US20070261619A1

US20070261619A1 - Thread Feeding Apparatus for an Automatic Embroidering Machine

Info

Publication number: US20070261619A1
Application number: US11/629,334
Authority: US
Inventors: Ham-Kyu Pak; Il-Gyu Park
Original assignee: Inbro Co Ltd
Current assignee: Inbro Co Ltd
Priority date: 2004-06-09
Filing date: 2005-06-09
Publication date: 2007-11-15
Also published as: JP2008501471A; EP1753905A1; WO2005121433A1

Abstract

The present invention relates to a thread feeding apparatus for an automatic embroidering machine supplying an upper thread from a thread supplying unit to a needle, comprising a thread tension adjuster having a thread contact portion allowing an upper thread to be at least partially wound thereon and be in contact therewith, and resisting the upper thread passing through the thread contact portion to adjust the tension of the upper thread; a take-out unit provided to rotate about a predetermined rotation axis, and rotated while holding the upper thread spaced from the rotation axis to put the upper thread on the thread tension adjuster; and a take

Description

FIELD OF THE INVENTION

The present invention relates to a thread feeding apparatus for an automatic embroidering machine, and more particularly, to a thread feeding apparatus for an automatic embroidering machine, having an improved structure of adjusting the tension of an upper thread.

BACKGROUND ART

An automatic embroidering machine is a kind of a sewing machine, which uses various colored threads and automatically embroiders a predetermined pattern, a trademark, or the like on clothes, a label of shoes, etc. according to a preset program.
In general, the automatic embroidering machine includes a head stem provided in front of a stationary frame; an upper thread supplying unit mounted to the head stem and supplying various colored upper threads from a plurality of bobbins toward an embroidering work place; and a needle-working unit sewing the supplied upper threads and performing embroidering works.
Further, the automatic embroidering machine is classified into a single needle type and a multi needle type according to the number of needles mounted in the upper thread supplying unit and the needle-working unit.
The single needle type automatic embroidering machine includes the upper thread supplying unit to supply one selected among various colored upper threads from the plurality of bobbins to the needle-working unit, and the needle-working unit having a single needle to sew one supplied upper thread and perform the embroidering works.
The multi needle type automatic embroidering machine includes the upper thread supplying unit to supply various colored upper threads from the plurality of bobbins to the needle-working unit, and the needle-working unit having a plurality of needles to sew the respective supplied upper threads and perform the embroidering works by one selected among the needles.
Hereinafter, the single needle type automatic embroidering machine will be described.
The conventional signal needle type automatic embroidering machine has been disclosed in Korean Patent Publication No. 2002-0068028, titled of “Thread feeding apparatus for automatic embroidering machine.”
Such a conventional thread feeding apparatus for the automatic embroidering machine includes a head stem having the needle-working unit; the thread supplying unit to supply one selected among various colored upper threads; a guide pipe assembly including a first guide pipe provided in the head stem and receiving the thread from the thread supplying unit, and a second guide pipe having an upper end spaced from the first guide pipe, forming a predetermined spaced portion along an axis direction and a lower end adjacent to the needle-working unit; and a thread take-up unit including an oscillating lever oscillating on a plane parallel with a thread supplying path, and a thread retainer coupled to a free end of the oscillating lever transversely to an oscillating direction of the oscillating lever and strengthening/releasing the tension of the thread by reciprocating within the spaced portion as the oscillating lever oscillates. Thus, the head stem is simplified, and excludes a curved path from a thread transferring path, thereby smoothly supplying the thread.
Further, the conventional thread feeding apparatus for the automatic embroidering machine includes a thread tension maintainer provided in an upper side of the head stem and adjusting the tension of the upper threads extended from the plurality of bobbins.
However, the conventional thread feeding apparatus for the automatic embroidering machine adjusts the tension of all upper threads extended from the plurality of bobbins, so that its structure is complicated, and a user has to connect the upper threads to the thread tension maintainer one by one and adjust the tension of the upper threads. Therefore, it is not easy to adjust the tension of the upper threads and it takes much work time.

