Shank transmission mechanism and hand grinder

Abstract

This disclosure provides a crank drive mechanism and a hand-cranked coffee grinder. The crank drive mechanism includes a lid, a drive shaft, and a crank assembly. The lid covers the feed inlet of the grinding body. A shaft mounting groove is formed on the side of the lid facing the feed inlet. The drive shaft is vertically mounted within the grinding body. The crank assembly is connected to the lid and drives the lid to rotate. The drive shaft is elastically slidably mounted in the shaft mounting groove and slidably engaged with the groove wall. The end of the drive shaft is magnetically connected to the bottom of the shaft mounting groove, so that when the drive shaft moves up and down relative to the grinding body, the lid maintains a preset distance from the feed inlet. This crank drive mechanism uses magnetic and elastic forces to automatically control the lifting and lowering of the lid, maintaining a preset distance between the lid and the feed inlet. This preset distance prevents external contaminants from entering and also avoids friction between the lid and the feed inlet when the crank assembly is driven.

Description

Technical Field

[0001] This disclosure relates to the technical field of coffee bean grinding, and in particular to a crank drive mechanism and a hand-cranked coffee grinder. Background Technology

[0002] With socio-economic development and the pursuit of a higher quality of life driven by consumption upgrades, the rise of coffee culture has led to the increasing popularity of coffee consumption, making coffee a necessity for many. A large proportion of consumers choose hand-cranked coffee grinders. To facilitate adjustment of the grind size, some manufacturers have developed both external and internal grinders. Internal grinders require opening the powder cup for adjustment, which can contaminate the coffee grounds with the user's fingers. Therefore, external grinders are more popular among consumers.

[0003] For example, Chinese patent document 202223589773.7 discloses a hand-cranked coffee grinder, including a housing, a detachable cover fixed to the top opening of the housing, an outer blade disc embedded and fixed inside the bottom opening of the housing, a lifting ring movably disposed in the housing to have the function of moving up and down, a vertical and rotatable central shaft inserted in the lifting ring and able to move up and down with the lifting ring, a crank handle fixed to the upper end of the central shaft and located above the housing, and an inner blade disc fixed to the lower end of the central shaft and concentrically disposed inside the outer blade disc; an adjustment ring is also provided on the top of the housing, the adjustment ring is screwed to the outside of the lifting ring, and a top cover is fixed to the upper opening of the adjustment ring. The upper end of the central shaft passes upward through the top cover and extends above the top cover. By rotating the adjustment ring, the lifting ring drives the central shaft to move up and down, thereby adjusting the gap between the outer wall of the inner blade disc and the inner wall of the outer blade disc.

[0004] However, the design of the aforementioned hand-cranked coffee grinder has the following problems:

[0005] In the aforementioned hand-cranked coffee grinder, when the lifting ring raises the central shaft, the central shaft protrudes relatively beyond the top opening of the housing. This increases the gap between the lid and the housing after the lid is placed over the top opening, leaving the coffee beans exposed and making them more susceptible to contamination from foreign objects. Conversely, when the lifting ring lowers the central shaft, it sinks relatively into the top opening of the housing. This reduces the gap between the lid and the housing after the lid is placed over the top opening, making it more prone to friction or interference between the lid and the housing during operation. Summary of the Invention

[0006] The purpose of this disclosure is to overcome the shortcomings of the prior art and provide a self-controlled lid lifting mechanism, an easy-to-use crank transmission mechanism, and a hand-cranked coffee grinder.

[0007] The purpose of this disclosure is achieved through the following technical solution:

[0008] A crank transmission mechanism, comprising:

[0009] A cover is provided for covering the feeding port of the grinding body; the cover has a central shaft mounting groove on the side facing the feeding port;

[0010] A transmission shaft is used for lifting and lowering within the grinding body;

[0011] A crank assembly is connected to the cover, and the crank assembly is used to drive the cover to rotate;

[0012] The transmission shaft is elastically slidably disposed in the shaft mounting groove and slidably engaged with the groove wall of the shaft mounting groove; the end of the transmission shaft is magnetically connected to the bottom of the shaft mounting groove, so that when the transmission shaft is raised and lowered relative to the grinding body, the cover can maintain a preset distance from the feeding port.

[0013] In one embodiment, the central shaft mounting groove includes a connected elastic lifting cavity and a snap-fit ​​transmission cavity; the transmission central shaft passes through the elastic lifting cavity and the snap-fit ​​transmission cavity respectively; an elastic element is provided between the peripheral wall of the transmission central shaft and the cavity wall of the elastic lifting cavity; the cavity wall of the snap-fit ​​transmission cavity is adapted to the peripheral wall of the transmission central shaft and achieves snap-fit.

[0014] In one embodiment, the cavity wall of the elastic lifting cavity is formed with a pressing protrusion, and a pressing protrusion ring is sleeved on the peripheral wall of the transmission shaft. An installation gap is formed between the pressing protrusion and the pressing protrusion ring. The elastic element is disposed in the installation gap, and both ends of the elastic element press against the pressing protrusion and the pressing protrusion ring respectively.

