EP0921225A1

EP0921225A1 - Threading device in sewing machine for embroidery

Info

Publication number: EP0921225A1
Application number: EP97933039A
Authority: EP
Inventors: Toshio Miyamoto
Original assignee: Miyamoto Giken YK
Current assignee: Miyamoto KK
Priority date: 1996-07-30
Filing date: 1997-07-28
Publication date: 1999-06-09
Also published as: KR20000029458A; JP3162082B2; JP2000073273A; JP3192153B2; WO1998004768A1; CN1225697A; EP0921225A4; WO1998004769A1

Abstract

A threading device for embroidery machinery designed to automate the process of changing the colored thread or when the thread is broken without requiring manual work, shorten the time required for such processes, and enhance the operating rate and productivity of the sewing machine, comprising a thread gripping member 31 for gripping the end portion of a thread 11 hanging from a thread let-off tube 28a, a thread tensioning mechanism 3 for leading the thread 11 gripped by the thread gripping member 31 to a position close to a needle 10 and applying the stretched thread on a balance mechanism 4, and a threading mechanism 7 for guiding the thread into the needle hole.

Description

Technical Field

The present invention relates to an embroidery machinery, and more particularly to an embroidery machinery capable of processing automatically without requiring manual work when changing the colored thread (also called thread or needle thread in the description) or when the thread is broken.

Background Art

Hitherto, the embroidery machinery depended on manual work when changing the colored thread or when the thread was broken.
In processing for colored thread change or thread break, the sewing machine must be stopped, and, particularly in the case of a colored thread change, it is necessary to change the colored threads in each one of several to as many as 30 sewing machine heads used in the embroidery machinery system. This machine stopping time can last for several hours, and the operating rate and productivity of the sewing machine are lowered.

Disclosure of the Invention

It is hence an objective of this invention to solve the problems of conventional embroidery machinery, and present an embroidery machine enhanced in operating rate and productivity by automatically processing, when changing the colored thread or when the thread is broken, without requiring manual work, thus shortening the stoppage time required.
To achieve the objective, the threading device in embroidery machinery of the invention is comprised of a thread gripping member for gripping the end portion of a thread hanging from a thread let-off tube, a thread tensioning mechanism for leading the thread gripped by the thread gripping member to a position close to a needle and applying the stretched thread on a balance mechanism, and a threading mechanism for guiding the thread into the needle hole.
According to the threading device in the embroidery machinery of the invention, it is possible to automate the process of changing the colored thread or rethreading when the thread is broken, thus shortening the time required for such processes, and enhance the operating rate and productivity of the sewing machine.
Also due to the threading device for embroidery machinery, threading precision can be enhanced.
In this case, by comprising the threading mechanism of a thread pull-out mechanism and an air nozzle, the threading precision is further enhanced, and the threading mechanism can be simplified.
Furthermore, by deploying a thread push-down mechanism for pushing down both ends of the thread inserted into the thread insertion hole formed in a guide member of the threading mechanism along the side surface of the guide member, the threading precision may be enhanced still more.

Brief Description of the Drawings

Fig. 1 is a front view showing a first embodiment of the thread feed device in embroidery machinery of the invention, Fig. 2 is its side view, Fig. 3 is its plan view, and Fig. 4 is a sectional view along line A-A of Fig. 1.
Fig. 5 is a perspective view showing the thread holder in the first embodiment of the thread feed device in embroidery machinery of the invention, Fig. 6 shows a thread tension canceling mechanism, (a) being a side view and (b) being a front view, Fig. 7 shows a thread length regulating mechanism, (a) being a side view and (b) being a plan view, and Fig. 8 shows the thread let-off motion, (a) being a side view, (b) being a front view, and (c) being a perspective view.
Fig. 9 is a front view showing a modified example of the first embodiment of the thread feed device in embroidery machinery of the invention, Fig. 10 is its side view, Fig. 11 is its essential plan view, and Fig. 12 is its essential perspective view.
Fig. 13 is a side sectional view showing a thread holder in a modified example of the first embodiment of the thread feed device in embroidery machinery of the invention.
Fig. 14 shows a first embodiment of a threading device of embroidery machinery of the invention, (a) being a side view and (b) being a front view.
Fig. 15 is a front view of a thread tensioning mechanism of the threading device of embroidery machinery of the invention, Fig. 16 is a side view of the thread tensioning mechanism, Fig. 17 shows essential parts of the thread tensioning mechanism, (a) being a plan view, (b) being a side view, and (c) being a front view, Fig. 18 shows the threading mechanism, (a) being a side view, (b) being a front view, and (c) being a plan view, Fig. 19 is an explanatory diagram showing the working state of a thread pressing mechanism of the threading mechanism, Fig. 20 is a perspective view of essential parts of the threading mechanism, Fig. 21 is a thread pull-out mechanism, (a) being a plan view, (b) being a side view, and (c) being an exploded perspective view, Fig. 22 shows a thread cut-off mechanism, (a) being a plan view and (b) being a front sectional view, Fig. 23 shows a broken thread recovery mechanism, (a) being a front view and (b) being a plan view, and Fig. 24 shows a sensor for detecting the state of the thread, (a) being a plan view and (b) being a perspective view.
Fig. 25 is a front view showing a second embodiment of embroidery machinery of the invention.
Fig. 26 shows a thread holder in a second embodiment of a thread feed device in embroidery machinery of the invention, (a) being a front view, (b) being a side view, and (c) being a plan view, Fig. 27 is a side view of the thread feed device in embroidery machinery of the invention, Fig. 28 shows a modified example of the second embodiment of the thread feed device in embroidery machinery of the invention, (a) being a front view and (b) being a side view, Fig. 29 is its perspective view, Fig. 30 is a front view of a thread regulating mechanism, Fig. 31 is a sectional view of essential parts of a pipe member, and Fig. 32 is a sectional view of essential parts of the thread regulating mechanism.
Fig. 33 is a front view of a second embodiment of a threading device of embroidery machinery of the invention, and Fig. 34 is its side view.
Fig. 35 shows a modified example of a thread gripping member of a thread tensioning mechanism, (a) being a front view, (b) being a plan view, and (c) being a side view, Fig. 36 is its perspective view, Fig. 37 is a perspective view of a thread pull-out mechanism, Fig. 38 is a perspective view of a modified example of the thread pull-out mechanism, Fig. 39 shows a thread recovery mechanism, (a) being a plan view and (b) being a front view, and Fig. 40 is its perspective view.

