Adjustable dumbbell

Abstract

A boss is coaxially arranged on the end face of one side of a dumbbell piece, a groove matched with the boss is formed in the end face of the side, away from the boss, of the dumbbell piece, the boss of the dumbbell piece rotates to a second position in the groove so that the boss can be connected into the groove in a threaded mode, a key is arranged on the dumbbell piece, and the dumbbell piece is connected with the key. A button assembling groove is formed in the side wall of the dumbbell piece, the button is movably arranged in the button assembling groove through a spring, a positioning column is arranged on the end face of one side of the dumbbell piece, and a sliding groove matched with the button is formed in the end face of the side, away from the positioning column, of the dumbbell piece. The upper end of the sliding groove is located on the key and extends on the key in the moving direction of the key to form a positioning groove. The centers of the dumbbell pieces are in threaded connection through matching of the bosses and the grooves, axial limiting and locking functions are achieved, on the other hand, the dumbbell pieces can be unlocked and separated only by manually moving the keys to enable the positioning columns to be separated from the positioning grooves and unscrewing the dumbbell pieces, the structure is stable, and safety is high.

Description

Technical Field

[0001] This utility model relates to the field of fitness equipment technology, and in particular to an adjustable dumbbell. Background Technology

[0002] Dumbbells are handheld fitness equipment used for muscle strength training and body shaping. When using dumbbells, users often adjust the weight by adding or removing weight plates.

[0003] Chinese utility model patent CN220714696U discloses an adjustable dumbbell. The dumbbell includes a handle and a counterweight assembly. The counterweight assembly includes a main counterweight and a secondary counterweight. The main counterweight is fixedly connected to both ends of the handle. A boss is provided on one side of the secondary counterweight. Fan-shaped protrusions are provided at both ends of the boss. Grooves that mate with the boss are provided on the side of the secondary counterweight away from the boss and on the side of the main counterweight away from the handle. Fan-shaped slots that mate with the fan-shaped protrusions are provided on both sides of the groove. A mounting slot that mates with the fan-shaped protrusions is provided between the inner side of the groove and the two fan-shaped slots. When adding weight to the dumbbell, insert the boss on one side of the secondary counterweight into the corresponding groove of the counterweight, while the two fan-shaped protrusions are also placed in the two fan-shaped slots. Rotating the secondary counterweight causes the boss to rotate within the groove, so that the two fan-shaped protrusions on both sides are inserted into the mounting slots on both sides. At the same time, the positioning ball rolls into the corresponding positioning slot under the elastic force of the positioning rod spring, limiting the counterweight and preventing it from becoming loose. When it is necessary to disassemble and reduce the weight, simply rotate the secondary counterweight in the opposite direction.

[0004] While the aforementioned adjustable dumbbells allow for quick loading and unloading of counterweights, the fan-shaped protrusion inserted into the mounting slot during installation only provides axial positioning. Circumferential positioning is required to prevent rotation. However, the circumferential positioning structure, with its positioning bead and spring, lacks stability. When picking up or putting down the dumbbells, users inevitably rotate the handle to adjust their posture. During this process, the secondary counterweight is highly susceptible to rotation due to inertia, overcoming the spring force to push the positioning bead into the positioning slot, causing the fan-shaped protrusion to disengage from the mounting slot and fall off, resulting in poor safety.

[0005] Therefore, this invention proposes an adjustable dumbbell to solve the above problems. Utility Model Content

[0006] The technical problem to be solved by this utility model is to provide an adjustable dumbbell that is easy to adjust in terms of weight, has a stable connection structure, and is highly safe.

