CN112442809A

CN112442809A - Thread cutting device of small-head-distance embroidery machine

Info

Publication number: CN112442809A
Application number: CN202011563592.XA
Authority: CN
Inventors: 陈天龙; 方狄永; 陈斌
Original assignee: Zhejiang Pumeike Intelligent Embroidery Equipment Co ltd
Current assignee: Zhejiang Pumeike Intelligent Embroidery Equipment Co ltd
Priority date: 2020-12-25
Filing date: 2020-12-25
Publication date: 2021-03-05

Abstract

A thread trimming device of a small-head-distance embroidery machine belongs to the technical field of embroidery machines. The device comprises a movable knife, a fixed knife and a movable knife driving mechanism; the movable knife and the fixed knife are arranged at the bottom of a needle plate of the embroidery machine, the movable knife and the fixed knife are respectively arranged at two sides of a needle plate hole and at two sides of the Y axis of the embroidery machine in the positive and negative directions, and the movable knife driving mechanism is arranged on a shuttle bed; the movable blade shearing line end of the movable blade is provided with a downward inclined surface, the inclined surface is provided with a groove, the front end of the movable blade shearing line end is provided with a notch for forming a movable blade shearing line end, and the other side of the groove far away from the movable blade shearing line end is provided with a movable blade cutting edge; the bottom of the fixed cutter shearing end of the fixed cutter is provided with a fixed cutter blade; the movable cutter driving mechanism drives the movable cutter to do linear motion towards the fixed cutter, and when the movable cutter moves, the end head of the cutting line of the movable cutter forks a bottom line and a facial line to be cut and continues to move towards the fixed cutter until the movable cutter and the fixed cutter coincide, the cutting edge of the movable cutter and the cutting edge of the fixed cutter act together to cut the bottom line and the facial line. The invention has the advantages of simple and convenient trimming, high trimming reliability and convenient disassembly, assembly and maintenance.

Description

Thread cutting device of small-head-distance embroidery machine

Technical Field

The invention belongs to the technical field of embroidery machines, and particularly relates to a thread trimming device of a small-head-distance embroidery machine.

Background

At present, in the industry of embroidery machines, when an embroidery finishes one graphic unit and begins to embroider another graphic unit, the upper thread and the bottom thread below a cloth cover need to be subjected to thread cutting treatment. The existing embroidery machine structure comprises an embroidery machine head, a thread buckling device and a thread cutting device, wherein the thread cutting device is used for cutting threads. Specifically, an upper thread driven by a needle of the embroidery machine penetrates through a cloth cover and is hooked by a rotating shuttle and is divided into a front strand and a rear strand, the front strand and the rear strand form a coil, a bottom thread in the rotating shuttle is wrapped by the rotating shuttle, after knotting is completed, one upper thread and the bottom thread are cut off by scissors, and a thread head formed by the cut upper thread and the bottom thread is positioned below the cloth cover.

The existing thread trimming device of the embroidery machine comprises a movable cutter, a fixed cutter and a movable cutter driving mechanism. Thread trimming devices are divided into two categories: adopt branching structure and do not adopt the trimming device of branching structure. The thread cutting device adopting the thread dividing structure is generally provided with a thread taking hook, a thread dividing hook and other similar structures on a movable cutter, when the movable cutter is opened, the thread dividing is firstly carried out, a facial thread at the rear side of a rotating shuttle is hooked and then pushed to one side of the opening direction of the thread cutting knife, meanwhile, the facial thread is fixed into a triangle-like coil by utilizing a thread buckling device, and finally, a bottom thread and a left facial thread are hooked and cut. Besides, the thread cutting device is also provided with an independent thread separating structure. The thread cutting device can be used for the small-head-distance embroidery machine, but the thread cutting device needs to realize thread cutting through dynamic cooperation between machines, has a complex process, and needs to cut threads after thread separation and hooking. Also, the possibility of thread separation failure is high, and particularly when the tension of the upper thread is not large enough, the two strands of upper threads are difficult to smoothly separate. In addition, the bottom thread cut by the existing thread cutting device is easy to hang on the rotating shuttle, and when the rotating shuttle idles, the bottom thread is easy to wind on the rotating shuttle, so that the loop of the upper thread is influenced. The thread cutting device without the thread separating structure generally comprises the following components: A. the upper thread is fixed by the thread-fastening device into a triangle-like coil, and the bottom thread is positioned in the middle of the triangle-like coil, and the coil can be divided into a left waist line segment, a right waist line segment and a bottom line segment. The upper thread can be divided into a part to be cut (namely a left waist line segment) which can be hooked by the thread cutter and can be hooked by the thread hooking cutter and sent to the thread clamp part (namely a right waist line segment) by the thread buckling device. Firstly, the upper thread and the bottom thread of the left waist line segment are hooked after penetrating from the middle of the upper thread and the bottom thread of the right waist line segment. The thread cutting device generally realizes thread cutting by the circular motion of the movable cutter towards the fixed cutter, the movable cutter and the fixed cutter are often arranged on the rotating shuttle box and positioned below the needle plate, the axis of the cutter bar of the movable cutter driving mechanism is superposed with the circle center of the motion track of the movable cutter, and the movable cutter shaft is arranged near the formation plane of the triangular thread loop to hook threads most stably. Generally, the thread cutting device is suitable for a large-head-distance embroidery machine, the small-head-distance embroidery machine cannot adopt the thread cutting device due to small space, and space interference exists. B. The bottom thread is hooked out first, the upper thread is fixed into a triangle-like coil by the thread-buckling device, and then the upper thread of the left waist line segment is hooked. Although the thread trimming device of the scheme B can be used for a small-head-distance embroidery machine, the thread trimming process needs two steps of thread hooking actions and then thread trimming, and the thread trimming process is complex and depends on dynamic cooperation between machines.