Best Modes for Carrying Out the Invention

Referring now to the drawings, embodiments of the embroidery machinery of the invention are described in detail below.
As shown in Fig. 1 and Fig. 2, the embroidery machinery is mainly composed of plural sewing machine heads 1, thread feed devices, a threading device 7 comprising a thread tensioning mechanism 3 and a threading mechanism 6, a balance mechanism 4, and auxiliary mechanisms 5 such as broken thread recovery mechanism.
The drawing of the embodiment shows one of the plural sewing machine heads, ranging from several to as many as 30 heads provided for one embroidery machinery system. The same constitution as in the illustrated embodiment is employed in the other sewing machine heads, and each sewing machine head is driven simultaneously by common drive sources of various types, and if necessary, a clutch is placed between the common drive source and each sewing machine head, or an independent drive source is provided for each sewing machine head, so that each sewing machine head may be driven independently. These mechanisms are basically the same as those in current embroidery machinery.
Although it is preferable to contain all of the thread feed device 2, auxiliary mechanisms 5 such as broken thread recovery mechanism, and the threading device 7 accommodated in the sewing machine head of the embroidery machinery of the embodiment, depending on the case, part of the devices may be replaced by other mechanism having similar operation, or they may be omitted.
In the embodiment, the air cylinder, solenoid and other items used as drive sources for each drive mechanism may be replace with other proper drive sources, although they are not mentioned on every occasion.
Also in the embodiment, the connection of the drive mechanism to the drive source is achieved by connection mechanisms such as link mechanisms, lever mechanisms, or wire mechanisms, but these connection mechanisms may be replaced with other proper ones as required, if not specifically described.
As a high pressure air source is used to carry out some functions, such as an air cylinder used for sending out thread toward the needle, an arbitrary high pressure air generating device may be used aside from the compressor.
These points are similar in the other embodiments mentioned later.
A first embodiment of the thread feed device 2 disposed above the sewing machine head 1 of embroidery machinery is shown in Fig. 1 through Fig. 8.
This thread feed device 2 is comprised of a bobbin housing 22 accommodating a plurality of bobbins 21 of colored threads, thread tension regulating mechanisms 25 disposed integrally with the bobbin housing 22, corresponding to the number of bobbins 21 accommodated, a thread regulating mechanism 24 having a semi-cylindrical main body 24a, comprising a thread length regulating mechanism 27 and a thread let-off motion 28 for holding a specified length of thread 11 being let off toward the needle 10, and a thread selecting mechanism 29 for positioning the thread let-off mechanism 28 corresponding to the required bobbin 21 selectively above the threading device 7 for passing the thread into the specified needle 10.
In the embodiment, the bobbin housing 22 and the thread regulating mechanism 24 disposed integrally therewith are assembled into a unit, and it is detachably mounted on the sewing machine head 1.
The bobbin housing 22 is, for example, inclined slightly forward and horizontally accommodates 12 bobbins in the upper stage and six in the lower stage, or 18 bobbins in total, and a spindle 22a for inserting and supporting the bobbins 21 is set up at the bottom, while a thread holder 23 for drawing out the threads 11 on the bobbins 21 without allowing entanglment is provided in the upper part, and a total of 18 threads 11 are drawn out at intervals from the thread holder 23, and sent into the thread tension regulating mechanism 25 of the thread regulating mechanism 24 provided integrally in the lower part of the bobbin housing 22.
The thread holder 23 is constituted by disposing oscillating pieces 23a opening thread insertion holes 23b for drawing out the threads 11 without entanglment onto an oscillating piece support shaft 23c planted between bobbins 21, oscillatably above the bobbins 21, and fitting notches 23d formed in the base part of the oscillating pieces 23a into the protrusions 23e projecting from the oscillating piece support shaft 23c, thereby fixing the oscillating piece 23a at a specified position.
By disposing the oscillating pieces 23a oscillatably, the bobbins 21 may be easily loaded and unloaded inside the bobbin housing 22.
Meanwhile, at the upper end of the oscillating piece support shaft 23c, an axial groove 23f is formed, and by slightly expanding the upper end of the groove 23f, the base part of the oscillating piece 23a is prevented from slipping out of the oscillating piece support shaft 23c.
The thread tension regulating mechanism 25 has three thread tension regulating members 25a, 25b, 25c for each of the threads 11 from each bobbin 21, provided on the outer circumference of the semi-cylindrical main body 24a of the thread regulating mechanism 24.
One thread tension regulating mechanism 25c is provided with a tension sensor 25d for measuring the tension of the thread 11, so that breakage of thread 11 may be detected.
The signal from the tension sensor 25d is sent, as an electric signal, into a control unit of the embroidery machinery from an electric contact (not shown) disposed in the thread regulating mechanism 24 through an electric circuit (not shown) having an electric contact located in the sewing machine head 1. This controls the driving of the embroidery machinery, and also warns the operator of breakage of the thread 11 by lighting a pilot lamp (not shown) displaying the state of the needle thread and looper thread in the sewing machine head 1 or the like.
Aside from the pilot lamp, at a proper position of the embroidery machinery, display devices, such as a liquid crystal display device for showing the operator the state of the embroidery machinery, and alarm devices such as buzzers may be situated.
In addition, when sending the thread 11 toward the needle 10, in order to prevent a large resistance from being applied to the thread 11, a thread tension canceling mechanism 26 is used eliminate the holding of the thread 11 by the thread tension regulating mechanism 26b.
This thread tension canceling mechanism 26 is set up, as shown in Fig. 6, so as to cancel the holding of the thread 11 by the thread tension regulating mechanism 25b, by compressing and operating the spring of the thread tension regulating mechanism 25b through an operation shaft 26c, by a thread tension canceling plate 26b oscillated and manipulated by solenoid 26a provided at the side of the sewing machine head 1.
A thread length regulating mechanism 27 provided beneath the thread tension regulating mechanism 25 is to holding the thread 11 to be sent toward the needle 10 at a specified length, and the thread 11 held by this thread length regulating mechanism 27 is let off as the thread length regulating mechanism 27 is canceled when the leading end of the thread 11 is guided nearly to the needle 10 by the threading device 7, and the thread 11 of the specified length needed when embroidery work is started is inserted into the needle 10.
This thread length regulating mechanism 27 is designed, as shown in Fig. 7, so as to let off the held thread 11, by projecting a thread length regulating piece 27c moved and manipulated through a wire 27a and lever 27c by a solenoid (not shown), holding the thread 11 at a specified length, and moving backward the thread length regulating piece 27c backwards.
In such a case, the leading end of the thread length regulating piece 27c is formed in a recess for the easy holding of the thread 11.
A thread let-off motion 28 located on the outer circumference of the semi-cylindrical main body 24a of the thread regulating mechanism 24 beneath the thread length regulating mechanism 27 is intended to unwind the thread 11 smoothly toward the needle 10, and as shown in Fig. 8, it is comprised of a thread let-off tube 28a for guiding the thread 11 above the threading device 7, and an air nozzle 28b connected to a high pressure air source (not shown) for sending the thread 11 toward the threading device 7 by means of a high pressure air stream.
For this, the air nozzle 28b is fixed so that the opening end of the air nozzle 28b may be located at the threading position, that is, near the upper opening of the thread let-off tube 28a positioned above the threading device 7, and the thread let-off tube 28a is inclined about the oscillating shaft 28d by the thrusting force of a torsion spring 28c, excluding the thread let-off tube 28a positioned above the threading device 7, so that the threading device 7 may accurately grip the thread 11 hanging down from the thread let-off tube 28a positioned above the threading device 7. Moreover, the thread let-off tube 28a positioned above the threading device 7 abuts against a position holding piece 28e fixed on the sewing machine head 1, or can be raised by resisting the thrusting force of the torsion spring 28c by manipulation from a proper drive mechanism (not shown).
The thread selecting mechanism 29 is intended to position the thread let-off tube 28a of the thread let-off motion 28 corresponding to a specified bobbin 21, selectively above the threading device 7 for passing thread into the specified needle 10, and it is comprised of a support shaft 29a located on the sewing machine head 1 for oscillatably mounting the thread regulating mechanism 24 through its bottom plate 24b, an oscillating element 29 oscillated and driven about the support shaft 29a by a link 29c coupled to a drive source (not shown), and a pin 29d fitted in a penetration hole 24c pierced in the bottom plate 24b of the thread regulating mechanism 24, and protruding from the oscillating element 29 for oscillating and driving the thread regulating mechanism 24 together with the oscillating element 29b.
