CN217324547U

CN217324547U - Sewing machine

Info

Publication number: CN217324547U
Application number: CN202221195095.3U
Authority: CN
Inventors: 潘宝国; 王志; 邱志远; 朱良华
Original assignee: Jack Technology Co Ltd
Current assignee: Jack Technology Co Ltd
Priority date: 2022-05-18
Filing date: 2022-05-18
Publication date: 2022-08-30
Anticipated expiration: 2032-05-18

Abstract

The application relates to the field of sewing equipment, in particular to a sewing machine. The sewing machine comprises a machine head and a workbench, wherein the machine head is arranged on the workbench and is used for operating cloth on the workbench; the sewing machine also comprises a cutter component and a first sensor, wherein the cutter component is arranged on the machine head and is used for chopping the cloth strips on the workbench; the first sensor is arranged on the workbench, is in signal connection with the cutter assembly and is used for sensing the position of the cloth strip on the workbench so as to control the action of the cutter assembly; wherein, along perpendicular to cloth feeding direction, the orthographic projection position of cutter unit spare on the workstation flushes with the position of first inductor, and first inductor is close to the cutter unit spare setting. The utility model has the advantages of: through making the orthographic projection position of cutter unit spare on the workstation flush with the position of first inductor, and first inductor is close to the cutter unit spare setting to improve the cutter unit spare and respond to the precision of cutting cloth through first inductor, and then promote sewing machine's sewing quality.

Description

Sewing machine

Technical Field

The application relates to the field of sewing equipment, in particular to a sewing machine.

Background

The sewing machine is one of the indispensable equipment of textile processing industry, and with people's higher and higher requirement to clothing and fabrics, the tailor is more and more meticulous, also increases increasingly to the requirement of processing, also increases more and more to the requirement of sewing machine.

Sensing device among the sewing machine on the existing market can the automated inspection current position of cloth, replaces the staff to tailor the cloth when sensing device senses needs to chop, and at the actual in-process of making up, often because make up the cloth too thick too big, some factors such as the environment light of actual work is too dark lead to that sensing device responds insensitively, tailors positional deviation serious, and then makes the sewing machine function unusually, still can cause the cloth to damage when serious.

SUMMERY OF THE UTILITY MODEL

In view of the above, it is desirable to provide a sewing machine capable of improving the sensing accuracy of a cloth.

A sewing machine comprises a machine head and a workbench, wherein the machine head is arranged on the workbench and is used for operating cloth on the workbench; the sewing machine further comprises a cutter assembly and a first sensor, wherein the cutter assembly is mounted on the machine head and used for chopping the cloth strips on the workbench; the first sensor is arranged on the workbench, is in signal connection with the cutter assembly and is used for sensing the position of the cloth strips on the workbench so as to control the action of the cutter assembly; wherein, along perpendicular to cloth feeding direction, the cutter unit is in the orthographic projection position on the workstation with the position of first inductor flushes, just first inductor is close to the cutter unit sets up.

It can be understood that, along perpendicular to cloth feeding direction, this application is through making cutter unit is in orthographic projection position on the workstation with the position of first inductor flushes, just first inductor is close to cutter unit sets up, thereby improves cutter unit passes through the precision of first inductor response cloth cutting, and then promotes sewing machine's sewing quality.

In one embodiment, a second inductor and a third inductor are further arranged on the workbench, the second inductor and the first inductor are arranged at an interval, and the third inductor and the second inductor are arranged at an interval.

It can be understood that three sensors are arranged on the workbench, so that the sensing of the state of the cloth strips is further enhanced, and a corresponding response is sensitively made.

In one embodiment, the second inductor is arranged between the first inductor and the third inductor, the second inductor and the first inductor are sequentially arranged on the workbench along the cloth strip feeding direction.

It can be understood that along the cloth feeding direction, through making the third inductor the second inductor the first inductor set gradually in on the workstation to the reinforcing carries out real-time induction monitoring to the whole process of cloth from the feeding to before cutting the cloth and then cutting the cloth after to, and then sensitive corresponding reaction of making.