The utility model patent CN201071451Y discloses an embroidery machine thread trimmer devices to specifically disclose the device including setting up on the faller of embroidery machine, the device moves the sword drive by moving sword, stationary knife and control and constitutes, moves the sword and sets up in the same sword subassembly that moves that sets up on the faller with the stationary knife, moves the sword and can be in with the stationary knife and overlap under the control that moves sword actuating mechanism, still is equipped with a thread catcher that pushes down the end of a thread at moving sword collude line, trimming in-process on the faller. When the needle changing or sewing is finished, the embroidery machine control system sends a signal to drive the thread changing connecting rod, and the moving knife extends out of the sliding guide rail along the sliding groove in the sliding guide rail under the driving of the thread changing connecting rod and moves towards the embroidery thread direction. The tip arranged at the end part of the movable knife enables the embroidery thread to move along two bevel edges of the tip, so that the embroidery thread falls into the reverse hook smoothly. And at the same time, the control system sends a signal to drive the electromagnet, and the electromagnet drives the iron core to move. The crescent plate is driven by the iron core hinged with the crescent plate to rotate by taking the torsion spring as a center, the other end of the crescent plate drives the line catching device to move through the fixing pin clamped in the groove, the line catching device moves towards the needle hole plate 2 direction and presses the bottom line, at the moment, the relative distance between the two feet of the torsion spring is reduced, and the restoring elasticity is stored in the torsion spring. And then, the thread changing connecting rod enables the movable knife to hook the embroidery thread and move towards the direction of the fixed knife under the action of the motor, and the embroidery thread is cut off when the cutting surface of the movable knife is in contact with the front surface of the fixed knife. After the trimming is finished, the electromagnet stops being electrified, under the action of the restoring elasticity of the torsion spring, the crescent plate and the electromagnet iron core are restored to the original state, the wire catching end of the wire catching device presses the bottom wire end to restore to the original position, and the next trimming is waited to start. In the whole thread trimming process, the thread catcher always presses the thread end of the bottom thread, so that the next sewing action can be started conveniently. The movable knife and the fixed knife of the device are distributed on the same side of the needle plate, and the movable knife needs to extend out of the hook wire and then returns to move to the side of the fixed knife to be cut off. The moving knife of the device has a complex structure, and the trimming is completed by matching the line catcher, so that the trimming process is complex.

Disclosure of Invention

Aiming at the problems in the prior art, the invention provides the thread cutting device of the embroidery machine, which is simple and convenient in thread cutting, high in thread cutting reliability and convenient to disassemble, assemble and maintain.

The invention is realized by the following technical scheme:

a thread cutting device of a small-head-distance embroidery machine comprises a movable knife, a fixed knife and a movable knife driving mechanism; the movable knife and the fixed knife are arranged at the bottom of a needle plate of the embroidery machine, the movable knife and the fixed knife are respectively arranged at two sides of a needle plate hole and at two sides of the Y axis of the embroidery machine in the positive and negative directions, and the movable knife driving mechanism is arranged on a shuttle bed; the movable knife is provided with a downward inclined surface facing the movable knife trimming end of the fixed knife, the inclined surface is provided with a groove, the front end of the movable knife trimming end is provided with a notch for forming a movable knife trimming end, and the other side of the groove far away from the movable knife trimming end is provided with a movable knife blade; the bottom of the fixed knife facing the fixed knife shearing end of the movable knife is provided with a fixed knife blade; the movable cutter driving mechanism drives the movable cutter to move towards the fixed cutter, the end head of the movable cutter shearing wire of the movable cutter forks a bottom wire and a facial line to be sheared and continues to move towards the fixed cutter during movement, and the movable cutter cutting edge and the fixed cutter cutting edge act together to shear the bottom wire and the facial line until the movable cutter is overlapped with the fixed cutter.

Generally, an embroidery machine includes a plurality of heads, and those skilled in the art will define a direction in which the plurality of heads are located as an X-axis direction of the embroidery machine, and a direction perpendicular to the X-axis direction as a Y-axis direction. The positive direction of the Y axis is the same as the direction of the front surface of the machine needle (namely the direction facing the machine station operator), and the negative direction of the Y axis is the same as the direction of the back surface of the machine needle (namely the front of the machine station operator). The positive direction of the X axis is the right direction of the machine station operator, and the negative direction of the X axis is the left direction of the machine station operator.

The movable knife and the fixed knife of the thread cutting device are arranged at the bottom of the needle plate of the embroidery machine, and when the needle plate is dismounted, the movable knife and the fixed knife can be dismounted together, so that the thread cutting device is convenient to dismount, mount and maintain. The movable knife and the fixed knife of the thread shearing device are respectively arranged on two sides of a needle plate hole (for example, the movable knife is positioned in the negative direction of a Y axis, and the fixed knife is positioned in the positive direction of the Y axis, and for example, the movable knife is positioned in the positive direction of the Y axis, and the fixed knife is positioned in the negative direction of the Y axis), so that the step that the movable knife firstly extends out to hook a thread to be sheared when the movable knife and the fixed knife are on the same side is omitted. The invention is mainly completed by the intersection of the cutting edges of the movable cutters and the fixed cutters which are positioned at the two sides of the needle plate hole, and the movable cutters or the fixed cutters have structures which extend to opposite directions and are also in the protection scope of the patent. The positive and negative directions of the Y axis of the embroidery machine limited by the invention cover the positive direction area of the Y axis and the negative direction area of the Y axis, namely the straight line motion track of the movable knife towards the fixed knife is not limited to be parallel to the Y axis (including the conditions of being coincident or parallel with the Y axis of the needle plate hole center and the like), and can also be intersected.