[0015] In one embodiment, the cavity wall of the central shaft mounting groove is further provided with a crank mounting cavity, through which the crank assembly extends into the central shaft mounting groove and is slidably engaged with the end of the transmission central shaft.

[0016] In one embodiment, the crank assembly includes a locking connector and a rocker arm, the locking connector being slidably disposed within the crank mounting cavity; the pushing end of the rocker arm extends into the crank mounting cavity and can push the locking connector toward the transmission central shaft.

[0017] In one embodiment, the end of the snap-fit ​​connector facing the transmission shaft is provided with an arc-shaped snap-fit, and the peripheral wall of the end of the transmission shaft is formed with a concave snap-fit ​​position. The arc-shaped snap-fit ​​engages with the concave snap-fit ​​position, and the transmission shaft can slide up and down within the arc-shaped snap-fit.

[0018] In one embodiment, the snap-fit ​​connector is elastically disposed within the crank mounting cavity so that the snap-fit ​​connector can automatically reset.

[0019] In one embodiment, the rocker arm includes a push rod and a folding rod. The push rod is slidably disposed in the rocker arm mounting cavity and can push the snap-fit ​​connector to move. The folding rod is rotatably connected to the push rod and is used to fold to one side of the grinding body.

[0020] In one embodiment, a positioning element is also provided between the rocker arm and the rocker handle mounting cavity.

[0021] A hand-cranked coffee grinder includes a grinding body, a lifting adjustment ring, and a crank transmission mechanism according to any of the above embodiments;

[0022] The transmission shaft is vertically and flexibly mounted within the grinding body via the lifting adjustment ring.

[0023] Compared with the prior art, this disclosure has at least the following advantages:

[0024] The aforementioned crank transmission mechanism has a crank assembly connected to the cover. The transmission shaft is elastically slidably disposed in the central shaft mounting groove and slidably engaged with the groove wall. This allows the cover to rotate via the central shaft mounting groove after being driven by the crank assembly, enabling the cover to drive the transmission shaft to rotate for grinding operations. Simultaneously, the transmission shaft can slide up and down along the central shaft mounting groove by overcoming elastic force. Since the transmission shaft is used for lifting and lowering within the grinding body, its end is magnetically connected to the bottom of the central shaft mounting groove. When the transmission shaft extends upwards beyond the feeding port of the grinding body, the cover covers the feeding port. Simultaneously, the bottom of the central shaft mounting groove magnetically attracts and abuts against the end of the transmission shaft, causing the cover to move closer to the feeding port against elastic force. A preset gap exists between the cover and the feeding port. When the transmission shaft is lowered into the feeding port of the grinding body, the magnetic force separating the bottom of the central shaft mounting groove from the end of the transmission shaft decreases. The elastic force pushes the cover away from the feeding port of the grinding body, while the magnetic force brings the cover closer to the feeding port of the grinding body. Finally, the magnetic force, the weight of the cover and the elastic force are balanced so that the cover and the feeding port still maintain a preset distance. Compared with the traditional technology, the crank transmission mechanism disclosed herein controls the lifting and lowering of the cover by magnetic force and elastic force, so that the cover and the feeding port maintain a preset distance. The preset distance between the cover and the feeding port can prevent external contaminants from entering, and also avoid friction between the cover and the feeding port when the crank assembly is driven. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a partial structural schematic diagram of a crank transmission mechanism according to an embodiment of the present disclosure;

[0027] Figure 2 for Figure 1 A partial sectional view of the crank transmission mechanism in its working state.

[0028] Figure 3 for Figure 1 The shown is a partial cross-sectional view of the crank transmission mechanism in the raised state when the transmission shaft is installed on the grinding body.

[0029] Figure 4 for Figure 1 The shown is a partial cross-sectional view of the crank transmission mechanism in the lowered state when the transmission shaft is installed on the grinding body.

[0030] Figure 5 for Figure 1 The shown is a partial cross-sectional view of the crank drive mechanism in its folded state when it is installed on the grinding body;

[0031] Figure 6 This is a partial cross-sectional view of the crank transmission mechanism in operation according to another embodiment of the present disclosure.

[0032] Figure 7 for Figure 6 The diagram shows a partial cross-sectional view of the crank transmission mechanism in the folded hand position.

[0033] Figure 8 This is a cross-sectional view of a hand-cranked coffee grinder according to another embodiment of the present disclosure.

[0034] Reference numerals: 10, hand-cranked coffee grinder; 100, crank transmission mechanism; 110, lid; 1110, central shaft mounting groove; 1111, elastic lifting cavity; 111a, mounting gap; 111b, first spring; 111c, pressing protrusion; 1112, snap-fit ​​transmission cavity; 1113, first magnetic suction element; 1130, crank mounting cavity; 1131, positioning element; 113a, ball-head plunger; 113b, first magnet; 113c, second magnet; 1132, slide groove; 120, transmission central shaft; 1210, concave locking position; 1220, pressing protrusion ring; 1230, Second magnetic suction element; 1240, Transmission shaft sleeve; 1241, Anti-slip vertical groove; 1242, Sleeve cavity; 1250, Transmission end; 130, Crank handle assembly; 1310, Snap connector; 1311, Arc-shaped snap; 1312, Second spring; 1320, Rocker arm; 1321, Push rod; 132a, First arc-shaped alignment groove; 1322, Folding rod; 1323, Rotating shaft; 132b, Second arc-shaped alignment groove; 200, Grinding body; 2010, Feeding port; 2020, Lifting adjustment ring; 2030, Lifting ring; 2040, Interval. Detailed Implementation

[0035] To facilitate understanding of this disclosure, a more complete description will be given below with reference to the accompanying drawings, which illustrate preferred embodiments of the present disclosure. However, this disclosure can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of the disclosure.