In one embodiment, the sewing machine further comprises a controller in signal connection with the second sensor, so that when the cloth strip covers the second sensor, the controller can control the cutter assembly to delay the chopping action according to the signal sent by the second sensor.

It can be understood that, when the cloth strip covers the second sensor, the controller controls the cutter assembly to delay chopping, and the cutter assembly quickly chops the cloth strip before the cloth strip is fed to the cutter assembly, so that the sensitivity of the whole cloth front-cutting process is improved.

In one embodiment, the sewing machine further comprises a controller in signal connection with the first sensor, so that when the cloth strip covers the first sensor and then leaves the first sensor, the controller can control the cutter assembly to chop the cloth strip according to the signal sent by the first sensor.

In one embodiment, the sewing machine further comprises a controller, wherein the controller is in signal connection with the first sensor, the second sensor and the third sensor respectively, so that when ambient light changes, the controller can control the first sensor, the second sensor and the third sensor to correspondingly adjust the induced voltage values according to the ambient light signals.

It can be understood that when ambient light changes, the controller controls the first sensor, the second sensor and the third sensor to adjust their own sensing voltage values, so that the first sensor, the second sensor and the third sensor are not affected by the ambient light and their own sensing sensitivities are not reduced.

In one embodiment, the sewing machine further comprises a controller, wherein the controller is respectively in signal connection with the first sensor, the second sensor and the third sensor, so that when the thickness of the cloth changes, the controller can control the first sensor, the second sensor and the third sensor to adjust the signal emission intensity of the first sensor, the second sensor and the third sensor according to the cloth thickness signal.

It can be understood that when the thickness of the cloth is changed, the controller controls the first sensor, the second sensor and the third sensor to adjust the signal emission intensity of the first sensor, the second sensor and the third sensor, so that the signal emission intensity of the first sensor, the second sensor and the third sensor can be adjusted in real time according to the cloth with different thickness degrees, and the normal operation of the sewing machine is prevented from being influenced by misjudgment.

In one embodiment, the sewing machine further comprises a transmitter for transmitting sensing signals, the transmitter being capable of being in signal connection with the first sensor, the second sensor and the third sensor, respectively, so that the first sensor, the second sensor and the third sensor are capable of receiving the sensing signals, respectively.

In one embodiment, the transmitter comprises a first transmitting unit, a second transmitting unit and a third transmitting unit which are respectively used for transmitting induction signals; the first transmitting unit is in signal connection with the first sensor, so that the first sensor receives the sensing signal transmitted by the first transmitting unit; the second transmitting unit is in signal connection with the second sensor so that the second sensor receives the sensing signal transmitted by the second transmitting unit, and the third transmitting unit is in signal connection with the third sensor so that the third sensor receives the sensing signal transmitted by the third transmitting unit; the first emitting unit and the first sensor, the second emitting unit and the second sensor, and the third emitting unit and the third sensor are opposite infrared sensors or photoelectric diffuse reflection sensors.

In one embodiment, the sewing machine further comprises a mounting plate mounted on the head, the emitter being mounted to the mounting plate.

Compared with the prior art, along perpendicular to cloth direction of feed, this application is through making cutter unit is in orthographic projection position on the workstation with the position of first inductor flushes, just first inductor is close to cutter unit sets up, thereby improves cutter unit passes through the precision of first inductor response cropping, and then promotes sewing machine's sewing quality.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments or the conventional technologies of the present application, the drawings used in the descriptions of the embodiments or the conventional technologies will be briefly introduced below, it is obvious that the drawings in the following descriptions are only some embodiments of the present application, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a perspective view of a sewing machine according to the present application;

FIG. 2 is a schematic view of another perspective view of the sewing machine of the present application;

fig. 3 is a schematic top view of the sewing machine provided in the present application.

Reference numerals: 100. a sewing machine; 10. a machine head; 20. a work table; 30. a cutter assembly; 40. a first inductor; 41. a second inductor; 42. a third inductor; 50. a transmitter; 51. a first transmitting unit; 52. a second transmitting unit; 53. a third transmitting unit; 60. and (7) mounting the plate.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and that modifications may be made by one skilled in the art without departing from the spirit and scope of the application and it is therefore not intended to be limited to the specific embodiments disclosed below.

