A lever-less 3-inch thermal printer mechanism

Abstract

This invention provides a lever-less 3-inch thermal printer mechanism, including a 3-inch mechanism body, a 3-inch thermal sheet substrate, a stepper motor, a cutter mechanism, and a gear cover mounted on the 3-inch mechanism body. The 3-inch thermal sheet substrate is used to attach the thermal printhead, the stepper motor provides power for the paper feeding action of the mechanism, the cutter mechanism is used to cut the paper, and the gear cover is used to protect the gear set inside the mechanism. This invention, by setting a stepper motor and a cutter motor, achieves automated drive through the printer's internal control unit. Replacing the traditional manual lever adjustment with a stepper motor and cutter motor prevents the cumbersome operation and unstable accuracy problems caused by manual lever adjustment of pressure, paper feeding, or paper cutting, reduces human operation errors, and improves equipment operating efficiency and stability.

Description

Technical Field

[0001] This utility model relates to the technical field of three-inch thermal printer mechanism, specifically a rockerless three-inch thermal printer mechanism. Background Technology

[0002] A thermal printer is a device that uses a thermal printhead to heat the chemical coating on the surface of thermal paper to achieve color printing. With its compact structure and fast printing speed, it is widely used in cash registers, logistics, medical and other scenarios. Its core working component is the printing mechanism, and the performance of the printing mechanism directly determines the printing accuracy, paper feeding stability and paper cutting reliability.

[0003] Existing thermal printer mechanisms have several shortcomings in their structural design and drive methods: many traditional mechanisms rely on manual cranks to adjust printhead pressure, control paper feed, and reset the cutter. Manual operation is not only cumbersome and increases the cost of human intervention, but also prone to uneven pressure between the printhead and paper due to uneven operating force and adjustment errors, resulting in problems such as blurry printing and paper feed deviation. Furthermore, long-term use will further exacerbate the decrease in accuracy due to mechanical wear of the crank. In addition, the V-shaped moving blade and cutter motor positioning structure in existing mechanisms are simple, often using a single buckle or bolt for fixation. This is prone to motor loosening and moving blade positioning deviation, resulting in uneven blade contact during paper cutting, causing incomplete paper cutting, paper jams, or even blade damage, thereby increasing costs and affecting printing efficiency. Utility Model Content

[0004] The purpose of this invention is to provide a lever-less three-inch thermal printer mechanism to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A lever-less 3-inch thermal printer mechanism includes:

[0007] The device comprises a 3-inch main body, a 3-inch thermal substrate, a stepper motor, a cutting mechanism, and a gear cover mounted on the main body. The 3-inch thermal substrate is used to attach the thermal printhead, the stepper motor provides power for the paper feeding action of the device, the cutting mechanism is used to cut the paper, and the gear cover is used to protect the gear set inside the device.

[0008] Preferably, the cutting mechanism includes a V-shaped movable blade, which is fixedly connected to the upper end face of the lower cutter cover. The lower cutter cover is connected to the upper end face of the cutter fixing bracket by a snap fastener. A cutting spring is provided above the V-shaped movable blade. The cutting spring presses down on the V-shaped movable blade to ensure cutting pressure. Both ends of the cutting spring are connected to the threaded holes of the cutter fixing bracket by bolts passing through the through holes of the lower cutter cover in sequence, thereby achieving a stable assembly of the cutting spring, the V-shaped movable blade, and the lower cutter cover on the cutter fixing bracket.

[0009] Preferably, the front end of the lower cutter cover has a slot for snap-fit ​​connection with the front end of the upper cutter cover, and both the rear end of the upper cutter cover and the rear end of the lower cutter cover have through holes for fixed connection by bolts.

[0010] Preferably, the inner sides of both the upper and lower cutter covers are provided with slots adapted to the cutter motor. The slot structure matches the outer contour of the cutter motor housing and is used to engage and fix the cutter motor to limit its displacement during operation and ensure that the cutter motor drives the cutter mechanism to operate normally.