[0007] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows: an adjustable dumbbell, including a handle and two dumbbell plate groups, the two dumbbell plate groups are respectively installed at both ends of the handle, each dumbbell plate group includes a number of dumbbell plates stacked axially, the innovation of which is: a boss is coaxially provided on one end face of the dumbbell plate, and a groove matching the boss is provided on the end face of the dumbbell plate away from the boss. The boss of the dumbbell plate enters the groove of the adjacent dumbbell plate from a first position, and rotates to a second position in the groove so that the boss is threadedly connected in the groove, thereby realizing the relative fixation of the adjacent dumbbell plates;

[0008] The dumbbell plate has a button, and a button mounting groove is formed on the side wall of the dumbbell plate. The button is movably mounted in the button mounting groove by a spring, and moves closer to or away from the boss between the third and fourth positions in the button mounting groove. A positioning post is provided on one end face of the dumbbell plate. A sliding groove is formed on the end face of the dumbbell plate away from the positioning post, which cooperates with the button. The two ends of the sliding groove are the lower end and the upper end, respectively. The lower end of the sliding groove is located on the dumbbell plate, and the upper end of the sliding groove is located on the button and extends along the button's movement direction to form a positioning groove. When the boss of the dumbbell plate enters the groove of the adjacent dumbbell plate from the first position, the positioning post enters the lower end of the sliding groove of the adjacent dumbbell plate. When the boss of the dumbbell plate rotates to the second position in the groove, the positioning post moves along the sliding groove to the upper end of the sliding groove. At this time, the button is in the third position. Under the action of the spring force, the button moves from the third position to the fourth position, and the positioning post enters the positioning groove, realizing the circumferential limitation of the adjacent dumbbell plates.

[0009] Furthermore, the outer wall of the boss is provided with a number of spaced external thread segments along the circumferential direction, and the inner wall of the groove is provided with a number of spaced internal thread segments that match the external thread segments along the circumferential direction. A first channel is provided between adjacent internal thread segments for the external thread segments to pass through when the boss is in the first position, and a second channel is provided between adjacent external thread segments for the internal thread segments to pass through when the boss is in the first position.

[0010] Furthermore, when the button moves between the third and fourth positions, there is always an opening between the groove on the button and the groove on the dumbbell plate for the positioning post to pass through. The groove on the button has an inclined surface. When the positioning post moves from the groove on the dumbbell plate through the opening into the groove on the button, the positioning post pushes the button to overcome the spring force and automatically move to the third position through the inclined surface.

[0011] Furthermore, the fourth position in the button assembly slot is located outside the third position, and the positioning slot is located on the side of the slide groove near the central axis of the dumbbell plate.

[0012] Furthermore, the dumbbell plate includes a dumbbell plate base, several counterweights, and a cover plate;

[0013] The dumbbell plate base has a cover plate assembly groove. The cover plate is set in the cover plate assembly groove and cooperates with the dumbbell plate base to form a counterweight assembly cavity. The middle part of the cover plate extends axially into the counterweight assembly cavity to form a limiting ring, and a groove is formed in the middle of the limiting ring. The end of the limiting ring abuts against the inner wall of the dumbbell plate base. Several counterweights are movably sleeved on the outside of the limiting ring and axially stacked in the counterweight assembly cavity. Several counterweights, the cover plate and the dumbbell plate base are detachably connected by bolts.

[0014] Furthermore, the boss and the positioning post are both set on the dumbbell plate base and integrally formed with the dumbbell plate base, and the slide groove is opened on the cover plate.

[0015] Furthermore, the button includes an integrally formed button body, a spring mounting block, and a sliding groove vertical plate. The spring mounting block is located in the middle of the button body and cooperates with the button body to form a T-shaped structure. The spring mounting block has two limiting blocks on both sides. The sliding groove vertical plate is located on the side of the button body closer to the spring mounting block and cooperates with the spring mounting block to form a cover plate slot for the cover plate to enter and move relative to it. The cover plate is set in the cover plate slot and cooperates with the dumbbell plate base to form a button assembly slot. Two limiting grooves corresponding to the limiting blocks are formed on both sides of the bottom of the button assembly slot. The spring mounting block is movably inserted into the button assembly slot. Each limiting block is movably set in its corresponding limiting groove. The spring is set in the button assembly slot. A spring mounting groove is opened on the side of the spring mounting block away from the button body. One end of the spring is set in the spring mounting groove, and the other end is connected to the bottom surface of the button assembly slot.

