Rotary cutting knife, grinding mechanism and hand-held coffee grinder

Abstract

Rotary cutting knife, grinding mechanism and hand-held coffee grinder. The knife body includes a base circle part, and a number of protruding cutter heads are provided on the base circle part. On one side of the cutter head along the rotation direction, a number of cutting ends for crushing coffee beans are provided radially. The rotary cutting knife is horizontally arranged in the travel of the coffee beans falling into the grinding tool, and the cutting ends of its cutter heads face the coffee beans and crush them. The rotary cutting knife of the present invention can crush the coffee beans into several small pieces, which is convenient for subsequent grinding; when several cutting ends arranged at different cutting depths can penetrate the coffee beans in sequence, since the roasted coffee beans are brittle due to certain carbonization properties, they can be easily crushed; the cutting edges on the outer edge of the cutting ends can also further cut the coffee beans.

Description

Technical Field

[0001] The present invention relates to the field of coffee bean grinding machinery, and specifically to a rotary cutting knife, a grinding mechanism and a hand-held coffee grinder. Background Art

[0002] Coffee is made from roasted and ground coffee beans and is very popular among people. In outdoor activities, there is sometimes a need to drink coffee, so there are appliances for on-site coffee preparation outdoors. However, due to limited outdoor conditions, the requirements and characteristics of coffee preparation appliances are also different from those indoors.

[0003] Coffee beans also need to be ground for outdoor coffee preparation. Many of the existing hand-held coffee grinders are mechanical hand-cranked types. The coffee particles ground by them will be non-uniform due to the changes of the grinding core and the hand-cranking force, and cannot meet the requirements of extremely fine grinding (such as espresso extraction, which requires fine particle grinding); and it is laborious and time-consuming during operation, and cannot meet the different extraction methods required by different coffees.

[0004] The hand-held electric coffee grinder can reduce variables and grinding time, and can also adjust the particle size according to the brewing method and personal taste by setting. Most of the existing hand-held coffee grinders use ceramic grinding cores or blades to crush coffee beans, and still have the following problems:

[0005] 1. The sizes of the ground coffee powder particles are not uniform, and the coffee bean grinding efficiency is very low. Generally, it takes 200 seconds to 800 seconds to grind 15 grams of coffee beans. If the efficiency is to be further improved, the electric power needs to be increased, and then the volume of the equipment will be increased, which will affect the outdoor portability of the equipment.

[0006] 2. Although the blade crushing method has a relatively higher efficiency than the hand-cranked type, the uniformity of the particles is still not good. If the crushing time is increased, the uniformity of the particles can be improved, but the particles are relatively fine. In addition, there will be problems of too high temperature and too many fragments due to too many unnecessary impacts on the coffee beans, and finally fine powder will be produced, affecting the taste of coffee brewing.

[0007] In addition, the existing cutting blades for coffee beans are suitable for high-speed movement. Their crushing method is to directly achieve the crushing effect by using the impact of high-speed movement. Their weakness is that the crushing uniformity caused by the impact is not good, and multiple impacts are required to achieve the crushing effect; during this process, the coffee beans are subjected to too many unnecessary impacts, which will not only affect the temperature but also damage the unity of the coffee taste, bringing the possibility of uncontrollable defects. Summary of the Invention

[0008] In order to solve the existing problems, the present invention aims to provide a rotary cutting knife, a grinding mechanism and a hand-held coffee grinder.

[0009] To achieve the above object, the technical solution adopted by the present invention provides a rotary cutting knife for coffee beans. The knife body includes a base circle portion, and the knife body can rotate horizontally around the center of the base circle portion. A number of protruding knife heads are provided on the base circle portion, and a number of cutting ends for crushing coffee beans are provided radially on one side of the knife head facing the rotation direction.

[0010] Among them, the diameters of the number of cutting ends are different, and there is an angular difference with the connection line of the center of the base circle portion, respectively forming a number of cutting depths, and can be successively inserted into the coffee beans during rotation.

[0011] Among them, the outer edge of the cutting end is a sharp edge.

[0012] Among them, there are three knife heads.

[0013] Among them, there are two cutting ends.

[0014] The present invention also provides a grinding mechanism for coffee beans, including the above-mentioned rotary cutting knife and a grinding tool; the rotary cutting knife is horizontally arranged in the travel of the coffee beans falling into the grinding tool, and the cutting end of its knife head faces the coffee beans and crushes them.

