A semi-automatic coffee machine extraction pressure maintaining mechanism

Abstract

The application discloses a kind of semi-automatic coffee machine extraction pressure keeping mechanism including powder pressing handle, transmission gear, lifting frame with vertical rack and fixed ratchet disc;Brewing powder pressing head is installed at the lower end of lifting frame;Powder pressing handle is connected with transmission gear, and transmission gear is engaged with vertical rack, so that when powder pressing handle drives transmission gear, brewing powder pressing head moves up and down with lifting frame;Ratchet disc is provided with one-way ratchet by blocking surface and inclined sliding surface, and lock slot is formed between adjacent one-way ratchet;Control key and lock pin are provided on powder pressing handle, and control key controls lock pin to enter or exit lock slot;During the rotation of powder pressing handle, lock pin enters lock slot and jumps on continuous multiple inclined sliding surfaces with rotation;Blocking surface prevents reverse rotation of powder pressing handle to complete self-locking;It can be rotated smoothly in positive direction, and direction is automatically locked without additional operation, and individualized accurate selection of pressure can be realized.

Description

Technical Field

[0001] This invention relates to the field of coffee machines, and more particularly to an extraction pressure maintaining mechanism for a semi-automatic coffee machine. Background Technology

[0002] With the popularization of coffee culture, people have increasingly higher demands for the quality and taste of coffee. Coffee is no longer just a refreshing drink, but has become a lifestyle enjoyment and a social medium. Therefore, consumers' demand for being able to make high-quality coffee at home or in the office is growing. To enhance the enjoyment of using coffee machines and meet the personalized needs of coffee extraction, semi-automatic manual tamping coffee machines have emerged. In this tamping system, the tamping head is pressed down by operating the handle. In some devices, the handle needs to be held for a prolonged period after tamping to maintain the tamping state, while others use a locking mechanism to lock this tamping mode.

[0003] Patent CN206525945U discloses a coffee powder extrusion molding device with a return air valve. The tamping head is connected to a vertical drive assembly for driving its movement. The vertical drive assembly includes a track support arranged vertically and a crank-connecting rod mechanism. The crank-connecting rod mechanism includes a crank and a connecting rod. The crank is connected to a handle, one end of the connecting rod is hinged to the crank, and the other end is hinged to the top of the tamping head. This molding device uses a crank-connecting rod structure with a hydraulic self-locking mechanism. First, the crank pushes the brewing head to near contact with the coffee powder, and then hydraulic pressure continues to push and press, locking the mixture in place. This mechanism is costly, and the hydraulic system is prone to failure. Summary of the Invention

[0004] Therefore, the technical problem to be solved by the present invention is to provide an extraction pressure maintaining mechanism for a semi-automatic coffee machine.

[0005] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a semi-automatic coffee machine extraction pressure holding mechanism, including a tamping handle, a transmission gear, a lifting frame with a vertical rack, and a fixed ratchet disc;

[0006] The powder-pressing head is mounted on the lower end of the lifting frame; the powder-pressing handle is connected to the transmission gear, and the transmission gear meshes with the vertical rack, so that when the powder-pressing handle drives the transmission gear, the powder-pressing head moves up and down with the lifting frame;

[0007] The ratchet disc is provided with one-way ratchet teeth consisting of a blocking surface and an inclined sliding surface, and a locking groove is formed between adjacent one-way ratchet teeth; the powder pressing handle is provided with a control key and a locking pin, and the control key controls the locking pin to enter or exit the locking groove;

[0008] During the rotation of the powder pressing handle, the locking pin enters the locking groove and bounces on multiple inclined sliding surfaces as it rotates; the blocking surface prevents the powder pressing handle from rotating in the opposite direction to complete the self-locking.

[0009] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: the powder pressing handle includes a disc part and a handle part located on one side of the disc part, the center of the disc part is provided with a shaft part, and the shaft part is connected to the transmission gear and cannot rotate relative to it;

[0010] The shaft pin is located inside the disc portion and is parallel to the shaft portion; the control key is located on the handle portion, with one end of the control key away from the locking pin extending out of the outer end of the powder pressing handle to form an operating end, and the other end cooperating with the locking pin to form an action end;

[0011] The control key's actuating end includes an inclined actuating surface located on the outer side; the inner wall of the locking pin's pin hole cooperates with the inclined actuating surface to allow the locking pin to slide along the inclined actuating surface, thereby realizing the extension and retraction of the locking pin.