[0016] The advantages of this utility model are:

[0017] This invention features a connection between adjacent dumbbell plates. Firstly, the center of each dumbbell plate is threaded using a boss and groove, providing both axial limiting and locking functions. Secondly, a positioning post, sliding groove, positioning slot, and button work together. When adjacent dumbbell plates are connected, the positioning post disengages from the sliding groove and enters the positioning slot. The button, under spring force, remains in the fourth position, locking the positioning post. Only by manually moving the button to disengage the positioning post from the positioning slot and loosening the dumbbell plate, rotating it to the first position, can the dumbbell plate be unlocked. This connection structure is stable and highly secure. Disassembling and assembling dumbbell plates only requires moving the button and rotating the dumbbell plate, facilitating weight adjustment.

[0018] The present invention employs a multi-segment spaced threaded section design between the boss and the groove. On the one hand, this effectively reduces the number of thread turns and shortens the axial dimension of the boss. On the other hand, users can determine whether the external threaded section on the boss is at the starting position of the threaded connection based on whether the positioning post is at the lower end of the groove of the adjacent dumbbell plate, which facilitates the installation and removal of the dumbbell plates.

[0019] When the button of this invention moves between the third and fourth positions, an opening is always maintained between the groove on the button and the groove on the dumbbell plate for the positioning post to pass through, ensuring that the groove remains unobstructed. This prevents the positioning post from getting stuck when it moves with the dumbbell plate. Furthermore, by setting an inclined surface in the groove on the button, when the positioning post enters the groove on the button during dumbbell plate installation, the button does not need to be moved manually. The button is automatically moved to the third position by the positioning post, allowing the positioning post to move smoothly to the top of the groove. This makes the operation convenient and enables quick installation of the dumbbell plate.

[0020] In this invention, the fourth position in the button assembly slot is located outside the third position, and the positioning slot is located on the side of the slide groove near the central axis of the dumbbell plate. When the dumbbell plate is unlocked, simply press the button inward to disengage the positioning pin from the positioning slot, saving time and effort.

[0021] The dumbbell plate base, counterweight, and cover plate of this utility model are detachably connected by bolts, making it convenient for users to replace the counterweight as needed. The cover plate extends axially in the middle to form a limiting ring, and the counterweight is stacked and sleeved on the limiting ring in the axial direction. The limiting ring limits the counterweight in the circumferential direction, while the two sides of the counterweight in the axial direction are limited by the cover plate and the dumbbell plate base, thereby preventing the counterweight from shaking during use.

[0022] The protrusion and positioning post of this utility model are both set on the dumbbell plate base and integrally formed with the dumbbell plate base. The sliding groove is opened on the cover plate. This design can effectively simplify the dumbbell manufacturing process and reduce the dumbbell manufacturing cycle and cost.

[0023] The button assembly slot of this utility model is formed by the cooperation of a cover plate and a dumbbell plate base, which makes button assembly very convenient. By designing a sliding groove vertical plate on the button body, in addition to facilitating the opening of the sliding groove, the sliding groove vertical plate also cooperates with the spring mounting block to form a cover plate slot. When the cover plate is assembled, it is placed in the cover plate slot, which can improve the axial position accuracy of the button on the one hand, and limit the inward movement distance of the button on the other hand. By setting limit blocks on both sides of the spring mounting block, which cooperate with the limit groove, the outward movement distance of the button is limited, preventing the button from moving out of the button assembly slot. Attached Figure Description

[0024] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0025] Figure 1 This is a schematic diagram of the adjustable dumbbell of this utility model.

[0026] Figure 2 This is an axial cross-sectional view of the adjustable dumbbell of this utility model.

[0027] Figure 3 This is a schematic diagram of the dumbbell plate of this utility model in the first direction.

[0028] Figure 4 This is a schematic diagram of the dumbbell plate of this utility model in the second direction.

[0029] Figure 5 This is an axial cross-sectional view of the dumbbell plate of this utility model.

[0030] Figure 6 This is a radial cross-sectional view of the dumbbell plate of this utility model.