[0015] Among them, the grinding tool includes a conical knife located in the inner circle and an annular knife located in the outer circle, and the diameter of the top surface of the conical knife is smaller than that of the bottom surface; the grinding tool grinds the coffee beans through the gap between the outer wall of the relatively rotatable conical knife and the inner wall of the annular knife.

[0016] Among them, the grinding tool is divided into an upper part and a lower part, and the gap of the upper part is larger than that of the lower part.

[0017] Among them, the inner wall of the annular knife in the upper part is set as an annular inclined plane with the upper end radially inclined outward.

[0018] Among them, the inner wall of the annular knife in the lower part is a vertical surface.

[0019] Among them, the conical knife rotates around its axis, and the annular knife is fixedly arranged.

[0020] Among them, the rotary cutting knife and the conical knife are coaxial and are driven by the output rod of the motor to rotate horizontally.

[0021] The present invention also provides a hand-held coffee grinder, including the above-mentioned grinding mechanism.

[0022] Among them, it also includes a housing. An opening for coffee beans to fall is provided on the upper end surface of the housing, a grinding mechanism is provided in the middle, and a motor is located in the lower part of the housing and drives the rotary cutting knife and the conical knife to rotate.

[0023] Among them, it also includes a cover plate, and the cover plate is located above the grinding mechanism; a notch for coffee beans to pass through is provided on the cover plate.

[0024] Compared with the prior art, the rotary cutting knife of the present invention can crush coffee beans into several small pieces, facilitating the subsequent grinding process; when several cutting ends provided at different cutting depths can successively penetrate into the coffee beans, since the roasted coffee beans are brittle due to certain carbonization properties, they can be easily crushed; the cutting edge on the outer edge of the cutting end can also further cut the coffee beans.

[0025] The grinding mechanism can achieve multi-stage crushing and grinding of coffee beans. After preliminary crushing, the coffee beans become medium-sized particles. Then, the line contact during the use of the grinding tool is changed to point contact, the contact area is greatly reduced, the force is balanced, the power requirement of the motor is reduced, and the increase in volume is avoided; after crushing, multi-stage fine grinding is carried out, and high-efficiency and uniform fine grinding particles can be obtained, with less impurities and fine powder, and the taste of coffee is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic structural diagram of a rotary cutting knife with a single cutting head;

[0027] Figure 2 is a schematic structural diagram of a rotary cutting knife with two cutting heads;

[0028] Figure 3 is a schematic structural diagram of a rotary cutting knife with three cutting heads;

[0029] Figure 4 is a schematic structural diagram of a rotary cutting knife with four cutting heads;

[0030] Figure 5 is an instruction diagram for the use of the rotary cutting knife;

[0031] Figure 6a 、 6b 、6c is an instruction diagram for the use of the grinding mechanism;

[0032] Figure 7 is a schematic structural diagram of a hand-held coffee grinder;

[0033] Figure 8 is a schematic diagram of the disassembly of the structure of the hand-held coffee grinder.

[0034] Referring to the drawings, rotary cutting knife 1, base circle part 101, cutting head 102, cutting end 103, cutting edge 104; grinding tool 2, conical knife 201, annular knife 202, annular inclined surface 203, vertical surface 204; housing 3, opening 301; motor 4, cover plate 5, output rod 6, coffee beans 7. DETAILED DESCRIPTION OF THE INVENTION

[0035] The present invention will be further described below in conjunction with the accompanying drawings.

[0036] Referring to Figures 1-4 , Figures 1-4Four embodiments of the present invention are shown, which are rotary cutting knives for coffee beans; the knife body includes a base circle part, and the knife body can rotate horizontally around the center of the base circle part. One to four knife heads protruding relative to the base circle part are respectively arranged on the base circle part, and a plurality of cutting ends for crushing coffee beans on the knife heads are all distributed along the radial direction on one side of the rotation direction.

[0037] See Figure 3 , taking the rotary cutting knife with three knife heads as an example, the diameter lengths of two cutting ends are different, which are R1 and R2, constituting different cutting depths:

[0038] The blade with radius R1 is the first cutting depth;

[0039] The blade with radius R2 is the second cutting depth.

[0040] See Figure 5 , during cutting, the rotational linear velocity of the knife head of the rotary cutting knife is 10M / min. The calculation method of the coffee bean pressure is P = F / S, where F is the cutting force, S is the area of the tip of the cutting end, and P is the crushing pressure of the coffee beans. The area of S is less than 0.04mm 2 . And the torque generated by the motor > 1.9NM, then P = 47N / mm 2 , while the generally roasted coffee beans can be crushed at 20N / mm 2 , which can meet the requirements.