Referring to fig. 1, fig. 1 shows three cases a, b, and c (marked at the axis of the knife bar of the moving knife driving mechanism). The situation a is a schematic diagram of the thread cutting principle of a thread cutting device on the embroidery machine with a large head distance, wherein the thread cutting device is positioned outside the outer diameter range of the rotating shuttle. The movable knife is arranged on a knife bar of the movable knife driving mechanism, namely the circle center of the motion track of the movable knife is superposed with the axis of the knife bar, and the dotted line in the figure is the swing track of the knife bar and the motion track of the movable knife. The case a corresponds to the thread trimming apparatus in the background art a. As can be seen from the drawing, the optimal angle of penetration from the upper thread and the lower thread of the right waist thread segment should be as perpendicular as possible to the X-axis direction of the embroidery machine. For a small-head embroidery machine, the thread cutting device cannot work normally in a limited space, and mechanical space interference exists. The situation b is a schematic diagram of the thread cutting principle of a thread cutting device on the small-head-distance embroidery machine, wherein the thread cutting device is positioned in the outer diameter range of the rotating shuttle. The movable knife is arranged on a knife bar of the movable knife driving mechanism, namely the circle center of the motion track of the movable knife is superposed with the axis of the knife bar, and the dotted line in the figure is the swing track of the knife bar and the motion track of the movable knife. The case B corresponds to the thread trimming device with the thread dividing structure and the thread trimming device B in the background art. Although the two thread cutting devices can be suitable for the small-head-distance embroidery machine, the thread cutting devices rely on the mechanical dynamic matching of the embroidery machine, and the thread dividing scheme has the problem of low reliability. Case c is a schematic view of the thread cutting principle of the thread cutting device of the present invention on a small-head embroidery machine, the thread cutting device being located within the range of the outer diameter of the rotating shuttle. The moving knife and the knife bar of the moving knife driving mechanism are separated, the moving path of the moving knife is a linear path, the bottom surface line to be cut can be forked at the optimal angle, and the knife bar has an independent moving path. The invention can realize the forking and cutting of the bottom surface thread to be cut in the process that the movable cutter moves towards the fixed cutter, and has simple realization process and high reliability. The principle analysis is described based on the moving blade driving mechanism in the form of a cutter bar, but the thread cutting device of the present invention is not limited to the moving blade driving mechanism in the form of a cutter bar.

In addition, compared with the existing thread cutting structure, the upper thread and the bottom thread which are cut off by the existing thread cutting device are positioned on the inner side of the rotating shuttle and are easy to wind into the rotating shuttle when the rotating shuttle idles, and the upper thread and the bottom thread which are cut off by the existing thread cutting device are positioned on the outer side of the rotating shuttle and do not interfere with the rotating shuttle to idle.

Preferably, the groove wall of the groove at the end of the other side of the groove far away from the end of the movable blade trimming line and the inclined surface form a movable blade edge.

Preferably, a concave hole or a through hole is formed in the groove bottom at the tail end of the other side, far away from the end of the movable blade trimming line, of the groove, and the movable blade cutting edge is formed by the hole wall of the concave hole and the inclined surface or the movable blade cutting edge is formed by the hole wall of the through hole and the inclined surface.

Preferably, the front end of the fixed cutter thread cutting end is provided with an extension part extending towards the movable cutter direction, so that the cutting edge of the fixed cutter is retracted in the extension part.

Preferably, the movable knife is provided with a sliding chute; the swing arm of the movable cutter driving mechanism slides in the sliding groove to drive the movable cutter to move.

Preferably, the embroidery machine thread cutting device further comprises a first base mounted at the bottom of the embroidery machine needle plate; the first base is used for supporting the movable knife when the movable knife and the fixed knife are overlapped, so that the cutting edge of the movable knife and the cutting edge of the fixed knife can interact to cut off a bottom thread and an upper thread.

Preferably, the first base is an elastic member; or an elastic part is arranged in the first base and acts on the movable knife.

Preferably, the thread trimming device of the embroidery machine further comprises a second base or a third base which is arranged at the bottom of the needle plate of the embroidery machine, the movable knife penetrates through the second base or the third base, and the movable knife driving mechanism drives the movable knife to move along the guide direction of the second base or the third base; the moving knife driving mechanism drives the moving knife to move along the guide direction of the second base or the third base.

Preferably, the thread trimming device of the embroidery machine further comprises a second base and a third base which are arranged at the bottom of the needle plate of the embroidery machine, the movable cutter penetrates through the second base and the third base, and the second base and the third base are used for guiding the moving direction of the movable cutter; or the movable knife device also comprises a second base or a third base arranged at the bottom of the needle plate of the embroidery machine, and a third base or a second base arranged on the shuttle bed, wherein the movable knife passes through the second base and the third base, and the second base and the third base are used for guiding the moving direction of the movable knife; or the movable knife also comprises a second base or a third base which is partially arranged at the bottom of the embroidery machine needle plate and partially arranged on the shuttle bed, and a third base or a second base which is arranged at the bottom of the embroidery machine needle plate, wherein the movable knife penetrates through the second base and the third base, and the second base and the third base are used for guiding the moving direction of the movable knife; or the movable knife also comprises a second base or a third base which is partially arranged at the bottom of the needle plate of the embroidery machine and partially arranged on the shuttle bed, and a third base or a second base arranged on the shuttle bed, wherein the movable knife penetrates through the second base and the third base, and the second base and the third base are used for guiding the moving direction of the movable knife.

