A control method and device for automatically switching paper output of double rolls

Abstract

This invention discloses a control method and device for automatic switching of paper dispensing between two rolls, belonging to the field of sanitary equipment technology. The device includes a switching mechanism, a floating clamping mechanism, first and second detection units, a control unit, and a paper dispensing drive unit. The switching mechanism selectively presses the first or second drive shaft against the driven shaft; the floating clamping mechanism adaptively adjusts the clamping force of the driven shaft; the detection units detect the presence or absence of paper rolls at the two paper inlets; the control unit controls the switching mechanism based on the detection results, causing the drive shaft on the side with the paper roll to press against the driven shaft, and the paper dispensing drive unit drives this drive shaft to output paper towels. This invention also provides a corresponding control method. This invention achieves automatic and smooth switching between two rolls, adaptive clamping for paper of different thicknesses, automatic paper loading through closed-loop detection throughout the process, precise control of the paper dispensing length, and a remote alarm function for paper shortages, improving the reliability and user experience of automatic paper dispensing equipment in public places.

Description

Technical Field

[0001] This invention relates to the field of sanitary equipment technology, and more specifically, to a control method and device for automatic switching of dual rolls of toilet paper or hand towel dispensers in public places. Background Technology

[0002] Currently, automatic paper dispensing devices are widely installed in public places such as airports, shopping malls, hospitals, and office buildings to facilitate cleaning for users. Users can automatically dispense a set length of paper towels by sensing a button or manually triggering it. These devices typically have a built-in paper roll, which needs to be replaced promptly by staff to ensure continuous availability. This single-roll dispensing method is simple in structure and low in cost, making it the mainstream solution in the current market.

[0003] However, single-roll paper output has significant limitations: when the paper roll runs out and staff fail to replenish it in time, the equipment will be unable to output paper, causing inconvenience to users and even leading to complaints. To address this issue, some existing technologies have proposed automatic switching solutions for dual-roll or multi-roll paper output. For example, some solutions use two paper output components with unidirectional drive wheels, selecting one output roller to drive by changing the rotation direction of the drive motor, thus achieving dual-roll switching; other solutions use stacked dual rolls, releasing the backup roll by rotating a support rod and allowing it to fall to the output position by gravity, with sensors enabling automatic switching; still other solutions use a swing switching mechanism or an electromagnet-driven pressure roller switching mechanism for roll switching in document printing or industrial paper laying applications.

[0004] Although the aforementioned existing technologies have achieved switching between dual or multiple rolls of paper to some extent, they still have the following shortcomings:

[0005] 1. Insufficient stability and adaptability of the switching mechanism: The switching scheme using a one-way drive wheel or an electromagnet pressure roller is prone to problems such as transmission slippage, pressure roller wear, or incomplete switching during long-term use. In particular, for paper towels of different thicknesses and materials, the clamping force cannot be adjusted adaptively, which can easily lead to paper jams or poor paper output.

[0006] 2. Lack of complete closed-loop detection and automatic paper loading logic: Most existing solutions only detect whether the paper roll is empty, but do not perform full-process detection on whether new paper is successfully loaded into the paper inlet and whether paper towels are output normally from the paper outlet. This results in the paper loading process requiring manual intervention or being prone to errors, making it impossible to achieve truly fully automatic operation.

[0007] 3. Low precision in paper output length control: Existing solutions mostly use timed paper output or simple rotation count estimation, which makes it difficult to accurately control the length of the paper towels output each time, which can easily lead to waste or paper output that is too short, affecting the user experience.

[0008] 4. No automatic maintenance prompts when paper is out: When both rolls are used up, the existing equipment usually only stops working and cannot actively issue a paper replenishment reminder, resulting in poor timeliness of equipment maintenance.

[0009] Therefore, there is an urgent need in the field for an automatic paper output technology that can achieve smooth switching between two rolls, adapt to different paper thicknesses, implement closed-loop detection and automatic paper loading throughout the entire process, and precisely control the paper output length. This invention proposes a solution to the aforementioned technical problems. Summary of the Invention

[0010] This invention aims to overcome the technical defects of existing dual-roll automatic paper dispensing equipment, such as poor stability of the switching mechanism, insufficient adaptability to different paper thicknesses, lack of closed-loop detection and automatic paper loading logic throughout the process, low accuracy of paper dispensing length control, and lack of active paper shortage reminders. It provides a control method and device for automatic dual-roll switching paper dispensing, so as to achieve smooth and reliable switching between dual rolls, adaptability to different paper thicknesses, fully automated operation, precise control of paper dispensing length, and intelligent maintenance reminder function, thereby improving the user experience and maintenance convenience of automatic paper dispensing equipment in public places.