It will be understood that when an element is referred to as being "secured to" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When a component is referred to as being "connected" to another component, it can be directly connected to the other component or intervening components may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used in the description of the present application are for illustrative purposes only and do not represent the only embodiments.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may mean that the first feature is in direct contact with the second feature, or that the first feature and the second feature are in indirect contact via an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature "under," "beneath," and "under" a second feature may be directly under or obliquely under the second feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the present application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in the description of this application, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 1 to 3, the present application provides a sewing machine 100, wherein the sewing machine 100 is one of the essential equipments in the textile processing industry, and as people have higher requirements for clothes and textiles, the tailoring becomes finer, the processing requirements are increased, and the requirements for the sewing machine 100 are also higher.

The problem that an existing sewing machine is insensitive to sensing when cutting cloth strips is solved. The utility model provides a sewing machine 100, which comprises a machine head 10 and a workbench 20, wherein the machine head 10 is arranged on the workbench 20 and is used for operating the cloth on the workbench 20; the sewing machine 100 further comprises a cutter assembly 30 and a first inductor 40, wherein the cutter assembly 30 is mounted on the machine head 10 and is used for cutting the cloth strips on the worktable 20; the first sensor 40 is arranged on the workbench 20 and is in signal connection with the cutter assembly 30, and is used for sensing the position of the cloth strips on the workbench 20 so as to control the action of the cutter assembly 30; wherein, along being perpendicular to cloth feeding direction, the orthographic projection position of cutter subassembly 30 on workstation 20 is flush with the position of first inductor 40, and first inductor 40 is close to cutter subassembly 30 and sets up.

It should be noted that, along the direction perpendicular to the cloth feeding direction, the orthographic projection position of the cutter assembly 30 on the workbench 20 is flush with the position of the first sensor 40, and the first sensor 40 is arranged close to the cutter assembly 30, so that the precision of the cutter assembly 30 sensing the cut cloth through the first sensor 40 is improved, and the sewing quality of the sewing machine 100 is further improved.

Usually, in the sewing process of the cloth, the cloth strips to be cut are left at the two ends of the cloth to realize the complete sewing of the cloth. Therefore, when the cloth is fed along a fixed feeding direction on the worktable 20, in order to allow the cloth to reach a certain designated position, the cutter assembly 30 can precisely cut the cloth strip at one end of the cloth, the existing sewing machine is provided with an inductor for inducing the position of the cloth on the worktable, when the cloth passes through the inductor, the inductor is covered, so that the inductor induces the existence of the cloth, when the inductor induces the existence of the cloth, the cloth is conveyed to the position where the inductor is arranged on the worktable, and the cloth strip on the cloth is cut by the cutter assembly through signal judgment and control.

However, the conventional sewing machine usually has a problem that the cloth strip is damaged due to inaccurate cutting position in the cloth cutting process, and the reason for the problem is mainly that the signal transmission process between the sensor and the cutter assembly is not accurate, and if the signal transmission process between the sensor and the cutter assembly is to be improved, the number of the sensors, the distribution of the sensors on the worktable, the positional relationship between the sensor and the cutter assembly, and how to protect the sensor from the environment and the thickness of the cloth, which will be described in detail in turn.

As shown in fig. 1 and 2, regarding the number of the sensors, since the existing sewing machine is usually provided with only two sensors, namely, the front sensor and the rear sensor, it is inevitable that the real-time position change of the cloth cannot be detected too accurately due to the too small number of the sensors, and further, a signal transmission error exists, which affects the cloth cutting accuracy. The present application therefore addresses this problem by increasing the number of inductors.

In this embodiment, the worktable 20 is provided with a first inductor 40, a second inductor 41 and a third inductor 42, the second inductor 41 is spaced apart from the first inductor 40, and the third inductor 42 is spaced apart from the second inductor 41. By arranging three sensors on the worktable 20, the real-time sensing of the cloth strips is further enhanced, and the cutter assembly 30 can make a corresponding response sensitively. Of course, in other embodiments, the number of the inductors may also be set to be four, five, six or even more, which is not limited herein.

