Device for calibrating radio frequency identification temperature sensor labels in batches

Abstract

The utility model belongs to the technical field of electronic equipment. A device for calibrating radio frequency identification temperature sensor labels in batches comprises a heat preservation box body, a heat preservation box cover and a control box, a stirring device, a temperature control device and a temperature measuring device which are electrically connected with the control box are arranged in the heat preservation box body, liquid is contained in the heat preservation box body, and a coil is arranged at the bottom of the heat preservation box body. A plurality of electronic tags are placed in the tag fixing base and located in a magnetic field of the coil, and after the control box controls the temperature control device to adjust the contained liquid to the preset temperature, the electronic tag read-write device conducts batch calibration operation on the electronic tags at the same time through the coil. According to the utility model, the consistency of calibration environments of a plurality of electronic tags is ensured, the accuracy of temperature measurement of the electronic tags is improved, and compared with the existing one-by-one calibration mode, the calibration efficiency can be greatly improved, and the temperature sensor electronic tag calibration device is suitable for operations such as calibration, data writing and the like of batch temperature sensor electronic tags.

Description

Technical Field

[0001] The utility model belongs to the technical field of electronic equipment, in particular to a device for batch calibrating radio frequency identification temperature sensor tags. Background Art

[0002] In today's Internet of Things application field, as a network node in the wireless sensor network, wireless sensor tags, supported by two major technologies, radio frequency identification tag technology and intelligent sensor technology, combine information perception and measurement functions with radio frequency data transmission functions, opening up countless intelligent applications in people's daily life and industrial ecology. On the one hand, as the core technology of the basic wireless transmission technology of the Internet of Things, radio frequency identification tag (RFID) technology has been widely used in many aspects of social life, such as logistics tracking, warehouse inventory, smart card payment, and access control applications, and the supporting data acquisition systems and mobile terminals are everywhere. Different from other wireless transmission technologies, the most prominent passive feature of radio frequency identification tag technology is that the tag does not require a battery when working. Passive radio frequency identification tag technology can sense energy from the surrounding electromagnetic field and convert it into electrical energy for the circuit inside the radio frequency identification chip to work, making it very suitable for large-scale and low-cost deployment in the field of Internet of Things technology, and has a very outstanding commercial value. On the other hand, intelligent sensor technology can convert the perceived and measured physical quantities in the surrounding environment into binary digital codes for digital storage and transmission, making it convenient for people to accurately display and further process the perceived and measured environmental information with digital devices. There is no doubt that passive RFID sensor tag technology is an innovative technological breakthrough in the field of Internet of Things, has huge application prospects, and is the preferred technology for the widespread implementation of wireless sensor networks.

[0003] In particular, in the fields of livestock breeding, pet health care, and biological and medical experiments, animal identification based on the international standard ISO11784 / 11785 has a more advanced application demand for biological sign monitoring in the basic application example of identity identification; and as one of the most important indicators of biological signs, the measurement of animal body temperature needs to achieve an accuracy of less than + / -0.1 degrees Celsius, and it needs to be collected into the data system together with the identity information. Unlike smart card tags in other fields or traditional ear tags in the field of animal identification, the main carrier of this application is a glass tube tag made of bioglass material. The glass tube tag has a built-in passive radio frequency identification chip with a resonant frequency of 134.25kHz. It is implanted in the animal's body, and people can read the animal's identity information through an external scanning and reading device. When the semiconductor temperature sensor is integrated into a 134.25kHz low-frequency animal identification tag chip, the voltage signal that is linearly proportional to the body's ambient temperature is sampled and quantized into a binary value with a certain accuracy (typically 8 to 24 bits), and is transmitted in the form of a modulated and encoded digital code stream via radio frequency communication, and is ultimately read by the data acquisition system.