[0011] Preferably, the stepper motor is fixedly connected to the lower part of the 3-inch machine body. The output shaft of the stepper motor is connected to the input gear of the gear set inside the machine body through gear meshing. The output gear of the gear set is connected to one end of the switch plate shaft through a key so that the power of the stepper motor is transmitted to the switch plate shaft through the gear set, driving the switch plate shaft to complete the paper feeding action.

[0012] Preferably, a metal switch plate is fixedly connected to the switch plate shaft, and the metal switch plate is attached to the 3-inch thermal sheet substrate. The rotation of the switch plate shaft is linked to the metal switch plate, so that the 3-inch thermal sheet substrate moves synchronously with the metal switch plate, thereby achieving stable control of the position of the thermal printhead attached to the 3-inch thermal sheet substrate.

[0013] Preferably, one side surface of the 3-inch thermal sheet substrate is provided with a mating plane adapted to the thermal printhead, which is used to tightly fit the thermal printhead for installation and positioning; the hardware switch plate is arranged opposite to the mating plane of the 3-inch thermal sheet substrate, and clamps and fixes the thermal printhead attached to it by cooperating with the 3-inch thermal sheet substrate to prevent the thermal printhead from shifting during operation.

[0014] Preferably, the 3-inch main body of the mechanism is provided with a slot, and the 3-inch thermal substrate, the hardware switch plate and the switch plate shaft are all inserted into and snapped into the slot from the top of the main body of the mechanism. The slot is matched with the contour of each component to achieve precise positioning and ensure the structural stability of each component after installation.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] This invention replaces the traditional manual crank adjustment mechanism by setting up a stepper motor and a cutter motor, and achieving automated drive through the printer's internal control unit. The stepper motor precisely drives the paper feed and adjusts the thermal printhead pressure via a gear set and switch plate shaft. The cutter motor drives the V-shaped movable blade to complete cutting and resetting through an eccentric wheel and linkage mechanism. Compared with the prior art, this invention avoids the cumbersome operation and unstable accuracy caused by manually adjusting the pressure, paper feed, or paper cutting with a crank, reduces human operation errors, and improves the efficiency and stability of equipment operation.

[0017] This utility model features a V-shaped movable blade, which is fixed to the upper surface of the lower cover of the cutter. The lower cover of the cutter is positioned by being engaged with the "L"-shaped groove of the cutter fixing bracket via cylindrical buckles on both sides, and is further secured by the cutter spring clip bolts to form pressure compensation. At the same time, the cutter motor is double-fixed by the inner grooves of the upper and lower covers of the cutter, as well as by the front and rear buckles and bolts, to achieve precise positioning and stable transmission between the motor and the V-shaped movable blade.

[0018] This invention utilizes a stepper motor connected to a switch board shaft via a gear set for transmission. The switch board shaft links the metal switch board and the 3-inch thermal paper substrate for synchronous movement. The 3-inch thermal paper substrate initially positions the thermal print head using a precision-fitting plane, while the metal switch board clamps and fixes it in place. This prevents printing blurriness caused by loose TPH installation or unstable pressure. It ensures uniform and controllable bonding pressure between the TPH and the thermal paper during paper feeding, and, combined with the precise paper feeding drive of the stepper motor, guarantees print clarity and positional accuracy. Attached Figure Description

[0019] Figure 1 This is a three-dimensional schematic diagram of the overall structure of this utility model;

[0020] Figure 2 This is a three-dimensional schematic diagram of the cutter cover of this utility model when opened;

[0021] Figure 3 This is a three-dimensional schematic diagram of the lower cover of the cutter, the cutter, and the installation of the cutter fixing bracket of this utility model;

[0022] Figure 4 This is a three-dimensional schematic diagram of the main body of the 3-inch movement of this utility model;

[0023] Figure 5 This is a three-dimensional schematic diagram of the 3-inch thermal substrate, the hardware switch board, and the connection between the switch board shaft and the stepper motor of this utility model.