Preferably, the fixed knife is installed at the bottom of the needle plate of the embroidery machine through a fixed block; or the fixed knife is directly arranged at the bottom of the needle plate or on the shuttle bed of the embroidery machine; or the fixed knife is arranged on the shuttle bed through a bracket.

Preferably, the moving blade driving mechanism comprises a cutter bar, a swing arm and a rotating shaft connecting rod; the cutter arbor is vertical to be located on the shuttle bed, the lower extreme of cutter arbor is connected the pivot connecting rod, swing arm one end is connected to the upper end of cutter arbor, and the swing arm other end has the driving piece, and when the cutter arbor drove the swing arm swing, the driving piece drove the sword motion.

Preferably, the thread cutting device of the embroidery machine further comprises a second base and a third base which are arranged at the bottom of the needle plate of the embroidery machine, the second base is positioned at the front end of the swing arm in the swing direction, the third base is positioned at the rear end of the swing arm in the swing direction, and the movable blade penetrates through the second base and the third base; or the swing arm device also comprises a guide rail arranged at the bottom of the needle plate, the guide rail is provided with a space allowing the swing arm to swing, the guide rail extends from the front end of the swing arm in the swing direction to the rear end of the swing arm in the swing direction, and the movable knife penetrates through the guide rail.

Preferably, the linear track of the linear motion of the movable knife towards the fixed knife is parallel to the Y-axis of the embroidery machine where the needle plate hole is located, or the linear track of the linear motion of the movable knife towards the fixed knife is intersected with the Y-axis of the embroidery machine where the needle plate hole is located.

Preferably, the fixed knife is arranged at the bottom of the embroidery machine needle plate in front of the embroidery machine rotating shuttle; the moving knife is arranged at the bottom of the embroidery machine needle plate above the rotating shuttle of the embroidery machine.

Preferably, when the moving blade driving mechanism drives the moving blade to make linear motion towards the fixed blade and change the linear motion into circular motion, the axis of the cutter bar is not overlapped with the center of the moving track of the moving blade.

In the case of the circular arc variant, the above-described preferred variant is equally applicable.

The invention has the following beneficial effects:

the utility model provides a small-head-range embroidery machine thread trimming device, utilizes and moves the sword towards the stationary knife motion process, once accomplishes the acquisition of waiting to cut bottom line and upper thread and bottom line cuts, and the thread trimming is high-efficient, convenient, and the thread trimming reliability is high.

Drawings

Fig. 1 is a schematic view illustrating a thread cutting principle of a thread cutting apparatus of an existing embroidery machine and a thread cutting apparatus according to the present invention;

FIG. 2 is a schematic perspective view illustrating a thread trimming apparatus (installed in an embroidery machine) of the small-pitch embroidery machine according to the present invention; wherein, the embroidery machine is provided with a machine head;

fig. 3 is a side view of a thread trimmer (installed on an embroidery machine) of a small-pitch embroidery machine according to the present invention;

FIG. 4 is a schematic structural view illustrating a thread trimming device of a small-pitch embroidery machine according to the present invention mounted on a needle plate of the embroidery machine;

FIG. 5 is a three-dimensional structure view of the thread trimming device and the rotating shuttle of the small-pitch embroidery machine of the present invention;

FIG. 6 is a side view of the thread trimmer assembly of the small head distance embroidery machine in cooperation with the rotary hook of the present invention;

FIG. 7 is a schematic structural view of a stationary knife in the thread cutting device of the small-head-distance embroidery machine according to the present invention;

FIG. 8 is a schematic structural view of a movable knife in the thread cutting device of the small-head-distance embroidery machine according to the invention;

FIG. 9 is a schematic structural view illustrating an embodiment of a thread trimming apparatus of a small-pitch embroidery machine according to the present invention;

FIG. 10 is a schematic structural view illustrating another embodiment of a thread cutting apparatus of a small-pitch embroidery machine according to the present invention;

fig. 11 is a schematic structural view of an embodiment of the thread trimmer of the small-head-distance embroidery machine in which a movable knife is engaged with a swing arm according to the invention.

Detailed Description

The following are specific embodiments of the present invention and are further described with reference to the drawings, but the present invention is not limited to these embodiments.

Referring to fig. 2 to 6, a thread cutting device of a small-head-distance embroidery machine comprises a movable knife 10, a fixed knife 20 and a movable knife driving mechanism. The movable knife 10 and the fixed knife 20 are arranged at the bottom of a needle plate 1 of the embroidery machine, the movable knife 10 and the fixed knife 20 are respectively arranged at two sides of a needle plate hole and at two sides of a Y-axis of the embroidery machine in the positive and negative directions, and the movable knife driving mechanism is arranged on a shuttle race 2. In one embodiment, the movable blade 10 may be disposed on a needle plate hole on the negative Y-axis side of the embroidery machine, and the fixed blade 20 may be disposed on a needle plate hole on the positive Y-axis side of the embroidery machine (see fig. 3, 9, and 10). That is, the fixed knife is provided at the bottom of the embroidery machine needle plate in front of the embroidery machine rotating shuttle 7, and the movable knife is provided at the bottom of the embroidery machine needle plate above the embroidery machine rotating shuttle 7. In another embodiment, the movable blade 10 may be disposed on a needle plate hole on the positive side of the Y-axis of the embroidery machine, and the fixed blade 20 may be disposed on a needle plate hole on the negative side of the Y-axis of the embroidery machine. The description will be given mainly by taking the former embodiment as an example, and the structure and the mounting method designed in the former embodiment are also applicable to the latter embodiment.