In this instance, in order to position the thread let-off tube 28a of the thread let-off motion 28 corresponding to the specified bobbin 21 accurately above the threading device 7 for passing thread into the specified needle 10, a positioning roller 29h is disposed at the leading end of the oscillating element 29g oscillated and driven about the support shaft 29f by a link 29e coupled to a drive source (not shown), and this positioning roller 29h is fitted into a gear 24d cut by adjusting to the angle of the thread let-off tube 29a of the thread let-off motion 28 on the periphery of the bottom plate 24b of the thread regulating mechanism 24.
Therefore, by controlling the thread selecting mechanism 29 with the control unit of the embroidery machinery, and preliminarily storing the types (colors) of the bobbins 21 accommodated in the bobbin housing 22 in the control unit, multiple colored threads can be automatically selected.
Incidentally, at appropriate positions on the outer circumference of the semi-cylindrical main body 24a of the thread regulating mechanism 24, in order to hold the threads 11 from the bobbins 21 so they will not become entangled, it is preferable to install thread holders 20a, 20b, 20c, 20d, and 20e forming the thread insertion holes at nearly equal intervals.
The thread tension regulating mechanism 25 and thread let-off motion 28 for composing the thread regulating mechanism 24 correspond to the number of bobbins 21 that can be accommodated in the bobbin housing 22, that is, in this embodiment, 18 sets are disposed on the outer circumference of the semi-cylindrical main body 24a of the thread regulating mechanism 24, whereas the thread tension canceling mechanism 26, the thread length regulating mechanism 27, the air nozzle 28b and the position holding piece 28e of the thread let-off motion 28 are disposed by one piece each at the side of the sewing machine head 1, and are designed to manipulate the one needed at the specified position out of the 18 sets, or to cooperate with the one at a specified position. This means, these mechanisms are commonly shared among the 18 sets.
The assembly of the bobbin housing 22 and its integrally disposed thread regulating mechanism 24 (hereinafter called the unit) is preferably prepared with a plural multiple of the number of sewing machine heads 1. Accordingly, when changing the colored thread, it is replaced in the unit, and the time required for a change of colored thread can be shortened. For example, when the units of the embodiment are prepared by a double number of the number of sewing machine heads, up to 36 colored threads can be changed in a short time. In this case, by preliminarily storing the types (colors) of the bobbins 21 accommodated in the bobbin housing 22 in the control unit of the embroidery machinery, multiple color threads can be changed automatically, by only replacing the units.
In the embodiment, the bobbin housing 22 and its integrally disposed thread regulating mechanism 24 are assembled as a unit, and they are detachably fitted to the sewing machine head 1 , but they may be also fixed integrally to the sewing machine head 1.
Also in the embodiment, the thread let-off tube 28a of the thread let-off motion 28 corresponding to the specified bobbin 21 are selectively positioned above the threading device 7 for passing thread to a specified needle 10, and therefore the thread regulating mechanism 24 is oscillated and driven about the support shaft 29a by the thread selecting mechanism 29, but a mechanism sliding within a horizontal plane may be also employed as the thread selecting mechanism.
A modified example of the first embodiment of the thread feed device 2 disposed above the sewing machine head 1 of the embroidery machinery is shown in Fig. 9 through Fig. 13.
This thread feed device 2 is comprised of a bobbin housing 22 accommodating a plurality of colored thread bobbins 21, thread tension regulating mechanisms 25 disposed integrally with the bobbin housing 22 corresponding to the number of bobbins 21 accommodated, a thread regulating mechanism 24 having a semi-cylindrical main body 24a comprising a thread length regulating mechanism for holding the thread 11 to be sent toward the needle 10 at a specified length (not shown; see the first embodiment), a thread let-off motion 28, and a thread selecting mechanism 29 for positioning the thread let-off motion 28 corresponding to the specified bobbin 21 selectively above the threading device 7 for passing the thread into the specified needle 10.
In this embodiment, the bobbin housing 22 and the upper half of the thread regulating mechanism 24 disposed integrally therewith, that is, the thread tension regulating mechanism 25 provided corresponding to the number of bobbins 21 accommodated, is equally divided into right and left sides as shown in Fig. 9 and Fig. 12, composed in units (called units 2A and 2B hereinafter), and they are detachably fitted to the thread selecting mechanism 29 disposed in the sewing machine head 1 through the bottom plate 24b of the thread regulating mechanism 24.
The bobbin housing 22 is, for example, inclined slightly forward in the upper stage, and nine bobbins can be accommodated each on the right and left sides, a total of 18 bobbins, and a spindle 22a for inserting and supporting the bobbins 21 is set up in the bobbin housing 22, and a bobbin guide 22b suited to the bobbin 21 to be used is disposed around the spindle 22a, and felt 22c is laid in the bottom so as to draw out the thread 11 from each bobbin 21 without entangling.
The spindle 22a is provided with a thread holder 23, and a total of 18 threads 11 are drawn out from the thread holder 23 at intervals, and sent into the thread tension regulating mechanism 25 installed integrally in the lower part of the bobbin housing 22.
The thread holder 23 is comprised of a guide plate 23p located at the upper end of the spindle 22a, a ceramic guide tube 23q located at the upper end opening of the spindle 22a, a hollow duct 23r of the spindle 22a, and a pipe member 23s connected to a hollow duct 23r. The thread 11 of each bobbin 21 is sent into the thread tension regulating mechanism 25 through the hollow duct 23r of the spindle 22a and the pipe member 23s.
In this case, by varying the extent of the projection of the front end of the pipe member 23s between adjacent pipe members 23s, the thread 11 let off from the pipe member 23s can be held easily.
Meanwhile, the job of inserting the thread 11 into the hollow duct 23r of the spindle 22a and the pipe member 23s can be easily done by blowing a high pressure air stream, together with the thread 11, from the upper end opening of the guide tube 23q.
The thread tension regulating mechanism 25 has three thread tension regulating members 25a, 25b, 25c for every thread 11 from each bobbin 21, provided on the outer circumference of the semi-cylindrical main body 24a of the thread regulating mechanism 24.
One thread tension regulating member 25c is provided with a tension sensor 25d for measuring the tension of the thread 11, so as to detect thread 11 breakage.
The signal from the tension sensor 25d is sent, as an electric signal, into a control unit of the embroidery machinery from an electric contact (not shown) disposed in the thread regulating mechanism 24 through an electric circuit (not shown) through an electric contact disposed in the sewing machine head 1. It controls the driving of the embroidery machinery, and also warns the operator of the breakage of thread 11 by lighting a pilot lamp (not shown) displaying the state of the needle thread and looper thread found in the sewing machine head 1 or the like.
Aside from the pilot lamp, at a proper position on the embroidery machinery, a display device, such as a liquid crystal display device, is set up to show the operator the state of the embroidery machinery, and an alarm device, such as buzzer, may be disposed.
Also, when sending the thread 11 toward the needle 10, in order to prevent too great a resistance from being applied to the thread 11, a thread tension canceling mechanism (not shown; see the first embodiment) is employed to stop the holding of the thread 11 by the thread tension regulating mechanism 25b.
A thread let-off motion 28 located on the outer circumference of the semi-cylindrical bottom plate 24b of the thread regulating mechanism 24 is intended to deploy the thread 11 smoothly toward the needle 10, and it is comprised of a thread let-off tube 28a for guiding the thread 11 above the threading device 7, and an air nozzle (not shown; see the first embodiment) connected to a high pressure air source (not shown) to send the thread 11 toward the threading device 7 with a high pressure air stream.
The air nozzle is, as in the first embodiment, fixed so that the open end of the air nozzle may be located at the threading position, that is, near the upper opening of the thread let-off tube 28a positioned above the threading device 7, and is inclined, excluding the thread let-off tube 28a positioned above the threading device 7 and at the embroidery position.
In this set up, it is preferred that the thread let-off tube 28a at the embroidery position be raised by manipulating a proper drive mechanism (not shown), and inclined immediately after embroidery operation, so that the threading device 7 may accurately grip the thread 11 hanging from the thread let-off tube 28a located above the adjacent threading device 7.
A thread selecting mechanism 29 is intended to position the thread let-off tube 28a of the thread let-off motion 28 corresponding to a specified bobbin 21, selectively above the threading device 7 for passing thread into a specified needle 10, and it is comprised of a support shaft 29a located on the sewing machine head 1 for oscillatably mounting the thread regulating mechanism 24 through its bottom plate 24b, an oscillating element 29b oscillated and driven about the support shaft 29a by a link 29c coupled to a drive source (not shown), and a pin 29d fitted in a penetration hole 24c pierced in the bottom plate 24b of the thread regulating mechanism 24, and protruding from the oscillating element 29 for oscillating and driving the thread regulating mechanism 24 together with the oscillating element 29b.