[0036] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0038] To better understand the technical solutions and beneficial effects of this disclosure, the following detailed description is provided in conjunction with specific embodiments:

[0039] like Figures 1 to 2 As shown, a crank transmission mechanism 100 of one embodiment includes a cover 110, a transmission shaft 120, and a crank assembly 130. The cover 110 is used to cover the feeding port 2010 of the grinding body 200. The cover 110 has a shaft mounting groove 1110 on the side facing the feeding port 2010. The transmission shaft 120 is used to be lifted and lowered in the grinding body 200. The crank assembly 130 is connected to the cover 110 and is used to drive the cover 110 to rotate. The transmission shaft 120 is elastically slidably disposed in the shaft mounting groove 1110 and slidably engaged with the groove wall of the shaft mounting groove 1110. The end of the transmission shaft 120 is magnetically connected to the bottom of the shaft mounting groove 1110 so that when the transmission shaft 120 is lifted and lowered relative to the grinding body 200, the cover 110 can maintain a preset distance 2040 from the feeding port 2010.

[0040] It is understandable that, because the crank assembly 130 is connected to the cover 110, and the transmission shaft 120 is elastically disposed in the shaft mounting groove 1110 and slidably engaged with the groove wall of the shaft mounting groove 1110, after the cover 110 is driven to rotate by the crank assembly 130, the cover 110 can drive the transmission shaft 120 to rotate through the shaft mounting groove 1110 to perform grinding operations. Simultaneously, the transmission shaft 120 can slide up and down along the shaft mounting groove 1110 by overcoming the elastic force. Furthermore, because the transmission shaft 120 is used for lifting and lowering within the grinding body 200, the end of the transmission shaft 120 is magnetically connected to the bottom of the shaft mounting groove 1110. Combined with... Figure 3 As shown, when the transmission shaft 120 extends upward beyond the feeding port 2010 of the grinding body 200, the cover 110 covers the feeding port 2010. Simultaneously, the bottom of the shaft mounting groove 1110 magnetically attracts and abuts against the end of the transmission shaft 120. The cover 110 overcomes the elastic force F2 and moves closer to the feeding port 2010 until a preset distance 2040 exists between the cover 110 and the feeding port 2010, thus combining... Figure 4 As shown, when the transmission shaft 120 is adjusted to sink downwards into the feeding port 2010 of the grinding body 200, the bottom of the shaft mounting groove 1110 separates from the end of the transmission shaft 120, causing the magnetic force F1 to decrease. The elastic force F2 pushes the cover 110 away from the feeding port 2010 of the grinding body 200. At the same time, the magnetic force F1 makes the cover 110 move closer to the feeding port 2010 of the grinding body 200. Finally, the magnetic force F1, the weight G of the cover 110, and the elastic force F2 are balanced (i.e., F1 + G = F2), making the magnetic force F1, the weight G of the cover 110, and the elastic force F2 balanced (i.e., F1 + G = F2). The cover 110 and the feeding port 2010 maintain a preset distance 2040. In contrast to conventional technology, the crank transmission mechanism 100 of this disclosure controls the lifting and lowering of the cover 110 by magnetic force and elastic force, so that the cover 110 and the feeding port 2010 maintain a preset distance 2040. The preset distance 2040 between the cover 110 and the feeding port 2010 can prevent external contaminants from entering, and also avoid friction between the cover 110 and the feeding port 2010 when the crank assembly 130 is driven.

[0041] In one embodiment, the preset interval 2040 is in the range of 0.2mm-0.5mm. It is understood that when the preset interval 2040 is set within the range of 0.2mm-0.5mm, the interval 2040 between the cover 110 and the feeding port 2010 is appropriate, which can better prevent external contaminants from entering, and also better avoid friction between the cover 110 and the feeding port 2010 when the crank assembly 130 is driven. Further, the preset interval 2040 can specifically be 0.2mm, 0.3mm, or 0.5mm; the value of the preset interval 2040 is not limited, and those skilled in the art can adjust it as needed.