[0011] To achieve the above-mentioned objectives, the first aspect of this invention provides a dual-roll automatic switching paper output device, which adopts a modular and functional upper-level structure, as detailed below:

[0012] The device includes:

[0013] A switching mechanism is used to selectively press a first drive shaft or a second drive shaft with a driven shaft. The switching mechanism is movable between two working positions: in a first working position, the first drive shaft is pressed with the driven shaft to form a first paper feed channel; in a second working position, the second drive shaft is pressed with the driven shaft to form a second paper feed channel.

[0014] A floating clamping mechanism is used to keep the driven shaft in contact with the currently selected drive shaft in a manner that adaptively adjusts the clamping force. This mechanism can automatically adjust the clamping force between the driven shaft and the drive shaft according to the paper thickness, so that paper towels of different thicknesses and materials can be stably fed without slippage or paper jams.

[0015] The first detection unit is located at the first paper inlet and is used to detect the presence or absence of the first paper roll. Preferably, the detection unit is an infrared phototransistor; when a tissue is inserted, the infrared light is blocked, generating a detection signal.

[0016] The second detection unit is located at the second paper inlet and is used to detect the presence or absence of the second paper roll.

[0017] The control unit is electrically connected to the switching mechanism, the first detection unit, and the second detection unit, respectively. Based on the detection results from the first and second detection units, the control unit controls the switching mechanism to engage the drive shaft on the side with the paper roll with the driven shaft. Specifically, if both working positions have paper rolls, the first working position is used first for paper output. Once the paper roll in the first working position is depleted, a paper shortage alarm is triggered, and the system automatically switches to the second working position for paper output. Sufficient time is allowed for the first working position to replenish paper before the paper roll in the second working position runs out. Once the paper roll in the second working position is depleted, a paper shortage alarm is also triggered, and this process repeats.

[0018] The paper output drive unit is used to drive the currently pressed drive shaft to rotate to output paper towels. The paper output drive unit includes a paper output motor and its transmission gear set. After the switching mechanism completes the position selection, the paper output motor starts and drives the selected drive shaft to rotate through gear transmission. The friction between the drive shaft and the driven shaft is used to transport the paper towels from the paper inlet to the paper outlet.

[0019] As a further improvement, the device also includes a third detection unit located at the paper output port to detect whether tissue paper has been output to the paper output port. When the third detection unit detects that tissue paper has arrived at the paper output port, the control unit issues a command to stop the paper output drive unit and triggers the paper cutting action. This setup achieves closed-loop verification of whether the paper output is successful.

[0020] As a further improvement, the device also includes a length control unit for measuring the length of the output tissue. When the preset length is reached, the control unit stops the paper output drive unit and triggers the paper cutting. The length control unit can be implemented using a counting wheel in conjunction with an infrared slotted tube: the counting wheel rotates in conjunction with the driven shaft or drive shaft, the counting wheel has multiple counting blades, and the infrared slotted tube is set on both sides of the counting wheel. By detecting the number of counting blades passing through, the length of the output tissue is converted, thereby achieving precise length control.

[0021] As a further improvement, the device also includes a paper cutting unit for cutting the paper towels output to a set length under the control of the control unit. The paper cutting unit includes a paper cutting motor and a cutter. When the paper output length reaches the set value, the paper cutting motor drives the cutter to cut the paper towel, completing a single paper dispensing operation.

[0022] A second aspect of the present invention also provides a control method for automatic switching between dual rolls of paper, comprising the following steps:

[0023] Step S1: Detection Step

[0024] The first detection unit detects whether there is a first paper roll at the first paper inlet, and the second detection unit detects whether there is a second paper roll at the second paper inlet.

[0025] Step S2: Switch steps

[0026] Based on the test results, control the switching mechanism to press the drive shaft on the side with the paper roll into contact with the driven shaft.

[0027] When there is paper in the first paper inlet, the control switching mechanism moves to the first working position, so that the first drive shaft and the driven shaft are pressed together, and the first paper inlet is set as the current working channel;

[0028] When the first paper inlet is empty and the second paper inlet is filled with paper, the control switching mechanism moves to the second working position, causing the second drive shaft to press against the driven shaft, and the second paper inlet is set as the current working channel. At the same time, a first paper shortage alarm signal is issued to prompt the replenishment of the paper roll from the first paper inlet.