As a result, in order to position the thread let-off tube 28a of the thread let-off motion 28 corresponding to the specified bobbin 21 accurately above the threading device 7 for passing thread into the specified needle 10, a positioning roller 29h is disposed at the leading end of an oscillating element 29g oscillated and driven about a support shaft 29f by a link 29e coupled to a drive source (not shown), and this positioning roller 29h is fitted into a gear 24d cut by adjusting the angle of the thread let-off tube 29a of the thread let-off motion 28 on the periphery of the bottom plate 24b of the thread regulating mechanism 24.
Herein, by controlling the thread selecting mechanism 29 with the control unit of the embroidery machinery and preliminarily storing the types (colors) of the bobbins 21 accommodated in the bobbin housing 22 in the control unit, multiple colored threads can be selected automatically.
Incidentally, at appropriate positions on the outer circumference of the semi-cylindrical main body 24a of the thread regulating mechanism 24, in order to hold the threads 11 from the bobbins 21 so as not to become entangled, it is preferred to install thread holders 20a, 20b, 20c, 20d, forming thread insertion holes at nearly equal intervals.
The thread tension regulating mechanism 25 and thread let-off motion 28 for composing the thread regulating mechanism 24 correspond to the number of bobbins 21 that can be accommodated in the bobbin housing 22, that is, in this embodiment, 18 sets are disposed on the outer circumference of the semi-cylindrical main body 24a and bottom plate 24b of the thread regulating mechanism 24, whereas the thread tension canceling mechanism, thread length regulating mechanism, and air nozzle 28b of the thread let-off motion 28 are dispersed as one piece each at the sewing machine head 1 side, and are designed to manipulate each one at the specified position out of 18 sets or to cooperate with each one at a specified position, that is, these mechanisms are commonly shared among the 18 sets.
Units 2A and 2B of the bobbin housing 22 and the integrally disposed thread regulating mechanism 25 are equally divided into right and left portions and are preferably prepared by a plural multiple of the number of sewing machine heads 1. Accordingly, when changing the colored thread, unit 2A or unit 2B can be replaced in assembly, and the time required for changing the colored thread can be shortened. For example, when units 2A or 2B of the embodiment are prepared by double the number of the sewing machine heads, up to 36 colored threads can be changed in a short time. In this case, by preliminarily storing the types (colors) of the bobbins 21 accommodated in the bobbin housing 22 in the control unit of the embroidery machinery, multiple colored threads can be changed automatically, just by replacing the units.
In the embodiment, the bobbin housing 22 and its integrally disposed thread regulating mechanism 24 are assembled as a unit, and they are detachably fitted to the sewing machine head 1, but they may also be fixed integrally to the sewing machine head 1.
Also in the embodiment, the thread let-off tube 28a of the thread let-off motion 28 corresponding to the specified bobbin 21 is selectively positioned above the threading device 7 for passing thread to a specified needle 10, and therefore the thread regulating mechanism 24 is oscillated and driven about the support shaft 29a by the thread selecting mechanism 29, but a mechanism sliding within a horizontal plane may be also employed as a thread selecting mechanism.
In the lower part of the thread feed device 2 of the sewing machine head 1, as shown in Fig. 14 through Fig. 24, a threading device 7 comprised of a thread tensioning mechanism 3 and a threading mechanism 6 is employed.
The thread tensioning mechanism 3 is intended to guide the end of the thread 11 hanging at a specified length from the thread let-off tube 28a of the thread feed device 2 nearly to the position of the needle 10 as shown in Fig. 14 through Fig. 17, and it is comprised of a thread gripping member 31, a lever 32 disposed at the front end of the thread gripping member 31, a sliding piece 33 for oscillatably supporting the base end of the lever 32, a guide tube 34 of the sliding piece 33 disposed nearly in a vertical direction to the thread tensioning mechanism main body 30, a belt 35 for raising and lowering the sliding piece 33 along the guide tube 34, a rack 36 deployed nearly to the descending position of the sliding piece 33 for defining the oscillating angle of the lever 32 by engagement with a pinion 32a fixed at the base end of the lever 32, a guide groove 37 formed nearly in a vertical direction of the thread tensioning mechanism main body 30 for defining the oscillating angle of the lever 32 by inserting a roller 32b found at the intermediate position of the lever 32, and a drive mechanism 38 for driving the belt 35.
Thus, by comprising the thread tensioning mechanism 3 of the oscillating lever 32 and elevating the sliding piece 33, among others, the thread tensioning mechanism 3 may be compactly designed, and in particular, the extent of the projection of the thread gripping member 31 ahead of the sewing machine head 1 can be shortened.
In this thread tensioning mechanism 3, by driving the belt 35, when the thread gripping member 31 is moved from the waiting position nearly at the middle to the highest position for gripping the end portion of the thread 11 hanging from the thread let-off tube 28a, the thread gripping member 31 can automatically grip the end portion of the thread 11, and moreover a shoe member 31e is disposed oscillatably on a bracket 1b protruding from the sewing machine head 1, and a roller 31f disposed at the front end of an operation piece 31d protruding from a movable gripping piece 31a of the thread gripping member 31 abuts against this shoe member 31e to open the movable gripping piece 31a by resisting the thrusting force of a spring member 31c, so that the end portion of the thread 11 hanging from the thread let-off tube 28a is inserted between the movable gripping piece 31a and the fixed gripping piece 31b, and then the shoe member 31e is oscillated by a drive mechanism (not shown), clearing the engagement of the shoe member 31e and operation piece 31d to return the movable gripping piece 31a, and the thread 11 inserted between the movable gripping piece 31a and fixed gripping piece 31b is gripped.
By driving the belt 35 in this state, the thread gripping member 31 is moved from the highest position to the lowest position, the thread 11 guided to the position close to the needle 10 is led into the needle hole 10a of the needle 10, and after passing the thread through, the end portion of the thread 11 gripped by the thread gripping member 31 is released by an operation member 31g disposed oscillatably beneath the thread tensioning mechanism main body 30, and by this operation member 31g, the roller 31f located at the front end of the operation piece 31d projecting from the movable gripping piece 31a of the thread gripping member 31 is pressed, so that the movable gripping piece 31a is released by resisting the thrusting force of the spring member 31dc.
The drive mechanism 38 is designed to drive a rotary shaft 38a of the belt 35 selectively in normal and reverse directions by means of a motor (not shown).
Moreover, the thread tensioning mechanism 3 is provided with a limit switch (not shown) at an appropriate position along the ascending and descending route of the sliding piece 33, for example, at a waiting position near the middle position of the thread gripping member 31, at the highest position for gripping the end portion of the thread 11 hanging from the thread let-off tube 38a by the thread gripping member 31, or at the lowest position for threading, so as to detect the position of the sliding piece 33. The position of the limit switch may be properly adjusted.
The thread 11 stretched between the thread let-off tube 28a of the thread feed device 2 and the position close to the needle 10 by the thread tensioning mechanism 3 is applied on the balance 41 and sub-balance 42 of the balance mechanism 4.
In this embodiment, the balance mechanism 4 and the needle 10 corresponding to the balance mechanism 4 are deployed in three sets, and the frame 1c incorporating these needles 10 oscillates within a horizontal plane, but, in another constitution, the number of sets of the needles 10 provided in the frame 1c may be increased or decreased, and the frame 1c may slide within a horizontal plane.
In the balance 41, a thread hook hole 41a is formed at the front end, and a notch 41b for inserting a driving pin 41c of the balance 41 is formed at the base end.
The sub-balance 42 is comprised of a ring-shaped thread hook hole 42a, a lever 42b forming the thread hook hole 42a at the front end, a sliding piece 42c for supporting the lever 42b slidably, a guide tube 42d for the sliding piece 42c placed in nearly a vertical direction in the thread tensioning mechanism main body 30, a magnet piece 42e for attracting the sliding piece 42c to the thread gripping member 31 of the thread tensioning mechanism 3 for moving up and down along the guide tube 34 along with the ascending and descending of the thread gripping member 31, a shoe member 42g for defining the position of the thread hook hole 42a by abutting a lever 42f disposed at other end of the lever 42b, and a spring member 42h for abutting, so that the roller 42f located at other end of the lever 42b may abut against the shoe member 42g.