[0042] Combination Figure 1 and Figure 2As shown, in one embodiment, the central shaft mounting groove 1110 includes a connected elastic lifting cavity 1111 and a snap-fit ​​transmission cavity 1112; the transmission central shaft 120 passes through the elastic lifting cavity 1111 and the snap-fit ​​transmission cavity 1112 respectively; an elastic element is provided between the peripheral wall of the transmission central shaft 120 and the cavity wall of the elastic lifting cavity 1111; the cavity wall of the snap-fit ​​transmission cavity 1112 is adapted to the peripheral wall of the transmission central shaft 120 and achieves snap-fit. It can be understood that by providing an elastic element between the peripheral wall of the transmission central shaft 120 and the cavity wall of the elastic lifting cavity 1111, when the transmission central shaft 120 moves downward in the elastic lifting cavity 1111, the elastic element can provide elasticity to create a gap 2040 between the cover 110 and the feeding port 2010, effectively avoiding friction between the cover 110 and the feeding port 2010. Simultaneously, the peripheral wall of the transmission shaft 120 adapts to and passes through the cavity wall of the engagement transmission cavity 1112, allowing the transmission shaft 120 and the engagement transmission cavity 1112 to engage and cooperate, enabling the transmission shaft 120 to rotate via the drive cover 110 for grinding operations. Furthermore, when the transmission shaft 120 rises and falls relative to the grinding body 200, it can still slide axially relative to the engagement transmission cavity 1112. In this embodiment, the cross-sections of both the engagement transmission cavity 1112 and the transmission shaft 120 are hexagonal. The hexagonal shape has more edges and is evenly distributed, resulting in a uniform radial friction distribution between the cavity wall of the engagement transmission cavity 1112 and the peripheral wall of the transmission shaft 120, leading to more stable and durable driving and reducing the likelihood of slippage. Of course, the shapes of the cross-sections of the engagement transmission cavity 1112 and the transmission shaft 120 are not limited; those skilled in the art can choose other shapes such as triangles or quadrilaterals as needed.

[0043] Combination Figure 1As shown, in this embodiment, a transmission shaft 120 is fitted with a transmission sleeve 1240, and the outer contour of the transmission sleeve 1240 engages with the contour of the cavity wall of the engagement transmission cavity 1112. This avoids direct friction between the transmission shaft 120 and the engagement transmission cavity 1112, thus extending the service life of the transmission shaft 120. Specifically, the outer peripheral wall of the transmission sleeve 1240 is provided with several anti-slip vertical grooves 1241, and the cavity wall of the engagement transmission cavity 1112 is provided with several limiting protrusions. When the transmission sleeve 1240 is installed in the engagement transmission cavity 1112, each anti-slip vertical groove 1241 is engaged between two adjacent limiting protrusions, thereby achieving transmission. Simultaneously, the transmission sleeve 1240, guided by the adjacent two limiting protrusions, can slide vertically relative to the engagement transmission cavity 1112. Furthermore, the transmission shaft sleeve 1240 has a sleeve cavity 1242, the cavity wall of which engages with the peripheral wall of the transmission end 1250 of the transmission shaft 120. The cross-sections of both the cavity wall of the sleeve cavity 1242 and the peripheral wall of the transmission end 1250 of the transmission shaft 120 are hexagonal. Hexagons have more edges that are evenly distributed, reducing the likelihood of slippage during transmission. Of course, the shape of the cross-sections of the sleeve cavity 1242 and the peripheral wall of the transmission end 1250 of the transmission shaft 120 is not limited; those skilled in the art can choose other shapes such as triangles or quadrilaterals as needed.

[0044] Combination Figure 1 and Figure 2 As shown, in one embodiment, a first magnetic attractor 1113 is provided at the bottom of the central shaft mounting groove 1110, and a second magnetic attractor 1230 is provided at the end of the transmission central shaft 120. It can be understood that through the mutual attraction between the first magnetic attractor 1113 and the second magnetic attractor 1230, when the transmission central shaft 120 moves up and down within the elastic lifting cavity 1111, the attraction between the first magnetic attractor 1113 and the second magnetic attractor 1230 can overcome the elastic force of the elastic element, ensuring that the cover 110 and the feeding port 2010 always maintain a preset distance 2040. It can be understood that both the first magnetic attractor 1113 and the second magnetic attractor 1230 are permanent magnets, making the attraction between them more stable. Furthermore, the first magnetic chuck 1113 is embedded, engaged, or fitted into the bottom of the central shaft mounting groove 1110, and the second magnetic chuck 1230 is embedded, engaged, sleeved, or fitted into the end of the transmission central shaft 120. It is understood that the connection method between the first magnetic chuck 1113 and the mounting groove, and between the second magnetic chuck 1230 and the end of the transmission central shaft 120, is not limited, and those skilled in the art can choose according to their needs.

[0045] In another embodiment, at least one of the first magnetic attractor 1113 and the second magnetic attractor 1230 is an electromagnet. It is understood that the magnitude of the magnetic force between the first magnetic attractor 1113 and the second magnetic attractor 1230 can be controlled by controlling the magnitude of the current. When the transmission shaft 120 rises relative to the grinding body 200, the user increases the current to allow the cover 110 to overcome its elasticity and approach the feeding port 2010 under the action of the magnetic force. Furthermore, by quantitatively adjusting the current, the distance 2040 between the cover 110 and the feeding port 2010 can be adjusted more flexibly, maintaining the distance between them within a predetermined range of 2040. This ultimately increases the controllability of the distance 2040 between the cover 110 and the feeding port 2010, making it more convenient to use. Specifically, the first magnetic attractor 1113 is an electromagnet, or the second magnetic attractor 1230 is an electromagnet, or both the first magnetic attractor 1113 and the second magnetic attractor 1230 can be electromagnets. There are no restrictions here, and those skilled in the art can make the settings as needed.