As shown in fig. 2-8, the movable blade 10 has a downwardly inclined surface 11 at the cutting end of the movable blade facing the stationary blade 20, and the inclined surface 11 is provided with a groove 111. Therefore, when the movable cutter moves towards the fixed cutter, the bottom thread and the upper thread to be cut are gathered in the groove, and the groove leaves a space for embroidery thread, so that the embroidery thread has an extension space in the groove and cannot be tightened, and the embroidery thread is prevented from cutting sections in advance after the movable cutter is contacted with the fixed cutter; in addition, the inclined surface can prevent the cutting edge of the fixed knife from pushing the embroidery thread to directly rub and break. In order to control the lengths of the cut bottom thread and the upper thread to be consistent, the length should not be too long, and should not be too short, the embroidery thread needs to be cut when the cutting edge of the fixed knife is intersected with the cutting edge of the movable knife, but not to be cut in advance when the cutting edge of the movable knife moves towards the cutting edge of the fixed knife (namely, when the cutting edge of the movable knife is not intersected), and the structural design is needed.

The front end of the movable blade trimming end is provided with a notch 12 for forming the movable blade trimming end, and the notch can be a U-shaped notch, a V-shaped notch or an arc notch. The front end of the movable blade thread cutting end is divided into two movable blade thread cutting ends by the notch 12, so that one movable blade thread cutting end is used for forking the bottom thread, and the other movable blade thread cutting end is used for forking the upper thread (left waist line segment). The invention is not limited to the two movable blade thread trimming ends, and can also adopt wave-shaped or a plurality of U-shaped or V-shaped or circular arc-shaped notches, so that three movable blade thread trimming ends are generated, wherein the two movable blade thread trimming ends are used for forking the bottom thread and the upper thread (left waist line segment), and one movable blade thread trimming end is used for separating the upper thread (right waist line segment) from the part to be trimmed.

The groove 111 is provided with a movable blade cutting edge at the other side far away from the movable blade trimming end. Specifically, the groove wall of the groove 111 at the end of the other side thereof away from the end of the movable blade trimming line and the inclined surface 11 form a movable blade edge. In order to further improve the sharpness of the cutting edge, a concave hole 112 or a through hole 112 is formed in the groove 111 at the bottom of the tail end of the other side of the groove, which is far away from the end of the movable blade trimming line, and the hole wall of the concave hole and the inclined surface form a movable blade cutting edge, or the hole wall of the through hole and the inclined surface form a movable blade cutting edge. Preferably, the through hole or the concave hole is an inclined hole to promote the blade edge of the movable blade to be sharper. The bottom of the fixed knife 20 facing the fixed knife line cutting end of the movable knife 10 is provided with a fixed knife blade. And (3) welding the raw material of the fixed cutter blade to the bottom of the fixed cutter, and grinding to obtain the fixed cutter blade. In one embodiment, the front end of the fixed-blade line-cutting end is flush with the front end of the fixed-blade cutting edge 201. In another embodiment, the front end of the fixed-blade line cutting end has an extension 202 extending toward the moving blade direction, so that the fixed-blade 201 is retracted into the extension 202. In the former embodiment, when the embroidery thread is stretched between the fixed knife edge and the cutting end of the fixed knife before the cutting edge of the movable knife intersects with the cutting edge of the fixed knife, the embroidery thread is cut off or the embroidery thread is cut. In the latter embodiment, due to the existence of the extension part, the extension part prevents the embroidery thread from contacting with the cutting edge of the fixed knife in advance, so that the embroidery thread is not tightened on the cutting edge of the fixed knife in advance to cut hair or cut the embroidery thread. Meanwhile, in the latter embodiment, it is also necessary to note that the extension portion is not too long, the too long extension portion will contact with the cutting edge of the moving knife first, and tension exists between the extension portion and the cutting edge of the moving knife in the process that the moving knife moves towards the fixed knife, so that the cutting edge of the moving knife cuts the embroidery thread in advance. The movable cutter driving mechanism drives the movable cutter to move towards the fixed cutter, the end head of the movable cutter shearing wire of the movable cutter forks a bottom wire and a facial line to be sheared and continues to move towards the fixed cutter during movement, and the movable cutter cutting edge and the fixed cutter cutting edge act together to shear the bottom wire and the facial line until the movable cutter is overlapped with the fixed cutter. In addition, the front end of the fixed cutter line shearing end can be a plane or a concave surface, so that embroidery threads can be conveniently gathered at the cutting edge when the front end of the fixed cutter line shearing end with the concave surface is adopted.