[0031] Figure 7 This is a schematic diagram of the button structure of this utility model. Detailed Implementation

[0032] To further illustrate the technical means and effects adopted by this utility model in order to achieve the intended utility model purpose, the following detailed description of the specific implementation methods, structure, features and effects of this utility model is provided in conjunction with the accompanying drawings and preferred embodiments.

[0033] Example

[0034] This embodiment provides an adjustable dumbbell, such as Figure 1-7 As shown, it includes a handle 1 and two dumbbell plate groups, which are respectively installed at both ends of the handle. Each dumbbell plate group includes several dumbbell plates 2 stacked axially.

[0035] A boss 4 is coaxially provided on one end face of the dumbbell plate 2. A groove 6 matching the boss 4 is provided on the end face of the dumbbell plate 2 away from the boss 4. The boss 4 of the dumbbell plate 2 enters the groove 6 of the adjacent dumbbell plate from the first position and rotates to the second position in the groove 6 so that the boss 4 is threadedly connected in the groove 6, thereby achieving relative fixation between the two adjacent dumbbell plates.

[0036] A button 3 is provided on the dumbbell plate 2. A button mounting groove 206 is opened on the side wall of the dumbbell plate 2. The button 3 is movably set in the button mounting groove 206 by a spring 9, and moves closer to or away from the boss 4 between the third position and the fourth position in the button mounting groove 206. A positioning post 5 is provided on one end face of the dumbbell plate 2. The positioning post 5 is located on the side of the dumbbell plate close to the button. A groove 7 is formed on the end face of the dumbbell plate 2 away from the positioning post 5, which cooperates with the button 3. The two ends of the groove 7 are the lower end and the upper end, respectively. The lower end of the groove 7 is located on the dumbbell plate 2, and the upper end of the groove 7 is located on the button 3 and extends along the moving direction of the button 3 to form a positioning groove 8. When the boss 4 of the dumbbell plate 2 enters the groove 6 of the adjacent dumbbell plate from the first position, the positioning post 5 enters the lower end of the groove 7 of the adjacent dumbbell plate. When the boss 4 of the dumbbell plate 2 rotates to the second position in the groove 6, the positioning post 5 moves along the groove 7 to the upper end of the groove 7. At this time, the button 3 is in the third position. Under the action of the spring 9, the button 3 moves from the third position to the fourth position, and the positioning post 5 enters the positioning groove 8, realizing the circumferential limit between the two adjacent dumbbell plates.

[0037] In this embodiment, two spaced external thread segments 401 are distributed circumferentially on the outer wall of the boss 4, and two spaced internal thread segments 601 that match the external thread segments 401 are distributed circumferentially on the inner wall of the groove 6. A first channel is provided between adjacent internal thread segments 601 for the external thread segments 401 to pass through when the boss 4 is in the first position, and a second channel is provided between adjacent external thread segments 401 for the internal thread segments 601 to pass through when the boss is in the first position. The multi-segment spaced thread segment design between the boss 4 and the groove 6 can effectively reduce the number of thread turns and shorten the axial dimension of the boss 4. On the other hand, the user can determine whether the external thread segments 401 on the boss 4 are in the starting position of the threaded connection based on whether the positioning post 5 is at the lower end of the groove 7 of the adjacent dumbbell plate, which facilitates the installation and removal of the dumbbell plate.

[0038] The fourth and third positions within the button mounting slot 206 are distributed radially along the dumbbell plate 2. The positioning slot 8 and the sliding groove 7 can have two relative positions. The first is that the positioning slot is located on the side of the sliding groove away from the central axis of the dumbbell plate. In this case, the fourth position within the button mounting slot is located inside the third position. When the dumbbell plate is unlocked, the button needs to be pulled outward to disengage the positioning post from the positioning slot. The second is that the positioning slot 8 is located on the side of the sliding groove 7 close to the central axis of the dumbbell plate 2. In this case, the fourth position within the button mounting slot 206 is located outside the third position. When the dumbbell plate 2 is unlocked, the button 3 is pressed inward to disengage the positioning post 5 from the positioning slot 8. Compared to the pulling operation, the second pressing operation is more time-saving and labor-saving than the outward pulling operation. Therefore, this embodiment adopts the second relative position relationship.

