A coffee grinder

Abstract

The utility model provides a coffee grinder, including grinding seat, fixed mill disc, dynamic mill disc, first transmission gear, second transmission gear, potentiometer, first drive mechanism, fixed mill disc sets up inside grinding seat, and the outer periphery of fixed mill disc is connected with the inner periphery of grinding seat threadedly, dynamic mill disc is located below the fixed disc and rotates and sets up in grinding seat, forms the grinding cavity between fixed mill disc and dynamic mill disc, first transmission gear sets up above fixed mill disc and is connected with fixed mill disc fixedly, first drive mechanism is connected with first transmission gear, second transmission gear is engaged with first transmission gear, and potentiometer is connected with second transmission gear coaxially, first drive mechanism drives first transmission gear and drives fixed mill disc rotation to adjust the grinding gap, second transmission gear will rotate with first transmission gear, and potentiometer determines the grinding gap by detecting the rotation angle of second transmission gear, and the detection precision is high, is not influenced by dust, and the structure is simple, does not occupy the space.

Description

[0001] This case claims Chinese priority, priority number: 2024214371699, priority date: 2024-06-21 Technical Field

[0002] This utility model belongs to the field of coffee machine technology, and specifically relates to a coffee grinder. Background Technology

[0003] A coffee grinder is a tool that grinds coffee beans into coffee powder by rapidly rotating mechanical blades. The fineness of the coffee powder is an important indicator of coffee quality, directly affecting the extraction conditions and the taste of the finished coffee. Different coffee beans require different particle sizes of ground coffee powder.

[0004] To meet diverse grinding needs, many coffee grinders feature adjustable grind size. A common adjustment method involves dividing the grinding blades into two groups, creating a grinding gap between them. The size of this gap is adjusted by changing the relative height of the two groups of blades, resulting in coffee powder of different diameters. Existing grinders typically determine this gap size using mechanical or non-contact sensors. However, existing mechanical sensors (such as limit switches and induction slots) rely on physical contact or position triggering, making them susceptible to mechanical wear and dust contamination, leading to large detection errors and potential malfunctions over time (e.g., the induction slot and sensor in Chinese patent CN116807262A). Existing non-contact sensors (such as infrared and ultrasonic sensors) are easily affected by dust in the coffee grinding environment; the sensor lens or transmitter can easily become covered in coffee powder, causing signal distortion or even failure. Furthermore, existing sensors must be installed in the core grinding area (such as near the grinding blades), occupying space and interfering with the feed path. Utility Model Content

[0005] The purpose of this invention is to provide a coffee grinder that uses a potentiometer to detect the distance between the stationary and moving grinding discs. The detection accuracy is high, unaffected by dust, and the structure is simple and space-saving.

[0006] To achieve the above objectives, the solution of this utility model is: a coffee grinder, including a grinding base, a fixed grinding disc, a movable grinding disc, a first transmission gear, a second transmission gear, a potentiometer, and a first drive mechanism;

[0007] The fixed grinding disc is disposed inside the grinding base, and the outer circumference of the fixed grinding disc is threadedly connected to the inner circumference of the grinding base. The movable grinding disc is located below the positioning disc and is rotatably disposed inside the grinding base. A grinding cavity is formed between the fixed grinding disc and the movable grinding disc.

[0008] The first transmission gear is disposed above the fixed grinding disc and is fixedly connected to the fixed grinding disc. The first drive mechanism is connected to the first transmission gear. The second transmission gear meshes with the first transmission gear. The potentiometer is coaxially connected to the second transmission gear.

[0009] The first drive mechanism drives the first transmission gear to rotate the fixed grinding disc. While the fixed grinding disc rotates, it moves up and down to adjust the distance between the fixed grinding disc and the moving grinding disc. At the same time, the second transmission gear rotates with the first transmission gear. The potentiometer determines the distance between the fixed grinding disc and the moving grinding disc by detecting the rotation angle of the second transmission gear.