DISCLOSURE OF INVENTION

Accordingly, it is an aspect of the present invention to provide a thread feeding apparatus for an automatic embroidering machine, which conveniently adjusts the tension of an upper thread and reduces work time.
The foregoing and other aspects of the present invention are achieved by providing a thread feeding apparatus for an automatic embroidering machine supplying an upper thread from a thread supplying unit to a needle, comprising a thread tension adjuster having a thread contact portion allowing an upper thread to be at least partially wound thereon and be in contact therewith, and resisting the upper thread passing through the thread contact portion to adjust the tension of the upper thread; a take-out unit provided to rotate about a predetermined rotation axis, and rotated while holding the upper thread spaced from the rotation axis to put the upper thread on the thread tension adjuster; and a take-out driver driving the thread take-out unit to rotate for at least partially winding the upper thread on the thread contact portion.
According to an aspect of the present invention, the take-out driver comprises a rotation shaft coupled to the take-out unit and rotating; a driving shaft spaced from the rotation shaft at a predetermined axis distance; a shaft driver driving the driving shaft to rotate; and a power transmission unit provided between the rotation shaft and the driving shaft and transmitting a rotational force from the driving shaft to the rotation shaft.
According to an aspect of the present invention, the thread feeding apparatus further comprises an oscillating bracket including a thread retainer to retain the upper thread transferred from the thread tension adjuster to the needle, and oscillating to strengthen and release the tension of the upper thread; a bracket driver driving the oscillating bracket to move the thread retainer of the oscillating bracket on a thread transferring path and put the upper thread on the thread retainer; and an oscillating bracket elastic member elastically urging the oscillating bracket to oscillate.
According to an aspect of the present invention, the thread feeding apparatus according to claim 1, wherein the bracket driver comprises a bracket driving cam formed with a cam profile on a lateral surface thereof; a moving pin moving along the camp profile of the bracket driving cam; and a cam driver to rotate the bracket driving cam by moving the moving pin along the cam profile of the bracket driving cam, wherein the oscillating bracket elastic member has a first end supported by the bracket driving cam and a second end supported by the oscillating bracket, and oscillates the oscillating bracket.
According to an aspect of the present invention, the bracket driver further comprises a cam elastic member elastically rotating the bracket driving cam to return an original position.
According to an aspect of the present invention, the thread feeding apparatus further comprises a thread take-up unit oscillating within a predetermined section to strengthen and release the tension of the upper thread; and a thread-take-out unit taking out the upper thread transferred from the thread tension adjuster to the needle working portion, and putting the upper thread on the thread take-up unit and the thread retainer, wherein the oscillating bracket oscillates in a vertical direction corresponding to the thread take-up unit.
According to an aspect of the present invention, the thread retainer is placed at a top dead point of the oscillating bracket when the thread take-up unit is placed at a top dead point thereof, and placed at a bottom dead point of the oscillating bracket when the thread take-up unit is placed at a bottom dead point thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating a thread feeding apparatus for an automatic embroidering machine according to a first embodiment of the present invention.
FIG. 2 is a partial sectional view of the thread feeding apparatus for the automatic embroidering machine of FIG. 1.
FIG. 3 is a partially enlarged perspective view of FIG. 2.
FIG. 4 is an exploded perspective view of FIG. 3.
FIGS. 5A, 5B, 6A and 6B are partial enlarged perspective views and side sectional views of illustrating processes of winding an upper thread on a thread tension adjuster of FIG. 2.
FIGS. 7A and 7B are plan views illustrating processes of winding the upper thread on a taking out unit and an oscillating bracket.
FIGS. 8A, 8B, 9A, 9B, 10A and 10B are side plan views illustrating processes of operating a bracket driver.
FIG. 11 is a partially enlarged perspective view of a thread feeding apparatus for an automatic embroidering machine according to a second embodiment of the present invention.
FIG. 12 is an exploded perspective view of FIG. 11.
FIGS. 13A and 13B are partially enlarged perspective views illustrating processes of operating a thread take-up unit and an oscillating bracket of FIG. 11.
FIGS. 14A and 14B are sectional views illustrating processes of operating the thread take-up unit and the oscillating bracket of FIG. 11.