The sub-balance 42 of the balance mechanism 4 moves, as the belt 35 of the thread tensioning mechanism 3 is driven, and the thread gripping member 31 from the waiting position nearly in the middle to the highest position for gripping the end portion of the thread 11 hanging from the thread let-off tube 28a, and then, being attracted to the thread gripping member 31, the sliding piece 42c also moves to the highest position, and the end portion of the thread 11 hanging from the thread let-off tube 28a is inserted into the thread hook hole 42a.
Gripping the thread 11 with the thread gripping member 31 positioned immediately beneath the thread hook hole 42a, when the belt 35 of the thread tensioning mechanism 3 is driven in this state, the thread gripping member 31 moves from the highest position to the lowest position. At this time, the sliding piece 42c also descends as though attracted to the thread gripping member 31 , but since the sliding piece 42c is prevented from descending further by a stopper member 42i provided nearly at the middle position, its attraction with the thread gripping member 31 is cleared, and it stops at this position, that is, the waiting position at the bottom dead center. Moreover, along with the descending of the sliding piece 42c, the lever 42b disposing the thread hook hole 42a in which the thread 11 is inserted at the front end resists the thrusting force of the spring member 42h as the roller 42f disposed at other end abuts against the shoe member 42g, and moves in a horizontal direction along the shape of the shoe member 42g, and while the sliding member 42c descends, the thread 11 is passed into the thread hook hole 41a formed at the front end of the balance 41.
Preferably, in the thread hook hole 41a of the balance 41, a trap or arresting means should be formed to prevent the passed thread 11 from slipping out.
As a result, the thread 11 is inserted into the thread hook hole 41a of the balance 41 and the thread hook hole 42a of the sub-balance 42, and embroidery is started in the state of a in specified Zigzag form.
In embroidery operation, as in conventional embroidery machinery, the balance 41 is driven reciprocally by the drive mechanism, while the sub-balance 42 is held at the waiting position at the bottom dead center.
The threading mechanism 6, as shown in Fig. 18 through Fig. 21, is designed to lead the thread 11 guided to a position close to the needle 10 by the thread tensioning mechanism 3 up to the needle hole 10a of the needle 10, where the thread is passed, and is comprised of a thread pull-out mechanism 61, a drive mechanism 62 of the thread pull-out mechanism 61, an air nozzle 63 disposed in the thread gripping member 31 for sending the thread 11 gripped by the thread gripping member 31 of the thread tensioning mechanism 3 toward the thread pull-out mechanism 61, and a thread push-down mechanism 64 located in the thread pull-out mechanism 61 for holding the thread 11 inserted into the thread pull-out mechanism 61 securely by the thread pull-out mechanism 61.
The thread pull-out mechanism 61 is comprised of, as shown specifically in Fig. 19 through Fig. 21, a hook member 61a formed like a hook at the front end, guide members 61b, 61b deployed at both sides of the hook member 61a through spacers 61f, 61f, and a holding member 61 for holding a front end member, comprised of the hook member 61a, guide members 61b, 61b, and spacers 61f, 61f.
The guide members 61b, 61b are comprised of leaf springs formed in a shape so as to abut against the side surface of the hook member 61a at the base of the front ends 61e, 61e, curved mutually outward so as to guide the hook member 61a into the center of the needle 10, that is, at the position of the needle hole 10a when abutting against the needle 10, and a thread insertion hole 61c is formed nearly in the center, and a thread release groove 61d is formed from the thread insertion hole 61c toward the front end.
The drive mechanism 62 of the thread pull-out mechanism 61 is comprised of, as shown specifically in Fig. 18, a frame 62a located in the support element 1d planted at the sewing machine head 1 side for supporting the holding member 61g of the thread pull-out mechanism 61, a driving lever 62b for driving the holding member 61g, and a driving mechanism 62c for the driving lever 62b.
The thread push-down mechanism 64 is comprised of a thread push-down piece 64a located in the thread pull-out mechanism 61 provided in the holding member 61g oscillatably through a shaft 64c, a torsion spring 64b for thrusting the thread push-down piece 64a in a direction for shielding the thread insertion hole 61c, that is, in the direction of pushing down the thread 11 along the side surface of the guide member 61b, and operation pieces 64d, 64e of the thread push-down piece 64a formed respectively in the thread push-down piece 64a and the frame 62a of the drive mechanism 62 for holding the thread insertion hole 61c in an open state by pushing up the thread push-down piece 64a by resisting the thrusting force of the torsion spring 64b.
The threading mechanism 6, as shown in Fig. 18 (a), pushes forward the front end of the driving lever 62b by means of the driving mechanism 62c, pushes down the pin 61h fixed in the holding member 61g inserted into a slit 62d opened at the base end side of the driving lever 62b, moves down the pin 61h along the groove 62e formed in the frame 62a, and moves down the pull-out mechanism 61 through the holding member 61g, fixing the pin 61h.
In this state, by further pushing forward the front end of the driving lever 62b with the driving mechanism 62c, an axis 62g of the driving lever 62b is moved forward along the groove 62e formed in the frame 62a, and the pin 61h fixed in the holding member 61g inserted into the slit 62d opened at the base end of the driving lever 62b is moved forward along the groove 62h formed in the frame 62a, so that the pull-out mechanism 61 is moved forward through the holding member 61g, fixing the pin 61h.
Thus, according to this drive mechanism 62, by driving and manipulating the driving lever 62b with the driving mechanism 62c, the thread pull-out mechanism 61 is lowered and moved forward, and while being guiding by the guide member 61b, the front end of the hook member 61a is inserted into the needle hole 10a.
It should also be noted that when the thread pull-out mechanism 61 is lowered and moved forward, the operation pieces 64d, 64e of the thread push-down piece 64a formed respectively in the thread push-down piece 64a and the frame 62a of the drive mechanism 62 abut against each other to push the thread push-down piece 64a down by resisting the thrusting force of the torsion spring 64b, so that the thread insertion hole 61c may be held in an open state.
In this state, sending out high pressure air from the air nozzle 63 disposed in the thread gripping member 31 toward the thread pull-out mechanism 61, the thread 11 gripped by the thread gripping member 31 of the thread tensioning mechanism 3 is inserted into the thread insertion hole 61 of the guide member 61b, and the end portion of the thread 11 gripped by the thread gripping portion 31 is released.
Later, by driving and manipulating the driving lever 62b with the driving mechanism 62c, the thread pull-out mechanism 61 is moved back, and the mutual contact of the operation pieces 64d, 64e of the thread push-down piece 64a formed respectively in the thread push-down piece 64a and the frame 62a of the drive mechanism 62 is cleared, and the thread push-down piece 64a is oscillated in a direction to shield the thread insertion hole 61c, and by pushing down the both ends of the thread 11 inserted into the thread insertion hole 61c along the side surface of the guide member 61b, the driving operation of the driving lever 62b of the drive mechanism 62 is continued while hooking the thread 11 inserted in the thread insertion hole 61c accurately into the hook member 61a of the thread pull-out mechanism 61. As a result, the thread pull-out mechanism 61 is moved back, and the thread is passed by pulling out the hook member 61a from the needle hole 10a, while hooking the thread 11 in the hook member 61a formed like a hook at the front end.
In the embroidery machinery of the invention, meanwhile, after passing the thread, as shown in Fig. 14 and Fig. 15, by driving the thread selecting mechanism 29 of the thread feed device 2, the thread let-off tube 28a is moved aside by one stage (to the right) with the thread 11 being applied, so that embroidery operation can be effected.
In the application route of the thread 11, the auxiliary mechanism 5 comprised of an upper thread clamp mechanism 51, a thread cutting mechanism 52, and a broken thread recovery mechanism 53 is deployed.
The upper thread clamp mechanism 51 is used to clamp the thread 11 temporarily, to prevent the thread 11 from being slipping from the bobbin 21 when cutting and recovering the thread 11, and, as shown in Fig. 14, it is comprised of a fixed gripping piece 51a fixed at the sewing machine head 1 side, a movable gripping piece 51b for clamping the thread 11 together with the fixed gripping piece 51a, and the driving mechanism 51c of the movable gripping piece 51b.
The thread cutting mechanism 52 is used for cutting off the thread 11 when it is being changed, and, as shown in Fig. 22, it is comprised of a fixed blade 52a fixed at the side of the sewing machine head 1, a movable blade 52c oscillating about an axis 52b, and the driving mechanism 52d for the movable blade 52c.
The broken thread recovery mechanism 53 is for recovering the thread 11 cut off by the thread cutting mechanism 52 when changing the thread 11, and, as shown in Fig. 23, it is comprised of an operation rod 53c forming a hook 53b for hooking the thread 11 at the front end, a driving mechanism 53d of the operation rod 53c, a suction tube 53e, in which the operation rod 53c is slidably inserted, for sucking and recovering the broken thread 11, lead tubes 53f, 53g of high pressure air for producing a suction force in the suction tube 53e, and a recovery container 53h, formed of a mesh, for holding the recovered thread 11, detachably located in the recovery mechanism main body 53a.