[0029] When there is no paper in the second paper inlet, a second paper shortage alarm signal is issued to prompt the replenishment of paper rolls in the second paper inlet. At the same time, the switching mechanism is controlled to move to the first working position, and this process is repeated.

[0030] Step S3: Paper output step

[0031] The paper output drive unit controls the rotation of the currently pressed drive shaft to output paper towels. Simultaneously, a third detection unit detects whether paper towels are being output from the paper outlet. If no paper towels are detected within a set time, a paper jam is detected, and a fault alarm is issued.

[0032] Step S4: Length control and paper cutting

[0033] When the output tissue length is detected to have reached a preset value, the paper output drive unit stops and the paper cutting unit is controlled to cut the tissue. The output tissue length is measured by a length control unit, specifically by using a counting wheel in conjunction with an infrared slotted tube to detect the number of times the counting blades pass by, which is then converted into the output tissue length.

[0034] As a preferred solution, this control method defaults to setting the first paper inlet as the priority working channel, meaning that as long as there is paper in the first paper inlet, the first paper roll is always used first; only when the first paper roll is exhausted and the second paper roll is available, will it automatically switch to the second paper roll. After switching to the second paper roll, if the first paper roll is replaced (i.e., the first detection unit detects paper again), it can be set to automatically switch back to the first paper roll, or maintain the second paper roll until it is exhausted before switching. The above logic can be implemented through control unit programming.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. Smooth and reliable switching, adaptable to different paper thicknesses: The switching mechanism of this invention uses translational mechanical displacement to achieve the pressing and separation of the drive shaft and driven shaft. It has a simple structure, reliable operation, and is not prone to wear or failure over long-term use. In particular, the introduction of a floating clamping mechanism allows the driven shaft to automatically adjust the clamping force according to the paper thickness, achieving stable feeding of both thin toilet paper and thick hand towels, effectively avoiding slippage or paper jams. In contrast, existing unidirectional drive wheels or electromagnet pressure rollers are difficult to adapt to different paper thicknesses.

[0037] 2. Closed-loop detection throughout the entire process, achieving truly fully automated operation: This invention sets up detection units at the first paper inlet, the second paper inlet, and the paper outlet, forming a complete closed loop of "paper feed detection—switching control—paper output verification—paper jam alarm." When a user or maintenance personnel loads a new paper roll, the paper feed detection unit automatically senses it, and the control unit then drives the switching mechanism to connect with the paper roll, automatically completing the entire process of paper feeding, cutting, and preparation without manual intervention. The detection unit at the paper outlet ensures successful verification of each paper output action, and can promptly alarm if a paper jam occurs. Most existing technologies only detect the presence or absence of a paper roll, lacking closed-loop control over the paper loading process and the paper output result.

[0038] 3. Precise control of paper output length, saving resources and improving user experience: This invention uses a length control unit (counting wheel + infrared grooved tube) to precisely measure the length of the output tissues. Compared with existing technologies that use timed paper output or rough estimation of the number of rolls, the accuracy is greatly improved. Users can obtain tissues of consistent length each time, avoiding waste and ensuring a good user experience. At the same time, precise length control also provides an accurate trigger signal for the paper cutting unit, ensuring neat cuts.

[0039] 4. Intelligent paper shortage alarm for convenient equipment maintenance: When the first paper roll runs out, the control unit immediately issues a paper shortage alarm signal to prompt for paper replenishment and automatically switches to the second paper roll, allowing sufficient time for replenishment before the second paper roll runs out. When the second paper roll runs out, a paper shortage alarm signal is also issued, and the system automatically switches back to the first paper roll, repeating this cycle to ensure continuous equipment availability. When both rolls are exhausted, a dual-roll paper shortage alarm is issued and transmitted via wireless communication module to the back-end management system or maintenance personnel's mobile phone, enabling intelligent inspection and maintenance scheduling.

[0040] 5. Modular design facilitates manufacturing and after-sales maintenance: The device of this invention adopts a functional modular design (switching mechanism, floating clamping mechanism, detection unit, control unit, paper output drive unit, length control unit, paper cutting unit, etc.), with clear interfaces for each module, facilitating industrial production and assembly. Furthermore, when a module malfunctions, it can be replaced individually, reducing after-sales maintenance costs. Attached Figure Description

[0041] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. The components in the drawings are for illustrative purposes only and are not strictly drawn to scale.