[0046] In one embodiment, the cavity wall of the elastic lifting cavity 1111 and the peripheral wall of the transmission shaft 120 form an installation gap 111a. Several elastic elements are filled in the installation gap 111a. It can be understood that by filling the installation gap 111a between the cavity wall of the elastic lifting cavity 1111 and the peripheral wall of the transmission shaft 120 with several elastic elements, when the transmission shaft 120 moves downward within the elastic lifting cavity 1111, the elastic elements can better provide elastic force, creating a gap 2040 between the cover 110 and the feeding port 2010. Specifically, the elastic elements can be elastic materials or structures such as spring sheets, coil springs, elastic balls, and elastic cotton; no limitation is made here, and those skilled in the art can replace them as needed.

[0047] Combination Figure 2As shown, in one embodiment, the cavity wall of the elastic lifting cavity 1111 has a pressing protrusion 111c, and a pressing protrusion ring 1220 is sleeved on the peripheral wall of the transmission shaft 120. An installation gap 111a is formed between the pressing protrusion 111c and the pressing protrusion ring 1220. An elastic element is disposed in the installation gap 111a, and both ends of the elastic element press against the pressing protrusion 111c and the pressing protrusion ring 1220, respectively. It can be understood that by the elastic element pressing against the pressing protrusion 111c and the pressing protrusion ring 1220, when the transmission shaft 120 moves downward in the elastic lifting cavity 1111, the elastic element can provide elasticity to create an installation gap 111a between the cover 110 and the feeding port 2010, effectively avoiding friction between the cover 110 and the feeding port 2010. It can be understood that the elastic element is a first spring 111b. The first spring 111b is sleeved on the outside of the transmission shaft 120 and located in the mounting gap 111a formed between the pressing protrusion 111c and the pressing ring 1220. The two ends of the first spring 111b press against the pressing protrusion 111c and the pressing ring 1220 respectively. By using the method of sleeved on the transmission shaft 120, the first spring 111b can be fixed more securely. Specifically, in another embodiment, there are several first springs 111b. Several first springs 111b are arranged around the peripheral wall of the transmission shaft 120 in the mounting gap 111a. The two ends of each first spring 111b press against the pressing protrusion 111c and the pressing ring 1220 respectively, so that a uniform and strong elastic force can be formed between the pressing protrusion 111c and the pressing ring 1220 through the several first springs 111b.

[0048] Combination Figure 2As shown, in one embodiment, the cavity wall of the central shaft mounting groove 1110 is further provided with a crank mounting cavity 1130. The crank assembly 130 extends into the central shaft mounting groove 1110 through the crank mounting cavity 1130 and is slidably engaged with the end of the transmission central shaft 120. It can be understood that by engaging the end of the transmission central shaft 120 with the crank assembly 130, the transmission central shaft 120 can be positioned using the crank assembly 130. This allows the cover 110 to be pre-connected to the transmission central shaft 120 when the crank assembly 130 drives the cover 110 to rotate, preventing the cover 110 from shifting or shaking with the transmission central shaft 120 during transmission, ultimately making the transmission of the cover 110 more stable and efficient. Simultaneously, because the crank assembly 130 is slidably connected to the end of the transmission central shaft 120, it does not restrict the up-and-down sliding process of the transmission central shaft 120 within the central shaft mounting groove 1110. In this embodiment, the crank mounting cavity 1130 is formed in the cavity wall of the snap-fit ​​transmission cavity 1112. The crank assembly 130 extends into the central shaft mounting groove 1110 through the snap-fit ​​transmission cavity 1112. By setting the snap-fit ​​transmission cavity 1112 in the above manner, the structure of the cover 110 can be made more compact. This is not limited here. Those skilled in the art can also set the position of the crank mounting cavity 1130 as needed.

[0049] Combination Figure 2 As shown, in one embodiment, the crank assembly 130 includes a snap-fit ​​connector 1310 and a rocker arm 1320. The snap-fit ​​connector 1310 is slidably disposed within the crank mounting cavity 1130. The pushing end of the rocker arm 1320 extends into the crank mounting cavity 1130 and can push the snap-fit ​​connector 1310 toward the transmission shaft 120. It can be understood that by causing the pushing end of the rocker arm 1320 to push the snap-fit ​​connector 1310 toward the transmission shaft 120, the rocker arm 1320 can be connected to the transmission shaft 120 through the snap-fit ​​connector 1310. The snap-fit ​​connector 1310 limits the transmission shaft 120, making the cover 110 more stable during transmission.