[0010] Furthermore, the coffee grinder also includes a housing, with the grinding seat disposed inside the housing. The first drive mechanism includes a transmission rod, one end of which is connected to a first transmission gear, and the other end of which extends out of the housing. The transmission rod can be manually driven to rotate the first transmission gear, or an electric drive device can be installed inside the grinding seat to drive the transmission rod.

[0011] Furthermore, the first transmission gear is a spur gear or a helical gear, and one end of the transmission rod is provided with a third transmission gear or rack that meshes with the first transmission gear.

[0012] Furthermore, the first transmission gear is a worm gear, the transmission rod is a worm to mesh with the worm gear, and the second transmission gear is a helical gear whose tooth profile and helix angle are matched with the worm gear.

[0013] Furthermore, the transmission rod and the second transmission gear are respectively disposed on both sides of the first transmission gear, the top of the grinding seat is provided with a material discharge port, and the first transmission gear and the fixed grinding disc are vertically connected to the middle to connect the material discharge port and the grinding chamber.

[0014] Furthermore, a grinding disc seat is fixed between the fixed grinding disc and the first transmission gear. The outer circumference of the grinding disc seat is threadedly connected to the inner circumference of the grinding seat. The fixed grinding disc is threadedly connected to the grinding seat through the grinding disc seat. The first transmission gear, the grinding disc seat, and the fixed grinding disc are vertically connected to the middle section to connect the material inlet and the grinding chamber.

[0015] Furthermore, the coffee grinder also includes a control board and a display screen. The display screen is located on the outside of the housing, and the control board is located inside the housing. The potentiometer and the display screen are both electrically connected to the control board. The potentiometer sends the rotation angle change information of the second transmission gear to the control board. The control board converts the angle change information into the distance change information between the fixed grinding disc and the moving grinding disc, and displays it on the display screen.

[0016] Furthermore, the potentiometer is a rotary resistance sensor.

[0017] Furthermore, the grinding seat is equipped with a displacement sensor for detecting the moving distance of the grinding disc, and the displacement sensor is electrically connected to the controller.

[0018] Furthermore, the coffee grinder also includes a second drive mechanism, which is connected to the moving grinding disc to drive the moving grinding disc to rotate. The second drive mechanism is a drive motor, and the rotating shaft of the drive motor is directly connected to the moving grinding disc, or connected to the moving grinding disc through a belt pulley transmission mechanism.

[0019] After adopting the above solution, the beneficial effects of this utility model are as follows:

[0020] This invention adjusts the grinding gap by rotating a first transmission gear, and a second transmission gear meshes with the first transmission gear on one side. The second transmission gear is coaxially connected to a potentiometer. When adjusting the grinding gap, the second transmission gear rotates with the first transmission gear. The potentiometer can determine the moving distance of the fixed grinding disc based on the change in the rotation angle of the second transmission gear, and thus determine the grinding gap. Specifically, the rotation angle is converted into axial displacement by the transmission ratio of the first and second transmission gears and the thread lead of the moving grinding disc, enabling high-precision detection and facilitating the user's judgment on whether the adjustment is in place. Moreover, the second transmission gear is located on one side of the first transmission gear, and the potentiometer can be installed above or below the second transmission gear. The installation position of the potentiometer is far away from the grinding core area and the material drop area, so it will not be affected by coffee dust and mechanical wear, nor will it interfere with the material drop path. Attached Figure Description

[0021] Figure 1 This is an exploded view of a grinding assembly according to an embodiment of the present invention;

[0022] Figure 2 This is an exploded view of the grinding assembly according to another embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the overall structure of another embodiment of the present utility model;

[0024] Figure 4 This is a cross-sectional view of another embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the grinding assembly assembly in another embodiment of the present invention;

[0026] Figure 6 This is a cross-sectional view of a grinding assembly according to another embodiment of the present invention.

[0027] Figure 7 This is a schematic diagram of the second drive mechanism and the grinding assembly of this utility model.