[0042] Figure 1 This is a perspective view of the overall structure of the dual-roll automatic paper switching device provided in an embodiment of the present invention, showing the relative positional relationship of the first paper inlet, the second paper inlet, the drive shaft, the driven shaft, the reversing shaft frame, and the detection unit.

[0043] Figure 2 for Figure 1 A schematic diagram of the internal structure of the front side of the device shown.

[0044] Figure 3 for Figure 1 A schematic diagram of the internal structure of the gearbox in the device shown.

[0045] Figure 4 The control system block diagram provided in the embodiment of the present invention shows the connection relationship between the control unit and each detection unit, execution unit (commutation motor, paper output motor, paper cutting motor) and wireless communication module;

[0046] Figure 5 A flowchart of a control method for automatic paper switching between two rolls provided in an embodiment of the present invention;

[0047] Figure 6 yes Figure 1 A schematic diagram of the internal structure of the rear side of the device shown.

[0048] Figure 7 This is a schematic diagram of the paper cutting unit at the paper outlet in an embodiment of the present invention, which focuses on showing the positional relationship between the paper cutting motor and the cutter.

[0049] Explanation of icon numbers:

[0050] 100-Frame; 101-Paper feed shaft holder fixing plate; 102-Shaft holder base plate; 103-First slot; 104-Second slot; 201-Reversing motor; 202-Motor gear; 203-Rack; 204-Reversing shaft holder; 301-First drive shaft; 302-Second drive shaft; 304-First drive gear; 305-Second drive gear; 306-Gearbox; 307-Intermediate transmission gear; 308-Paper output motor; 401-Driven shaft; 40 2-Driven bushing; 404-Irregularly shaped spring; 406-Irregularly shaped spring legs; 501-First paper inlet; 502-Second paper inlet; 601-First detection unit; 602-Second detection unit; 603-Third detection unit; 701-Counting wheel; 702-Counting blade; 703-Infrared slotted tube pair; 801-Paper cutting motor; 802-Moving knife assembly; 803-Paper outlet; 804-Moving cutter; 805-Static cutter; 806-Worm gear transmission mechanism. Detailed Implementation

[0051] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0052] Example 1: Specific structure of the dual-roll automatic paper switching device

[0053] like Figures 1 to 3 As shown, this embodiment provides a dual-roll automatic paper feeding device, suitable for wall-mounted or tabletop automatic paper feeders in public places.

[0054] The device includes a frame 100, which includes an integrally formed shaft support base plate 102. A paper feed shaft support fixing piece 101 is also fixed on the frame 100, forming a first vertically extending slot 103 (for sliding of the reversing shaft support). The two ends of the reversing shaft support 204 are embedded in the slot 103 and can slide back and forth within the length of the slot 103. Limit switches are provided at the upper and lower limit positions of the reversing shaft support 204. The limit switches are slotted photoelectric pairs located on the outside of the rack 203. A detection slot is opened at the corresponding position on the rack 203. When the reversing shaft support 204 moves to the upper or lower limit position, the detection slot moves into the detection area of ​​the slotted photoelectric pair, thereby determining the position of the reversing shaft support 204.

[0055] The commutator motor 201 is fixed to the frame 100, and its output shaft is equipped with a motor gear 202. A rack 203 is fixedly connected to the upper side of the commutator shaft bracket 204, and the rack 203 meshes with the motor gear 202. When the commutator motor 201 rotates forward or in reverse, the motor gear 202 drives the rack 203 to move linearly, thereby driving the commutator shaft bracket 204 to slide in the strip groove 103.

[0056] A first drive shaft 301 and a second drive shaft 302 are arranged side by side on the reversing shaft bracket 204. Both ends of each drive shaft are mounted in bushings within the reversing shaft bracket 204 via drive shaft bearings, allowing free rotation. One end of each drive shaft extends into the gearbox 306 and is fixedly fitted with a drive gear: a drive gear 304 is mounted on the first drive shaft 301, and a drive gear 305 is mounted on the second drive shaft 302. The gearbox 306 contains an intermediate transmission gear 307 that is connected to the output shaft of the paper output motor 308. The power from the paper output motor 308 can be selectively transmitted to either the drive gear of the first drive shaft 301 or the second drive shaft 302, depending on the position of the reversing shaft bracket 204 (described in detail below).