[0004] When a passive temperature sensor tag is measuring temperature, on the one hand, due to the limited ability of each module of the passive RFID tag to suppress the AC disturbance of the power supply voltage, the node voltage of each module will be modulated to varying degrees by the disturbed power supply voltage. This noise-like modulation disturbance will hinder the accuracy of the temperature measurement of the passive RFID tag. On the other hand, when semiconductor chip manufacturers manufacture passive RFID tags, the manufactured RFID tags are affected by the process, so the performance of their manufacturing circuits will also fluctuate to varying degrees. This fluctuation directly leads to a large range of errors and inconsistencies in the conversion of physical quantities representing temperature when different RFID tags manufactured by the same semiconductor chip manufacturing process are converted. That is, when different RFID tags are used to measure the same temperature, different digital codes will be obtained, that is, when different RFID tags are used to measure the same temperature, different temperature values ​​will be obtained. In this way, the consistency of the temperature measurement of the passive RFID tag cannot be guaranteed. This is a fatal weakness for mass production, which directly affects whether the product can eventually enter the market and be accepted by users.

[0005] Therefore, existing passive temperature sensor tags need to undergo consistency calibration before leaving the factory, and the calibration of existing passive temperature sensor tags needs to be calibrated one by one on the calibration equipment, which has the problem of low calibration efficiency, seriously limiting the large-scale use of temperature sensor tags. In addition, the continuous calibration process will also make the calibration environment inconsistent, resulting in certain inconsistencies in the calibrated electronic tags. Utility Model Content

[0006] The utility model aims to provide a device for batch calibration of radio frequency identification temperature sensor tags, so as to solve the problems of low efficiency, poor consistency and the like existing in the existing electronic tag calibration.

[0007] To achieve the above-mentioned purpose, the technical solution adopted by the utility model is a device for batch calibration of radio frequency identification temperature sensor tags, including an insulation box body, an insulation box cover and a control box. The insulation box body is provided with a stirring device, a temperature control device and a temperature measuring device which are electrically connected to the control box respectively. The insulation box body is filled with liquid, a coil is provided at the bottom of the insulation box body, and a plurality of electronic tags are placed in the tag fixing seat. The electronic tags are located in the magnetic field of the coil. After the control box controls the temperature control device to adjust the contained liquid to a preset temperature, the electronic tag reading and writing device in the control box simultaneously performs batch calibration operations on the plurality of electronic tags through the coil.

[0008] The technical solution for achieving the purpose of the utility model further includes that the control box is fixed to one side of the insulation box body, a controller is provided inside the control box, and a control knob, a display screen, a switch button, a data interface and a power interface electrically connected to the controller are provided outside the control box.

[0009] The technical solution for achieving the purpose of the utility model further includes that the stirring device is a motor fixed to the inner wall of the insulation box cover, and a fan blade fixed on the motor shaft, the connecting rod of the fan blade is facing the cavity direction of the insulation box body and is perpendicular to the inner wall of the insulation box cover, and the plane of the fan blade is parallel to the inner wall of the insulation box cover and immersed in the liquid contained in the insulation box body.

[0010] Furthermore, the temperature measuring device is a temperature sensor fixed in the heat preservation box. The four corners of the heat preservation box are vertically installed with temperature sensor fixing seats. The bracket is transversely fixed to the bottom of the temperature sensor fixing seat. The two are connected to form an L-shaped structure. The temperature sensor is fixed on the bracket and faces the central axis direction of the heat preservation box. The temperature sensor is a PT100 probe temperature sensor, which is divided into two layers, upper and lower, and is respectively arranged in the four corners of the heat preservation box.

[0011] A coil bracket is provided at the front end of the bracket, a coil slot is provided at the top of the coil bracket, the coil is clamped in the coil slot, and its head and tail ends are connected to the electronic tag reading and writing device in the control box.

[0012] Furthermore, the label fixing seat includes two parts: a label base and a label disk. A raised connecting seat is provided in the middle of the label base, and a label bottom hole is provided on the surface of the label base. A corresponding opening is provided in the middle of the label disk and is inserted into the connecting seat to connect the label base with the label disk. The label disk is provided with label holes corresponding to the positions and numbers of the label bottom holes. The glass tube type electronic tag passes through the label holes and the bottom falls into the label bottom holes, so that the electronic tag is placed in the label fixing seat in a vertical state. At least one positioning column is provided on the side of the label base. The side edge of the label disk corresponds to the opening and is inserted into the positioning column to limit the label disk in the axial direction of the label base. The positioning cap is inserted into the top of the positioning column to limit the label disk in the longitudinal direction of the label base.