MODES FOR CARRYING OUT THE INVENTION

Hereinbelow, a single needle automatic embroidering machine will be described as an embodiment of the present invention with reference to accompanying drawings, wherein like reference numerals refer to like elements throughout, and repetitive descriptions will be avoided as necessary.
As shown in FIGS. 1 through 4, a thread feeding apparatus 1 for an automatic embroidering machine according to a first embodiment of the present invention includes a thread supplying unit 5 to supply one upper thread 3 selected among a plurality of upper threads different in color; a thread guide 8 to guide the upper thread 3 supplied from the thread supplying unit 5 to a needle 13; and a thread take-up unit 11 oscillating within a predetermined section, taking up the upper thread 3 passing through the thread guide 8, and strengthening and releasing the tension of the upper thread 3.
The thread supplying unit 5 includes a thread supplying channel 6, and supplies one upper thread 3 selected among the plurality of standby upper threads different in color to the thread guide 8 using compressed air.
The thread guide 8 is formed with a thread guide channel 9 to guide the upper thread 3 supplied from the thread supplying unit 5. In this embodiment, the thread guide 8 is shaped like a block having a rectangular section, but not limited to and may be formed as a tube-like body having various shaped sections
Meanwhile, thread supplying unit 5 and the thread guide 8 are spaced from each other along a thread transferring path, thereby forming a space portion 15.
The space portion 15 includes a thread tension adjuster 21 on which the upper thread 3 passing through the space portion 15 is wound and contacts, and adjusting the tension of the upper thread 3; and a take-out unit 25 rotating while holding the upper thread passing through the space portion 15, and winding the upper thread 3 on the thread tension adjuster 21.
The thread tension adjuster 21 is shaped like a disc, and has a thread contact portion 23 recessed along the circumference thereof and on which the upper thread 3 is partially wound and contacts. The thread tension adjuster 21 is accommodated in an accommodating groove 29 of the take-out unit 25 to be described later. The thread contact portion 23 resists passing the upper thread 3 being in contact therewith, thereby adjusting the tension of the upper thread 3. Preferably, the thread tension adjuster 21 is pivotally coupled to a rotation shaft 31 of a take-out driver 30 (to be described later), but not limited to. Alternatively, the thread tension adjuster 21 may be coupled to the rotation shaft 31 and rotated integrally with the rotation shaft 31.
The take-out unit 25 is provided between the thread tension adjuster 21 and the bottom of the thread supplying unit 5. Further, the take-out unit 25 is coupled to the rotation shaft 31 of the take-out driver 30. Here, an axis line of the rotation shaft 31 is spaced from the thread transferring path of the upper thread 3 passing through the space portion 15 at a predetermined distance. Further, the take-out unit 25 is formed with a thread passing hole employed as a holder 27 holding the upper thread 3 passing the space portion 15 and passing therethrough. Alternatively, one end of the take-out unit 25 may be formed with a semicircular-arc shaped holing groove instead of the thread passing hole, thereby holding the upper thread 3 passing the space portion 15.
The take-out unit 25 is formed with the accommodating groove 29 to accommodate the thread tension adjuster 21. Further, the take-out unit 25 is rotated by the take-out driver 30 and partially winds the upper thread 3 on the thread contact portion 23 of the thread tension adjuster 21.
In this embodiment, the take-out driver 30 includes the rotation shaft 31 coupled to the take-out unit 25 and rotating, a driving shaft 33 spaced from the rotation shaft 31 at a predetermined axis distance, a shaft driver to rotate the driving shaft 33, and a power transmission unit to transmit a rotational force from the driving shaft 33 to the rotation shaft 31.
The rotation shaft 31 is rotatably coupled to a frame 19 supported by a head stem 17. The rotation shaft 31 has a first end coupled to the take-out unit 25, and a second end coupled to a driven pulley 35.
The driving shaft 33 is parallel with the rotation shaft 31, and rotatably coupled to the frame 19. The driving shaft 33 has a first end coupled to a driving pulley 37 corresponding to the driven pulley 35. The driving pulley 37 and the driven pulley 35 are connected by a belt 39 to transmit the rotational force from the driving shaft 33 to the rotation shaft 31.
Further, the rotation shaft 31 and the driving shaft 33 are rotatably supported by a bearing 41 accommodated and supported in the frame 19.