[0024] Figure 6 This is a three-dimensional schematic diagram of the hardware switch board and the connection between the switch board shaft and the stepper motor of this utility model;

[0025] Figure 7 This is an exploded view of the overall structure of this utility model;

[0026] Figure 8 This is a schematic diagram of the internal structure of the mechanism of this utility model and its linkage with the printer.

[0027] In the diagram: 1. Cutter top cover; 2. Cutter bottom cover; 3. Cutter spring; 4. V-shaped movable blade; 5. Cutter motor; 6. Cutter fixing bracket; 7. 3-inch main body of the mechanism; 8. Hardware switch board; 9. 3-inch thermal sheet substrate; 10. Switch board shaft; 11. Stepper motor; 12. Gear cover. Detailed Implementation

[0028] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0029] Example:

[0030] Please see Figures 1 to 6 This utility model provides a technical solution:

[0031] A lever-less 3-inch thermal printer mechanism includes a 3-inch main body 7 with a pre-set slot structure. The outline of the slot matches the shape of the 3-inch thermal substrate 9, the hardware switch plate 8, and the switch plate shaft 10. All three are inserted into and snapped into the slot from the top of the main body. Positioning is achieved through outline adaptation, ensuring the relative position stability of each component and providing a basic guarantee for the accuracy of subsequent printing, paper feeding, and other operations.

[0032] The thermal printhead (TPH) is mounted and fixed by a 3-inch thermal substrate 9, a metal switch plate 8, and a switch plate shaft 10. One side surface of the 3-inch thermal substrate 9 is processed to form a mating plane adapted to the thermal printhead. The surface roughness and flatness are strictly controlled to ensure tight contact with the bottom surface of the thermal printhead, thereby achieving the initial positioning of the printhead.

[0033] like Figure 5 As shown, the metal switch plate 8 and the 3-inch thermal sheet substrate 9 are arranged opposite each other, forming a clamping space. When the thermal printhead is attached to the 3-inch thermal sheet substrate 9, the metal switch plate 8 forms a bidirectional clamping and fixing of the printhead through a rigid fit with the substrate, effectively offsetting the displacement force caused by vibration during printing and preventing blurry or misaligned printing caused by printhead displacement.

[0034] like Figure 6As shown, the switch plate shaft 10 serves as the linkage core, with one end fixedly connected to the hardware switch plate 8. The hardware switch plate 8 can be directly linked by the rotation of the shaft, thereby driving the 3-inch thermal sheet substrate 9 to move synchronously, realizing dynamic adjustment and stable control of the working position of the thermal print head, and ensuring uniform bonding pressure between the print head and the thermal paper.

[0035] It should be noted that the thermal printhead (TPH) is the core component of a thermal printer, enabling its printing function. It generates heat through internally arranged heating elements when powered on, causing the chemical coating on the thermal paper to change color, thus forming text or images. The specific structure, heating principle, and circuit control of the thermal printhead are standard technologies in existing thermal printers and will not be elaborated upon here. Regarding the linkage with the printing paper, the switch plate shaft 10 serves as the core linkage component. One end of it is fixedly connected to the hardware switch plate 8. When the switch plate shaft 10 rotates under the power transmitted by the stepper motor 11 through the gear set, it will trigger the hardware switch plate 8 to synchronously move the 3-inch thermal sheet substrate 9. This dynamically adjusts the adhesion pressure between the thermal printhead and the printing paper, ensuring uniform and stable contact during printing and guaranteeing print clarity.