[0050] contrast Figure 4 and Figure 5As can be seen, in one embodiment, the snap-fit ​​connector 1310 is elastically disposed within the crank handle mounting cavity 1130 so that the snap-fit ​​connector 1310 can automatically reset. It is understood that when the pushing end of the crank arm 1320 pushes the snap-fit ​​connector 1310 toward the transmission shaft 120, it can overcome the elastic force and snap onto the end of the transmission shaft 120. When the pushing end of the crank arm 1320 makes a return motion within the crank handle mounting cavity 1130, the snap-fit ​​connector 1310 can reset under the action of the elastic force, thereby automatically releasing the restriction on the transmission shaft 120, facilitating the removal of the cover and the insertion of raw materials, making the use process more convenient. In this embodiment, a second spring 1312 is sleeved on the snap-fit ​​connector 1310. The second spring 1312 is used to press against the cavity wall of the crank mounting cavity 1130. When the pushing end of the rocker arm 1320 pushes the snap-fit ​​connector 1310 to move toward the transmission central shaft 120, a restoring force is generated between the rocker arm 1320 and the cavity wall of the crank mounting cavity 1130, which makes it easier to use.

[0051] Combination Figure 5 As shown, in one embodiment, the rocker arm 1320 includes a push rod 1321 and a folding rod 1322. The push rod 1321 is slidably disposed within the rocker arm mounting cavity 1130 and can push the snap-fit ​​connector 1310 to move. The folding rod 1322 is rotatably connected to the push rod 1321 and is used to fold to one side of the grinding body 200. It can be understood that because the push rod 1321 is slidably disposed within the rocker arm mounting cavity 1130, it can push the snap-fit ​​connector 1310 along the rocker arm mounting cavity 1130, causing the snap-fit ​​connector 1310 to snap onto the end of the transmission shaft 120. Simultaneously, because the folding rod 1322 is rotatably connected to the push rod 1321, the folding rod 1322 can be folded to one side of the grinding body 200 after use. This makes the aforementioned rocker arm transmission mechanism 100 occupy less space and is easier to store. Specifically, the folding rod 1322 is fitted to one side of the grinding body 200. In this embodiment, the folding rod 1322 and the push rod 1321 are connected by a pivot 1323 or a mortise screw. This is not limited, and those skilled in the art can make other choices as needed.

[0052] In one embodiment, a positioning element is provided between the rocker arm 1320 and the handle mounting cavity 1130, which can position the rocker arm 1320 at a specific position in the handle mounting cavity 1130, such as the position where the rocker arm 1320 pushes the locking connector 1310 to engage with the transmission shaft 120, or the position where the rocker arm 1320 returns to a position away from the locking connector 1310. It can be understood that the positioning element is a ball plunger 113a, which is disposed on the shaft of the rocker arm 1320. The cavity wall of the handle mounting cavity 1130 is provided with an arc-shaped alignment groove that interacts with the ball plunger 113a, so that the rocker arm 1320 can be temporarily fixed at a specific part of the handle mounting cavity 1130 through the arc-shaped alignment groove and the ball plunger 113a, such as the position where the rocker arm 1320 pushes the locking connector 1310 to engage with the transmission shaft 120, or the position where the rocker arm 1320 returns to a position away from the locking connector 1310. In this embodiment, the rocker arm 1320 includes a push rod 1321 and a folding rod 1322. The arc-shaped alignment groove includes a first arc-shaped alignment groove 132a and a second arc-shaped alignment groove 132b. The first arc-shaped alignment groove 132a is formed in the body of the push rod 1321, and the second arc-shaped alignment groove 132b is formed in the body of the folding rod 1322. Figure 4 As shown, in the working state, the folding rod 1322 extends into the crank mounting cavity 1130, and the ball plunger 113a slides and engages with the first arc-shaped alignment groove 132a, so that the folding rod 1322 remains horizontally positioned in the cover 110, making it easier for the user to apply force. Figure 5 As shown, after the work is completed, the folding rod 1322 is pulled out of the crank mounting cavity 1130 and folded for storage. The ball plunger 113a slides and engages with the second arc-shaped alignment groove 132b to limit the push rod 1321 and prevent the push rod 1321 from slipping out of the crank mounting cavity 1130.

[0053] Combination Figure 6 As shown, in another embodiment, the positioning element 1131 is a magnet, and there are two magnets, namely a first magnet 113b and a second magnet 113c; the pushing end of the rocker arm 1320 is provided with a rotating shaft 1323, and the cavity wall of the rocker arm mounting cavity 1130 is provided with a sliding groove 1132 that cooperates with the rotating shaft 1323. The first magnet 113b is provided at the pushing end of the rocker arm 1320, and the second magnet 113c is provided at the cavity wall of the rocker arm mounting cavity 1130. The pushing end of the rocker arm 1320 extends into the rocker arm mounting cavity 1130, and the rotating shaft 1323 slides in cooperation with the sliding groove 1132. It can be understood that, as Figure 6 As shown, during operation, the pushing end of the rocker arm 1320 is inserted into the handle mounting cavity 1130. When the positions of the first magnet 113b and the second magnet 113c correspond, the rocker arm 1320 is positioned within the handle mounting cavity 1130, keeping the folding rod 1322 horizontally positioned on the cover 110, making it easier for the user to apply force. Figure 7As shown, after the work is completed, the rocker arm 1320 is pulled out of the rocker arm mounting cavity 1130. The pushing end of the rocker arm 1320 is limited by the slide groove 1132 and rotates around the pivot 1323 for folding and storage, making it more convenient to use.