[0012] The preferred technical solution adopted by the present invention to solve the above-mentioned technical problem is: the outer end of the locking pin is provided with a first elastic element, which drives the locking pin to extend inward into the locking groove;

[0013] The front end of the control key is provided with a second elastic element, which drives the operating end of the control key to extend backward out of the powder pressing handle and the inclined action surface to disengage from the inner wall of the pin hole so that the locking pin extends inward into the locking groove.

[0014] The preferred technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: the working end of the control key includes a rectangular segment on the front side and a trapezoidal segment on the rear side, the inclined working surface is the outer surface of the trapezoidal segment, and the inner surfaces of the rectangular segment and the trapezoidal segment are the same plane perpendicular to the shaft; a straight guide surface is provided on the outer side of the rectangular segment, located on the front side of the inclined working surface and perpendicular to the shaft.

[0015] The preferred technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: the powder pressing handle includes a first half shell and a second half shell, the first half shell includes a first semi-disc and a first half handle; the second half shell includes a second semi-disc and a second half handle.

[0016] The outer periphery of the first semi-disc is provided with a recessed groove, the second semi-disc is sleeved on the outside of the first semi-disc, and the locking pin is provided in the recessed groove;

[0017] The locking pin includes a first small diameter portion, a large diameter portion, and a second small diameter portion from the inside to the outside. The first half-shell has a through hole with a diameter larger than the first small diameter portion and smaller than the large diameter portion. The first small diameter portion extends out of the through hole and engages with the ratchet disc.

[0018] The preferred technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: an ear is fixedly provided on the inner side of the powder pressing handle, a guide hole is provided on the ear, and the locking pin extends out of the powder pressing handle and cooperates with the ratchet disc through the guide hole.

[0019] The preferred technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: the rear end of the powder pressing handle has a beveled surface that slopes from top to bottom and from front to back, the rear end of the powder pressing handle forms a notch on the upper side, and the operating end of the control key extends out of the beveled surface and is located at the notch.

[0020] The preferred technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: the inner side of the powder pressing handle is provided with a shaft portion, the shaft portion includes a first circular protrusion, the outer periphery of the first circular protrusion is provided with a first spline, the transmission gear is provided with a first spline groove that mates with the first spline; the center of the circular protrusion is provided with a threaded post, and the center of the transmission gear is provided with a threaded hole that connects to the threaded post.

[0021] The preferred technical solution adopted by the present invention to solve the above-mentioned technical problem is as follows: a strip-shaped first sliding block and a second sliding block are fixedly fixed on both sides of the lifting frame in a vertical parallel interval, a first vertical rack is provided on the rear side of the first sliding block, and a second vertical rack is provided on the rear side of the second sliding block.

[0022] The powder pressing handle is connected to the first transmission gear via a spline, and the first transmission gear is connected to a second transmission gear that is parallel and spaced apart from the first transmission gear via a connecting shaft;

[0023] The first transmission gear meshes with the first vertical rack; the second transmission gear meshes with the second vertical rack.

[0024] The preferred technical solution adopted by the present invention to solve the above-mentioned technical problem is as follows: the transmission gear is provided with a limiting protrusion, the limiting protrusion contacts the vertical rack and thus prevents the transmission gear from rotating further in the forward direction.

[0025] Compared with existing technologies, the advantages of this invention are: the cooperation between the locking pin and the ratchet disc allows for smooth forward rotation and reverse self-locking when the locking pin is inserted into the locking groove between the one-way ratchet teeth of the ratchet disc. The inclined sliding surface allows the tamping handle to move smoothly when adjusting the height in forward rotation, reducing jamming and friction, and helping the locking pin gradually enter the locking groove during rotation, avoiding sudden impacts and noise, making the adjustment process more stable. The blocking surface prevents the locking pin from interacting in reverse, thus keeping the brewing tamping head in a pressed state without the control key releasing the locking pin. After the tamping module presses the brewing tamping head into place, it automatically locks the brewing tamping head in brewing mode without other operations, achieving pressure-maintaining extraction of coffee powder, maintaining the stability of the tamping state, avoiding extraction pressure fluctuations, and thus improving the taste and aroma of the coffee. Throughout the process, the user can easily adjust the height of the brewing tamping head simply by rotating the tamping handle in the forward direction, without the need for additional locking operations, simplifying the operation process.