[0028] Label Explanation:

[0029] 1. Housing; 2. Grinding assembly; 21. Grinding base; 211. Feed inlet; 212. Discharge outlet; 213. Baffle; 22. Fixed grinding disc; 23. Moving grinding disc; 24. First transmission gear; 25. Transmission rod; 251. Third transmission gear; 26. Grinding disc base; 27. Second transmission gear; 28. Potentiometer; 29. ​​Grinding chamber; 3. Second drive mechanism; 31. Drive motor; 32. Belt pulley transmission mechanism; 321. Driving wheel; 322. Driven wheel; 323. Belt; 4. Knob; 5. Display screen; 6. Mounting base; 61. Feeding channel; 7. Bean hopper; 8. Discharge channel; 9. Grinding disc support. Detailed Implementation

[0030] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] like Figure 1-7 As shown, this utility model provides a coffee grinder, including a housing 1, a grinding assembly 2, and a second drive mechanism 3. The grinding assembly 2 includes a grinding seat 21, a fixed grinding disc 22, a movable grinding disc 23, a first transmission gear 24, a first drive mechanism, a grinding disc seat 26, a second transmission gear 27, and a potentiometer 28.

[0032] The grinding seat 21 is fixed inside the housing 1, specifically located at the top of the housing 1. The grinding seat 21 is a housing structure with an internal chamber and a material inlet 211 at the top. The fixed grinding disc 22 and the moving grinding disc 23 are arranged vertically within the grinding seat 21, forming a grinding chamber 29 between them. The grinding chamber 29 is connected to the material inlet 211. The second driving mechanism 3 is located inside the housing 1 and connected to the moving grinding disc 23. Coffee beans are placed into the grinding chamber 29 through the material inlet 211. The moving grinding disc 23 is driven by the second driving mechanism 3 to rotate relative to the fixed grinding disc 22, thereby grinding the coffee beans into powder. The ground coffee powder falls out through the gap between the fixed grinding disc 22 and the moving grinding disc 23. The size of the ground coffee powder depends on the size of the gap between the fixed grinding disc 22 and the moving grinding disc 23, i.e., the size of the grinding gap. The grinding gap can be adjusted by driving the fixed grinding disc 22 to rise and fall. In this utility model, the fixed grinding disc 22 is driven to move up and down by the first transmission gear 24 and the first driving mechanism. The outer circumference of the fixed grinding disc 22 is threadedly connected to the inner circumference of the grinding seat 21. The first driving mechanism drives the first transmission gear 24 to rotate, and the second transmission gear 24 can drive the fixed grinding disc 22 to rotate. Since the fixed grinding disc 22 is threadedly connected to the grinding seat 21, the fixed grinding disc 22 will move up and down while rotating, thereby adjusting the distance between the fixed grinding disc 22 and the moving grinding disc 23.

[0033] Key references Figure 2 and Figure 7The second transmission gear 27 is located on one side of the first transmission gear 24 and meshes with the first transmission gear 24. The potentiometer 28 is coaxially connected to the second transmission gear 27. Specifically, a connecting shaft can be set at the bottom or top of the potentiometer 28 to connect with the center of the second transmission gear 27. When adjusting the grinding gap, the second transmission gear 27 will rotate with the first transmission gear 24. The potentiometer 28 can detect the angle change of the second transmission gear 27 and determine the moving distance of the fixed grinding disc 22 based on the rotation angle change of the second transmission gear 27, thereby determining the grinding gap, which makes it convenient for the user to judge whether the adjustment is in place. The specific principle is as follows: the relationship between the rotation angle of the first transmission gear 24 and the lifting amount of the fixed grinding disc 22 can be calculated, and the transmission ratio between the first transmission gear 24 and the second transmission gear 27 can also be accurately calculated. Therefore, based on the detected change in the rotation angle of the second transmission gear 27, the size of the grinding gap can be calculated. This calculation can be performed by a calculation element on a control board (not shown in the figure). The control board is located inside the housing 1, and a potentiometer 28 is electrically connected to the control board. The potentiometer 28 sends the detected angle change information to the control board, which converts the angle change information into information about the change in distance between the fixed grinding disc 22 and the moving grinding disc 23. Figure 1 As shown, to facilitate user judgment, a display screen 5 can be installed on the outside of the housing 1. The display screen 5 is electrically connected to the control board. The control board sends information about changes in the grinding gap to the display screen 5, which displays the changes. The changes in the grinding gap can be displayed in the form of numbers or patterns, which is equivalent to displaying the grinding fineness. Alternatively, a dial can be installed on the outside of the housing 1 to display the grinding fineness, specifically through pointers and scales.