[0013] The utility model discloses a device for batch calibration of radio frequency identification temperature sensor tags. After the temperature control device is used to adjust the liquid in the heat preservation box to a preset temperature, the electronic tag reading and writing device simultaneously performs batch calibration operations on multiple electronic tags placed in the tag fixing seat. This not only ensures the consistency of the calibration environment of multiple electronic tags and improves the accuracy of the temperature measured by the electronic tags, but also greatly improves the calibration efficiency compared to the existing one-by-one calibration method. The utility model is suitable for calibration of batch temperature sensor electronic tags, data writing and other operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 This is the overall three-dimensional structural diagram of the utility model;

[0015] Figure 2 This is a three-dimensional structural diagram of the thermal insulation box of the utility model;

[0016] Figure 3 This is a top view of the structure of the thermal insulation box of the utility model;

[0017] Figure 4 This is a three-dimensional structural diagram of the thermal insulation box cover of the utility model;

[0018] Figure 5 This is a three-dimensional structural diagram of the bracket of the utility model;

[0019] Figure 6 This is a three-dimensional diagram of the combined structure of the bracket and the coil of the utility model;

[0020] Figure 7 This is a top view of the combined structure of the bracket and the coil of the utility model;

[0021] Figure 8 This is a three-dimensional structural diagram of the label base of the utility model;

[0022] Fig. 9 This is a three-dimensional structural diagram of a set of label fixing seats of the utility model;

[0023] Fig.10 This is a three-dimensional structural diagram of two groups of label fixing seats of the utility model;

[0024] Fig.11 This is a main structural diagram of two groups of label fixing seats of the utility model;

[0025] Fig.12 It is a three-dimensional diagram of the combined structure of two groups of label fixing seats, brackets and coils of the utility model. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] like Figure 1-3 As shown, the device for batch calibration of radio frequency identification temperature sensor tags described in the utility model comprises an insulation box body 1, an insulation box cover 2 and a control box 3. The insulation box body 1 is provided with a stirring device, a temperature control device and a temperature measuring device which are electrically connected to the control box 3 respectively. The insulation box body 1 contains liquid, a coil 16 is provided at the bottom of the insulation box body 1, and a plurality of electronic tags are placed in the tag fixing seat 4. The electronic tags are located in the magnetic field of the coil 16. After the control box 3 controls the temperature control device to adjust the contained liquid to a preset temperature, the electronic tag reading and writing device in the control box 3 simultaneously performs batch calibration operations on the plurality of electronic tags through the coil 16, which not only ensures the consistency of the calibration environment of the plurality of electronic tags and improves the accuracy of the temperature measured by the electronic tags, but also, compared with the existing one-by-one calibration method, the utility model can greatly improve the efficiency of calibration, and is suitable for calibration, data writing and other operations of batch temperature sensor electronic tags.

[0028] The bottom of the insulation box 1 is provided with a rubber bottom pad (not shown in the figure), which plays a role in buffering pressure and vibration. The connection structure between the insulation box 1 and the insulation box cover 2 adopts a snap-fit ​​structure, or a hinged flip structure, or one of other similar detachable structures. The two are tightly combined to form a space with a certain sealing and heat preservation effect, so that the liquid contained in the insulation box is maintained at a specific temperature for a period of time to ensure the consistency of the calibration environment of multiple electronic tags. The side wall of the insulation box 1 is fixed with an upper cover bracket 17, which can support and fix the insulation box cover 2 after opening to prevent the connection between the motor and the control box from breaking.

[0029] The control box 3 is fixed to one side of the heat preservation box 1. A controller is provided inside the control box 3. A control knob 31, a display screen 32, a switch button 33, a data interface 34 and a power interface (not shown in the figure) electrically connected to the controller are provided outside the control box 3. After the power interface is connected to the power supply, the switch button 33 turns on the switch, and the heat preservation box 1 enters the working state. By rotating the control knob 31, the display screen 32 displays different instructions. By pressing the control knob 31, the instruction displayed on the display screen 32 can be selected to perform corresponding operations, such as the operation of the temperature control device, the operation of the temperature measuring device, the operation of the stirring device, and the writing of data to the electronic tag, etc.