[0054] Combination Figure 1 and Figure 7 As shown, in one embodiment, the snap-fit ​​connector 1310 has an arc-shaped snap-fit ​​opening 1311 at one end facing the transmission shaft 120, and a concave snap-fit ​​position 1210 is formed on the peripheral wall of the end of the transmission shaft 120. The arc-shaped snap-fit ​​opening 1311 engages with the concave snap-fit ​​position 1210, and the transmission shaft 120 can slide up and down within the arc-shaped snap-fit ​​opening 1311. It can be understood that through the snap-fit ​​engagement between the arc-shaped snap-fit ​​opening 1311 and the concave snap-fit ​​position 1210, the arc-shaped snap-fit ​​opening 1311 is smoother, allowing the transmission shaft 120 to still rotate or slide up and down within the arc-shaped snap-fit ​​opening 1311 of the snap-fit ​​connector 1310, reducing the constraint on the movement of the transmission shaft 120.

[0055] like Figure 8 As shown, this disclosure also provides a hand-cranked coffee grinder 10, including a grinding body 200, a lifting adjustment ring 2020, and a crank transmission mechanism 100 of any of the above embodiments; the transmission shaft 120 is movably disposed within the grinding body 200 via the lifting adjustment ring 2020. It can be understood that the lifting adjustment ring 2020 can be screwed to a lifting ring 2030 outside the transmission shaft 120, allowing the lifting ring 2030 to be adjusted via the lifting adjustment ring 2020, thereby driving the transmission shaft 120 to rise or fall within the grinding body 200. Furthermore, by providing the crank transmission mechanism 100 of this disclosure, the lid 110 is raised and lowered automatically by magnetic and elastic forces, maintaining a preset distance 2040 between the lid 110 and the feeding port 2010. This preset distance 2040 between the lid 110 and the feeding port 2010 prevents external contaminants from entering and also avoids friction between the lid 110 and the feeding port 2010 when the crank assembly 130 is driven.

[0056] In one embodiment, for better understanding, the working process of the hand-cranked coffee grinder 10 in the above embodiment is described below:

[0057] like Figure 8As shown, during use, the user first opens the cover 110 and puts coffee beans into the feed port 2010 of the grinding body 200. Then, the user aligns the central shaft mounting slot 1110 with the transmission central shaft 120 and presses down the cover 110 to compress the elastic element, causing the end of the transmission central shaft 120 to extend into and magnetically connect to the bottom of the central shaft mounting slot 1110. At this time, the gap 2040 between the cover 110 and the feed port 2010 of the grinding body 200 is 0.5mm. Then, by extending the crank assembly 130 from the crank mounting cavity 1130 into the central shaft mounting slot 1110, the end of the crank assembly 130 engages with the end of the transmission central shaft 120. Finally, by pushing the crank assembly 130, the user can drive the cover 110 to drive the transmission central shaft 120 for grinding. When it is necessary to adjust the coarseness of the coffee bean powder, the user rotates the lifting adjustment ring 2020 to move the transmission central shaft 120 up and down within the grinding body 200. Figure 3 As shown, when the transmission shaft 120 extends upward beyond the feeding port 2010 of the grinding body 200, the bottom of the shaft mounting groove 1110 magnetically attracts and abuts against the end of the transmission shaft 120. The magnetic force F1 is greater than the elastic force F2, and the cover 110 overcomes the elastic force and approaches the feeding port 2010, maintaining a 0.5mm gap 2040 between the cover 110 and the feeding port 2010. Figure 4 As shown, when the transmission shaft 120 is adjusted and lowered into the feeding port 2010 of the grinding body 200, the bottom of the shaft mounting groove 1110 separates from the end of the transmission shaft 120, causing the magnetic force F1 to decrease. The elastic force F2 pushes the cover 110 away from the feeding port 2010 of the grinding body 200, while the magnetic force F2 also makes the cover 110 closer to the feeding port 2010 of the grinding body 200. Finally, the magnetic force F1, the weight G of the cover 110, and the elastic force F2 are balanced, so that a 0.5mm gap 2040 is maintained between the cover 110 and the feeding port 2010. Figure 5 As shown, after use, the crank assembly 130 is pulled out to release the restriction on the end of the transmission shaft 120, and the cover 110 is pressed down so that the end of the transmission shaft 120 is magnetically connected to the bottom of the shaft mounting groove 1110. At this time, the gap 2040 between the cover 110 and the feeding port 2010 of the grinding body 200 is still 0.2mm.