The driving shaft has a second end coupled to a driving cam 43 used as one element of the shaft driver to rotate the driving shaft 33. Further, a cam profile 43 a is formed on the outer circumference of the driving cam 43 and curved along the lengthwise direction of the driving cam 43. The cam profile 43 a accommodates a driving pin 45 therein. The driving pin 45 has a first end connected to a driving means (not shown), so that the driving cam 43 is rotated when the driving pin 45 is driven by the driving means to move along the cam profile 43a of the driving cam 43.
Alternatively, the take-out driver 30 may be achieved by either connecting a motor or a hydraulic cylinder as well as the foregoing structure directly to the take-out unit 25, thereby rotating the take-out unit 25. Further, in this embodiment, the driving pulley 37, the driven pulley 35, and belt 39 are employed as the power transmission unit, but not limited to. Alternatively, a pair of gears engaged with each other can be used in transmitting the rotation force of the driving shaft 33 to the rotational shaft 31.
Further, the thread feeding apparatus 1 for the automatic embroidering machine according to an embodiment of the present invention includes an oscillating bracket 71 oscillating to strengthen and release the tension of the upper thread 3, a bracket driver 81 to drive the oscillating bracket 71 to put the upper thread 3 on the oscillating bracket 71, and an oscillating bracket elastic member 91 for oscillating the oscillating bracket 71 with predetermined elasticity.
The oscillating bracket 71 is coupled to a bush 75 rotatably fitted to the outer circumference of the rotation shaft 31 of the take-out driver 30. The oscillating bracket 71 has an upper end 71 a having a semicircular shape, a lower end 71 b spaced from the upper end 71 a at a predetermined distance and into which the bush 75 penetrates, and a connecting portion 71 c connecting the upper end 71 a with one edge of the lower end 71 b and spacing the upper end 71 a from the lower end 71 b. The upper end 71 a of the oscillating bracket 71 is provided with a thread retainer 73 in which the upper thread 3 facing from the thread tension adjuster 21 toward the needle 13 is retained. In this embodiment, a thread through hole is formed as the thread retainer 73. Alternatively, the upper end 71 a of the oscillating bracket 71 is formed with a semicircular-arc shaped holding groove instead of the thread through hole, thereby putting the upper thread 3 on the thread holding groove.
The bracket driver 81 moves the thread retainer 73 of the oscillating bracket 71 to the thread transferring pat, thereby driving the oscillating bracket 71 to put the upper thread 3 on the thread retainer 73. The bracket driver 81 includes a bracket driving cam 83 formed with a predetermined cam profile 83 a thereon, a moving pin 85 moving along the cam profile 83 a of the bracket driving cam 83, and a cam driver 87 to move the moving pin 85 along the cam profile 83 a of the bracket driving cam 83, thereby rotating the bracket driving cam 83.
The cam profile 83 a is formed on the outer circumference of the bracket driving cam 83, inclined at a predetermined angle to the axis line of the bracket driving cam 83 along the lengthwise direction thereof, and rotatably coupled to the bush 75.
The cam profile 83 a of the bracket driving cam 83 accommodates the moving pin 85 moving along the cam profile 83 a.
The moving pin 85 is connected to the cam driver 87 at one end thereof. Thus, when the cam driver 87 drives the moving pin 85 to move along the cam profile 83 a of the bracket driving cam 83, the bracket driving cam 83 rotates. Here, a motor, a hydraulic cylinder, etc. can be used as the cam driver 87.
The oscillating bracket elastic member 91 is provided between the oscillating bracket 71 and the bracket driver 81. The oscillating bracket elastic member 91 has a first end supported by the bracket driving cam 83 and a second end supported by the oscillating bracket 71. Thus, the oscillating bracket 71 oscillates within a predetermined section by the oscillating bracket elastic member 91. In this embodiment, a coil spring is used as the oscillating bracket elastic member 91, but not limited to. Alternatively, a spiral spring or the like as well as the coil spring can be used as the oscillating bracket elastic member 91.
Further, the bracket driver 81 can include a cam elastic member 95 to elastically rotate the bracket driving cam 83, thereby urging the bracket driving cam 83 to return to its original position. The cam elastic member 95 has a first end supported by the bracket driving cam 83, and a second end supported by the frame 19. In this embodiment, a coil spring is used as the cam elastic member 95, but not limited to. Alternatively, a spiral spring or the like as well as the coil spring can be used as the cam elastic member 95.
Therefore, when the upper thread 3 is replaced, the cam driver 87 drives the thread retainer 73 of the oscillating bracket 71 to move on the thread transferring path, and thus the moving pin 85 moves along the cam profile 83 a of the bracket driving cam 83. Then, the bracket driving cam 83 rotates and allows the thread retainer 73 to communicate with the holder 27 of the take-out unit 25. At this time, the thread is not tangled in the oscillating bracket 71 even though the take-out unit 25 rotates winding the upper thread 3 on the thread tension adjuster 21.