[0030] The stirring device is a motor 22 fixed to the inner wall of the heat preservation box cover 2, and a fan blade 23 fixed to the motor shaft. Figure 4 As shown, the connecting rod of the fan blade 23 is oriented toward the cavity direction of the insulation box body 1 and is perpendicular to the inner wall of the insulation box cover 2, while the plane of the fan blade 23 is parallel to the inner wall of the insulation box cover 2 and is immersed in the liquid contained in the insulation box body 1. When the temperature control device adjusts the temperature of the contained liquid, the motor 22 drives the fan blade 23 to rotate and stir the liquid to ensure the uniformity of the liquid temperature in the insulation box body.

[0031] The temperature control device can be a refrigeration device or a heating device. This embodiment takes the calibration of an electronic tag for measuring the temperature of a biological body as an example. Therefore, the control device in this embodiment is a heating rod 11 fixed in the thermal insulation box 1. The heating rod 11 is fixed to the inner wall of the thermal insulation box 1 through a heating rod fixing seat 111. Similarly, multiple heating rods 11 can be provided according to usage requirements, and the position can be set on the inner wall or the bottom, etc.

[0032] The temperature measuring device is a temperature sensor 12 fixed in the heat preservation box 1. Temperature sensor fixing seats 121 are vertically installed at the four corners of the heat preservation box 1. The bracket 13 is horizontally fixed to the bottom of the temperature sensor fixing seat 121. The two are connected to form an L-shaped structure. The temperature sensor 12 is fixed on the bracket 13 and faces the central axis direction of the heat preservation box 1. The temperature sensor 12 is a PT100 probe temperature sensor, which is divided into two layers, upper and lower, and is respectively arranged in the four corners of the heat preservation box 1 to realize temperature detection at different positions and depths of the liquid in the heat preservation box. If the temperature is inconsistent, the stirring device is started to stir the liquid in the heat preservation box.

[0033] One end of the bracket 13 is connected to the temperature sensor fixing seat 121 to form an L-shaped structure, and the bracket 13 can move up and down on the temperature sensor fixing seat 121 to adjust the height of the temperature sensor 12. The connection structure between the bracket 13 and the temperature sensor fixing seat 121 can be in various forms, such as longitudinally setting a plurality of screw holes on the temperature sensor fixing seat 121, screwing the bracket 13 into the screw holes at different heights by screws, so as to adjust the height of the bracket, or setting the connection between the two as a mortise and tenon structure, clamping the bracket in the slide groove of the temperature sensor fixing seat, and sliding up and down in the slide groove to adjust the height of the bracket. The preferred implementation scheme of the utility model is to adopt a mortise and tenon structure that is easy to adjust, such as Figure 5 .

[0034] The front end of the bracket 13 is provided with a coil bracket 131, and the top of the coil bracket 131 is provided with a coil slot 132. The coil 16 is clamped in the coil slot 132, and its ends are connected to the electronic tag reading and writing device in the control box 3. Figure 6 and Figure 7 .

[0035] A label fixing seat support plate 133 is provided at the top of the bracket 13, and four label fixing seat support plates 133 extending toward the center of the insulation box body 1 at the four corners form a placement platform for the label fixing seat 4, and the diameter of the circle formed by the four coil brackets 131 is slightly larger than the diameter of the label fixing seat 4, so as to limit the label fixing seat 4 placed on the platform.

[0036] The label fixing seat 4 includes two parts: a label base 41 and a label plate 42. A protruding connection seat 411 is provided in the middle of the label base 41, and a label bottom hole 412 is provided on the surface of the label base 41. Figure 8 The corresponding opening in the middle of the label plate 42 is inserted into the connecting seat 411, and the label base 41 is connected to the label plate 42. The label plate 42 is provided with label holes 421 corresponding to the position and number of the label bottom holes 412, such as Fig. 9 The glass tube-shaped electronic tag passes through the tag hole 421 and the bottom falls into the tag bottom hole 412 , so that the electronic tag is placed in the tag fixing seat 4 in a vertical state.

[0037] At least one positioning column 413 is provided on the side of the label base 41, and the label plate 42 has a corresponding opening on the side and is inserted into the positioning column 413 to limit the label plate 42 in the axial direction of the label base 41. The positioning cap 414 is inserted into the top of the positioning column 413 to limit the label plate 42 in the longitudinal direction of the label base 41.