[0034] Specifically, the potentiometer 28 is an angular displacement sensor capable of measuring rotation angle, preferably a rotary resistance sensor. A rotary resistance sensor is an angular displacement sensor based on changes in resistance value. When the second transmission gear 27 rotates, the resistance of the rotary resistance sensor changes, and the relationship between the resistance of the rotary resistance sensor and the rotation angle of the second transmission gear 27 can be calculated. The calculation element on the control board calculates the change in grinding gap based on the resistance change. The resistance variation range of the rotary resistance sensor is approximately 0–100Ω. When the first transmission gear 24 rotates forward, causing the fixed mold plate 22 to descend, the resistance of the rotary resistance sensor gradually increases, and vice versa. Of course, the resistance of the rotary resistance sensor can also be set to increase as the first transmission gear 24 rotates in reverse.

[0035] In addition to potentiometer 28, a displacement sensor (not shown in the figure) can be installed inside the grinding seat 21 to detect the moving distance of the fixed grinding disc 22, and can also detect the moving distance of the grinding disc seat 26. The displacement sensor is electrically connected to the control board. The calculation element on the control board calculates the moving distance of the fixed grinding disc 22 as the size of the grinding gap. Potentiometer 28 and displacement sensor can be selected as one or both.

[0036] Specifically, the first driving mechanism includes a transmission rod 25. The transmission rod 25 and the second transmission gear 27 are located on both sides of the first transmission gear 24, and one end of the transmission rod 25 is connected to the first transmission gear 24 in a transmission manner, while the other end extends outside the housing 1. The transmission rod 25 can be manually driven to drive the first transmission gear 24 to rotate, or an electric drive device (not shown in the figure) can be installed inside the housing 1 to drive the transmission rod 25, and a switch can be installed on the outside of the housing 1 to control the electric drive device.

[0037] Key references Figure 1 In one embodiment, the first transmission gear 24 is a common spur gear or helical gear, and the second transmission gear 27 is a spur gear or helical gear that meshes with the first transmission gear 24. One end of the transmission rod 25 is provided with a third transmission tooth 251 that meshes with the first transmission gear 24. Rotating the transmission rod 25 can drive the third transmission gear 251 to rotate, thereby driving the first transmission gear 24 to rotate. The end of the transmission rod 25 that extends outside the housing 1 is provided with a knob 4 for easy manual rotation control. Alternatively, an electric drive device (e.g., a motor) can be provided inside the housing 1 to drive the transmission rod 25 to rotate. Alternatively, a rack structure that meshes with the first transmission gear 24 can be provided at one end of the transmission rod 25. The first transmission gear 24 can be driven to rotate by manually pushing the transmission rod 25. Alternatively, an electric drive device (e.g., a lead screw module) can be provided inside the housing 1 to drive the transmission rod 25 to move.

[0038] Key references Figure 2 and Figure 7 In another embodiment, the first transmission gear 24 is a worm gear, and the transmission rod 25 is a worm that meshes with the worm gear. Rotating the transmission rod 25 can also drive the first transmission gear 24 to rotate. The second transmission gear 27 is a helical gear (e.g., a helical gear with worm-like tooth profile) whose tooth shape and helix angle match those of the worm gear, thus meshing with the worm gear. This embodiment uses a worm gear mechanism to adjust the grinding gap. It has a simple and compact structure, low cost, and convenient adjustment. Furthermore, the worm gear mechanism has the characteristics of high reduction ratio and good transmission stability, enabling higher adjustment accuracy and more precise adjustment.

[0039] Key references Figure 3The top of the housing 1 is provided with a mounting base 6, on which a bean hopper 7 is mounted. The bottom of the mounting base 6 is provided with a material discharge channel 61, which connects the bean hopper 7 and the material discharge port 211. The bean hopper 7 is used to store coffee beans. The mounting base 6 is provided with a plug for blocking the material discharge channel 61. Pulling the plug can open the material discharge channel 61, and the coffee beans in the bean hopper 7 will fall into the material discharge channel 61. This is existing technology and will not be described in detail here.