The fixed knife and the movable knife can cut off the bottom thread and the upper thread, and the tension action between the fixed knife and the movable knife is mainly relied on when the fixed knife and the movable knife are intersected. In one embodiment, at least one of the fixed blade and the movable blade is designed to have an elastically deformable function. When only the fixed knife has the elastic deformation function design, when the movable knife moves to the intersection position towards the fixed knife, the self deformation of the fixed knife provides tension for cutting the embroidery thread, so that the thread cutting device can smoothly cut the embroidery thread. When only the movable knife has the elastic deformation function design, when the movable knife moves to the intersection position towards the fixed knife, the deformation of the movable knife provides tension for cutting the embroidery thread, so that the thread cutting device can smoothly cut the embroidery thread. Similarly, when both have the function design of elastic deformation, both provide the tension required for cutting the embroidery thread when they intersect. In another embodiment, the thread cutting apparatus of the embroidery machine of the present invention further comprises a first base 3 installed at the bottom of the needle plate of the embroidery machine. The first base 3 is used for supporting the movable knife when the movable knife and the fixed knife are overlapped, so that the cutting edge of the movable knife and the cutting edge of the fixed knife can interact to cut off the bottom thread and the upper thread. The first base 3 is a base with a U-shaped structure or a base with a square-shaped structure, and is fixed at the bottom of a needle plate of the embroidery machine through a fastener (such as a bolt). Wherein the first base is an elastic component; or an elastic part is arranged in the first base and acts on the movable knife. Because the first base is used for supporting the movable knife, the first base with elastic deformation capability provides tension for cutting the embroidery threads, so that the thread cutting device can smoothly cut the embroidery threads. In another embodiment, at least one of the fixed blade and the movable blade may be designed to have an elastically deformable function and may be provided as a first base of an elastic member or a first base provided with an elastic member. I.e. a combination of the two embodiments described above.

The thread cutting device of the small-head-distance embroidery machine is also provided with a structure for positioning and guiding the moving direction of the movable cutter. In one embodiment, the thread cutting device of the embroidery machine further comprises a second base 4 or a third base 5 which is installed at the bottom 1 of the needle plate of the embroidery machine, the movable knife penetrates through the second base 4 or the third base 5, and the swing arm of the movable knife driving mechanism drives the movable knife to move along the guiding direction of the second base 4 or the third base 5. The second base is arranged at the front end of the driving mechanism in the direction that the driving mechanism drives the movable knife to move towards the fixed knife; the third base is arranged at the rear end of the driving mechanism in the direction that the movable knife is driven by the driving mechanism to move towards the fixed knife. Thus, the moving blade driving mechanism (when the moving blade driving mechanism comprises a swing arm, the swing arm is used) is combined with a certain base to realize the guiding of the moving blade. In an embodiment, the thread cutting device of the embroidery machine further comprises a second base 4 or a third base 5 which is installed on the shuttle machine, the movable knife penetrates through the second base 4 or the third base 5, and the swing arm of the movable knife driving mechanism drives the movable knife to move along the guiding direction of the second base 4 or the third base 5. In another embodiment (see fig. 4), the embroidery machine thread cutting device of the invention further comprises a second base 4 and a third base 5 which are installed at the bottom of the embroidery machine needle plate 1, and the movable knife passes through the second base 4 and the third base 5, the second base 4 and the third base 5 are used for guiding the moving direction of the movable knife; or, the thread trimming device of the embroidery machine further comprises a second base 4 or a third base 5 arranged at the bottom of the needle plate 1 of the embroidery machine, and a third base 5 or a second base 4 arranged on the shuttle race 2, wherein the movable knife 10 passes through the second base 4 and the third base 5, and the second base 4 and the third base 5 are used for guiding the moving direction of the movable knife; or, the embroidery machine thread cutting device of the invention also comprises a second base 4 or a third base 5 which is partially arranged at the bottom of the embroidery machine needle plate 1 and partially arranged on the shuttle race 2, and the third base 5 or the second base 4 arranged at the bottom of the embroidery machine needle plate 1, wherein the moving blade penetrates through the second base 4 and the third base 5, and the second base 4 and the third base 5 are used for guiding the moving direction of the moving blade; or, the embroidery machine thread cutting device of the invention further comprises a second base 4 or a third base 5 which is partially arranged at the bottom of the embroidery machine needle plate 1 and partially arranged on the shuttle race 2, and the third base 5 or the second base 4 arranged on the shuttle race 2, wherein the movable knife penetrates through the second base 4 and the third base 5, and the second base 4 and the third base 5 are used for guiding the moving direction of the movable knife.

The first base 3 and the second base 4 both adopt bases with the same specification, so that the levelness of the moving knife and the fixed knife when the moving knife and the fixed knife are intersected are at the same height. Or, the first base 3, the second base 4 and the third base 5 all adopt bases with the same specification, so that the levelness of the moving knife and the levelness of the moving knife when the moving knife is intersected with the fixed knife are at the same height. Or, the first base 3 and the third base 5 both adopt bases with the same specification, so that the levelness of the moving blade and the fixed blade when the moving blade and the fixed blade are intersected are at the same height.

The movable blade guide may be arranged in a linear direction. In an embodiment (as shown in fig. 9), the movable knife is designed to be a straight-bar structure, the fixed knife and the movable knife are arranged on the same straight line, the straight line track of the linear motion of the movable knife towards the fixed knife is parallel to the axis of the Y axis of the embroidery machine where the needle plate hole is located, that is, the fixed knife and the movable knife are linearly distributed along the Y axis of the embroidery machine, and at this time, the second base 4 and the third base 5 are both arranged in the length direction of the movable knife, so that the thread cutting process of the linear motion of the movable knife towards the fixed knife can be realized. In another embodiment, the movable knife is designed to be a straight strip type structure, the straight line track of the straight line motion of the movable knife towards the fixed knife is intersected with the Y-axis of the embroidery machine where the needle plate hole is located, namely the movable knife is obliquely arranged, the second base 4 and the third base are both arranged in the length direction of the movable knife, and the thread cutting process of the oblique line motion of the movable knife towards the fixed knife can be realized. In addition, the movable knife can be guided and arranged in the arc direction, in another embodiment (as shown in fig. 10), the movable knife is designed to be of an arc structure, the arc track of the arc motion of the movable knife towards the fixed knife is intersected with the axis of the Y axis of the embroidery machine where the needle plate hole is located, the fixed knife is arranged at one end of the arc of the movable knife, and at the moment, the second base 4 and the third base 5 are both arranged in the arc direction of the movable knife, so that the thread cutting process of the arc motion of the movable knife towards the fixed knife can be realized. In this embodiment, the center of the moving path of the moving blade does not coincide with the axis of the knife bar of the moving blade driving mechanism (when the coincidence scheme is adopted, the bottom line to be cut cannot be obtained according to the optimal angle, specifically referring to the case c in fig. 1 and its related content analysis). The three embodiments can be applied to the embroidery machine with small head distance (such as the head distance is less than 60 cm).