[0038] Due to the limitation of the physical dimensions of the insulation box 1, the bracket 13, the label base 41, the label plate 42 and other related parts, the number of electronic tags that can be placed on the label fixing seat 4 at one time will be limited. In order to increase the number of electronic tags that are synchronously calibrated, the utility model adopts a structure in which multiple groups of label bases 41 and label plates 42 are combined in the longitudinal direction, that is, a screw hole (not shown in the figure) is provided on the back side of the label base 41, and the screw hole corresponds to the thread on the top of the connecting seat 411. The top of the connecting seat 411 is screwed into the screw hole on the back side of another group of label bases 41, so that the two groups of label fixing seats are connected as a whole in the longitudinal direction, such as Fig.10 and Fig.11 The number of electronic tags that can be calibrated simultaneously is doubled. The stacked multiple tag holders are placed on a placement platform formed by the tag holder support plate, the coil is located outside the tag holder, and the multiple electronic tags in the tag holder are just within the magnetic field range of the coil. Fig.12 (In order to clearly show its structure, only the tag holder, bracket and coil are drawn in the figure, and the rest of the parts are omitted). Therefore, the electronic tag reading and writing device in the control box can perform synchronous batch calibration on all electronic tags through the coil. Similarly, the number of tag holders can be further superimposed to increase the number of electronic tags for synchronous calibration, which greatly improves the efficiency of tag calibration compared to the existing method of calibrating single electronic tags one by one.

[0039] Working principle of the utility model: first, insert the electronic tags to be calibrated into the tag holes 421 one by one, and insert the bottom of the electronic tags into the tag bottom hole 412, so that the electronic tags are vertically loaded into the tag fixing seat 4, and then place the tag fixing seat 4 on the placement platform formed by the tag fixing seat support plate 133; second, add liquid, such as water, into the heat preservation box 1 to the liquid level line 18, and ensure that the liquid level is higher than the height of the tag fixing seat 4 and the temperature sensor 12, and then fix the heat preservation box cover 2 to the top of the heat preservation box 1; third, connect the power interface on the control box 3 to the power supply, turn on the power switch button 33, and the heat preservation box 1 enters the working state; fourth, rotate the control knob 31, the display screen 32 displays different instructions, press the control knob 31, select the heating instruction displayed on the display screen 32, The heating rod 11 starts to heat the liquid, the temperature measuring device monitors the temperature of the liquid, and the stirring device stirs the liquid; the fifth step, when the liquid is heated to the preset temperature, the heating rod 11 stops heating, and the stirring device continues to stir the liquid for a certain period of time and then stops stirring, so that the temperature of the liquid in the heat preservation box 1 is uniform; the sixth step, after rotating the control knob 31 and the display screen 32 displays the calibration instruction, press the control knob 31, and the electronic tag reading and writing device in the control box 3 can perform parallel reading and writing operations on all electronic tags through the coil 16, that is, complete the batch calibration operation of the electronic tags; the seventh step, after the display screen 32 shows that the calibration is completed, open the heat preservation box cover 2, take out the tag fixing seat, put in the next tag fixing seat, and wait until the temperature in the box is uniform, then calibrate the next batch of electronic tags. The utility model can calibrate multiple electronic tags synchronously, which not only ensures the consistency of the calibration environment of multiple electronic tags, improves the accuracy of the temperature measurement of the electronic tags, but also greatly improves the efficiency of calibration compared with the existing one-by-one calibration method, and is suitable for batch temperature sensor electronic tag calibration, data writing and other operations.

Claims

1. A device for batch calibration of radio frequency identification temperature sensor tags, comprising an insulation box, an insulation box cover and a control box, wherein the insulation box is provided with a stirring device, a temperature control device and a temperature measuring device which are electrically connected to the control box respectively, and characterized in that: The heat preservation box (1) contains liquid, a coil (16) is provided at the bottom of the heat preservation box (1), a plurality of electronic tags are placed in the tag fixing seat (4), and the electronic tags are located in the magnetic field of the coil (16). After the control box (3) controls the temperature control device to adjust the contained liquid to a preset temperature, the electronic tag reading and writing device in the control box (3) simultaneously performs batch calibration operations on the plurality of electronic tags through the coil (16).