[0040] Key references Figure 3-6 The grinding disc base 26 is disposed between the first transmission gear 24 and the fixed grinding disc 22. The top of the grinding disc base 26 is fixed to the first transmission gear 24, and the bottom of the grinding disc base 26 is fixed to the fixed grinding disc 22. The outer periphery of the grinding disc base 26 is threadedly connected to the grinding seat 21. The fixed grinding disc 22 is threadedly connected to the grinding seat 21 through the grinding disc base 26, thus eliminating the need for threads on the outer periphery of the fixed grinding disc 22, facilitating the processing of the fixed grinding disc 22, and also facilitating the design of different thread leads. The first transmission gear 24, the grinding seat 21, and the fixed grinding disc 22 can all be connected by screws. The first transmission gear 24, the grinding disc base 26, and the fixed grinding disc 22 are all annular structures with a through-center, allowing the material inlet 211 to communicate with the grinding chamber 29. The material outlet 61 can be funnel-shaped, with its bottom end extending into the middle of the grinding disc base 26, allowing coffee beans to fall accurately into the grinding chamber 29 without affecting the grinding between the fixed grinding disc 22 and the moving grinding disc 23.

[0041] The fixed grinding disc 22 and the moving grinding disc 23 used in this invention are both annular grinding discs. Changes in the distance between the fixed grinding disc 22 and the moving grinding disc 23 will not cause changes in the relative area between the fixed grinding disc 22 and the moving grinding disc 23, thus ensuring that the coffee beans are ground sufficiently and evenly.

[0042] In addition, the second transmission gear 27 facilitates the installation of the potentiometer 28, eliminating the need to install the potentiometer 28 on the first transmission gear 24 or the grinding disc base 26, which would affect the material feeding and the connection between the first transmission gear 24, the grinding disc base 26 and the fixed grinding disc 22. Furthermore, the installation position of the potentiometer 28 is far away from the grinding core area, so it will not be affected by coffee dust and mechanical wear, resulting in a long service life.

[0043] Furthermore, the coffee grinder also includes a discharge channel 8, and the side wall of the grinding seat 21 is provided with a discharge port 212. The top of the discharge channel 8 is connected to the discharge port 212, and the bottom of the discharge channel 8 extends to the outside of the housing 1. A baffle 213 is provided at the discharge port 212 to block the drop port 211. After grinding is completed, the baffle 213 is opened, and the ground coffee powder will fall out from the discharge channel 8. This is the prior art and will not be described in detail here.

[0044] Key references Figure 4 and Figure 7 The second driving mechanism 3 is a driving motor 31, which is located below the moving grinding disc 23. The rotating shaft of the driving motor 31 is directly connected to the moving grinding disc 23, specifically through a grinding disc bracket 9. The moving grinding disc 23 is fixed on the grinding disc bracket 9, and the center of the grinding disc bracket 9 is directly fixed to the rotating shaft of the driving motor 31 by bolts. Furthermore, the drive motor 31 can also be connected to the moving grinding disc 23 via a belt pulley transmission mechanism 32. The belt pulley transmission mechanism 32 includes a drive wheel 321, a driven wheel 322, and a belt 323. The belt 323 meshes with the drive wheel 321 and the driven wheel 322. The drive wheel 321 is connected to the shaft of the drive motor 31, and the driven wheel 322 is coaxially connected to the grinding disc support 9. Both the drive wheel 321 and the driven wheel 322 are gears. The inner circumference of the belt 323 has teeth that mesh with the drive and driven wheels, making the belt 323 less prone to slippage or wear. The tension of the belt 323 must also be properly controlled to further prevent slippage and wear. This application's belt pulley transmission mechanism 32 allows the drive motor 31 and the grinding assembly 2 to be arranged side-by-side, enabling the coffee grinder to be configured in different shapes to meet the needs of different customers. Moreover, the belt pulley transmission mechanism 32 has the function of reducing speed and increasing torque, and can also reduce the heat transferred from the drive motor 31 to the moving grinding disc 23, avoiding affecting the grinding of coffee powder.