[0041] Preferably, there is an angular difference between the connecting line of the cutting end and the center of the base circle part. When the rotary cutting knife rotates, the two cutting ends can sequentially penetrate into the coffee beans. Further, the outer edges of the two cutting ends are both set as sharp edges, which can further cut the coffee beans at the moment of crushing.

[0042] The rotary cutting knife of the above embodiment is applicable to low-speed movement, and its crushing method is non-impact. The layered cutting is used to achieve the crushing effect, that is, the layered cutting purpose is achieved by using the rotation method in cooperation with the angle and radius position of the knife body. In addition, the coffee beans themselves have a certain degree of carbonization (fragmentation) after roasting. Under their mutual action, the crushing effect can be produced. The principles of other blades are the same and will not be elaborated.

[0043] Based on the above rotary cutting knife, see Figures 6a-6c , another embodiment of the present invention provides a coffee bean grinding mechanism. In this embodiment, the above rotary cutting knife with three knife heads is selected, and it also includes a coffee bean grinding tool. The coffee beans fall into the grinding mechanism from above. The rotary cutting knife is horizontally arranged in the travel of the coffee beans falling into the grinding tool and above the grinding tool, forming a double-knife coffee bean grinding structure. The cutting ends of its knife heads can face the coffee beans and crush them into medium particles.

[0044] In this embodiment, the grinding tool includes a conical knife located in the inner ring and an annular knife located in the outer ring, wherein the diameter of the top surface of the conical knife is smaller than that of the bottom surface; the grinding tool grinds coffee beans through the gap between the outer wall of the relatively rotatable conical knife and the inner wall of the annular knife.

[0045] In this embodiment, the rotary cutting knife and the conical knife are coaxial and are driven by the output rod of the motor to rotate horizontally. The grinding tool is divided into an upper part and a lower part. The inner wall of the annular knife in the upper part is provided with an annular inclined surface with the upper end radially inclined outward. The inner wall of the annular knife in the lower part is a vertical surface. Therefore, the gap in the upper part is larger than that in the lower part, which can meet the requirements of secondary grinding.

[0046] The grinding tool in the above embodiment can also be an existing multi-stage grinding disc structure, that is, different gaps between grinding discs with different diameters and the inner wall of the annular knife are used to grind coffee beans, and the effect is the same.

[0047] The specific operation process of this grinding mechanism is as follows:

[0048] 1. Refer to Figure 6a , when the coffee beans fall, under the rotation and crushing of the rotary cutting knife, the coffee beans are first cut into medium-sized particles about three pieces. The purpose is to change the line contact of grinding the beans into point contact when the coffee beans enter the grinding tool, which can greatly reduce the contact area, reduce the power requirement of the motor, and can directly perform effective secondary rough grinding on the coffee beans.

[0049] 2. Refer to Figure 6b , the coffee fragments that have been cut into medium-sized particles enter the secondary rough grinding, which can make the grinding tool apply pressure to the medium-sized particles more evenly, so as to achieve uniform stress and save power consumption. If the large particles directly enter the grinding tool for rough grinding, it is in line contact with the coffee beans, and the required effective grinding force must be greater than that of the medium-sized particles, which requires a larger motor power and the stress is also uneven; this is also a common bad design in current hand-held grinding coffee machines.

[0050] 3. Refer to Figure 6c , after the rough grinding of the medium-sized particles, the third-stage fine grinding of fine particles is carried out. Because of the uniformity of the rough grinding of the medium-sized particles, not only the grinding efficiency is improved in the fine grinding, but also the stress is average and the motor power requirement is small, and the result can obtain an efficient and power-saving fine grinding effect.

[0051] In summary, the grinding mechanism of this embodiment changes from the original single-knife single-structure grinding of beans, that is, the original single-knife two-process grinding method (directly breaking the original beans and then directly to fine grinding) to a double-knife three-process grinding method (first sharply cutting the original beans into medium-sized particles and then to three processes of fine grinding), so an efficient and uniform bean grinding process can be obtained.

[0052] Refer to Figure 7 and Figure 8, based on the above-mentioned grinding mechanism, this embodiment provides a hand-held coffee grinder for preparing coffee during outdoor activities. The hand-held coffee grinder is provided with a housing, which is composed of several segments connected together; an opening for coffee beans to fall into is provided on the upper end surface of the housing, and the above-mentioned grinding mechanism is provided in the middle. The motor is located at the lower part of the housing and drives the rotary cutting knife and the conical knife to rotate.