[0026] Pressure is applied via a rack and pinion mechanism, allowing for fine-tuning of the tamping pressure. This means users can more precisely control the compactness of the coffee grounds, thereby optimizing extraction. Different coffee grounds may require different compactions to achieve optimal extraction. By fine-tuning the pressure, users can optimize parameters for different types of coffee grounds to achieve their preferred extraction results. Attached Figure Description

[0027] The present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will understand that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be construed as limiting the scope of the invention. Furthermore, unless specifically indicated, the drawings are only schematic representations of the composition or structure of the described objects and may contain exaggerated depictions, and the drawings are not necessarily drawn to scale.

[0028] Figure 1 A schematic diagram of an extraction pressure maintaining mechanism for a semi-automatic coffee machine. Figure 1 ;

[0029] Figure 2 A schematic diagram of an extraction pressure maintaining mechanism for a semi-automatic coffee machine. Figure 2 ;

[0030] Figure 3 A schematic diagram of the internal structure of an extraction pressure maintaining mechanism in a semi-automatic coffee machine. Figure 1 ;

[0031] Figure 4 For a semi-automatic coffee machine extraction pressure holding mechanism Figure 3 A magnified view of a portion of the image;

[0032] Figure 5 This is a schematic diagram of the internal structure of an extraction pressure maintaining mechanism in a semi-automatic coffee machine.

[0033] Figure 6 For a semi-automatic coffee machine extraction pressure holding mechanism Figure 5 A magnified view of a portion of the image;

[0034] Figure 7 An exploded view of an extraction pressure maintaining mechanism in a semi-automatic coffee machine;

[0035] Figure 8 An exploded view of an extraction pressure maintaining mechanism and corresponding supporting structures for a semi-automatic coffee machine;

[0036] Figure 9 This is a structural diagram of the lifting and transmission mechanism of an extraction pressure holding mechanism in a semi-automatic coffee machine.

[0037] Figure 10 A structural diagram of a control key for an extraction pressure holding mechanism in a semi-automatic coffee machine;

[0038] Figure 11 This is a structural diagram of a locking pin in the extraction pressure holding mechanism of a semi-automatic coffee machine. Detailed Implementation

[0039] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely descriptive and exemplary and should not be construed as limiting the scope of the invention.

[0040] It should be noted that similar labels in the following figures indicate similar items; therefore, once an item is defined in one figure, it will not be further defined and explained in subsequent figures.

[0041] In the description of this invention, it should be noted that the terms "upper," "lower," "front," "rear," "left," "right," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this invention is in use. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention. Similarly, "first" and "second" are only for ease of understanding and have no other directional meaning, and should not be considered as limitations on this invention.

[0042] like Figure 1-6As shown, this embodiment provides a semi-automatic coffee machine extraction pressure holding mechanism, including a tamping handle 1, a transmission gear 2, a lifting frame 4 with a vertical rack 3, and a fixed ratchet disc 5. A brewing tamping head 9, used for tamping coffee powder and spraying hot water onto the coffee powder, is mounted at the lower end of the lifting frame 4. The tamping handle 1 is connected to the transmission gear 2, which meshes with the vertical rack 3, so that when the tamping handle 1 drives the transmission gear 2, the brewing tamping head 9 moves up and down with the lifting frame 4. The ratchet disc 5 has one-way ratchet teeth 51 with a blocking surface a and an inclined sliding surface b, and a locking groove c is formed between adjacent one-way ratchet teeth 51. The tamping handle 1 is equipped with a control key 7 and a locking pin 6. The control key 7 controls the locking pin 6 to enter or exit the locking groove c. During the rotation of the tamping handle 1, the locking pin 6 enters the locking groove c and bounces on multiple consecutive inclined sliding surfaces b as it rotates. The blocking surface a prevents the tamping handle 1 from rotating in the opposite direction to achieve self-locking.

[0043] For coffee machines, if the coffee grounds are not tamped during brewing, water may choose the path of least resistance during extraction, creating a channeling effect. This can lead to over-extraction of some coffee grounds and under-extraction of others, affecting the overall taste of the coffee. The tamping head 9 compresses the coffee grounds into a dense puck, filling every space in the container. The tamped grounds create resistance to the water flow, slowing it down. This helps the flavor compounds in the coffee dissolve fully in the water, providing more even pressure during extraction and allowing water to penetrate the coffee grounds evenly, resulting in a rich, aromatic coffee. Manually tamping the grounds by rotating the tamper handle 1 increases the user's involvement and enjoyment in coffee preparation, encouraging active participation rather than simply waiting for the coffee to finish. Furthermore, the speed and force of manual rotation can be controlled by the user, allowing them to adjust the density of the coffee grounds according to their personal taste and preferences, thus personalizing the coffee's flavor.