[0039] In this embodiment, when button 3 moves between the third and fourth positions, an opening is always maintained between the groove on button 3 and the groove on dumbbell plate 2 for the positioning post 5 to pass through, thus keeping the groove unobstructed and ensuring that the positioning post 5 moves without jamming as the dumbbell plate rotates. The groove on button 3 has an inclined surface 701. When the positioning post 5 moves from the groove on dumbbell plate 2 through the opening into the groove on button 3, the positioning post 5 pushes button 3 against the spring force of spring 9 via the inclined surface 701, automatically moving it to the third position. No manual movement of button 3 is required; button 3 is automatically moved to the third position by the positioning post 5, allowing the positioning post 5 to smoothly move to the upper end of the groove 7. This convenient operation enables quick installation of the dumbbell plate 2.

[0040] In this embodiment, the dumbbell plate 2 includes a dumbbell plate base 201, two counterweights 203, and a cover plate 202. A cover plate mounting groove is formed on the dumbbell plate base 201. The cover plate 202 is disposed within the cover plate mounting groove and cooperates with the dumbbell plate base 201 to form a counterweight assembly cavity. A limiting ring 204 extends axially from the center of the cover plate 202 into the counterweight assembly cavity, and a groove 6 is formed in the center of the limiting ring 204. The end of the limiting ring 204 is flush with the interior of the dumbbell plate base 201. The two counterweights 203 are movably sleeved on the outside of the limiting ring 204 and axially stacked in the counterweight assembly cavity. The two counterweights 203, the cover plate 202 and the dumbbell plate base 201 are detachably connected by bolts. The two counterweights 203, the cover plate 202 and the dumbbell plate base 201 are fitted with bolt holes 205. The bolt holes are threaded and connected in the bolt holes 205, so that the two counterweights 203, the cover plate 202 and the dumbbell plate base 201 are relatively fixed.

[0041] The two counterweights 203 are circumferentially limited by the limiting rings 204, and the sides are limited by the cover plates 202 and the dumbbell plate bases 201, thus preventing the counterweights 203 from shaking during use. The dumbbell plate bases 201, counterweights 203 and cover plates 202 are detachably connected by bolts, which allows users to easily replace counterweights of different materials or with different degrees of hollowness to adjust the weight of individual dumbbell plates as needed.

[0042] In this embodiment, the boss 4 and the positioning post 5 are both set on the outer end face of the dumbbell plate base 201 and integrally formed with the dumbbell plate base 201. The groove 7 is opened on the outer end face of the cover plate 202. This design can effectively simplify the dumbbell manufacturing process and reduce the dumbbell manufacturing cycle and cost.

[0043] In this embodiment, the button 3 includes an integrally formed button body 301, a spring mounting block 302, and a sliding groove vertical plate 303. The spring mounting block 302 is located in the middle of the button body 301 and cooperates with the button body 301 to form a T-shaped structure. Two limiting blocks 304 are located on both sides of the spring mounting block 302, and the two limiting blocks 304 cooperate with the spring mounting block 302 to form an inverted T-shaped structure. The sliding groove vertical plate 303 is located on the side of the button body 301 closest to the spring mounting block 302 and cooperates with the spring mounting block 302 to form a cover plate slot 305 for the cover plate 202 to enter and move relative to it. 02 is set in the cover plate slot 305 and cooperates with the dumbbell plate base 201 to form a button assembly slot 206. Two limiting slots corresponding to the limiting blocks 304 are formed on both sides of the bottom of the button assembly slot 206. The spring mounting block 302 is movably inserted into the button assembly slot 206. Each limiting block 304 is movably set in the corresponding limiting slot. The spring 9 is set in the button assembly slot 206. A spring mounting slot 306 is opened on the side of the spring mounting block 302 away from the button body 301. One end of the spring 9 is set in the spring mounting slot 306, and the other end is connected to the bottom surface of the button assembly slot 206.