[0057] The driven shaft 401 is located between the first drive shaft 301 and the second drive shaft 302, and the axes of the three are parallel to each other and approximately in the same plane (minor tolerances are allowed). Both ends of the driven shaft 401 are fixed to the driven shaft sleeve 402 by driven shaft bearings. The outer side of the driven shaft sleeve 402 is designed with a flat structure (e.g., a milled rectangular cross-section). The reversing shaft bracket 204 has a second slot 104 (parallel to the first slot 103) inside. The flat portion of the driven shaft sleeve 402 is embedded in this second slot 104, allowing the driven shaft sleeve 402 to move slightly up and down along the second slot 104.

[0058] The floating clamping mechanism is one of the core improvements of this invention. It includes a shaped spring 404 (i.e., an elastic element) made of piano wire or spring steel strip, in a rectangular or "U" shape. The center of the shaped spring 404 is fixed to the paper feed shaft holder fixing plate 101 by screws, forming a groove between its two legs. The flat groove of the driven shaft sleeve 402 fits precisely between the two legs of the shaped spring 404. The shaped spring 404 provides a certain preload, ensuring that the driven shaft 401 always tends to move closer to the drive shaft.

[0059] When the reversing shaft bracket 204 moves to a certain working position, such as the first working position above, the first drive shaft 301 and the driven shaft 401 are directly opposite each other. The irregular spring 404 pushes the driven shaft 401 against the first drive shaft 301, forming the first paper inlet 501 between them. If the paper towel is thick, the driven shaft 401 will overcome the slight elasticity of the irregular spring 404 and retract outward, thereby automatically adjusting the clamping force; if the paper towel is thin, the irregular spring 404 will keep the driven shaft 401 pressed more tightly. This design can accommodate toilet paper or hand towels of different thicknesses from 30g / m² to 60g / m².

[0060] Similarly, when the reversing shaft bracket 204 moves to the lower second working position, the second drive shaft 302 presses against the driven shaft 401 to form the second paper inlet 502.

[0061] A first detection unit 601 and a second detection unit 602 are respectively provided on the downstream side of the first paper inlet 501 and the second paper inlet 502 (near the engagement point of the drive shaft and the driven shaft). In this embodiment, the detection unit is an infrared pair, each pair including an infrared emitting tube and an infrared receiving tube, which are respectively installed on both sides of the paper feeding channel. When a tissue is inserted, the infrared light is blocked, and the receiving tube outputs a low-level signal to the control unit (not shown in the figure).

[0062] A third detection unit 603 is set at the paper outlet 803, which also uses an infrared pair to detect whether the paper towel has been successfully output to the paper outlet.

[0063] A counting wheel 701 is linked to the output end of the paper output motor 308 (it can also be linked to the driven shaft 401 or the drive shaft). Multiple radial counting blades 702 (e.g., 6 or 8 blades) are evenly distributed on the counting wheel 701. An infrared slotted tube 703 is fixed to one side of the counting wheel 701, with its U-shaped groove spanning both sides of the counting blades 702. When the paper output motor 308 rotates, the counting wheel 701 rotates accordingly, and the counting blades 702 sequentially pass through the detection area of ​​the infrared slotted tube 703, generating a pulse for each blade. The control unit converts the number of pulses into the number of rotations of the driven shaft 401, and then, combined with the diameter ratio of the drive shaft and the driven shaft and the known paper towel conveying linear speed coefficient, calculates the actual output paper towel length (e.g., 5 mm per pulse).

[0064] The paper cutting motor 801 and the cutter assembly 802 constitute the paper cutting unit. For example... Figure 6 and Figure 7As shown, the cutter assembly 802 includes a movable cutter 804 and a stationary cutter 805. The movable cutter 804 is located above the paper outlet 803 and is connected to the paper cutting motor 801 via a worm gear transmission mechanism 806. The stationary cutter 805 is fixed to the lower side of the paper outlet 803. When a preset length (e.g., 200mm) is reached, the control unit stops the paper outlet motor 308 and drives the paper cutting motor 801 to operate once, cutting the paper towel.