[0044] In this embodiment, pressure is applied via a rack and pinion mechanism, allowing for fine-tuning of the tamping pressure. This means users can more precisely control the compactness of the coffee grounds, thereby optimizing extraction. Different coffee grounds may require different compactions to achieve optimal extraction. By fine-tuning the pressure, users can optimize parameters for different types of coffee grounds to achieve their preferred extraction.

[0045] The locking pin 6 and ratchet disc 5 work together to ensure smooth forward rotation while simultaneously achieving reverse self-locking when the locking pin 6 is inserted into the locking groove c between the one-way ratchet teeth 51 of the ratchet disc 5. The inclined sliding surface b allows the tamping handle 1 to move smoothly during forward height adjustment, reducing jamming and friction. This helps the locking pin 6 gradually enter the locking groove c during rotation, avoiding sudden impacts and noise, and making the adjustment process more stable. The blocking surface a prevents the locking pin 6 from interacting in the reverse direction, so that the brewing tamping head 9 remains in the pressed state without the control key 7 releasing the locking pin 6. After the tamping module 6 presses the brewing tamping head 9 into place, it automatically locks the brewing tamping head 9 without other operations, maintaining it in brewing mode. This achieves pressure-holding extraction of coffee powder, maintains the stability of the tamping state, avoids extraction pressure fluctuations, and thus improves the taste and aroma of the coffee.

[0046] Throughout the process, users can easily adjust the height of the brewing tamping head 9 simply by rotating the tamping handle 1 forward, without the need for additional locking operations, thus simplifying the operation process.

[0047] Preferably, such as Figure 3 , 9 As shown, the transmission gear 2 is provided with a limiting protrusion p, which contacts the vertical rack 3 and thus prevents the transmission gear 2 from rotating further in the forward direction. The contact point between the limiting protrusion p and the vertical rack 3 can serve as a precise stopping point for the rotation of the transmission gear 2, ensuring the accuracy and consistency of the transmission stroke. In addition, it effectively prevents the transmission gear 2 from over-rotating during forward rotation, avoiding damage to the mechanism or functional failure caused by over-rotation.

[0048] like Figure 1 As shown, the tamper handle 1 has an anti-slip texture to enhance the feel and further improve the user experience. The brewing tamper head 9 is equipped with a pressure sensor, and the coffee machine has a visual interface or indicator light to indicate the current tamping level or the recommended rotation level, helping users better master tamping techniques.

[0049] like Figure 2 , 8 As shown, the powder pressing handle 1 includes a disc portion 11 and a handle portion 12 located on one side of the disc portion 11. A shaft portion 13 is provided at the center of the disc portion 11. The shaft portion 13 is connected to the transmission gear 2 and cannot rotate relative to it. A pin is provided inside the disc portion 11 and is parallel to the shaft portion 13.

[0050] like Figure 1 , 2As shown in Figures 4, 7, 8, and 10, the control key 7 is located on the handle 12. One end of the control key 7, away from the locking pin 6, extends outward from the powder pressing handle 1 to form an operating end 71, while the other end engages with the locking pin 6 to form an action end 72. The action end 72 of the control key 7 includes an inclined action surface m located on the outer side. The inner wall of the pin hole of the locking pin 6 engages with the inclined action surface m, and the locking pin 6 slides along the inclined action surface m, so that the locking pin 6 slides inward and outward along the center line of the locking pin cylinder.

[0051] This allows the locking pin 6 to extend and retract. A first elastic element 8 is provided at the outer end of the locking pin 6, and the elastic force of the first elastic element 8 causes the locking pin 6 to approach the one-way ratchet 51. A second elastic element 10 is provided at the front end of the control key 7, and the elastic force of the second elastic element 10 causes the inclined action surface m to disengage from the pin hole g. The control key 7 can control the locking pin 6 to enter or exit the one-way ratchet 51. The locking pin 6 engages with the one-way ratchet 51 and rotates along the one-way ratchet 51 when the powder pressing handle 1 rotates forward, and completes self-locking when the powder pressing handle 1 rotates in the reverse direction. Preferably, the operating end of the control key 7 is located on the button 701, the action end of the control key is located on the push block 702, and the end of the button 701 abuts against the push block 702. Preferably, the first elastic element and the second elastic element are connected to each other as a single elastic element.