[0045] The above description is only a preferred embodiment of this utility model and is not intended to limit the design of this case. All equivalent changes made based on the key design of this case shall fall within the protection scope of this case.

Claims

1. A coffee grinder, characterized in that: It includes a grinding base, a fixed grinding disc, a movable grinding disc, a first transmission gear, a second transmission gear, a potentiometer, and a first drive mechanism; The fixed grinding disc is disposed inside the grinding base, and the outer circumference of the fixed grinding disc is threadedly connected to the inner circumference of the grinding base. The movable grinding disc is located below the positioning disc and is rotatably disposed inside the grinding base. A grinding cavity is formed between the fixed grinding disc and the movable grinding disc. The first transmission gear is disposed above the fixed grinding disc and is fixedly connected to the fixed grinding disc. The first drive mechanism is connected to the first transmission gear. The second transmission gear meshes with the first transmission gear. The potentiometer is coaxially connected to the second transmission gear. The first drive mechanism drives the first transmission gear to rotate the fixed grinding disc. While the fixed grinding disc rotates, it moves up and down to adjust the distance between the fixed grinding disc and the moving grinding disc. At the same time, the second transmission gear rotates with the first transmission gear. The potentiometer determines the distance between the fixed grinding disc and the moving grinding disc by detecting the rotation angle of the second transmission gear.

2. The coffee grinder as described in claim 1, characterized in that: The coffee grinder also includes a housing, with the grinding base disposed inside the housing. The first drive mechanism includes a transmission rod, one end of which is connected to a first transmission gear, and the other end of which extends out of the housing. The transmission rod can be manually driven to rotate the first transmission gear, or an electric drive device can be installed inside the grinding base to drive the transmission rod.

3. A coffee grinder as described in claim 2, characterized in that: The first transmission gear is a spur gear or a helical gear, and one end of the transmission rod is provided with a third transmission gear or rack that meshes with the first transmission gear.

4. A coffee grinder as described in claim 2, characterized in that: The first transmission gear is a worm gear, the transmission rod is a worm to mesh with the worm gear, and the second transmission gear is a helical gear whose tooth profile and helix angle are matched with the worm gear.

5. A coffee grinder as described in any one of claims 2-4, characterized in that: The transmission rod and the second transmission gear are respectively located on both sides of the first transmission gear. The top of the grinding seat is provided with a material discharge port. The first transmission gear and the fixed grinding disc are connected vertically to connect the material discharge port and the grinding chamber.

6. A coffee grinder as described in claim 5, characterized in that: A grinding disc seat is also fixed between the fixed grinding disc and the first transmission gear. The outer circumference of the grinding disc seat is threadedly connected to the inner circumference of the grinding seat. The fixed grinding disc is threadedly connected to the grinding seat through the grinding disc seat. The first transmission gear, the grinding disc seat and the fixed grinding disc are vertically connected to the middle to connect the material inlet and the grinding chamber.

7. A coffee grinder as described in claim 2, characterized in that: The coffee grinder also includes a control board and a display screen. The display screen is located on the outside of the housing, and the control board is located inside the housing. The potentiometer and the display screen are both electrically connected to the control board. The potentiometer sends the rotation angle change information of the second transmission gear to the control board. The control board converts the angle change information into the distance change information between the fixed grinding disc and the moving grinding disc, and displays it on the display screen.

8. A coffee grinder as described in claim 7, characterized in that: The potentiometer is a rotary resistance sensor.

9. A coffee grinder as described in claim 7, characterized in that: The grinding seat is equipped with a displacement sensor for detecting the moving distance of the grinding disc, and the displacement sensor is electrically connected to the controller.

10. A coffee grinder as described in claim 1, characterized in that: The coffee grinder also includes a second drive mechanism, which is connected to the moving grinding disc to drive the moving grinding disc to rotate. The second drive mechanism is a drive motor, and the rotating shaft of the drive motor is directly connected to the moving grinding disc, or connected to the moving grinding disc through a belt pulley transmission mechanism.

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