After retaining the upper thread 3 in the thread retainer 73 of the oscillating bracket 71, when the cam driver 87 drives the thread retainer 73 of the oscillating bracket 71 to be not aligned with the holder 27 of the take-out unit 25 and moves the moving pin 85 along the cam profile 83 a of the bracket driving cam 83, the oscillating bracket 71 returns to its original position by the elasticity of the cam elastic member 95. Thus, the upper thread 3 passing through the oscillating bracket 71 is oscillated by the elasticity of the oscillating bracket elastic member 91 as well as the tension of the upper thread 3 adjusted by the thread tension adjuster 21, so that the tension of the upper thread 3 is strengthened and released.
Here, the oscillating bracket 71, the bracket driver 81, the oscillating bracket elastic member 91 and the cam elastic member 95 can be optionally provided.
With this configuration, when the upper thread 3 is replaced or cut as a color is changed or the upper thread 3 is cut while embroidering, a process of adjusting the tension of the upper thread 3 supplied to the needle 13 using the thread feeding apparatus 1 according to the first embodiment of the present invention is as follows.
First, the take-out driver 30 is driven to place the holder 27 of the take-out unit 25 on the thread transferring path of the space portion 15 provided between the thread supplying unit 5 and the thread guide 8. At the same time, the oscillating bracket 71 is rotated to align the thread retainer 73 thereof with the holder 27 of the take-out unit 25. A process of putting the upper thread 3 on the oscillating bracket 71 will be described later.
Next, one upper thread 3 selected among the plurality of standby upper threads different in color is supplied by the compressed air from the thread supplying unit 5 to the needle 13 via the thread supplying channel 6 of the thread supplying unit 5, the space portion 15, the thread guiding channel 9 of the thread guide 8.
As shown in FIGS. 5A and SB, the upper thread 3 come out of the thread supplying channel 6 penetrates the thread retainer 73 of the oscillating bracket 71 via the holder 27 of the take-out member 25, and is then guided to the thread guiding channel 9 of the thread guide 8.
Then, the take-out unit 25 is rotated in one direction to partially winding the upper thread 3 on the thread contact portion 23 of the thread tension adjuster 21.
That is, the driving means (not shown) drives the driving pin 45 to move along the cam profile 43 a of the driving cam 43, thereby rotating the driving cam 43. As the driving cam 43 rotates, the driving shaft 33 is rotated and its rotational force is transmitted to the rotation shaft 31 via the driving pulley 37 and the driven pulley 35 connected by the belt 39, so that the take-out unit 25 rotates in one direction.
As the take-out unit 25 rotates, as shown in FIGS. 6A and 6B, the upper thread 3 held by the holder 27 of the take-out unit 25 is taken-out from the thread transferring path of the space portion 15, and then wound on the thread contact portion 23 of the thread tension adjuster 21. Preferably, the take-out unit 25 is rotated once to wind the upper thread 3 on the thread contact portion 23 once.
Thus, the upper thread 3 wound on the thread contact portion 23 of the thread tension adjuster 21 is resisted while passing through the thread contact portion 23 of the thread tension adjuster 21, thereby strengthening the tension of the upper thread 3 moving along the thread contact portion 23.
After the upper thread 3 transferred to the thread guide 8 via the thread tension adjuster 21 is put on the thread retainer 73 of the oscillating bracket 71, the oscillating bracket 71 returns to its original position by the elasticity of the cam elastic member 95, and oscillates by the elasticity of the oscillating bracket elastic member 91. Thus, the tension of the upper thread 3 passing through the oscillating bracket 71 is strengthened and released by not only its tension adjusted by the thread tension adjuster 21 but also the oscillation of the oscillating bracket 71.
Here, the process of putting the upper thread 3 on the thread retainer 73 of the oscillating bracket 71 is as follows.
As shown in FIGS. 7A, the cam driver 87 drives the thread retainer 73 of the oscillating bracket 71 to be aligned with the holder 27 of the take-out unit 25, and moves the moving pin 85 along the cam profile 83 a of the bracket driving cam 83. As shown in FIGS. 8A, 8B, 9A, 9B, 10A and 10B, the bracket driving cam 83 rotates as the moving pin 85 moves upward along the cam profile 83 a of the bracket driving cam 83, so that the oscillating bracket 71 rotates. Therefore, the thread retainer 73 of the oscillating bracket 71 is aligned and communicates with the holder 27 of the take-out unit 25 as shown in FIG. 7B.