[0052] The ingenious design of the control key 7 and the locking pin 6 achieves a high degree of operational linkage. The front end 72 of the control key 7 is inserted into the pin hole g of the locking pin 6. Through the cooperation between the inclined action surface m and the inner wall of the locking pin 6, the slight movement of the control key 7 can drive the locking pin 6 to slide along the inclined action surface m, so that the locking pin 6 slides inward and outward along the center line of the locking pin cylinder.

[0053] This allows the locking pin 6 to engage or disengage from the one-way ratchet 51. This linkage mechanism ensures that the user can control the state of the locking pin 6 simultaneously while operating the powder pressing handle 1, without requiring additional steps, thus improving the continuity and efficiency of the operation.

[0054] By setting the first elastic element 8 and the second elastic element 10, which are respectively used to disengage the locking pin 6 from the pin hole g near the one-way ratchet 51 and the inclined action surface m of the control key 7, the automatic return of the locking pin 6 and the reset function of the control key 7 are realized. Users can easily engage or disengage the locking pin 6 by simply pressing or releasing the control key 7, eliminating the need for strenuous or complicated operations and greatly improving operational convenience. Furthermore, the design of the control key 7 and the locking pin 6 allows users to complete the entire adjustment process with one hand, further enhancing operational ease.

[0055] like Figure 4 , 10As shown, the actuating end of the control key 7 includes a rectangular segment 721 located on the front side and a trapezoidal segment 722 located on the rear side. The inclined actuating surface m is the outer surface of the trapezoidal segment 722, and the inner surfaces of the rectangular segment 721 and the trapezoidal segment 722 are on the same plane perpendicular to the shaft portion 13. A straight guide surface n is provided on the outer side of the rectangular segment 721, located in front of the inclined actuating surface m and perpendicular to the shaft portion 13.

[0056] like Figure 10 As shown, the inner surfaces of the rectangular segment 721 and the trapezoidal segment 722, as well as the straight guide surface n, ensure that the locking pin 6 can move smoothly along the predetermined path during the extension and retraction process, providing a clear and stable guide, effectively preventing the locking pin 6 from deviating or getting stuck during the movement, avoiding the separation of the control key 7 and the locking pin 6, and ensuring the accuracy and smoothness of the operation.

[0057] like Figure 7 , 8 As shown, the powder pressing handle 1 includes a first half-shell 101 and a second half-shell 102. The first half-shell 101 includes a first semi-disc 111 and a first half-handle 121. The second half-shell 102 includes a second semi-disc 112 and a second half-handle 122. The outer periphery of the first semi-disc 111 is provided with a recessed groove k, and the second semi-disc 112 is fitted outside the first semi-disc 111. A locking pin 6 is provided in the recessed groove k.

[0058] like Figure 4 , 11 As shown, the locking pin 6 includes a first small-diameter portion 61, a large-diameter portion 62, and a second small-diameter portion 63 from the inside out. The second small-diameter portion 63 is used to accommodate the first elastic element 8. The first semi-shell 101 has a through hole with a diameter larger than the first small-diameter portion 61 and smaller than the large-diameter portion 62. The first small-diameter portion 61 extends out of the through hole and engages with the ratchet disc 5. By placing the locking pin 6 in the recessed groove k of the first semi-disc 111 and having the second semi-disc 112 fitted over it, the locking pin 6 is completely concealed. This design makes the appearance of the powder pressing handle 1 more concise and streamlined, without any protruding parts or gaps, thus improving the overall aesthetics. The concealed locking pin 6 design avoids direct contact between the user and the locking pin 6 during operation, reducing the possibility of misoperation, and also improving the overall quality of the product and the user experience. The diameter of the through hole in the first half-shell 101 is designed to be larger than that of the first small diameter portion 61 but smaller than that of the large diameter portion 62. This precise fit ensures that the locking pin 6 can pass through the through hole stably during the extension and retraction process without shifting or getting stuck.