In one embodiment, the fixed knife may be installed at the bottom of the needle plate of the embroidery machine by a fixing block 6. Under this embodiment, can ensure that the degree of cooperation is more unified between stationary knife and the moving sword. In another embodiment, the stationary knife may be mounted on the shuttle bed by a bracket. In another embodiment, the fixed knife may be directly installed at the bottom of the needle plate of the embroidery machine. In another embodiment, the stationary knife may be mounted directly on the shuttle bed. The above-mentioned mode all is applicable to the stationary knife installation scheme that is located Y axle negative direction or Y axle positive direction.

As shown in fig. 2-6, the moving blade driving mechanism includes a blade bar 31, a swing arm 32, and a rotating shaft connecting rod 33. The cutter arbor 31 is vertically arranged on the shuttle race 2, the lower end of the cutter arbor 31 is connected with the rotating shaft connecting rod 33, the upper end of the cutter arbor 31 is connected with one end of the swing arm 32, the other end of the swing arm 32 is provided with a driving piece, and when the cutter arbor 31 drives the swing arm 32 to swing, the driving piece drives the movable cutter to move. The drive member may be a pin, ball, bearing, pin, or the like. Correspondingly, the moving blade 10 is provided with a sliding slot 101 (as shown in fig. 7), and the driving member slides in the sliding slot to drive the moving blade to move. On the contrary (as shown in fig. 11), the swing arm is provided with a sliding groove, and the movable knife is provided with a driving piece, such as a pin, a ball, a bearing and the like. The driving piece 01 on the movable knife slides in the sliding groove 02 on the swing arm, and the swing arm drives the movable knife to move. Further, the movable knife driving mechanism further comprises a mounting plate for mounting the knife bar 31, or the shuttle bed is provided with a knife bar mounting platform. The invention is not limited to the above moving blade driving mechanism, and the moving blade driving mechanism may also adopt other driving mechanisms which can drive the moving blade to move towards the fixed blade, such as an air cylinder driving mechanism or a motor driving mechanism. The movable knife driving mechanism can be arranged on the front side of the shuttle race, also can be arranged on the rear side of the shuttle race, and also can be arranged at the bottom of the needle plate. The invention is not limited to the moving blade driving mechanism, and the moving blade driving mechanism can adopt a shifting fork structure to realize moving blade driving or can also adopt a driving shaft structure to realize moving blade driving.

The small-head-distance embroidery machine thread cutting device further comprises a second base 4 and a third base 5 which are arranged at the bottom of the needle plate of the embroidery machine, the second base is located at the front end of the swing arm in the swing direction, the third base is located at the rear end of the swing arm in the swing direction, and the moving blade penetrates through the second base and the third base. Or the swing arm device also comprises a guide rail arranged at the bottom of the needle plate, the guide rail is provided with a space allowing the swing arm to swing, the guide rail extends from the front end of the swing arm in the swing direction to the rear end of the swing arm in the swing direction, and the movable knife penetrates through the guide rail.

As can be seen from fig. 6, the spatial position of the fixed knife in the thread trimmer device of the present invention is slightly higher than the spatial position of the movable knife, i.e., the fixed knife is located above the movable knife. The invention is not limited to the space position, and the fixed knife and the movable knife can be exchanged, so long as the movable knife moves towards the fixed knife, and the embroidery thread is cut off by matching the cutting edge of the fixed knife and the cutting edge of the movable knife when the fixed knife and the movable knife are overlapped.

It will be appreciated by persons skilled in the art that the embodiments of the invention described above and shown in the drawings are given by way of example only and are not limiting of the invention. The objects of the present invention have been fully and effectively accomplished. The functional and structural principles of the present invention have been shown and described in the examples, and any variations or modifications of the embodiments of the present invention may be made without departing from the principles.

Claims

1. A thread cutting device of a small-head-distance embroidery machine comprises a movable knife, a fixed knife and a movable knife driving mechanism; the movable knife and the fixed knife are arranged at the bottom of a needle plate of the embroidery machine, the movable knife and the fixed knife are respectively arranged at two sides of a needle plate hole and at two sides of the Y axis of the embroidery machine in the positive and negative directions, and the movable knife driving mechanism is arranged on a shuttle bed; the movable knife is provided with a downward inclined surface facing the movable knife trimming end of the fixed knife, the inclined surface is provided with a groove, the front end of the movable knife trimming end is provided with a notch for forming a movable knife trimming end, and the other side of the groove far away from the movable knife trimming end is provided with a movable knife blade; the bottom of the fixed knife facing the fixed knife shearing end of the movable knife is provided with a fixed knife blade; the movable knife driving mechanism drives the movable knife to do linear motion towards the fixed knife, the end head of the movable knife cutting line of the movable knife forks a bottom line and a facial line to be cut and continues to move towards the fixed knife during the motion, and the movable knife edge and the fixed knife edge act together to cut the bottom line and the facial line until the movable knife is overlapped with the fixed knife.