[0036] In this embodiment, the paper feeding power is provided by a stepper motor 11, which transmits power through a gear set to form a complete paper feeding drive chain. The stepper motor 11 is mounted inside the 3-inch main body 7 via a motor bracket (not shown in the figure). Its output shaft is connected to the input gear of the gear set (not shown in the figure) inside the main body of the main body through a precision gear meshing method. The gear teeth are modified to ensure that the meshing clearance is controlled within 0.02mm, so as to ensure that the power transmission is smooth and without slippage. The output gear of the gear set is rigidly connected to the other end of the switch plate shaft 10 through a key connection. The circumferential fixing characteristic of the key connection can efficiently transmit the rotational power of the stepper motor 11 to the switch plate shaft 10. Then, the switch plate shaft 10 links the paper feeding structure (such as rubber rollers) inside and outside the printer main body, so as to achieve smooth and continuous paper feeding. Moreover, the stepping characteristic of the stepper motor 11 can precisely control the paper feeding length to meet the size requirements of different printed content.

[0037] It should be noted that the gear cover 12 covers the outside of the gear set inside the machine mechanism and is detachably connected to the 3-inch machine mechanism body 7 by a buckle or bolt. It can effectively prevent external dust, paper scraps and other debris from entering the gear meshing area, while buffering the impact of external collisions on the gears, ensuring the long-term stable transmission performance of the gear set, and indirectly improving the reliability of paper feeding and linkage actions. The stepper motor 11 is preferably a 16-ohm stepper motor 11. This impedance specification is compatible with the internal circuit and power requirements of the machine mechanism. It can provide stable paper feeding power while achieving precise control of motor speed and rotation angle, ensuring that the power output transmitted to the switch plate shaft 10 through the gear set is uniform and stable, thereby ensuring the smoothness of paper feeding and the accuracy of paper feeding length, meeting the core requirements of 3-inch thermal printers for paper feeding accuracy.

[0038] The 3-inch movement body 7 is also equipped with a cutting structure. It is installed on the 3-inch movement body 7 by a cutting bracket 6. A hook e is provided at the lower front end of the cutting bracket 6. A hook groove f is opened on the 3-inch movement body 7. The hook e is positioned by hooking the hook groove d. Then, the cutting bracket 6 is fixed to the upper end face of the 3-inch movement body 7 by bolts.

[0039] The cutting structure includes a V-shaped movable blade 4 and a cutting motor 5. A cutting spring 3 is mounted above the V-shaped movable blade 4. The two ends of the spring pass through the through holes of the lower cover 2 of the cutting blade with bolts and are then threadedly connected to the pre-set threaded holes of the cutting blade fixing bracket 6. After assembly, the cutting spring 3 is in a slightly deformed state, applying continuous and uniform downward pressure to the V-shaped movable blade 4. This pressure can compensate for paper thickness deviations, ensuring effective contact between the blade and the paper during the cutting process and avoiding incomplete paper cutting or paper jams.

[0040] The V-shaped movable blade 4 is fixed to the upper end face of the cutter lower cover 2. The cutter lower cover 2 has protruding cylindrical buckles c on both sides, and the cutter fixing bracket 6 has "L"-shaped slots d on both sides. The buckles c and slots d are engaged to initially fix the blade. Then, the V-shaped movable blade 4, the cutter lower cover 2 and the cutter fixing bracket are connected by bolts through the cutter spring 3 to ensure the cutting position accuracy of the V-shaped movable blade 4.

[0041] The cutter motor 5 is the power source for the paper cutting action, and it is fixed by a slot positioning system. The inner sides of both the upper cutter cover 1 and the lower cutter cover 2 are provided with slots that match the contour of the cutter motor 5's housing (e.g., ...). Figure 1As shown), after the motor is embedded, the slot can restrict its radial displacement; at the same time, the front end of the upper cutter cover 1 is connected to the recessed slot b at the front end of the lower cutter cover 2 through the buckles a protruding to both sides. After the upper cutter cover 1 and the lower cutter cover 2 are combined, the rear end of the upper cutter cover 1 overlaps with the rear end of the lower cutter cover 2 and is fixed by bolts passing through the preset through holes, forming a two-way constraint at the front and rear, which firmly fixes the cutter motor 5 in the preset position, ensuring that the motor output power can be efficiently transmitted to the cutter mechanism to drive the V-shaped movable blade 4 to complete the precise paper cutting action.