[0059] like Figure 7 As shown, an ear piece 20 is fixedly provided on the inner side of the powder pressing handle 1. The ear piece 20 is provided with a guide hole s. The locking pin 6 extends out of the powder pressing handle 1 and cooperates with the ratchet disk 5 through the guide hole, which further ensures the smooth movement of the locking pin 6.

[0060] like Figure 1As shown, the rear end of the powder pressing handle 1 has a sloping surface j that slopes from top to bottom and from front to back. This sloping surface j creates a notch above the operating part of the powder pressing handle 1, and the operating end 71 of the control key 7 extends out of the sloping surface j and is located at this notch. This technical solution achieves the linkage between the rotation of the powder pressing handle 1 and the operation of the control key 7 by designing the sloping surface j at the rear end of the powder pressing handle 1 and the position of the control key 7.

[0061] When the powder tamp handle 1 is rotated forward, the control button 7 is obscured by the beveled surface j because the fingertip is positioned on the lower surface of the handle 1, making it difficult to reach. This effectively hides and protects the control button 7 when not in use, thus preventing accidental unlocking of the locking pin 6. When the powder tamp handle 1 is rotated backward, the thumb can naturally press the control button 7 located at the notch. Without changing hand posture or adding extra steps, a single force is sufficient to simultaneously unlock the locking pin 6 and rotate the handle. This design not only simplifies the operation process and improves convenience but also enhances the continuity and efficiency of operation.

[0062] like Figure 7-9 As shown, the shaft portion 13 includes a first circular protrusion 131, and a first spline y is provided on the outer periphery of the first circular protrusion 131. The transmission gear 2 is provided with a first spline groove w that mates with the first spline y.

[0063] This connection method is not only compact in structure but also capable of transmitting large torques, ensuring the stability and reliability of the transmission. A threaded post is located at the center of the circular protrusion, and a threaded hole for connection with the threaded post is located at the center of the transmission gear 2. This connection method further enhances the connection strength between the powder pressing handle 1 and the transmission gear 2, preventing loosening or detachment due to vibration or external forces.

[0064] like Figure 8 , 9 As shown, the lifting frame 4 has strip-shaped first sliding blocks 41 and second sliding blocks 42 fixed vertically and parallelly on both sides. A first vertical rack 31 is located behind the first sliding block 41, and a second vertical rack 32 is located behind the second sliding block 42. The powder pressing handle 1 is connected to a first transmission gear 21 via a spline. The first transmission gear 21 is connected to a second transmission gear 22 parallel to and spaced apart from the first transmission gear 21 via a connecting shaft 30. The first transmission gear 21 meshes with the first vertical rack 31. The second transmission gear 22 meshes with the second vertical rack 32, achieving smooth lifting and synchronous control of the lifting frame 4. Because the two transmission gears 2 rotate parallel and synchronously, they ensure that the first sliding blocks 41 and second sliding blocks 42 on both sides of the lifting frame 4 move at the same speed and displacement, thus ensuring the stability of the lifting frame 4.

[0065] This invention describes a semi-automatic coffee machine extraction pressure maintaining mechanism and coffee brewing method. Specific examples are used to illustrate the principles and implementation methods of the invention. The descriptions of these embodiments are merely for the purpose of helping to understand the invention and its core ideas. It should be noted that those skilled in the art can make various improvements and modifications to the invention without departing from its principles, and these improvements and modifications also fall within the scope of protection of the claims.

Claims

1. A semi-automatic coffee machine extraction pressure maintaining mechanism, characterized in that: It includes a powder pressing handle, a transmission gear, a lifting frame with a vertical rack, and a fixed ratchet disc; The powder-pressing head is mounted on the lower end of the lifting frame; the powder-pressing handle is connected to the transmission gear, and the transmission gear meshes with the vertical rack, so that when the powder-pressing handle drives the transmission gear, the powder-pressing head moves up and down with the lifting frame; The ratchet disc is provided with one-way ratchet teeth consisting of a blocking surface and an inclined sliding surface, and a locking groove is formed between adjacent one-way ratchet teeth; the powder pressing handle is provided with a control key and a locking pin, and the control key controls the locking pin to enter or exit the locking groove; During the rotation of the powder pressing handle, the locking pin enters the locking groove and bounces on multiple inclined sliding surfaces as it rotates; the blocking surface prevents the powder pressing handle from rotating in the opposite direction to complete the self-locking.

