100 and driven by the driver 100 to be lifted up and down; a rotating motion transformer transforming a driving operation of the driver 100 into a rotating motion and rotating the thread winding unit 25 with respect to the thread tension adjusting body 21 so as to wind the upper thread 3 on the thread tension adjusting body 21; and the straight line motion transformer transforming the driving operation of the 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 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 from and parallel with the lifting link 105. In the present invention, the hydraulic cylinder is used as the driver 100, but not limited thereto. Alternatively, a motor or the like as well as the hydraulic cylinder can be used as the 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 25.

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 25; 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 25. Further, the second rotating shaft 123 is coupled with the bush 35, 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. 13 through 22, the threading apparatus 140 includes a needle bar lifting unit 143 to which a needle bar 141 is coupled so that the needle bar 141 can be lifted up and down. Therefore, the needle 9 mounted to the needle bar 141 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 9a of the needle 9.

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 141 therein, and guiding the needle bar 141 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 141, and accommodated in the elastic unit accommodating groove 145 of the upper guide unit 143a, thereby elastically connecting the needle bar 141 with the needle bar lifting unit 143. Further, the needle bar elastic unit 147 absorbs a shock from the needle bar 141 when the needle 9 sews.

Further, the threading apparatus 140 according to an embodiment of the present invention 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 9a; 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 9a of the needle 9. 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 9a of the needle 9. 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 9a of the needle 9 to return to its original position from the eye 9a of the needle 9 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 9.

Thus, when the needle bar lifting unit 143 and the lifting link 105 are driven by the 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 9a.

The thread transferring unit 181 catches the upper thread 3 retained in the hook 153 to transfer it to the hook body and includes a thread transferring bracket 183 that catches the upper thread 3 passed through the eye 9a 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 9a of the needle 9 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 9a of the needle 9. 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 141 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 141 and the needle bar lifting unit 143 are lifted up and down.

Thus, both the needle bar 141 and the needle bar lifting unit 143 move down as the needle 9 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 9a of the needle 9 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 threading apparatus 140 further includes a thread guiding unit 111 guiding the upper thread 3 supplied from a thread feeder to the plane formed by the eye 9a of the needle 9 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 and guiding the upper thread 3 to the plane formed by the eye 9a of the needle 9 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, 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 9a of the needle 9 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 9a of the needle 9 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 143 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 9a of the needle 9 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 9 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.

With this configuration, when the upper thread 3 is replaced according as a color is changed or cut while embroidering, the thread feeding apparatus 1 for an embroidering machine according to the present invention operates as follows.

First, the holder 27 of the thread winding unit 25 is placed on the thread transferring path of the space part 17 between the thread feeding block 11 and the thread guiding block 15.

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 15a of the thread guiding block 15.

Further, the cam driver is driven to move the cam pin 45 along the cam profile 43a of the shaking unit driving cam 43, so that the thread retaining hole 33 of the shaking unit 31 is coaxially aligned with the holder 27 of the thread winding unit 25. As the cam pin 45 is lifted up while moving along the cam profile 43a of the shaking unit driving cam 43, the shaking unit 31 rotates along with the shaking unit driving cam 43, so that the thread retaining hole 33 of the shaking unit 31 is aligned coaxially with and communicates with the holder 27 of the thread winding unit 25 (refer to FIGS. 6A and 6B).

Then, one upper thread 3 is selected among a plurality of standby upper threads having various colors from the thread feeder, and then transferred by compressed air from the thread feeding path 11a of the thread feeding block 11 to the needle 9 via the space part 17 and the thread guiding path 15a of the thread guiding block 15.

At this time, the upper thread 3 gets out of the thread feeding path 11a and passes through the holder 27 of the thread winding unit 25, the thread retaining hole 33 of the shaking unit 31, the thread guiding path 15a, 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 9 positioned in the bottom dead point of the sewing work section.

Then, the driver 100 drives the needle 9 to be positioned in the top dead point of the sewing work section, thereby lifting up the lifting link 105.

At this time, as the lifting link 105 moves upward, the thread winding unit 25 rotates in a first direction by the driving cam 113, so that the upper thread 3 held by the holder 27 of the thread winding unit 25 is taken out from the thread transferring path of the space part 17 and wound along the thread contacting part 23 of the thread tension adjusting body 21. The upper thread 3 wound on the thread contacting part 23 of the thread tension adjusting body 21 makes resistance while passing through the thread contacting part 23 of the thread tension adjusting body 21, thereby tensing the upper thread 3 moving along the thread contacting part 23.

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 25 in a first direction.