Aiming at the distribution situation of the plurality of inductors on the workbench 20, in order to enable the first inductor 40, the second inductor 41 and the third inductor 42 to better sense the position of the cloth on the workbench 20, the third inductor 42, the second inductor 41 and the first inductor 40 are sequentially arranged at intervals along the cloth feeding direction, namely, arranged at the front, middle and rear positions of the workbench 20 along the cloth feeding direction. That is to say, when the cloth is initially fed, the third sensor 42 is firstly covered, when the cloth is fed to the middle section of the workbench 20, the second sensor 41 is covered by the cloth, when the cloth is fed to the rear section of the workbench 20, the first sensor 40 is covered by the cloth, and when the cloth leaves the workbench 20 after sewing, the cloth is changed from the covering state to the uncovering state on the first sensor 40.

Along the cloth feeding direction, the third inductor 42, the second inductor 41 and the first inductor 40 are sequentially arranged on the workbench 20, so that the whole process of feeding the cloth to the front cloth chopping and then to the back cloth chopping is inductively monitored in real time, and the cutter assembly 30 sensitively performs corresponding chopping actions.

Referring to fig. 3 in conjunction with fig. 1 and 2, in order to further enhance the accuracy of the cutter assembly 30 in cutting the fabric strip, so that the cutter assembly 30 can precisely cut the fabric strip at the rear end of the fabric just before the fabric leaves the worktable 20, the fabric needs to be located at the cutter assembly 30 at the same time as the first sensor 40. That is, the orthographic projection position of the cutter assembly 30 on the worktable 20 is aligned with the position of the first inductor 40 along the direction perpendicular to the feeding direction of the cloth, so that the cloth is simultaneously positioned at the cutter assembly 30 while covering the first inductor 40, the first inductor 40 can simultaneously transmit signals to the cutter assembly 30 and control the cutter assembly 30 to chop the cloth, and thus, the signal transmission error between the first inductor 40 and the cutter assembly 30 is reduced.

In addition, in the process of signal transmission, the distance also affects the signal transmission time, and therefore, in order to further improve the signal transmission precision between the first sensor 40 and the cutter assembly 30, the first sensor 40 is arranged close to the cutter assembly 30, so that the signal transmission error between the first sensor 40 and the cutter assembly 30 is lower, and the cutter assembly 30 is more precise in cutting the cloth strips.

Further, the sewing machine 100 further includes a controller in signal connection with the first sensor 40, so that when the cloth strip covers the first sensor 40 and then leaves the first sensor 40, the controller can control the cutter assembly 30 to chop the cloth strip according to the signal sent by the first sensor 40.

It should be noted that, because a part of the cloth is still disposed below the cutter assembly 30 when the cloth just covers the first sensor 40, the cutting only damages the cloth, and only when the cloth covers the first sensor 40 and the cloth leaves the critical point between the first sensor 40, the cloth is disposed below the cutter assembly 30, and the cutting operation performed by the cutter assembly 30 is to cut the cloth without damaging the cloth.

Further, the controller is in signal connection with the second sensor 41, so that when the second sensor 41 is covered by the cloth strip, the controller can control the cutter assembly 30 to delay the chopping action according to the signal sent by the second sensor 41.

It should be noted that, when the cloth covers the second sensor 41, the cutter assembly 30 is ready to cut the cloth at the front end of the cloth, but since the cloth is conveyed from the second sensor 41 to the third sensor 42 with a certain distance, when the cloth covers the second sensor 41, the controller needs to control the cutter assembly 30 to delay the cutting operation according to the distance between the second sensor 41 and the first sensor 40, and when the cloth reaches the first sensor 40, the cutter assembly 30 quickly cuts the cloth at the front end of the cloth, thereby improving the sensitivity of the whole front fabric cutting process.