[0042] The cutter motor 5 preferably uses a 24V voltage specification. This voltage is compatible with the power requirements of the cutter mechanism and can provide a stable and sufficient driving force for the paper cutting action. This ensures that when cutting thermal paper of different thicknesses, the power can be efficiently transmitted to the V-shaped movable blade 4 through the transmission mechanism. Combined with the pressure compensation effect of the cutter spring 3, the cutting action can be quickly responded to and accurately executed, ensuring the reliability and stability of the paper cutting process.

[0043] It should be noted that the output shaft of the cutter motor 5 is connected to the linkage structure of the cutter mechanism through an eccentric wheel structure. When the cutter motor 5 receives the control signal that printing is complete, the output shaft of the cutter motor 5 rotates and drives the linkage to move. The linkage converts the rotational power of the motor into a thrust on the V-shaped movable blade 4, driving the V-shaped movable blade 4 to swing downward with the cutter fixed bracket 6 as the fulcrum. At the same time, under the elastic pressure applied in advance by the cutter spring 3, the V-shaped movable blade 4 makes close contact with the corresponding fixed blade surface to complete the paper cutting. After the cutting action is completed, the cutter motor 5 rotates in the opposite direction, the transmission component drives the V-shaped movable blade 4 to reset, and the elastic force of the cutter spring 3 helps it return to the initial ready-to-cut state, realizing the cyclic control of the paper cutting action. The eccentric wheel structure and the linkage are conventional technologies in existing thermal printers, and their specific structures and installation methods will not be described in detail here.

[0044] In this embodiment, a fully automated mechanical structure and motor drive replace the rocker arm used for manually adjusting printhead pressure, manually feeding paper, or resetting the cutter in the traditional mechanism. The paper feeding action is precisely driven by the stepper motor 11 through a gear set and the switch plate shaft 10, eliminating the need for manual rocker arm intervention. The printhead position adjustment and pressure control are automatically completed by the switch plate shaft 10 in conjunction with the hardware switch plate 8 and the 3-inch thermal sheet substrate 9, replacing the pressure adjustment function of the manual rocker arm. The paper cutting action is driven by the cutter motor 5 through an eccentric wheel and linkage mechanism to drive the V-shaped movable blade 4, and is reset with the assistance of the cutter spring 3, eliminating the need for manual rocker arm operation of the cutter. Through motor drive and automated linkage, precise control of the entire process of printing, paper feeding, and paper cutting is achieved, improving print clarity and paper cutting accuracy.

[0045] Ideally, a small microcontroller (MCU) should be installed inside the printer as the main control core, integrating timing control functions for paper feeding, printing, and paper cutting. For example... Figure 8As shown, after receiving the external printing command, the main control unit (small MCU) is powered by the power module and connected to the stepper motor 11, the cutter motor 5 and the heating module of the thermal print head (TPH) through the drive circuit. The main control unit outputs control signals according to the preset logic to drive the stepper motor 11 to achieve precise paper feeding, control the TPH heating element to heat up as needed to complete printing, and trigger the cutter motor 5 to drive the cutter mechanism to move after printing is completed. The entire process is replaced by manual crank operation through circuit signal linkage, with a compact structure and no complicated peripherals.

[0046] In use, the mechanism is installed inside the thermal printer. Thermal paper is fed into the paper inlet of the mechanism. After receiving the external printing command, the printer starts the stepper motor 11 and drives the switch plate shaft 10 to rotate through the gear set. This drives the metal switch plate 8 and the 3-inch thermal sheet substrate 9 to bring the thermal print head into contact with the paper. The thermal print head is powered on and heated to make the thermal paper develop color and complete the printing. During the printing process, the stepper motor 11 synchronously drives the paper to be fed smoothly. After the preset content is printed, the cutter motor 5 receives the signal and drives the V-shaped movable blade 4 to swing downward through the eccentric wheel and linkage mechanism. The paper is cut under the pressure of the cutter spring 3. After cutting, the cutter motor 5 rotates in the opposite direction to drive the V-shaped movable blade 4 to reset. The gear cover 12 provides continuous protection for the gear set. The entire process of automatic printing, paper feeding and paper cutting can be achieved without manual crank operation.