Meanwhile, the upper thread 3 transferred to the thread guiding block 15 through the thread tension adjusting body 21 is retained in the thread retaining hole 33 of the shaking unit 31. Then the shaking unit 31 returns to its original position by the elasticity of the cam elastic unit 49. The returned shaking unit 31 shakes by the elasticity of the shaking-unit elastic unit 51. Thus, the upper thread 3 passing through the shaking unit 31 is tensed and released by not only the tension of the upper thread 3 itself caused by the thread tension adjusting body 21 but also the shaking operation of the shaking unit 31.

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. 10A). Then, as shown in FIG. 10B, 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 driver 100 is driven to lift up the lifting link 105 so that the needle 9 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 141 moves up by the elasticity of the needle bar elastic unit 147. At this time, to prevent the needle bar 141 from interfering with the needle bar driver (not shown), the needle bar 141 is disconnected from the needle bar driver by a clutch (not shown). Then, as the needle bar 141 moves upward, the needle 9 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 9a of the needle 9 and the hook 153 of the thread catcher 151 are aligned on the same plane, as shown in FIG. 15.

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 9 and the needle bar 141 are maintained in the thread alignment position. As shown in FIG. 16, as 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 9a of the needle 9 moves toward and passes through the eye 9a of the needle 9.

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 9a of the needle 9 and the hook 153, and is at the same time retained on the thread catcher 151 (refer to FIG. 17). 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 driver 100 drives the needle bar lifting unit 143 to move from the threading work position to the threading alignment position, thereby lifting the lifting link 105 down (refer to FIG. 18).

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 9a of the needle 9 while catching the upper thread 3, and is then disposed at a predetermined space from the needle 9. At this time, the upper thread 3 is still remained to be retained on the hook 153 even though it passes through the eye 9a of the needle 9.

Then, the driver 100 drives the needle bar lifting unit 143 to move down, to the sewing work section, thereby moving the needle 9 from the threading work section. When the needle bar lifting unit 143 moves down, the needle 9 and the needle bar 141 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. 20, 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. 21 when the needle bar 141 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 catches the upper thread 3 passed through the eye 9a of the needle 9 and retained on the hook body 155, thereby moving it toward the hook body 155.

Then, the driver 100 drives the lifting link 105 to move down, thereby moving the needle 9 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 25 winds the upper thread 3 on the thread tension adjusting body as shown in FIGS. 7A and 7B while rotating in the first direction. Thus, the holder 27 of the thread winding unit 25 returns to its original position where it communicates with the thread feeding path 11a of the thread feeding block 11.

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 15a of the thread guiding block 15 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 of the space part 17 as shown in FIG. 11.

At this time, as shown in FIGS. 10C and 11, the upper thread 3 passes through the thread guiding path 15a of the upper thread guiding block 15 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 15a of the lower thread guiding block 15, thereby being transferred to the needle 9.

Then, as shown in FIG. 12, 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 141 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 9a of the needle 9, thereby completing the threading work as shown in FIGS. 19 and 22.

Thus, the single driver drives the upper thread not only to be partially wound on the thread tension adjusting body but also to be retained on the thread retainer of the thread take-up unit. Additionally, the single driver can drive the upper thread to be threaded through the eye of the needle. Therefore, it takes relatively short time to replace the upper thread, thereby enhancing productivity. Further, the number of components provided in the embroidering machine is reduced, so that the embroidering machine can have a simple structure and its production cost can be decreased.

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 a thread feeding apparatus for an embroidering machine, in which a single driver drives an upper thread not only to be partially wound on a thread tension adjusting body but also to be retained on a thread retainer of a thread take-up unit, so that it takes relatively short time to replace the upper thread, thereby enhancing productivity. Further, the number of components provided in the embroidering machine is reduced, so that the embroidering machine can have a simple structure and its production cost can be decreased.

Claims

1. A thread feeding apparatus for an embroidering machine, comprising:

a thread tension adjuster that comprises a thread tension adjusting body on which an upper thread is partially wound and which males resistance to the upper thread, and a thread winding unit provided in a predetermined rotating shaft and winding the upper thread on the thread tension adjusting body by rotating while holding the upper thread spaced apart from the rotating shaft, and adjusting the tension of the upper thread;

a thread take-up unit that comprises a thread retainer on which the upper thread is retained, and oscillates within a predetermined section to tense and release the upper thread;

a thread take-out unit that comprises a thread take-out lever reciprocating between a take-out position in which the upper thread is taken out from a thread transferring path and a thread retaining position on which the upper thread is retained, and retains the upper thread on the thread retainer by talking out the upper thread on the thread transferring path;

a driver that drives the thread winding unit to rotate and the thread take-out lever to reciprocate;

a rotating motion transformer that transforms a driving operation of the driver into a rotating motion, and rotates the thread winding unit to wind the upper thread on the thread tension adjusting body; and

a straight line motion transformer that transforms the driving operation of the driver into a straight line motion, and moves the thread take-out lever to retain the upper thread on the thread retainer.