Thus, one upper thread 3 selected among the plurality of standby upper threads different in color is supplied by the compressed air from the thread supplying channel 6 of the thread supplying unit 5, retained in the thread retainer 73 of the oscillating bracket 71 via the holder 27 of the take-out unit 25, and transferred to the needle 13 via the thread guiding channel 9 of the thread guide 8.
Further, after retaining the upper thread 3 on the thread retainer 73 of the oscillating bracket 71, the cam driver 87 drives the thread retainer 73 of the oscillating bracket 71 to be not aligned with the holder 27 of the take-out unit 25, and moves the moving pin 85 downward along the cam profile 83 a of the bracket driving cam 83. Then, as shown in FIG. 8A, the oscillating bracket 71 returns to its original position by the elasticity of the cam elastic member 95, and oscillates within a predetermined section, thereby strengthening and releasing the tension of the upper thread 3.
Meanwhile, FIG. 11 is a partially enlarged perspective view of a thread feeding apparatus for an automatic embroidering machine according to a second embodiment of the present invention, and FIG. 12 is an exploded perspective view of FIG. 11. As shown therein, contrary to the first embodiment, in a thread feeding apparatus 1′ for an automatic embroidering machine according to the second embodiment of the present invention, an oscillating bracket 71′ oscillating to strengthen and release the upper thread 3 is rotatably coupled to not the bush 75 of the take-out driver 30 but an auxiliary frame 51 coupled to the frame 19 by a hinge pine 53 in a vertical direction. Here, the oscillating bracket 71′ oscillates in the vertical direction corresponding to the thread take-up unit 11, i.e., between a top dead point and a bottom dead point.
The oscillating bracket 71′ according to the second embodiment of the present invention includes a pin coupling portion 71 a′ to which the hinge pin 53 is coupled, a tension plate 71 b′ bent and extended from the one side of the pin coupling portion 71 a′.
The tension plate 71 b′ of the oscillating bracket 71′ is provided with a thread retainer 73′ in which the upper thread 3 facing from the thread tension adjuster 21 toward the needle 13 is retained. In this embodiment, a thread through hole is formed as the thread retainer 73′. Also, the thread retainer 73′ allows a thread take-out lever 7 to penetrate therethrough, wherein the thread take-out lever 7 is used as the thread take-out unit for taking out the upper thread 3 transferred to the needle 13 via the thread supplying channel 6 and the thread guiding channel 9 when the upper thread 3 is replaced, and putting the upper thread 3 on the thread take-up unit 11. Here, the thread take-out lever 7 is installed at a predetermined angle to the thread guiding channel 9 and reciprocates within a lever accommodating hole 10 formed in the thread guide 8.
Contrary to the first embodiment, a bracket driver 81′ according to the second embodiment of the present invention includes a tension plate clutch 88 nearing to and apart from the pin coupling portion 71 a′ of the oscillating bracket 71′, and a clutch driver 89 lifting up and down the tension plate clutch 88.
In this embodiment, a hydraulic cylinder is employed as the clutch driver 89 expanded and retracted by a hydraulic pressure and reciprocating the tension plate clutch 88. Alternatively, a motor, a cam device, a solenoid, etc. can be used as the clutch driver 89 for driving the tension plate clutch 88.
Further, an oscillating bracket elastic member 91′ according to the second embodiment of the present invention has a first end supported by the hinge pin 53, and a second end supported by the oscillating bracket 71′. The oscillating bracket elastic member 91′ urges the oscillating bracket 71′ to oscillate within a predetermined section, i.e., between the top dead point and the bottom dead point. In this embodiment, a torsion spring is used as the oscillating bracket elastic member 91′.
In the meantime, an oscillating bracket control pin 97 is provided between the oscillating bracket 71′ and the tension plate clutch 88, and coupled to an elongated hole 51 a of the auxiliary frame 51, so that it is used as a tension adjusting member for controlling the oscillation of the oscillating bracket 71′. Here, the oscillating bracket control pin 97 is adjacent to the pin coupling portion 71 a′ of the oscillating bracket 71′. As shown in FIGS. 14A and 14B, the oscillating bracket control pin 97 is spaced from the pin coupling portion 71 a′ of the oscillating bracket 71′ when the tension of the upper thread 3 retained in the thread retainer 73′ of the oscillating bracket 71′ is strengthened, and is in contact with the pin coupling portion 71 a′ of the oscillating bracket 71′ when the tension of the upper thread 3 retained in the thread retainer 73′ of the oscillating bracket 71′ is released. Further, the oscillating bracket control pin 97 is moved along the elongated hole S1 a of the auxiliary frame 51, thereby controlling the bottom dead point of the oscillating bracket 71′, i.e., adjusting the tension of the upper thread 3 transferred to the needle 13 via the thread take-up unit 11.