[0065] Figure 4 This is a block diagram of a control system provided in an embodiment of the present invention. The control unit includes a microcontroller and a motor drive circuit. The input terminals of the control unit are respectively connected to: a first detection unit 601 (for detecting whether there is paper in the first paper inlet), a second detection unit 602 (for detecting whether there is paper in the second paper inlet), a third detection unit 603 (for detecting whether there is paper in the paper outlet), and an infrared slotted diode pair 703 (for outputting counting pulses). The output terminals of the control unit are respectively connected to: a reversing motor 201 (for driving the switching mechanism), a paper output motor 308 (for outputting paper towels), and a paper cutting motor 801 (for cutting paper towels). In addition, the control unit 900 is also bidirectionally connected to a wireless communication module (for reporting paper shortage status and receiving remote commands), and unidirectionally connected to an audible and visual alarm (for fault alarm). Furthermore, the device may also include an infrared induction reflective sensor and an infrared pyroelectric sensor. The infrared induction reflective sensor is installed at the paper dispensing window on the device panel to sense paper dispensing gestures and trigger a paper dispensing signal. The infrared pyroelectric sensor is used to identify the flow of people, can count the frequency of equipment use, provide data reference for maintenance personnel, and realize intelligent management.

[0066] The specific workflow of this invention embodiment is as follows:

[0067] Automatic paper loading process: When maintenance personnel insert the beginning of a new paper roll into the first paper inlet 501, the first detection unit 601 is triggered. After detecting this signal, the control unit first determines the current position of the reversing shaft 204 (which can be determined by the Hall sensor of the reversing motor 201 or the limit switch). If it is not currently in the first working position, the reversing motor 201 is started to rotate forward, driving the reversing shaft 204 to move to the position where the first drive shaft 301 and the driven shaft 401 are pressed together (positioned by the limit switch or the number of stepper motor pulses). Subsequently, the paper output motor 308 starts, driving the first drive shaft 301 to rotate and conveying the paper towel to the paper output outlet 803. When the third detection unit 603 detects that the paper towel has reached the paper output outlet, the paper output motor 308 stops, the paper cutting motor 801 drives the cutter 802 to cut the paper once, completing the paper loading, and the equipment enters the standby state.

[0068] Normal paper feeding process: The user triggers a paper feeding signal (such as an infrared sensor or button), and the control unit calls the current working channel (default first paper inlet 501). The paper output motor 308 starts, and the counting wheel 701 starts counting. When the cumulative number of pulses reaches the number of pulses corresponding to the preset length, the paper output motor 308 stops, and the paper cutting motor 801 operates to complete one paper feeding cycle.

[0069] Dual paper rolls can be installed simultaneously. The control unit is set by default to prioritize the first paper inlet 501 as the working channel. That is, as long as there is paper in the first paper inlet 501, the first paper roll is always used first; only when the first paper roll is exhausted and the second paper roll is available will it automatically switch to the second paper roll. When the first paper roll is replenished (the first detection unit 601 detects paper again), the control unit can be set to automatically switch back to the first paper roll, or maintain the second paper roll until it is exhausted before switching. The above logic can be implemented through control unit programming.

[0070] Automatic paper shortage switching: When the paper roll at the first paper inlet 501 is depleted, the first detection unit 601 continuously detects no paper (and the third detection unit 603 also fails to detect paper output during multiple paper feeding attempts). The control unit determines that the first paper inlet 501 is out of paper and immediately sends a first paper shortage alarm signal to the staff via the wireless communication module, prompting them to replenish the paper roll at the first paper inlet. Simultaneously, the control unit checks the status of the second paper inlet 502: if there is paper, the reversing motor 201 reverses, driving the reversing shaft bracket 204 to move to the second working position, causing the second drive shaft 302 to engage with the driven shaft 401, and switching the current working channel to the second paper inlet 502, automatically executing the paper loading process. Sufficient time is allowed for replenishing the first paper roll before the second paper roll is depleted; when the second paper roll is depleted, a second paper shortage alarm signal is issued, and the system automatically switches to the first paper roll for output, repeating this process to ensure that replenishment time is always available during the dual-roll switching process. If the second paper inlet 502 is also out of paper, a paper shortage alarm signal (dual roll paper shortage) will be sent through the wireless communication module.

[0071] Paper jam handling: During the paper feeding process, if the paper feeding motor 308 starts for more than the set time (e.g., 2 seconds) and the third detection unit 603 still does not detect the paper towel, the control unit determines that there is a paper jam, stops all motors, and issues an alarm through the sound and light alarm, while simultaneously reporting the fault through the wireless communication module.