[0044] The button mounting slot 206 is formed by the cooperation of the cover plate 202 and the dumbbell plate base 201. When assembling the button 3, simply insert the cover plate 202 into the cover plate slot 205 of the button 3, and then fasten the cover plate into the cover plate mounting slot of the dumbbell plate base 201 to complete the installation and fixation of the button 3. The assembly is very convenient. By designing a sliding groove vertical plate 303 on the button body 301, in addition to facilitating the opening of the sliding groove 7 and the installation of the button 3, it can improve the axial position accuracy of the button 3. On the other hand, the cover plate 202 can be used to limit the inward movement distance of the button 3. By setting limit blocks 304 on both sides of the spring mounting block 302, which cooperate with the limit groove, the outward movement distance of the button 3 is limited, preventing the button 3 from moving out of the button mounting slot 206.

[0045] In this embodiment, each dumbbell plate group has a fixing group and an end face group on both sides. The cover plate of the fixing group is flat and fixedly connected to the handle. There are no buttons on the side wall of the fixing group. The rest is the same as the structure of the dumbbell plate. The outer end face of the dumbbell plate base of the end face group is flat. The rest is the same as the structure of the dumbbell plate. The connection method between the fixing group, the end face group and the dumbbell plate adjacent to the dumbbell plate group is the same as the connection method between two adjacent dumbbell plates of the dumbbell plate group.

[0046] When installing dumbbell plates, adjust the angle of the dumbbell plates to be installed so that the positioning pins of the adjacent dumbbell plates are aligned with the lower end of the slide groove of the dumbbell plates to be installed. At this time, the boss is in the first position. Move the dumbbell plates to be installed axially so that the bosses of the adjacent dumbbell plates enter the grooves and the positioning pins of the adjacent dumbbell plates enter the lower end of the slide groove of the dumbbell plates to be installed. Rotate and tighten the dumbbell plates to be installed. At this time, the bosses rotate to the second position and the positioning pins move to the upper end of the slide groove. The button moves outward to the fourth position under the push of the spring force, and the positioning pins enter the positioning groove, completing the operation.

[0047] To unlock the dumbbell plates, press the button on the dumbbell plate to be unlocked, causing the button to move inward to the third position against the spring force. The positioning pins of the adjacent dumbbell plates will disengage from the positioning groove. Rotate the dumbbell plate to be unlocked, causing the positioning pins of the adjacent dumbbell plates to move to the lower end of the slide groove. Move the dumbbell plate to be unlocked axially, causing the bosses of the adjacent dumbbell plates to disengage from the grooves of the dumbbell plates to be unlocked, thus completing the operation.

[0048] The adjustable dumbbells feature a screw-on connection between adjacent dumbbell plates. This connection utilizes a boss and groove at the center of the plates, providing both axial limiting and locking functions. Furthermore, a positioning post, slide, positioning groove, and button work together. When adjacent dumbbell plates are connected, the positioning post disengages from the slide and enters the positioning groove. The button, under spring force, remains in the fourth position, locking the positioning post. Only by manually moving the button to disengage the positioning post from the positioning groove and loosening the dumbbell plate, rotating it to the first position, can the dumbbell plate be unlocked. This stable connection structure ensures high safety. Adjusting the weight is convenient; simply move the button and rotate the dumbbell plate.

[0049] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Although the present utility model has been disclosed above with reference to a preferred embodiment, it is not intended to limit the present utility model. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present utility model. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present utility model without departing from the scope of the present utility model shall still fall within the scope of the present utility model.