[0053] Preferably, referring to Figure 8 , it further includes a cover plate, and the cover plate is located above the grinding mechanism; a notch for coffee beans to pass through is provided on the cover plate. The cover plate can fix the position where the coffee beans fall into, and plays a role in closing and protecting the grinding mechanism.

[0054] The above embodiment can realize the multi-stage crushing and grinding of coffee beans. After the initial puncturing and crushing, the coffee beans have become medium-sized particles. Then, the line contact during the use of the grinding tool is changed to point contact, the contact area is greatly reduced, the force is balanced, the power requirement of the motor is reduced, and the increase in volume is avoided; after the puncturing and crushing, multi-stage fine grinding is carried out, and then high-efficiency and uniform fine grinding particles can be obtained, with less impurities and fine powder, and the taste of the coffee is improved.

[0055] For a hand-held coffee grinder for outdoor use, if the grinding efficiency is to be improved, the electric power of the coffee grinder must be increased, which will inevitably increase the volume; but it is limited by the actual outdoor needs, and the power of the motor must be within a certain size. Therefore, only by improving the efficiency of the grinding structure mechanism can the convenience and portability requirements of the hand-held coffee grinder be met.

[0056] The embodiments of the present invention have been described above in conjunction with the accompanying drawings and examples. The structures given in the examples do not constitute limitations on the present invention. Skilled technicians in the art can make adjustments as needed, and various deformations or modifications within the scope of the appended claims are within the scope of protection.

Claims

1. A rotary cutting knife for coffee beans, the knife body includes a base circle part, and the knife body can rotate horizontally around the center of the base circle part, and is characterized in that: A number of protruding cutter heads are provided on the base circle part. A number of cutting ends for crushing coffee beans are arranged radially on one side of the cutter head facing the rotation direction, and the cutting ends are provided with cutting tips. The diameters of the number of cutting ends are different, and there is an angular difference with the center line of the base circle part, respectively forming a number of cutting depths, and can be sequentially inserted into the coffee beans during rotation.

2. The rotary cutting tool according to claim 1, wherein: The outer edge of the cutting end is a sharp edge.

3. The rotary cutting tool according to claim 1 or 2, characterized in that: There are three cutter heads.

4. The rotary cutting tool according to claim 1 or 2, characterized in that: There are two cutting ends.

5. A grinding mechanism for coffee beans, characterized in that: It includes the rotary cutting knife according to any one of claims 1-4, and a grinding tool; the rotary cutting knife is horizontally arranged in the travel of the coffee beans falling into the grinding tool, and the cutting ends of its cutter head face the coffee beans and crush them.

6. The grinding mechanism according to claim 5, wherein: The grinding tool includes a conical knife located in the inner circle and an annular knife located in the outer circle, wherein the diameter of the top surface of the conical knife is smaller than that of the bottom surface; the grinding tool grinds the coffee beans through the gap between the outer wall of the relatively rotatable conical knife and the inner wall of the annular knife.

7. The grinding mechanism according to claim 6, characterized in that: The grinding tool is divided into an upper part and a lower part, and the gap of the upper part is larger than that of the lower part.

8. The grinding mechanism according to claim 7, characterized in that: The inner wall of the annular knife in the upper part is set as an annular inclined surface with the upper end radially outwardly inclined.

9. The grinding mechanism according to claim 7, wherein: The inner wall of the annular knife in the lower part is a vertical surface.

10. The grinding mechanism according to claim 6, wherein: The conical knife rotates around its axis, and the annular knife is fixedly arranged.

11. The grinding mechanism according to any one of claims 6-9, characterized in that: The rotary cutting knife and the conical knife are coaxial and are driven by the output rod of the motor to rotate horizontally.

12. The grinding mechanism according to claim 5, wherein: The grinding tool is a number of grinding discs with different diameters.

13. A hand-held coffee grinder, characterized in that: It includes the grinding mechanism according to any one of claims 5-12.

14. The hand-held coffee grinder according to claim 13, wherein: It further includes a housing. An opening for the coffee beans to fall is provided on the upper end surface of the housing, and a grinding mechanism according to any one of claims 5-12 is provided in the middle. The motor is located in the lower part of the housing and drives the rotary cutting knife and the conical knife to rotate.

15. The hand-held coffee grinder according to claim 14, characterized in that: It further includes a cover plate. The cover plate is located above the grinding mechanism; a notch for the coffee beans to pass through is provided on the cover plate.

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