[0072] In other optional embodiments of the present invention, the irregular spring 404, in addition to spring wire, can also be a helical compression spring in conjunction with a floating bearing seat to achieve adaptive clamping of the driven shaft, but the guiding structure of the driven shaft sleeve must be ensured; the infrared pairs of each detection unit can be replaced with microswitches or Hall sensors, but the infrared method is non-contact and has higher reliability; the software of the control unit can be set to "first paper inlet 501 priority" or "alternate use" mode to balance the usage frequency of the two rolls of paper and avoid aging caused by long-term idleness of one roll. A "roll change button" can also be set on the control panel of the control unit. When the maintenance personnel press it, the control unit automatically moves the current channel to the paperless side for easy manual paper loading; in addition, the control unit can also be designed with a remote reset function to receive remote commands through a wireless communication module to realize equipment status query, parameter setting (such as paper output length), and fault reset.

[0073] Example 2: Control method for automatic paper output switching between dual rolls

[0074] Based on the above-described apparatus, this embodiment details the steps and flow of the control method, which consists of... Figure 5 The flowchart shown illustrates this, and it is implemented by the firmware program within the control unit.

[0075] Step S101 (Power-on Initialization): After the control unit is powered on, it first drives the reversing motor 201 to find the zero position (for example, by using a limit switch to determine the middle position of the reversing shaft 204 or the position of the first paper inlet 501). Then, it reads the status of the first detection unit 601 and the second detection unit 602. If there is paper in a certain paper inlet, it automatically switches to that side and performs paper loading (see steps S102 to S104).

[0076] Step S102 (Paper Roll Detection and Channel Selection): The control unit periodically (every 100ms) reads the signals from the first detection unit 601 and the second detection unit 602. If the detection unit of the current working channel shows that there is paper, the current channel is maintained; if there is no paper in the current channel but there is paper in another channel, the switching process is initiated.

[0077] Step S103 (Switch Execution): The control unit outputs PWM pulses (forward or reverse rotation) to the commutator motor 201, while simultaneously monitoring the position sensor (limit switch or encoder) of the commutator shaft 204. When the target position is reached (for example, the first paper feed port 501 corresponds to pulse number N1, and the second paper feed port 502 corresponds to N2), the commutator motor 201 is locked.

[0078] Step S104 (Paper Loading or Discharging): If the current channel is a newly switched channel and paper loading has not yet been completed (as recorded by the flag), the paper loading subroutine is executed: the paper discharging motor 308 runs at a low speed (e.g., 200 rpm) until the third detection unit 603 detects the paper towel, then stops and cuts the paper once, setting the "Paper Loaded" flag. If the current channel has completed paper loading and a user paper removal command is received, the normal paper discharging subroutine is executed: the paper discharging motor 308 runs at a high speed (e.g., 400 rpm), and the counting wheel 701 starts counting, stopping and cutting the paper after reaching the preset length.

[0079] Step S105 (Fault Handling): If the paper output motor 308 runs for more than 2 seconds and the third detection unit 603 has no signal, a paper jam alarm is triggered, the fault code is recorded, and an attempt is made to reverse the paper output motor 308 a short distance to release the paper jam. If it fails three times in a row, a permanent alarm is triggered and the service is stopped.

[0080] Step S106 (Paper Out Alarm): When the first detection unit 601 or the second detection unit 602 detects that there is no paper, the control unit sends an HTTP request to the server via the wireless communication module 903 (such as ESP8266) to inform it of the identification code and the paper out status. At the same time, the audible and visual alarm 904 issues an audible and visual alert.

[0081] Through prototype testing, the inventors demonstrated that using various paper towels with thicknesses ranging from 0.1mm to 0.3mm, no paper jams or switching failures occurred after 500 consecutive switching cycles; the paper output length error was controlled within ±2mm; and the paper shortage detection and remote alarm response time was less than 1 second. Compared to existing single-roll equipment, the average trouble-free operating time was extended by 3 times, and the user complaint rate decreased by 80%.

[0082] The dual-roll automatic paper feeding device and method of the present invention can be widely used in automatic toilet paper machines and hand towel machines in public places such as airports, high-speed rail stations, shopping malls, hospitals, and office buildings. It can also be used in the paper towel supply module of smart toilet seats in homes, and has good industrial applicability and market prospects.