Claims

1. An adjustable dumbbell, comprising a handle and two dumbbell plate groups, the two dumbbell plate groups being respectively mounted at both ends of the handle, each dumbbell plate group comprising a plurality of axially stacked dumbbell plates, characterized in that: A boss is coaxially provided on one end face of the dumbbell plate, and a groove matching the boss is provided on the end face of the dumbbell plate away from the boss. The boss of the dumbbell plate enters the groove of the adjacent dumbbell plate from the first position and rotates to the second position in the groove so that the boss is threadedly connected in the groove, thereby fixing the adjacent dumbbell plates relatively. The dumbbell plate has a button, and a button mounting groove is formed on the side wall of the dumbbell plate. The button is movably mounted in the button mounting groove by a spring, and moves closer to or away from the boss between the third and fourth positions in the button mounting groove. A positioning post is provided on one end face of the dumbbell plate. A sliding groove is formed on the end face of the dumbbell plate away from the positioning post, which cooperates with the button. The two ends of the sliding groove are the lower end and the upper end, respectively. The lower end of the sliding groove is located on the dumbbell plate, and the upper end of the sliding groove is located on the button and extends along the button's movement direction to form a positioning groove. When the boss of the dumbbell plate enters the groove of the adjacent dumbbell plate from the first position, the positioning post enters the lower end of the sliding groove of the adjacent dumbbell plate. When the boss of the dumbbell plate rotates to the second position in the groove, the positioning post moves along the sliding groove to the upper end of the sliding groove. At this time, the button is in the third position. Under the action of the spring force, the button moves from the third position to the fourth position, and the positioning post enters the positioning groove, realizing the circumferential limitation of the adjacent dumbbell plates.

2. The adjustable dumbbell according to claim 1, characterized in that: The outer wall of the boss is provided with a number of spaced external thread segments along the circumferential direction, and the inner wall of the groove is provided with a number of spaced internal thread segments that match the external thread segments along the circumferential direction. A first channel is provided between adjacent internal thread segments for the external thread segments to pass through when the boss is in the first position, and a second channel is provided between adjacent external thread segments for the internal thread segments to pass through when the boss is in the first position.

3. The adjustable dumbbell according to claim 1, characterized in that: When the button moves between the third and fourth positions, there is always an opening between the groove on the button and the groove on the dumbbell plate for the positioning post to pass through. The groove on the button has an inclined surface. When the positioning post moves from the groove on the dumbbell plate through the opening into the groove on the button, the positioning post pushes the button through the inclined surface to overcome the spring force and automatically move to the third position.

4. The adjustable dumbbell according to claim 1, characterized in that: The fourth position in the button assembly slot is located outside the third position, and the positioning slot is located on the side of the slide groove near the central axis of the dumbbell plate.

5. The adjustable dumbbell according to claim 1, characterized in that: The dumbbell plate includes a dumbbell plate base, several counterweights, and a cover plate; The dumbbell plate base has a cover plate assembly groove. The cover plate is set in the cover plate assembly groove and cooperates with the dumbbell plate base to form a counterweight assembly cavity. The middle part of the cover plate extends axially into the counterweight assembly cavity to form a limiting ring, and a groove is formed in the middle of the limiting ring. The end of the limiting ring abuts against the inner wall of the dumbbell plate base. Several counterweights are movably sleeved on the outside of the limiting ring and axially stacked in the counterweight assembly cavity. Several counterweights, the cover plate and the dumbbell plate base are detachably connected by bolts.

6. The adjustable dumbbell according to claim 5, characterized in that: The boss and positioning post are both set on the dumbbell plate base and integrally formed with the dumbbell plate base, and the slide groove is opened on the cover plate.

7. The adjustable dumbbell according to claim 6, characterized in that: The button includes an integrally formed button body, a spring mounting block, and a sliding vertical plate. The spring mounting block is located in the middle of the button body and cooperates with the button body to form a T-shaped structure. The spring mounting block has two limiting blocks on both sides. The sliding vertical plate is located on the side of the button body closer to the spring mounting block and cooperates with the spring mounting block to form a cover plate slot for the cover plate to enter and move relative to it. The cover plate is set in the cover plate slot and cooperates with the dumbbell plate base to form a button assembly slot. Two limiting grooves corresponding to the limiting blocks are formed on both sides of the bottom of the button assembly slot. The spring mounting block is movably inserted into the button assembly slot. Each limiting block is movably set in its corresponding limiting groove. The spring is set in the button assembly slot. A spring mounting groove is opened on the side of the spring mounting block away from the button body. One end of the spring is set in the spring mounting groove, and the other end is connected to the bottom surface of the button assembly slot.

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