2. The extraction pressure maintaining mechanism for a semi-automatic coffee machine according to claim 1, characterized in that: The powder pressing handle includes a disc portion and a handle portion located on one side of the disc portion. The disc portion has a shaft portion at its center, and the shaft portion is connected to the transmission gear and cannot rotate relative to it. The shaft pin is located inside the disc portion and is parallel to the shaft portion; the control key is located on the handle portion, with one end of the control key away from the locking pin extending out of the outer end of the powder pressing handle to form an operating end, and the other end cooperating with the locking pin to form an action end; The control key's actuating end includes an inclined actuating surface located on the outer side; the inner wall of the locking pin's pin hole cooperates with the inclined actuating surface, and the locking pin slides along the inclined actuating surface, causing the locking pin 6 to slide along the center line of the locking pin cylinder, thereby realizing the extension and retraction of the locking pin.

3. The extraction pressure maintaining mechanism for a semi-automatic coffee machine according to claim 2, characterized in that: The outer end of the locking pin is provided with a first elastic element, which drives the locking pin to extend inward into the locking groove; The front end of the control key is provided with a second elastic element, which drives the operating end of the control key to extend backward out of the powder pressing handle and the inclined action surface to disengage from the inner wall of the pin hole so that the locking pin extends inward into the locking groove.

4. The extraction pressure maintaining mechanism for a semi-automatic coffee machine according to claim 2, characterized in that: The first elastic element and the second elastic element are connected to each other as the same elastic element.

5. The extraction pressure maintaining mechanism for a semi-automatic coffee machine according to claim 2, characterized in that: The operating end of the control key is located on the button, and the action end of the control key is located on the push block. The push block includes a rectangular segment on the front side and a trapezoidal segment on the rear side. The inclined action surface is the outer side of the trapezoidal segment. The inner sides of the rectangular segment and the trapezoidal segment are the same plane perpendicular to the axis. The outer side of the rectangular segment is provided with a straight guide surface located on the front of the inclined action surface and perpendicular to the axis.

6. The extraction pressure maintaining mechanism for a semi-automatic coffee machine according to claim 2, characterized in that: The powder pressing handle includes a first half-shell and a second half-shell. The first half-shell includes a first semi-disc and a first half-handle. The second half-shell includes a second semi-disc and a second half-handle. The outer periphery of the first semi-disc is provided with a recessed groove, the second semi-disc is sleeved on the outside of the first semi-disc, and the locking pin is provided in the recessed groove; The locking pin includes a first small diameter portion, a large diameter portion, and a second small diameter portion from the inside to the outside. The first half-shell has a through hole with a diameter larger than the first small diameter portion and smaller than the large diameter portion. The first small diameter portion extends out of the through hole and engages with the ratchet disc.

7. The extraction pressure maintaining mechanism for a semi-automatic coffee machine according to claim 1, characterized in that: The rear end of the powder pressing handle has a beveled surface that slopes from top to bottom and from front to back. The rear end of the powder pressing handle forms a notch on the upper side, and the operating end of the control key extends out of the beveled surface at the notch.

8. The extraction pressure maintaining mechanism for a semi-automatic coffee machine according to claim 1, characterized in that: The inner side of the powder pressing handle is provided with a shaft portion, the shaft portion including a first circular protrusion, the outer periphery of the first circular protrusion is provided with a first spline, the transmission gear is provided with a first spline groove that mates with the first spline; the center of the circular protrusion is provided with a threaded post, and the center of the transmission gear is provided with a threaded hole that connects to the threaded post.

9. The extraction pressure maintaining mechanism for a semi-automatic coffee machine according to claim 1, characterized in that: The lifting frame is vertically and parallelly fixed with strip-shaped first sliding blocks and second sliding blocks on both sides. The first sliding block is provided with a first vertical rack on the rear side, and the second sliding block is provided with a second vertical rack on the rear side. The powder pressing handle is connected to the first transmission gear via a spline, and the first transmission gear is connected to a second transmission gear that is parallel and spaced apart from the first transmission gear via a connecting shaft; The first transmission gear meshes with the first vertical rack; the second transmission gear meshes with the second vertical rack.

10. The extraction pressure maintaining mechanism for a semi-automatic coffee machine according to claim 3, characterized in that: The transmission gear is provided with a limiting protrusion, which contacts the vertical rack and thus prevents the transmission gear from rotating further in the forward direction.

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