Further, the sewing machine 100 further includes a transmitter 50 for transmitting the sensing signal and a mounting plate 60, the mounting plate 60 is mounted on the head 10, and the transmitter 50 is mounted on the mounting plate 60. The transmitter 50 includes a first transmitting unit 51, a second transmitting unit 52 and a third transmitting unit 53 for transmitting the sensing signal, respectively; the first transmitting unit 51 is in signal connection with the first sensor 40, so that the first sensor 40 receives the sensing signal transmitted by the first transmitting unit 51; the second transmitting unit 52 is in signal connection with the second sensor 41, so that the second sensor 41 receives the sensing signal transmitted by the second transmitting unit 52, and the third transmitting unit 53 is in signal connection with the third sensor 42, so that the third sensor 42 receives the sensing signal transmitted by the third transmitting unit 53.

Wherein, three transmitting element and three inductor one-to-one constitute a set of sensor. Optionally, in this embodiment, the first emitting unit 51 and the first sensor 40, the second emitting unit 52 and the second sensor 41, and the third emitting unit 53 and the third sensor 42 are a correlation infrared sensor or a photoelectric diffuse reflection sensor. Of course, in other embodiments, other types of sensors such as an ultrasonic sensor may be used as long as the fabric blocking can be detected, and the detection is not limited herein.

This point to the influence that reduces the environment to the inductor, because in current sewing machine, often because the ambient light of work is too dark to lead to the inductor response insensitive, can't respond to the position of cloth and can't send the cloth cutting signal to the cutter unit, can't reach the function of automatic cloth cutting, for solving this problem, this application through make the controller respectively with first inductor 40, signal connection between second inductor 41 and the third inductor 42, when ambient light changes, the controller can be according to the first inductor 40 of ambient light signal control, second inductor 41 and third inductor 42 correspond the induced voltage value of adjustment self. That is, when the ambient light is too dark, the first sensor 40, the second sensor 41 and the third sensor 42 compensate their own induced voltage values; when the ambient light is too strong, the first sensor 40, the second sensor 41 and the third sensor 42 reduce their own induced voltage values, thereby ensuring the sensitivity of the first sensor 40, the second sensor 41 and the third sensor 42.

To this point of the influence is produced to the inductor to cloth thickness degree, because in current sewing machine, often because the cloth is too thick too big leads to the inductor response insensitive, the position of response cloth can't send the cloth cutting signal to the cutter subassembly, can't reach the function of automatic cloth cutting, for solving this problem, this application is through making the controller respectively with first inductor 40, second inductor 41 and third inductor 42 signal connection, in order when the thickness of cloth produces the change, the controller can adjust self signal emission intensity according to cloth thickness signal control first inductor 40, second inductor 41 and third inductor 42.

That is, when the thickness of the fabric is too thick, the light of the emitter 50 cannot penetrate through the fabric to reach the sensor, and at this time, the sensor needs to be controlled by the controller to enhance the signal emission intensity of the sensor, so as to ensure the sensitivity of the first sensor 40, the second sensor 41, and the third sensor 42 to the fabric; when the thickness of cloth is too thin, just need reduce self signal emission intensity through controller control inductor this moment to guarantee the sensitivity of first inductor 40, second inductor 41 and third inductor 42 to the cloth.

The utility model provides a sewing machine 100's cloth cutting process does: when the third sensor 42 detects that the cloth is shielded, the presser foot of the sewing machine 100 is lifted up to be placed with the cloth, the cloth is normally sewn after the cloth is placed, the cloth is continuously fed forwards, when the second sensor 41 detects that the cloth is shielded, the controller controls the cutter assembly 30 to delay chopping, when the cloth is going to pass through the first sensor 40, the cutter assembly 30 chops the cloth at the front end of the cloth, the cloth is continuously fed forwards, and when the cloth covers the first sensor 40 to a critical point that the cloth is going to leave the first sensor 40, the cutter assembly 30 chops the cloth at the rear end of the cloth quickly, so that the whole cloth cutting process is completed, the motor is stopped, and the sewing machine 100 is restored to an initial state.