[0047] All other parts of this utility model not described herein are the same as existing technologies, or are known technologies, or can be implemented using existing technologies, and will not be described in detail here.

[0048] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A leverless three-inch thermal printer mechanism, characterized by, include: The 3-inch main body (7) and the 3-inch thermal substrate (9), stepper motor (11), cutter mechanism and gear cover (12) mounted on the 3-inch main body (7); the 3-inch thermal substrate (9) is used to attach the thermal print head, the stepper motor (11) provides power for the paper feeding action of the main body, the cutter mechanism is used to complete the paper cutting, and the gear cover (12) is used to protect the gear set inside the main body.

2. A racking leverless three-inch thermal printer mechanism according to claim 1, characterized in that: The cutting mechanism includes a V-shaped movable blade (4), which is fixedly connected to the upper end face of the lower cover (2). The lower cover (2) is connected to the upper end face of the cutting bracket (6) by a snap fastener. A cutting spring (3) is provided above the V-shaped movable blade (4). The cutting spring (3) presses down on the V-shaped movable blade (4) to ensure cutting pressure. The two ends of the cutting spring (3) are threadedly connected to the threaded holes of the cutting bracket (6) after passing through the through holes of the lower cover (2) in sequence by bolts.

3. A racking leverless three-inch thermal printer mechanism according to claim 2, wherein: The front end of the lower cover (2) of the cutter has a slot for snapping with the front end of the upper cover (1) of the cutter. The rear end of the upper cover (1) of the cutter and the rear end of the lower cover (2) of the cutter are both provided with through holes and are fixedly connected by bolts.

4. A racking leverless three-inch thermal printer mechanism according to claim 3, wherein: The inner sides of the upper cover (1) and lower cover (2) of the cutter are provided with slots that are adapted to the cutter motor (5). The slot structure matches the outer shell contour of the cutter motor (5) and is used to lock and fix the cutter motor (5) to limit the displacement of the cutter motor (5) during operation.

5. A racking leverless three-inch thermal printer mechanism according to claim 1, wherein: The stepper motor (11) is fixedly connected to the lower part of the 3-inch main body (7). The output shaft of the stepper motor (11) is connected to the input gear of the gear set inside the main body through gear meshing. The output gear of the gear set is connected to one end of the switch plate shaft (10) through a key.

6. A racking leverless three-inch thermal printer mechanism according to claim 5, wherein: The switch plate shaft (10) is fixedly connected to the hardware switch plate (8), and the hardware switch plate (8) is in contact with the 3-inch thermal sheet substrate (9). The 3-inch thermal sheet substrate (9) moves synchronously with the hardware switch plate (8) by rotating the switch plate shaft (10).

7. A racking leverless three-inch thermal printer mechanism according to claim 6, wherein: The 3-inch thermal sheet substrate (9) has a mating plane on one side surface that is adapted to the thermal print head, which is used to tightly fit the thermal print head to achieve installation and positioning; the hardware switch plate (8) is arranged opposite to the mating plane of the 3-inch thermal sheet substrate (9), and clamps and fixes the thermal print head attached to it by cooperating with the 3-inch thermal sheet substrate (9).

8. A racking leverless three-inch thermal printer mechanism according to claim 7, wherein: The 3-inch main body (7) is provided with a slot, and the 3-inch thermal substrate (9), the hardware switch plate (8) and the switch plate shaft (10) are all inserted from the top of the main body and snapped into the slot.

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