[0058] Compared with the prior art, this disclosure has at least the following advantages:

[0059] The aforementioned crank transmission mechanism, because the crank assembly 130 is connected to the cover 110, and the transmission shaft 120 is elastically disposed in the central shaft mounting groove 1110 and slidably engaged with the groove wall of the central shaft mounting groove 1110, allows the cover 110 to rotate after being driven to do so by the crank assembly 130. This enables the cover 110 to drive the transmission shaft 120 to rotate via the central shaft mounting groove 1110 for grinding operations. Simultaneously, the transmission shaft 120 can slide up and down along the central shaft mounting groove 1110 by overcoming the elastic force. Furthermore, because the transmission shaft 120 is used for lifting and lowering within the grinding body 200, its end is magnetically connected to the bottom of the central shaft mounting groove 1110. When the transmission shaft 120 extends upwards beyond the feeding port 2010 of the grinding body 200, the cover 110 covers the feeding port 2010. Simultaneously, the bottom of the shaft mounting groove 1110 magnetically attracts and abuts against the end of the transmission shaft 120. The cover 110 overcomes the elastic force and moves closer to the feeding port 2010 until a preset distance 2040 exists between the cover 110 and the feeding port 2010. When the transmission shaft 120 is adjusted to sink downwards into the feeding port 2010 of the grinding body 200, the magnetic force separating the bottom of the shaft mounting groove 1110 from the end of the transmission shaft 120 decreases, and the elastic force pushes the cover 110 away from the feeding port 2010 of the grinding body 200. At the same time, the magnetic force brings the cover 110 closer to the feeding port 2010 of the grinding body 200. Ultimately, the magnetic force, the weight of the cover 110 and the elastic force are balanced so that the cover 110 and the feeding port 2010 still maintain a preset distance 2040. Compared with the conventional technology, the crank transmission mechanism 100 of this disclosure controls the lifting and lowering of the cover 110 through magnetic force and elastic force, so that the cover 110 and the feeding port 2010 maintain a preset distance 2040. The preset distance 2040 between the cover 110 and the feeding port 2010 can prevent external contaminants from entering, and also avoid friction between the cover 110 and the feeding port 2010 when the crank assembly 130 is driven.

[0060] The embodiments described above are merely illustrative of several implementations of this disclosure, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this disclosure, and these all fall within the protection scope of this disclosure. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A crank transmission mechanism, characterized in that, include: A cover is provided for covering the feeding port of the grinding body; the cover has a central shaft mounting groove on the side facing the feeding port; A transmission shaft is used for lifting and lowering within the grinding body; A crank assembly is connected to the cover, and the crank assembly is used to drive the cover to rotate; The transmission shaft is elastically slidably disposed in the shaft mounting groove and slidably engaged with the groove wall; the end of the transmission shaft is magnetically connected to the bottom of the shaft mounting groove, so that when the transmission shaft is raised and lowered relative to the grinding body, the cover can maintain a preset distance from the feeding port; the shaft mounting groove includes a connected elastic lifting cavity and a engaging transmission cavity; the transmission shaft passes through the elastic lifting cavity and the engaging transmission cavity respectively; an elastic element is provided between the peripheral wall of the transmission shaft and the cavity wall of the elastic lifting cavity; the cavity wall of the engaging transmission cavity adapts to the peripheral wall of the transmission shaft and achieves engaging; a first magnetic element is provided at the bottom of the shaft mounting groove, and a second magnetic element is provided at the end of the transmission shaft.

2. The crank transmission mechanism according to claim 1, characterized in that, The cavity wall of the elastic lifting chamber has a pressing protrusion, and the peripheral wall of the transmission shaft is fitted with a pressing protrusion ring. An installation gap is formed between the pressing protrusion and the pressing protrusion ring. The elastic element is disposed in the installation gap, and both ends of the elastic element press against the pressing protrusion and the pressing protrusion ring respectively.

3. The crank transmission mechanism according to claim 1, characterized in that, The cavity wall of the central shaft mounting groove is also provided with a crank mounting cavity. The crank assembly extends into the central shaft mounting groove through the crank mounting cavity and is slidably engaged with the end of the transmission central shaft.

4. The crank transmission mechanism according to claim 3, characterized in that, The crank assembly includes a locking connector and a rocker arm. The locking connector is slidably disposed within the crank mounting cavity. The pushing end of the rocker arm extends into the crank mounting cavity and can push the locking connector toward the transmission central shaft.

5. The crank transmission mechanism according to claim 4, characterized in that, The end of the clamp facing the transmission shaft is provided with an arc-shaped clamp, and the peripheral wall of the end of the transmission shaft is formed with a concave clamping position. The arc-shaped clamp engages with the concave clamping position, and the transmission shaft can slide up and down within the arc-shaped clamp.

6. The crank transmission mechanism according to claim 4, characterized in that, The locking connector is elastically disposed within the crank mounting cavity so that the locking connector can automatically reset.

7. The crank transmission mechanism according to claim 4, characterized in that, The rocker arm includes a push rod and a folding rod. The push rod is slidably disposed in the rocker arm mounting cavity and can push the snap-fit ​​connector to move. The folding rod is rotatably connected to the push rod and is used to fold to one side of the grinding body.

8. The crank transmission mechanism according to claim 4, characterized in that, A positioning element is also provided between the rocker arm and the rocker handle mounting cavity.

9. A hand-cranked coffee grinder, characterized in that, Includes a grinding body, a lifting adjustment ring, and a crank transmission mechanism as described in any one of claims 1 to 8; The transmission shaft is vertically and flexibly mounted within the grinding body via the lifting adjustment ring.

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