With this configuration, the tension of the upper thread 3 supplied to the needle 13 using the thread feeding apparatus 1′ according to the second embodiment of the present invention is adjusted as follows.
According to the second embodiment, the process of winding the upper thread 3 on the thread contact portion 23 of the thread tension adjuster 21 is the same as the foregoing process according to the first embodiment, so that repetitive descriptions will be avoided as necessary. Below, the process of adjusting the tension of the upper thread 3 retained in the thread retainer 73′ of the oscillating bracket 71′ will be described.
In the state that the thread take-up unit is placed in the bottom dead point, the oscillating bracket 71′ is lift up and the clutch driver 89 is driven, so that the thread retainer 73′ of the oscillating bracket 71′ communicates with the lever accommodating hole 10 of the thread guide 8. Further, one upper thread 3 selected among the plurality of standby upper threads different in color is supplied by the compressed air from the thread supplying channel 6 of the thread supplying unit 5, retained in the thread retainer 73′ of the oscillating bracket 71′ via the thread supplying channel 6 of the thread supplying unit 5 and the holder 27 of the take-out unit 25, and then transferred to the needle 13 via the thread guiding channel 9 of the thread guide 8. At this time, the upper thread 3 transferring through the thread guiding channel 9 is held by the thread take-out lever 7 accommodated in the lever accommodating hole 10, and transferred to the needle 13.
Further, the thread take-out lever 7 is moved frontward to near the thread take-up unit 11, so that the thread take-out lever 7 passes through the thread retainer 73′ of the oscillating bracket 71′, thereby putting the upper thread 3 on the thread take-up unit 11.
After putting the upper thread 3 on the thread take-up unit 11, the thread take-out lever 7 is moved backward to be spaced from the thread take-up unit 11, so that the thread take-out lever 7 comes out of the thread retainer 73′ of the oscillating bracket 71′ and is accommodated in the lever accommodating hole 10 of the thread guide 8.
Further, after retaining the upper thread 3 in the thread retainer 73′ of the oscillating bracket 71′, the clutch driver 89 is driven to make the thread retainer 73′ of the oscillating bracket 71′ do not communicate with the lever accommodating hole 10 of the thread guide 8, thereby lifting down the oscillating bracket 71′. Then, the oscillating bracket 71′ returns to its original position by the elasticity of the oscillating bracket elastic member 91′. That is, the thread retainer 73 is placed at the top dead point of the oscillating bracket 71′.
Meanwhile, the upper thread 3 transferred to the needle 13 via the thread tension adjuster 21 and the thread guide 8 is held by the thread take-out lever 7, and retained in the thread take-up unit 11 and the thread retainer 73 of the oscillating bracket 71′, and then the tension of the upper thread 3 is strengthened and released by the oscillation of the thread take-up unit 11.
As shown in FIG. 13A and 14A, when the thread take-up unit 11 is placed at the top dead point, the tension plate 71 b′ of the oscillating bracket 71′ is also placed at the top dead point, so the tension of the upper thread 3 is strengthened. On the other hand, as shown in FIG. 13B and 14B, when the thread take-up unit 11 is placed at the bottom dead point, the tension plate 71 b′ of the oscillating bracket 71′ is also placed at the bottom dead point, so the tension of the upper thread 3 is released.
Therefore, the tension of the upper thread 3 passing through the oscillating bracket 71′ is strengthened and released by not only the tension of the upper thread 3 adjusted by the thread tension adjuster 21 but also interaction of the oscillating bracket 71′ and the thread take-up unit 11.
In particular, in the thread feeding apparatus 1′ according to the second embodiment of the present invention, the oscillating bracket 71′ is more adjacent to the needle 13 than that of the first embodiment, so that the tension of the upper thread 3 is more effectively adjusted.
Thus, when the take-out unit is rotated as holding the upper thread spaced from the axis line of the rotation shaft, the upper thread is partially wound on the thread tension adjuster, and resisted while passing the thread tension adjuster, so that the tension of the upper thread is conveniently adjusted and work time is reduced.
In the meantime, it will be appreciated by those skilled in the art that the present invention is not limited to the single needle automatic embroidering machine and can be applied to a multi needle automatic embroidering machine.
As described above, the present invention provides a thread feeding apparatus for an automatic embroidering machine, which has an improved structure of adjusting the tension of an upper thread, thereby adjusting the tension of the upper thread conveniently and reducing work time.