The sewing machine head 1 is provided with a cover 8 as shown in Fig. 14.
The cover 8 is provided with a lower thread clamp mechanism 81 for clamping the thread 11, and a sensor 82 for detecting the state of the thread 11, in the applied route of the thread 11 when the thread let-off tube 28a is moved to the embroidery position by one stage (to the right) with the thread 11 being applied.
The lower thread clamp mechanism 81 clamps the thread 11 temporarily to prevent the thread 11 from being let off beneath the lower thread clamp mechanism 81 when starting embroidery, and to prevent the end portion of the thread 11 from coming out to the surface of the cloth of embroidery. It is comprised of a fixed gripping piece 81a fixed at the sewing machine head 1 side, a movable gripping piece 81b for clamping the thread 11 together with the fixed gripping piece 81a, and a driving mechanism 81c of the movable gripping piece 81b.
The sensor 82 for detecting the state of the thread 11 prevents the occurrence of defective pieces by optically detecting the return of twist in the thread 11, stopping embroidery when return of twist in the thread 11 is detected, and changing the thread 11, and, as shown in Fig. 24, it is comprised of a light emitting and detecting element 82a, and a mirror 82b placed opposite the light emitting and detecting element 82a across the thread 11.
A second embodiment of the thread feed device 2 found in the upper part of the sewing machine head 1 of the embroidery machinery is described below by referring to Fig. 25 through Fig. 32.
This thread feed device 2 is comprised of a bobbin housing 22 accommodating a plurality of colored thread bobbins 21, thread tension regulating mechanisms 25 deployed integrally with the bobbin housing 22 corresponding to the number of bobbins 21 accommodated, a thread regulating mechanism 24 having a flat rectangular main body 24a comprising a thread length regulating mechanism 27 for holding the thread 11 to be sent toward the needle 10 at a specified length and a thread let-off motion 28, and a thread selecting mechanism 29 for positioning the thread let-off motion 28 corresponding to the specified bobbin 21 selectively above the threading device 7 for passing the thread into the specified needle 10.
In this case, the number of bobbins 21 that can be accommodated in the bobbin housing 22, and the number of thread tension regulating mechanisms 25 may not necessarily match, and by setting a number of bobbins 21 that can be accommodated in the bobbin housing 22 greater than the number of the thread tension regulating mechanisms 25, the bobbins 21 for applying the thread to the thread tension regulating mechanism 25 can be exchanged.
The bobbin housing 22 accommodates, for example, a total of 4 x 7 = 28 bobbins 21, and a spindle 22a for inserting and Supporting the bobbins 21 is planted in the bobbin housing 22, and bobbin guides (not shown) suitable to the bobbins 21 to be used are disposed around the spindle 22a, and a felt 22c for drawing out the thread 11 from each bobbin 21 without entanglment is laid down at the bottom.
The spindle 22a is provided with a thread holder 23, and is intended to draw out a total of 28 threads 11 from the thread holder 23 at intervals, and send into the thread tension regulating mechanism 25 of the thread regulating mechanism 25 mounted integrally in the lower part of the bobbin housing 22.
Of the total 28 threads 11 , eight are held by the thread holder 23.
The thread holder 23 is composed of a ceramic guide tube (not shown) placed at the upper end opening of the spindle 22a, a hollow duct of the spindle 22a, a pipe member 23s communicating with the hollow duct, and a ceramic guide tube 23t placed at the front end opening of the pipe member 23s, and is designed to send the thread 11 of each bobbin 21 into the thread tension regulating mechanism 25 through the hollow duct and pipe member 23s of the spindle 22a.
The job of inserting the thread 11 into the hollow duct and pipe member 23s of the spindle 22a is easily done by blowing in a high pressure air stream, together with the thread 11, from the upper end opening of the guide tube 23q.
In this embodiment, the bobbin housing 22 is fixed in the sewing machine head 1, but not limited to this. In a modified example, as shown in Fig. 28 and Fig. 29, the bobbin housing 22 may be equally divided into right and left units, and detachably mounted on the upper part of the flat rectangular main body 24a of the thread regulating mechanism 24.
This bobbin housing 22 accommodates, for example, 2 x 5 bobbins or 10 each on the right and left sides, or a total of 20 bobbins 21, and a spindle 22a for inserting and supporting the bobbins 21 is planted in the bobbin housing 22, and bobbin guides (not shown) suitable to the bobbins 21 to be used are dispersed around the spindle 22a, and a felt 22c for drawing out the thread 11 from each bobbin 21 without entanglment is laid down on the bottom.
A stand 22d on which the spindle 22a is planted is detachably fitted by sliding a guide rail 33i formed on the upper part of the main body 24a of the thread regulating mechanism 24.
In this case, a pipe member holding member 23u fixing the front end opening of a pipe member 23s communicating with a hollow duct of the spindle 22a is disposed selectively at support shaft 22f, planted on the stand 22d when separating the stand 22d, or at support shaft 22g planted on the upper part of the main body 24a of the thread regulating mechanism 24 when mounting the stand 22d.
Ahead of the guide rail 22i, a support 22d is fixed for smoothly sliding the stand 22 along the guide rail 22i by provisionally placing the stand 22d when mounting the stand 22d on the guide rail 22i, and a pipe member support frame 22h is slidably disposed for preventing entanglment and adjusting the sagging amount of the pipe member 23s by supporting the pipe member 23s.
The stand 22d of the bobbin housing 22 is preferably prepared with a plural multiple of the number of sewing machine heads 1. Accordingly, when changing the colored thread, it is replaced in the unit of the stand 22d, and the time required for changing colored thread can be shortened. For example, when the stands 22d of the bobbin housing 22 in this modified example are prepared with a number double that of the sewing machine heads, up to 40 colored threads can be changed in a short time. In this case, by preliminarily storing the types (colors) of the bobbins 21 accommodated in the stands 22d of the bobbin housing 22 in the control unit of the embroidery machinery, multiple colored threads can be changed automatically, by only replacing the stands 22d.
In this modified example, the stand 22d is detachably fitted by sliding on the guide rail 22i formed on the upper part of the main body 24a of the thread regulating mechanism 24. But the stand 22d can be also fitted detachably by being mounted on the upper part of the main body 24a of the thread regulating mechanism 24.
The number of divisions of the bobbin housing 22 is not limited to only two, but may be divided into three or more sections.
In the second embodiment, the thread tension regulating mechanism 25 has two thread tension regulating members 25b, 25c for every thread 11 from each bobbin 21, provided on the outer circumference of the flat rectangular main body 24a of the thread regulating mechanism 24.
One thread tension regulating member 25c is provided with a tension sensor 25d for measuring the tension of the thread 11, so that breakage of the thread 11 may be detected.
The signal from the tension sensor 25d is sent, as an electric signal, into a control unit of the embroidery machinery from an electric contact 25e located in the thread regulating mechanism 24 through an electric circuit 25g containing an electric contact 25f found in the sewing machine head 1, and controls the driving of the embroidery machinery, and also warns the operator of breakage of the thread 11 by lighting a pilot lamp (not shown) displaying the state of the needle thread and looper thread in the sewing machine head 1 or the like.
Aside from the pilot lamp, at a proper position on the embroidery machinery, a display device, such as liquid crystal display device, for showing the operator the state of the embroidery machinery, is set, and an alarm device, such as buzzer, may be used.
When sending the thread 11 toward the needle 10, in order to prevent a large resistance from being applied to the thread 11, a thread tension canceling mechanism 26 is used to terminate the holding of the thread 11 by the thread tension regulating mechanism 25b (for details, see the thread tension canceling mechanism 26 in the first embodiment).
The sewing machine head 1 near the main body 24a of the thread regulating mechanism 24 is provided with a thread tension regulating tool 25h for adjusting the magnitude of the tension of the thread 11 applied from the two thread tension regulating members 25b, 25c.
This thread tension regulating tool 25h is designed to apply a tension equivalent to the tension applied to the thread 11 through the balance 41, sub-balance 42, and needle 10 located beneath the thread feed device 2 described below, to the thread 11, and therefore without having to apply the thread 11 to the balance 41, sub-balance 42 and needle 10, the magnitude of the tension of the thread 11 from each bobbin 21 applied by the two thread tension regulating members 25b, 25c can be adjusted uniformly. Accordingly, the thread tension regulating tool 25h, having a magnet at the base, can be detachably positioned selectively at a proper position to the sewing machine head 1, more specifically at a downward position of the thread let-off tube 28a of the thread let-off motion 28 provided for sending the thread 11 from each bobbin 21 toward the needle 10.