2. The small-head-distance embroidery machine thread cutting device according to claim 1, wherein the groove forms the movable blade edge at the groove wall and the inclined surface at the end of the other side of the groove away from the movable blade thread cutting end.

3. The small-head-distance embroidery machine thread cutting device according to claim 2, wherein the groove is provided with a concave hole or a through hole at the bottom of the end of the other side of the groove away from the movable cutter thread cutting end, the wall of the concave hole and the inclined surface form a movable cutter blade, or the wall of the through hole and the inclined surface form a movable cutter blade.

4. The thread trimmer according to claim 1, wherein the front end of the thread trimming end of the fixed cutter has an extension part extending in the moving-cutter direction, so that the cutting edge of the fixed cutter is retracted into the extension part.

5. The small-head-distance embroidery machine thread cutting device according to claim 1, wherein the movable knife is provided with a sliding chute; the swing arm of the movable cutter driving mechanism slides in the sliding groove to drive the movable cutter to move.

6. The small-head-distance embroidery machine thread cutting device according to claim 1, further comprising a first base installed at the bottom of the embroidery machine needle plate; the first base is used for supporting the movable knife when the movable knife and the fixed knife are overlapped, so that the cutting edge of the movable knife and the cutting edge of the fixed knife can interact to cut off a bottom thread and an upper thread.

7. The small-head-distance embroidery machine thread cutting device according to claim 6, wherein the first base is an elastic member; or an elastic part is arranged in the first base and acts on the movable knife.

8. The small-head-distance embroidery machine thread cutting device according to claim 1 or 6, further comprising a second base or a third base mounted at the bottom of the embroidery machine needle plate, wherein the movable knife penetrates through the second base or the third base, and the movable knife driving mechanism drives the movable knife to move along the guiding direction of the second base or the third base; the moving knife driving mechanism drives the moving knife to move along the guide direction of the second base or the third base.

9. The small-head-distance embroidery machine thread cutting device according to claim 1 or 6, characterized by further comprising a second base and a third base which are arranged at the bottom of the embroidery machine needle plate, the movable knife penetrates through the second base and the third base, and the second base and the third base are used for guiding the moving direction of the movable knife; or the movable knife device also comprises a second base or a third base arranged at the bottom of the needle plate of the embroidery machine, and a third base or a second base arranged on the shuttle bed, wherein the movable knife passes through the second base and the third base, and the second base and the third base are used for guiding the moving direction of the movable knife; or the movable knife also comprises a second base or a third base which is partially arranged at the bottom of the embroidery machine needle plate and partially arranged on the shuttle bed, and a third base or a second base which is arranged at the bottom of the embroidery machine needle plate, wherein the movable knife penetrates through the second base and the third base, and the second base and the third base are used for guiding the moving direction of the movable knife; or the movable knife also comprises a second base or a third base which is partially arranged at the bottom of the needle plate of the embroidery machine and partially arranged on the shuttle bed, and a third base or a second base arranged on the shuttle bed, wherein the movable knife penetrates through the second base and the third base, and the second base and the third base are used for guiding the moving direction of the movable knife.

10. The small-head-distance embroidery machine thread cutting device according to claim 1, wherein the fixed knife is mounted at the bottom of the embroidery machine needle plate through a fixed block; or the fixed knife is directly arranged at the bottom of the needle plate or on the shuttle bed of the embroidery machine; or the fixed knife is arranged on the shuttle bed through a bracket.

11. The small-head-distance embroidery machine thread cutting device according to claim 1, wherein the moving blade driving mechanism comprises a cutter bar, a swing arm and a rotating shaft connecting rod; the cutter arbor is vertical to be located on the shuttle bed, the lower extreme of cutter arbor is connected the pivot connecting rod, swing arm one end is connected to the upper end of cutter arbor, and the swing arm other end has the driving piece, and when the cutter arbor drove the swing arm swing, the driving piece drove the sword motion.

12. The small-head-distance embroidery machine thread cutting device according to claim 11, further comprising a second base and a third base which are arranged at the bottom of the embroidery machine needle plate, wherein the second base is positioned at the front end of the swing arm in the swing direction, the third base is positioned at the rear end of the swing arm in the swing direction, and the movable knife penetrates through the second base and the third base; or the swing arm device also comprises a guide rail arranged at the bottom of the needle plate, the guide rail is provided with a space allowing the swing arm to swing, the guide rail extends from the front end of the swing arm in the swing direction to the rear end of the swing arm in the swing direction, and the movable knife penetrates through the guide rail.

13. The small-head-distance embroidery machine thread cutting device according to claim 1, wherein the straight-line path of the straight-line motion of the movable knife toward the fixed knife is parallel to the Y-axis of the embroidery machine where the needle plate hole is located, or the straight-line path of the straight-line motion of the movable knife toward the fixed knife intersects the Y-axis of the embroidery machine where the needle plate hole is located.

14. The small-head-distance embroidery machine thread cutting device according to claim 1, wherein the fixed knife is arranged at the bottom of the embroidery machine needle plate in front of the rotating shuttle of the embroidery machine; the moving knife is arranged at the bottom of the embroidery machine needle plate above the rotating shuttle of the embroidery machine.

15. The small-head-distance embroidery machine thread cutting device according to claim 11, wherein when the movable knife driving mechanism drives the movable knife to move linearly towards the fixed knife and to move in an arc, the axis of the knife bar does not coincide with the center of the moving track of the movable knife.