Claims

1. A thread feeding apparatus for an automatic embroidering machine supplying an upper thread from a thread supplying unit to a needle, comprising:

a thread tension adjuster having a thread contact portion allowing an upper thread to be at least partially wound thereon and be in contact therewith, and resisting the upper thread passing through the thread contact portion to adjust the tension of the upper thread;

a take-out unit provided to rotate about a predetermined rotation axis, and rotated while holding the upper thread spaced from the rotation axis to put the upper thread on the thread tension adjuster; and

a take-out driver driving the thread take-out unit to rotate for at least partially winding the upper thread on the thread contact portion.

2. The thread feeding apparatus according to claim 1, wherein the take-out driver comprises:

a rotation shaft coupled to the take-out unit and rotating;

a driving shaft spaced from the rotation shaft at a predetermined axis distance;

a shaft driver driving the driving shaft to rotate; and

a power transmission unit provided between the rotation shaft and the driving shaft and transmitting a rotational force from the driving shaft to the rotation shaft.

3. The thread feeding apparatus according to claim 1, further comprising:

an oscillating bracket including a thread retainer to retain the upper thread transferred from the thread tension adjuster to the needle, and oscillating to strengthen and release the tension of the upper thread;

a bracket driver driving the oscillating bracket to move the thread retainer of the oscillating bracket on a thread transferring path and put the upper thread on the thread retainer; and

an oscillating bracket elastic member elastically urging the oscillating bracket to oscillate.

4. The thread feeding apparatus according to claim 1, wherein the bracket driver comprises:

a bracket driving cam formed with a cam profile on a lateral surface thereof;

a moving pin moving along the camp profile of the bracket driving cam; and

a cam driver to rotate the bracket driving cam by moving the moving pin along the cam profile of the bracket driving cam,

wherein the oscillating bracket elastic member has a first end supported by the bracket driving cam and a second end supported by the oscillating bracket, and oscillates the oscillating bracket.

5. The thread feeding apparatus according to claim 4, wherein the bracket driver further comprises a cam elastic member elastically rotating the bracket driving cam to return an original position.

6. The thread feeding apparatus according to claim 3, further comprising:

a thread take-up unit oscillating within a predetermined section to strengthen and release the tension of the upper thread; and

a thread-take-out unit taking out the upper thread transferred from the thread tension adjuster to the needle working portion, and putting the upper thread on the thread take-up unit and the thread retainer,

wherein the oscillating bracket oscillates in a vertical direction corresponding to the thread take-up unit.

7. The thread feeding apparatus according to claim 6, wherein the thread retainer is placed at a top dead point of the oscillating bracket when the thread take-up unit is placed at a top dead point thereof, and placed at a bottom dead point of the oscillating bracket when the thread take-up unit is placed at a bottom dead point thereof.