2. The thread feeding apparatus according to claim 1, further comprising a lifting link connected to the driver and moves up and down by the driving operation of the driver,

wherein the rotating motion transformer comprises:

a driving pin protruded from one side of the lifting link;

a driving cam formed with a predetermined cam profile movably engaged with the driving pin, and rotatably coupled to a predetermined rotating shaft; and

a power transmission unit transferring the rotation of the driving cam to the thread winding unit.

3. The thread feeding apparatus according to claim 2, wherein the straight line motion transformer comprises:

a bracket provided in one of the lifting link and the thread take-out unit, and formed with an elongated hole at a predetermined angle to a lifting direction of the lifting link; and

a movable pin provided in the other one of the lifting link and the thread take-out unit, and moving in a straight line while being movably engaged with the elongated hole.

4. The thread feeding apparatus according to claim 2, further comprising a needle bar lifting unit to which a needle bar mounted with a needle is liftably coupled, and which is connected with the lifting link,

wherein the driver drives the needle bar lifting unit to move up and down to move from a sewing work section to a predetermined threading work section.

5. The thread feeding apparatus according to claim 4, further comprising:

a thread catcher that comprises a hook for catching the upper thread and a hook body for supporting the hook, and threads the upper thread through an eye of the needle while reciprocating to pass the hook through the eye of the needle; and

a thread catcher driver that comprises a thread catcher supporter to support the thread catcher, and a thread catcher driving link formed with a pin sloping part at a predetermined angle to the lifting direction of the lifting link to contact the driving pin within the threading work section of the needle, and reciprocates the thread catcher,

wherein the driver drives the driving pin to move along the pin sloping part, and allows to pass the hook through the eye of the needle by making the thread catcher driving link press and release the thread catcher supporter.

6. The thread feeding apparatus according to claim 5, further comprising:

a thread transferring bracket that is formed with a needle bar sloping part having a predetermined angle transversely to the lifting direction of the needle bar, and is rotatably installed in a predetermined rotating shaft while being parallel with a plane formed by the eye of the needle and the hook; and

a thread unwinding bracket provided in the needle bar lifting unit, and rotating the thread transferring bracket while sliding on and getting in contact with the needle bar sloping part to take up the upper thread retained in the hook and transfer the upper thread to the hook body,

wherein the driver drives the lifting link to move down from the threading work position to the sewing work section and allows to rotate the thread transferring bracket by the thread unwinding bracket to thread the upper thread through the eye of the needle while the upper thread is moved to and released from the hook body.

7. The thread feeding apparatus according to claim 3, further comprising a needle bar lifting unit to which a needle bar mounted with a needle is liftably coupled, and which is connected with the lifting link,

wherein the driver drives the needle bar lifting unit to move up and down to move from a sewing work section to a predetermined threading work section.

8. The thread feeding apparatus according to claim 7, further comprising:

a thread catcher that comprises a hook for catching the upper thread and a hook body for supporting the hook, and threads the upper thread through an eye of the needle while reciprocating to pass the hook through the eye of the needle; and

a thread catcher driver that comprises a thread catcher supporter to support the thread catcher, and a thread catcher driving link formed with a pin sloping part at a predetermined angle to the lifting direction of the lifting link to contact the driving pin within the threading work section of the needle, and reciprocates the thread catcher,

wherein the driver drives the driving pin to move along the pin sloping part, and allows to pass the hook through the eye of the needle by malting the thread catcher driving link press and release the thread catcher supporter.

9. The thread feeding apparatus according to claim 8, further comprising:

a thread transferring bracket that is formed with a needle bar sloping part having a predetermined angle transversely to the lifting direction of the needle bar, and is rotatably installed in a predetermined rotating shaft while being parallel with a plane formed by the eye of the needle and the hook; and

a thread unwinding bracket provided in the needle bar lifting unit, and rotating the thread transferring bracket while sliding on and getting in contact with the needle bar sloping part to take up the upper thread retained in the hook and transfer the upper thread to the hook body,

wherein the driver drives the lifting link to move down from the threading work position to the sewing work section and allows to rotate the thread transferring bracket by the thread unwinding bracket to thread the upper thread through the eye of the needle while the upper thread is moved to and released from the hook body.