2. The device for batch calibration of radio frequency identification temperature sensor tags according to claim 1, characterized in that: The control box (3) is fixed to one side of the heat preservation box (1); a controller is provided inside the control box (3); a control knob (31), a display screen (32), a switch button (33), a data interface (34) and a power interface electrically connected to the controller are provided outside the control box (3).

3. The device for batch calibration of radio frequency identification temperature sensor tags according to claim 1, characterized in that: The stirring device comprises a motor (22) fixed to the inner wall of the thermal insulation box cover (2), and a fan blade (23) fixed to the shaft of the motor, wherein the connecting rod of the fan blade (23) faces the cavity direction of the thermal insulation box body (1) and is perpendicular to the inner wall of the thermal insulation box cover (2), while the plane of the fan blade (23) is parallel to the inner wall of the thermal insulation box cover (2) and is immersed in the liquid contained in the thermal insulation box body (1).

4. The device for batch calibration of radio frequency identification temperature sensor tags according to claim 1, characterized in that: The temperature control device is a heating rod (11) fixed in the heat preservation box (1); the heating rod (11) is fixed to the inner wall of the heat preservation box (1) via a heating rod fixing seat (111).

5. The device for batch calibration of radio frequency identification temperature sensor tags according to claim 1, characterized in that: The temperature measuring device is a temperature sensor (12) fixed in the heat preservation box (1); temperature sensor fixing seats (121) are vertically installed at the four corners in the heat preservation box (1); a bracket (13) is transversely fixed to the bottom of the temperature sensor fixing seat (121); the two are connected to form an L-shaped structure; the temperature sensor (12) is fixed on the bracket (13) and faces the central axis direction of the heat preservation box (1).

6. The device for batch calibration of radio frequency identification temperature sensor tags according to claim 5, characterized in that: The temperature sensor (12) is a PT100 probe-type temperature sensor, which is divided into two layers, an upper layer and an lower layer, and is respectively arranged at the four corners of the thermal insulation box (1).

7. The device for batch calibration of radio frequency identification temperature sensor tags according to claim 5, characterized in that: A coil bracket (131) is provided at the front end of the bracket (13), a coil slot (132) is provided at the top of the coil bracket (131), the coil (16) is clamped in the coil slot (132), and its head and tail ends are connected to the electronic tag reading and writing device in the control box (3).

8. The device for batch calibration of radio frequency identification temperature sensor tags according to any one of claims 5 or 7, characterized in that: A label fixing seat support plate (133) is provided at the top end of the bracket (13); four label fixing seat support plates (133) extending from the four corners of the heat preservation box (1) toward the center of the heat preservation box form a placement platform for the label fixing seat (4); and the diameter of the circle formed by the four coil brackets (131) is larger than the diameter of the label fixing seat (4), so as to limit the label fixing seat (4) placed on the platform.

9. The device for batch calibration of radio frequency identification temperature sensor tags according to claim 1, characterized in that: The label fixing seat (4) comprises two parts, a label base (41) and a label plate (42); a raised connection seat (411) is provided in the middle of the label base (41), and a label bottom hole (412) is provided on the surface of the label base (41); a corresponding hole is opened in the middle of the label plate (42) and is inserted into the connection seat (411); the label base (41) is connected to the label plate (42); label holes (421) corresponding in position and number to the label bottom holes (412) are provided on the label plate (42); a glass tube type electronic tag passes through the label hole (421) and its bottom falls into the label bottom hole (412), so that the electronic tag is placed in the label fixing seat (4) in a vertical state.

10. The device for batch calibration of radio frequency identification temperature sensor tags according to claim 9, characterized in that: At least one positioning column (413) is provided on the side of the label base (41); a corresponding hole is opened on the side of the label plate (42) and is inserted into the positioning column (413) to limit the label plate (42) in the axial direction of the label base (41); a positioning cap (414) is inserted into the top of the positioning column (413) to limit the label plate (42) in the longitudinal direction of the label base (41).

11. The device for batch calibration of radio frequency identification temperature sensor tags according to any one of claims 9 or 10, characterized in that: The back side of the label base (41) is provided with a screw hole, and the screw hole corresponds to the thread on the top of the connecting seat (411) provided on the other side of the label base. The top of the connecting seat (411) is screwed into the screw hole on the back side of another set of label bases (41), so that the two sets of label fixing seats (4) are connected in the longitudinal direction into one piece.

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