An adjustable dumbbell

Abstract

The application discloses an adjustable dumbbell, which comprises a handle assembly and a dumbbell piece, the handle assembly comprises a connecting rod and a handle, hangers are arranged at the two ends of the connecting rod, the hangers are provided with hanging cavities, the handle is rotationally matched with the hangers, the handle is sleeved outside the connecting rod, guide sleeves are sleeved at the two ends of the connecting rod, the guide sleeves are provided with gear grooves, a gear transmission set is arranged in the hangers and is engaged with the gear grooves, the end of the handle is provided with a rotating part, the rotating part is provided with an engagement gear which is engaged with the gear transmission set, the rotating part is further fixed with a gear guiding piece, the gear guiding piece is provided with a plurality of guide grooves, a guide piece is arranged between the two adjacent guide grooves, the guide piece is provided with a guide surface, the hangers are provided with a positioning piece, the positioning piece elastically presses the gear guiding piece, and when the positioning piece is pressed on the guide surface, the positioning piece has a tendency to slide towards the guide grooves on the two sides of the guide surface. The cooperation of the guide grooves on the gear guiding piece, the guide piece, the guide surface and the positioning piece can realize reliable gear shifting of the adjustable dumbbell and avoid the dumbbell piece from falling off.

Description

Technical Field

[0001] This invention relates to the field of fitness equipment, specifically to an adjustable dumbbell. Background Technology

[0002] Dumbbells are auxiliary equipment used in weightlifting and fitness exercises, primarily for muscle strength training. They are popular among fitness enthusiasts due to their small size and ease of use. Currently, dumbbells on the market can be divided into two types: fixed weight and adjustable weight. Adjustable weight dumbbells, in particular, offer greater versatility because they allow for weight adjustments to meet different training intensities. Adjustable weight dumbbells mainly consist of a grip assembly and a weight assembly. The weight assembly primarily comprises dumbbell plates. Multiple adjacent dumbbell plate mounting positions are located at both ends of the grip assembly. The grip assembly also features a telescopic rod that extends to these mounting positions. By extending or retracting the telescopic rod, the number of dumbbell plates can be changed, thus adjusting the dumbbell weight.

[0003] However, in actual use, when the user rotates the grip to move the telescopic bar, if the grip is not rotated to the set position (i.e., between two adjacent positions), the telescopic bar is not fully inserted into the dumbbell plate, causing the corresponding dumbbell plate to be in a semi-engaged state. While the grip assembly can lift the dumbbell plate in this state, it is prone to wobbling or even slipping off. This imbalance in the weight distribution at both ends of the grip can easily cause injury to the user, especially if the dumbbell plate accidentally slips off during use. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an adjustable dumbbell that is simple in structure, reliable in conversion and adjustment, and convenient in use.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: an adjustable dumbbell, comprising a grip assembly and a weight assembly, wherein the weight assembly includes dumbbell plates, the grip assembly includes a connecting rod and a grip, both ends of the connecting rod are provided with hangers, the hangers are provided with hanging cavities for hanging dumbbell plates, the grip is rotatably engaged with the hangers, the grip is sleeved on the outside of the connecting rod, the connecting rod is prismatic, both ends of the connecting rod are movably sleeved with guide sleeves movable into the hanging cavities, the guide sleeves are provided with toothed grooves along their length, and a gear transmission assembly is provided inside the hangers. The moving part meshes with the toothed groove to drive the guide sleeve to translate along the connecting rod. The end of the grip is provided with a rotating part, which is provided with a meshing gear that meshes with the gear transmission assembly. The rotating part is also fixed with a gear guide plate. The gear guide plate is provided with multiple guide grooves. A guide member is provided between two adjacent guide grooves. The guide member is provided with a guide surface. The hanger is provided with a positioning assembly. The positioning assembly includes a positioning member. The positioning member elastically presses the gear guide plate. When the positioning member is pressed against the guide surface, it has a tendency to slide toward either guide groove on both sides of the guide surface and drive the gear guide plate to rotate so that the positioning member is located in the guide groove.

[0006] Furthermore, the guide member has inclined sliding surfaces on both sides, and the guide surface is located between the two sliding surfaces. The guide surface is arc-shaped and smoothly transitions with the sliding surface. The advantage is that by setting the arc-shaped guide surface to cooperate with the sliding surface, the reliability of the positioning member and the positioning guide piece can be ensured, and the phenomenon of the gear guide piece moving stuck or not rotating into place can be avoided.