The thread let-off motion 28 disposed on the outer circumference of the flat rectangular main body 24a of the thread regulating mechanism 24 is intended to unwind the thread 11 smoothly toward the needle 10, and it comprised of a thread let-off tube 28a for guiding the thread 11 above the threading device 7, a high pressure air feed tube 28f connected to a high pressure air source (not shown), and an air nozzle 28b for sending the thread 11 toward the threading device 7 by means of a high pressure air stream.
The air nozzle 28b is fixed so that the opening end of the air nozzle 28b is located near the upper opening of the thread let-off tube 28a, and the high pressure air feed tube 28f is slidable, so that high pressure air may be supplied from the high pressure air feed pipe 28f to the air nozzle 28b of the thread let-off tube 28a located above the threading device 7 and at the embroidery position.
The high pressure air feed tube 28f and air nozzle 28b are constituted so that the high pressure air feed tube 28f and air nozzle 28b may be inserted as shown in the embodiment by sliding the high pressure air feed tube 28f, and it may also be constituted so that the high pressure air feed tube 28f and air nozzle 28b may be tightly connected by the seal member found at the open end of the high pressure air feed tube 28f and air nozzle 28b.
A thread selecting mechanism 29 is intended to position the thread let-off tube 28a of the thread let-off motion 28 corresponding to a specified bobbin 21, selectively above the threading device 7 for passing thread into the specified needle 10, and it is constituted so as to mount the thread regulating mechanism 24, together with the bobbin housing 22, slidably within the horizontal plane on a sliding shaft 29i found on the sewing machine head 1, connect the main bodies 24a of the adjacent thread regulating mechanisms 24 together through a coupling member 24e, interlock and slide the main bodies 24a of all thread regulating mechanisms 24 along the sliding shaft 29i by a drive source (not shown), and position the thread let-off tube 28a of the thread let-off motion 28 corresponding to the specified bobbin 21 accurately above the threading device 7 for passing thread into the specified needle 10.
Herein, by controlling the thread selecting mechanism 29 with the control unit of the embroidery machinery and preliminarily storing the types (colors) of the bobbins 21 accommodated in the bobbin housing 22 in the control unit, multiple colored threads can be selected automatically.
The constitution of the thread length regulating mechanism 27 and others disposed beneath the thread tension regulating mechanism 25 is same as in the first embodiment.
A second embodiment of the threading device 7 comprised of the thread tensioning mechanism 3 and threading mechanism 6 found in the lower part of the thread feed device 2 of the sewing machine head 1 of the embroidery machinery, is shown in Fig. 33 through Fig. 40.
The thread tensioning mechanism 3 is intended to guide the end portion of the thread 11 hanging at a specified length from the thread let-off tube 28a of the thread feed device 2 nearly to the position of the needle 10 as shown in Fig. 33 and Fig. 34, and it is comprised of a thread gripping member 31, a lever 32 located at the front end of the thread gripping member 31, a sliding piece 33 for supporting the base end of the lever 32, a belt 35 for raising and lowering the sliding piece 33, a guide groove 37 formed in nearly a vertical direction of the thread tensioning mechanism main body 30 for defining the oscillating angle of the lever 32 by inserting a roller 32b placed at the intermediate position of the lever 32, and a drive mechanism 38 for driving the belt 35.
Thus, by using the thread tensioning mechanism 3 of the lever 32 and the elevating sliding piece 33, among others, the thread tensioning mechanism 3 may be designed compactly, and in particular, the protruding extent of the thread gripping member 31 ahead of the sewing machine head 1 can be shortened.
In this thread tensioning mechanism 3, by driving the belt 35 when the thread gripping member 31 is moved from the waiting position nearly at the middle (the sliding piece 33 at the position of the position sensor 39c) to the highest position for gripping the end portion of the thread 11 hanging from the thread let-off tube 28a (the sliding piece 33 at the position of the position sensor 39a), through the open position of the thread gripping member 31 (the sliding piece 33 at the position of the position sensor 39b), in order that the thread gripping member 31 can automatically grip the end portion of the thread 11, a shoe member is oscillatably disposed on a bracket protruding from the sewing machine head, and a roller 31f located at the front end of an operation piece protruding from a movable gripping piece of the thread gripping member 31 abuts against this shoe member to open the movable gripping piece 31a by resisting the thrusting force of a spring member, so that the end portion of the thread 11 hanging from the thread let-off tube 28a is inserted between the movable gripping piece 31a and fixed gripping piece 31b, and then the shoe member is oscillated by a drive mechanism, clearing the engagement of the shoe member and operation piece to return the movable gripping piece 31a, and the thread 11 inserted between the movable gripping piece 31a and the fixed gripping piece 31b is gripped (same as in the first embodiment).
By driving the belt 35 in this state, the thread gripping member 31 is moved from the highest position (the sliding piece 33 at the position of the position sensor 39a) to the lowest position (the sliding piece 33 at the position of the position sensor 39d), the thread 11 guided to the position close to the needle 10 is led into the needle hole 10a of the needle 10, and after passing the thread, in order that the end portion of the thread 11 gripped by the thread gripping member 31 may be released, an operation member is disposed oscillatably beneath the thread tensioning mechanism main body 30, and by this operation member, the roller 31f located at the front end of the operation piece protruding from the movable gripping piece 31a of the thread gripping member 31 is pressed, so that the movable gripping piece 31a is released by resisting the thrusting force of the spring member (same as in the first embodiment).
The drive mechanism 38 is designed to drive the rotary shaft 38a of the belt 35 selectively in normal and reverse direction by means of a motor (not shown).
The locations of the position sensors 39, 39b, 39c, 39d may be properly adjusted.
As the mechanism for feeding high pressure air to the air nozzle 63 found in the thread gripping member 31, the air nozzle 63 is directly connected to the high pressure air source (not shown) through the high pressure air feed pipe, or, alternatively, the air nozzle 63 and the high pressure air feed pipe located at the fixed side are connected when the thread gripping member 31 is moved to the lowest position (the sliding piece 33 at the position of the position sensor 39d), or, as shown in Fig. 34, the air nozzle 63 and the high pressure air feed pipe 63a are tightly connected with the seal member found at air nozzle 63 and the open end of the high pressure air feed pipe 63a.
In the embodiment, the opening and closing motion of the thread gripping member 31 of the thread tensioning mechanism 3 is executed by the shoe member and operation member disposed above and below the thread tensioning mechanism main body 30, but not limited to this, as a modified example shown in Fig. 35 and Fig. 36, in which a torsion spring 31j thrusting in the direction for closing the thread gripping member 31 may be disposed between the movable gripping piece 31a and the fixed gripping piece 31b to comprise the thread gripping member 31, and the opening and closing motion of the thread gripping member 31 may be effected by a proper operation member 31h and its driving mechanism 31i located above and beneath the thread tensioning mechanism main body 30.
The thread 11 stretched between the thread let-off tube 28a of the thread feed device 2 and the position close to the needle 10 by the thread tensioning mechanism 3 is applied on the balance 41 and sub-balance 42 of the balance mechanism 4.
In the embodiment, the balance mechanism 4 and the needle 10 corresponding to the balance mechanism 4 are deployed in three sets, and the frame 1c comprising these needles 10 is designed to oscillate within a horizontal plane. But, in another constitution, the number of sets of needles 10 provided in the frame 1c may be increased or decreased, and the frame 1c may slide on horizontal plane.
In the balance 41, a thread hook hole 41a is formed at the front end, and a notch 41b for inserting the driving pin 41c of the balance 41 is formed at the base end.
The sub-balance 42 is comprised of a ring-shaped thread hook hole 42a, a lever 42b forming the thread hook hole 42a at the front end, a sliding piece 42c for supporting the lever 42b slidably, a guide tube 42d of the sliding piece 42c located in nearly a vertical direction in the thread tensioning mechanism main body 30, a magnet piece 42e for attracting the sliding piece 42c to the thread gripping member 31 of the thread tensioning mechanism 3 for moving up and down along the guide tube 34 along with the ascending and descending of the thread gripping member 31, a shoe member 42g for defining the position of the thread hook hole 42a by abutting a lever 42f placed at other end of the lever 42b, and a spring member 42h for abutting so that the roller 42f disposed at other end of the lever 42b may abut against the shoe member 42g.
As a result, the thread 11 is applied in the thread hook hole 41a of the balance 41 and the thread hook hole 42a of the sub-balance 42, and embroidery is started in a state used in a specified zigzag form.
In embroidery operation, as in conventional embroidery machinery, the balance 41 is driven reciprocally by the drive mechanism, while the sub-balance 42 is held at the waiting position at the bottom dead center.
These basic constitutions and operations are the same as in the first embodiment.