The utility model provides a sewing machine 100 flushes through the orthographic projection position that makes cutter unit spare 30 on workstation 20 with first inductor 40's position, and first inductor 40 is close to cutter unit spare 30 and sets up to improve cutter unit spare 30 and respond to the precision of cropping through first inductor 40, and then promote sewing machine 100's sewing quality.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present application, and the description thereof is more specific and detailed, but not construed as limiting the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, which falls within the scope of protection of the present application. Therefore, the protection scope of the present application shall be subject to the appended claims.

Claims

1. A sewing machine comprises a machine head (10) and a workbench (20), wherein the machine head (10) is arranged on the workbench (20) and is used for operating cloth on the workbench (20);

the sewing machine is characterized by further comprising a cutter assembly (30) and a first inductor (40), wherein the cutter assembly (30) is mounted on the machine head (10) and used for chopping the cloth strips on the workbench (20);

the first sensor (40) is arranged on the workbench (20) and is in signal connection with the cutter assembly (30) and used for sensing the position of cloth strips on the workbench (20) so as to control the action of the cutter assembly (30);

the orthographic projection position of the cutter assembly (30) on the workbench (20) is flush with the position of the first inductor (40) along the direction perpendicular to the cloth strip feeding direction, and the first inductor (40) is arranged close to the cutter assembly (30).

2. The sewing machine of claim 1, wherein a second sensor (41) and a third sensor (42) are further disposed on the table (20), the second sensor (41) being spaced apart from the first sensor (40), and the third sensor (42) being spaced apart from the second sensor (41).

3. Sewing machine as in claim 2, characterized in that said second inductor (41) is arranged between said first inductor (40) and said third inductor (42), said second inductor (41) and said first inductor (40) being arranged in sequence on said table (20) along the direction of feed of the fabric strips.

4. The sewing machine according to claim 3, further comprising a controller in signal communication with the second sensor (41) to control the cutter assembly (30) to delay the chopping action in response to a signal sent by the second sensor (41) when the strip covers the second sensor (41).

5. The sewing machine of claim 3, further comprising a controller in signal communication with the first sensor (40) to control the cutter assembly (30) to chop the fabric strip based on signals sent by the first sensor (40) when the fabric strip covers the first sensor (40) and then exits the first sensor (40).

6. The sewing machine of claim 3, further comprising a controller, wherein the controller is in signal connection with the first sensor (40), the second sensor (41) and the third sensor (42), respectively, so that when the ambient light changes, the controller can control the first sensor (40), the second sensor (41) and the third sensor (42) to adjust the sensed voltage values thereof according to the ambient light signal.

7. The sewing machine according to claim 3, further comprising a controller in signal connection with the first sensor (40), the second sensor (41) and the third sensor (42), respectively, so that when the thickness of the cloth changes, the controller can control the first sensor (40), the second sensor (41) and the third sensor (42) to adjust the emission intensity of the signals thereof according to the cloth thickness signal.

8. The sewing machine according to claim 2, characterized in that it further comprises a transmitter (50) to transmit an induction signal, said transmitter (50) being respectively signally connectable with said first inductor (40), said second inductor (41) and said third inductor (42) to enable said first inductor (40), said second inductor (41) and said third inductor (42) to receive said induction signal, respectively.

9. The sewing machine according to claim 8, wherein the transmitter (50) comprises a first transmitting unit (51), a second transmitting unit (52) and a third transmitting unit (53) for transmitting the sensing signal, respectively;

the first transmitting unit (51) is in signal connection with the first sensor (40), so that the first sensor (40) receives the sensing signal transmitted by the first transmitting unit (51); the second transmitting unit (52) is in signal connection with the second inductor (41), so that the second inductor (41) receives the induction signal transmitted by the second transmitting unit (52), and the third transmitting unit (53) is in signal connection with the third inductor (42), so that the third inductor (42) receives the induction signal transmitted by the third transmitting unit (53);

wherein the first emitting unit (51) and the first inductor (40), the second emitting unit (52) and the second inductor (41), and the third emitting unit (53) and the third inductor (42) are a correlation infrared sensor or a photoelectric diffuse reflection sensor.

10. Sewing machine as in claim 8, characterized in that it further comprises a mounting plate (60), said mounting plate (60) being mounted on said head (10), said emitter (50) being mounted on said mounting plate (60).