Claims

1. A dual-roll automatic paper switching device, characterized in that, include: A switching mechanism for selectively pressing a first drive shaft or a second drive shaft against a driven shaft; A floating clamping mechanism is used to keep the driven shaft in contact with the currently selected drive shaft in a manner that allows for adaptive adjustment of the clamping force; The first detection unit is located at the first paper inlet and is used to detect the presence or absence of the first paper roll. The second detection unit is located at the second paper inlet and is used to detect the presence or absence of the second paper roll. The control unit is electrically connected to the switching mechanism, the first detection unit, and the second detection unit respectively. The control unit controls the switching mechanism to operate according to the detection results of the first detection unit and the second detection unit, so that the drive shaft on the side with the paper roll is pressed against the driven shaft. The paper output drive unit is used to drive the currently pressed drive shaft to rotate in order to output paper towels.

2. The dual-roll automatic paper switching device according to claim 1, characterized in that, The switching mechanism includes: A commutator motor, the output shaft of which is equipped with a motor gear; A rack meshes with the motor gear; The reversing shaft bracket is fixedly connected to the rack and can be slidably mounted in the strip groove on the frame; The first drive shaft and the second drive shaft are arranged side by side on the reversing shaft bracket and move with the movement of the reversing shaft bracket.

3. The dual-roll automatic paper switching device according to claim 1 or 2, characterized in that, The floating clamping mechanism includes: A driven shaft is disposed between the first drive shaft and the second drive shaft; Driven bushings are fitted onto both ends of the driven shaft. The outer side of the driven bushings has a flat structure and slides in fit with the strip groove on the frame. An elastic element is fixed to the frame, and the flat structure of the driven bushing is fitted between the two feet of the elastic element to provide adaptive clamping force.

4. The dual-roll automatic paper switching output device according to claim 1, characterized in that, Also includes: The third detection unit is located at the paper outlet and is used to detect whether the paper towel is output to the paper outlet; The control unit also controls the paper output drive unit to stop outputting and triggers the paper cutting action based on the detection signal from the third detection unit.

5. The dual-roll automatic paper switching device according to claim 1, characterized in that, Also includes: The length control unit measures the length of the output tissue. When the preset length is reached, the control unit stops the paper output drive unit and triggers the paper cutting.

6. The dual-roll automatic paper switching device according to claim 5, characterized in that, The length control unit includes: A counting wheel, rotating in conjunction with a driven shaft or a driving shaft, wherein the counting wheel is provided with multiple counting blades; and, Infrared slotted tubes are arranged on both sides of the counting wheel to detect the number of times the counting blades pass by.

7. The dual-roll automatic paper switching output device according to claim 1, characterized in that, Also includes: The paper cutting unit is used to cut the paper towels output to a set length under the control of the control unit.

8. A control method for automatic switching between dual rolls of paper, characterized in that, Includes the following steps: Step S1: The first detection unit detects whether there is a first paper roll at the first paper inlet, and the second detection unit detects whether there is a second paper roll at the second paper inlet; Step S2: Based on the detection results, control the switching mechanism to press the drive shaft on the side with the paper roll into contact with the driven shaft; Step S3: Control the paper output drive unit to drive the currently pressed drive shaft to rotate and output paper towels; Step S4: When the output tissue length is detected to reach the preset value, stop the paper output drive unit and control the paper cutting unit to cut the tissue.

9. The control method for automatic switching between dual rolls of paper as described in claim 8, characterized in that, Step S2 specifically includes: When there is paper in the first paper inlet, the control switching mechanism moves to the first working position, so that the first drive shaft and the driven shaft are pressed together, and the first paper inlet is set as the current working channel; When the first paper inlet is empty and the second paper inlet is filled with paper, the control switching mechanism moves to the second working position, causing the second drive shaft to press against the driven shaft, and the second paper inlet is set as the current working channel. At the same time, a first paper shortage alarm signal is issued to prompt the replenishment of the paper roll from the first paper inlet. When there is no paper in the second paper inlet, a second paper shortage alarm signal is issued to prompt the replenishment of the paper roll in the second paper inlet, and at the same time, the switching mechanism is controlled to move to the first working position.

10. The control method for automatic switching between dual rolls of paper as described in claim 8, characterized in that, The step S3 is followed by: The third detection unit detects whether there is paper towel output from the paper tray. If no paper towel is detected within the set time, a paper jam is determined and a fault alarm is issued. In step S4, the number of counting blades passing through is detected by a counting wheel in conjunction with an infrared groove tube, and then converted into the output paper towel length.

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