The basic constitution of the threading mechanism 6 is the same as in the first embodiment. The thread push-down mechanism 64 is comprised as shown in Fig. 37, so that the thread 11 applied to the hook member 61a may not be dislocated from the hook member 61a, by forming the front end 64f of the thread push-down piece 64a disposed oscillatably through the shaft 64c on the thread pull-out mechanism 61 in a hook form.
In the embodiment, in order that the thread 11 may be applied securely on the hook member 61a of the thread pull-out mechanism 61 of the threading mechanism 6, the thread push-down mechanism 64 is used. But it is not limited to this, as a modified example in Fig. 38 shows, air nozzles 65a, 65b may be placed beside the guide members 61b, 61b of the thread pull-out mechanism 61, and by injecting high pressure air from the air nozzles 65a, 65b downward, both sides of the thread 11 inserted into the thread insertion hole 61c of the thread pull-out mechanism 61 may be pressed down.
In the embroidery machinery of the embodiment, the same as in the embroidery machinery of the first embodiment, after passing the thread, by driving the thread selecting mechanism 29 of the thread feed device 2, the thread let-off tube 28a is moved aside by one stage (to the right) with the thread 11 being applied, so that embroidery operation can be effected.
In the application route of the thread 11, the auxiliary mechanism comprised of an upper thread clamp mechanism, a thread cutting mechanism, and a broken thread recovery mechanism 53 is placed.
Above all, the broken thread recovery mechanism 53 is for recovering the thread 11 cut off by the thread cutting mechanism when changing thread 11, and, as shown in Fig. 39 and Fig. 40, it is comprised of an operation rod 53c forming a hook 53b for hooking the thread 11 at the front end, a driving mechanism 53d of the operation rod 53c, suction tubes 53e, 53i, in which the operation rod 53c is slidably inserted, for sucking and recovering the broken thread 11, lead tubes 53f, 53g of high pressure air for producing the suction force and sending it in the suction tubes 53e, 53i, 53j, a recovery container 53h formed of a mesh for holding the recovered thread 11, located detachably at the front end of the suction tube 53j, and a driving mechanism 53k for oscillating and driving the recovery mechanism main body 53a between the waiting position and the recovery position of the thread 11, around an oscillating shaft 53m.
In the embroidery machinery of the embodiment, as in the embroidery machinery of the first embodiment, the sewing machine head 1 is provided with a cover, and this cover is provided with a lower thread clamp mechanism for clamping the thread 11, and a sensor for detecting the state of the thread 11 in the applied route of the thread 11 when the thread let-off tube 28a is moved to the embroidery position by one stage (to the right) with the thread 11 being applied.
The method of operation for the embroidery machinery of these embodiments (first embodiment and second embodiment) is described below.
First, the method of operation of the preliminary stage of embroidery is explained.
When starting embroidery operation, bobbins 21 of various colored threads are accommodated into the bobbin housing 22 of the thread feed device 2 located on or separately above the sewing machine head 1 of the embroidery machinery, the thread 1 being let off from the bobbin 21 is applied to the thread tension regulating mechanism 24 through the thread holder 23, and the end portion of the thread 11 is hung from the thread let-off tube 28a at a specified length.
The embroidery starting operation is described below.
By driving the thread selecting mechanism 29, the thread feed device 2 furnished with thread 11 is positioned selectively and accurately above the threading device 7 for threading the thread let-off tube 28a of the thread let-off motion 28 corresponding to the specified bobbin 21.
Afterwards, while supplying high pressure air from the air nozzle 28b into the thread let-off tube 28a, and by driving the belt 35 of the thread tensioning mechanism 3, the thread gripping member 31 is moved from the waiting position near the middle position to the highest position for gripping the end portion of the thread 11 hanging from the thread let-off tube 28a, and the end portion of the thread 11 is gripped by the thread gripping member 31.
While preventing resistance due to the thread tension regulating mechanism 25 from being applied to the thread 11 by the thread tension canceling mechanism 26, the thread length regulating piece 27c of the thread length regulating mechanism 27 is moved forward and the thread 11 is held at a specified length, and by driving the belt 35 of the thread tensioning mechanism 3, the thread gripping member 31 is lowered, and the end portion of the thread 11 is guided nearly to the position of the needle 10 at the threading position.
At this time, the thread 11 stretched between the thread let-off tube 38a and the position close to the needle 10 at the threading position by the thread tensioning mechanism 3 is applied on the balance 41 and sub-balance 42 of the balance mechanism 4.
Later, by clearing the thread tension canceling mechanism 26, the resistance due to the thread tension regulating mechanism 25 is applied to the thread 11, and in this state, by lowering and moving forward beforehand, the thread 11 gripped by the thread gripping member 31 of the thread tensioning mechanism 3 is inserted into the thread insertion hole 61c of the guide member 61b of the thread pull-out mechanism 61, with the front end of the hook member 61a penetrating into the needle hole 10a of the needle 10, by feeding high pressure air from the air nozzle 63 found in the thread gripping member 31 toward the thread pull-out mechanism 61, and the thread length regulating piece 27c of the thread length regulating mechanism 27 is moved back so that the held thread 11 may be unwound, and gripping of the thread 11 by the thread gripping member 31 is cleared, and the thread 11 at a specified length held by the thread length regulating mechanism 27 is inserted into the thread insertion hole 61c of the guide member 61b of the thread pull-out mechanism 61.
After stopping supply of high pressure air from the air nozzle 63, the thread pull-out mechanism 61 is moved back, and the thread push-down piece 64a is oscillated in a direction to shield the thread insertion hole 61c, and both ends of the thread 11 inserted into the thread insertion hole 61c are pushed down along the side surface of the guide member 61b, and therefore, the thread 11 inserted into the thread insertion hole 61c is accurately applied on the hook member 61a of the thread pull-out mechanism 61, and the thread pull-out mechanism 61 is moved back, so that the thread is passed by pulling out the hook member 61a from the needle hole 10a.
In this case, by driving the thread selecting mechanism 29 of the thread feed device 2 with proper timing, the thread let-off tube 28a is moved aside by one stage (to the right) with the thread 11 being applied.
Then, by driving the belt 35 of the thread tensioning mechanism 3, the thread gripping member 31 is returned to the waiting position near the middle position, and embroidery operation is started.
Upon start of embroidery operation, by temporarily clamping the thread 11 with the lower thread clamp mechanism 81, letting-off of the thread 11 below the lower thread clamp mechanism 81 is prevented, and the end portion of the thread 11 is prevented from coming out to the surface of the embroidery cloth.
After this step, clamping of the thread 11 by the lower thread clamp mechanism 81 is cleared, and embroidery is started.
When changing the thread 11, the thread 11 is clamped by the upper thread clamp mechanism 51 to prevent more from being let off from the bobbin 21, and the thread 11 is applied to the hook 53b formed at the front end of the operation rod 53c of the broken thread recovery mechanism 53, and beneath the throat plate and in the thread cutting mechanism 52, the thread 11 is cut off before and after, and broken thread 11 is recovered in the recovery container 53h through the suction pipe 53e of the broken thread recovery mechanism 53.
Similarly, hereinafter, threading and embroidery processes are repeated.

Industrial Applicability

According to the threading device for embroidery machinery of the invention, processing when changing the colored thread, or when the thread is broken, can be done automatically without manual work, and the time required for such a process can be shortened, and hence the operating rate and productivity of the sewing machine can be enhanced, and it is particularly apt for embroidery machinery in which multiple colored threads are frequently changed.

Claims

A threading device for embroidery machinery comprising a thread gripping member for gripping the end portion of a thread hanging from a thread let-off tube, a thread tensioning mechanism for leading the thread gripped by the thread gripping member to a position close to a needle and applying the stretched thread on a balance mechanism, and a threading mechanism for guiding the thread into the needle hole.
A threading device for embroidery machinery of claim 1, wherein the threading mechanism is comprised of a thread pull-out mechanism comprising a hook member formed like a hook at the front end, and a guide member forming a thread insertion hole and a thread release groove, disposed at both sides of the hook member, and an air nozzle for sending the thread gripped by the thread gripping member into the thread insertion hole formed in the guide member of the thread pull-out mechanism.
A threading device for embroidery machinery of claims 1 or 2, further comprised a thread push-down mechanism for pushing down both ends of the thread inserted into the thread insertion hole formed in the guide member of the threading mechanism along the side surface of the guide member.