[0007] Furthermore, multiple guide grooves are evenly distributed in a ring on the side of the gear guide plate, and the gear guide plate is detachably coupled with the rotating part. The advantage is that the multiple evenly distributed ring-shaped guide grooves facilitate reliable engagement with the positioning assembly as the rotating part rotates. Simultaneously, the detachable gear guide plate facilitates maintenance and installation, reduces production costs, and is especially convenient for replacement after wear and tear from prolonged use.

[0008] Furthermore, the fixture is provided with multiple positioning components corresponding to the guide groove, and the contact surface between the positioning component and the gear guide plate is an arc surface. The advantage is that the multiple positioning components can provide sufficient driving force to the gear guide plate, especially when the guide plate rotates to be aligned with the positioning component, thereby forcing the gear guide plate to continue rotating and ensuring that the positioning component can be reliably positioned in the positioning groove.

[0009] Furthermore, the positioning component includes a positioning seat, the positioning element is movably disposed within the positioning seat, and the positioning seat is also provided with a compression spring for pressing the positioning element; the advantage is that the compression spring can ensure reliable pressing between the positioning element and the gear guide plate, thereby ensuring the accuracy of gear shifting of the adjustable dumbbell.

[0010] Furthermore, the guide sleeve is provided with a sliding hole that matches the connecting rod, and the guide sleeve fits snugly against the connecting rod; the advantage is that the sliding hole that matches the connecting rod can ensure the stability of the lateral movement of the guide sleeve and prevent the circumferential rotation of the guide sleeve, thus ensuring reliable gear shifting for the adjustable dumbbell.

[0011] Furthermore, the gear transmission assembly includes transmission teeth, which include a drive gear and a driven gear and an intermediate gear fixedly arranged coaxially. The driven gear meshes with the meshing gear, the intermediate gear meshes with the drive gear, and the drive gear meshes with the tooth groove. The advantage is that the gear transmission assembly ensures the stability and reliability of the guide sleeve being driven by the gear assembly when rotating the grip.

[0012] Furthermore, intermediate gears are fixed on both sides of the driven gear, and each intermediate gear meshes with a corresponding drive gear. The outer side of the guide sleeve is provided with tooth grooves that mesh with the corresponding drive gears. The advantage is that by setting intermediate gears on both sides of the driven gear, as well as drive gears and tooth grooves that cooperate with the intermediate gears, the stability of the lateral movement of the guide sleeve is ensured, and interference and jamming phenomena caused by the shaking of the guide sleeve are avoided when the guide sleeve is driven by a single drive gear. The stability of the force on both sides can be ensured by driving with double rows of drive gears.

[0013] Furthermore, the hanger is equipped with a fixed base, which has two opposing support plates. The gear transmission assembly is rotatably mounted between the two opposing support plates. The fixed base is also equipped with a telescopic hole, and the guide sleeve is laterally movable within the telescopic hole. The advantage is that the support plates can provide stable support for the gear transmission assembly, while the telescopic hole can support and limit the sliding of the guide sleeve, reducing radial sway.

[0014] Preferably, the present invention further includes an unlocking disc and a locking assembly disposed on the hanger for locking the grip bar. The locking assembly includes a locking groove and a locking block. The locking block is slidably disposed in the locking groove, and a locking spring for pressing the locking block is disposed in the locking groove. The rotating part is provided with an anti-rotation groove that engages with the locking block. The unlocking disc is provided with an unlocking element corresponding to the locking block. When the positioning element is located in the guide groove, the locking block is aligned with the anti-rotation groove. When the hanger is placed in the unlocking disc, the unlocking element lifts the locking block, thereby unlocking the locking assembly. The advantage is that the cooperation of the unlocking disc and the locking assembly ensures the safety of the user when using the adjustable dumbbell. That is, the user can only unlock the locking block and adjust the weight when the adjustable dumbbell is placed on the unlocking disc.

[0015] Compared with existing technologies, this invention has the following advantages: The reliable adjustment and shifting of the adjustable dumbbell is achieved through the cooperation of the guide groove, guide component, guide surface, and positioning component on the gear shift guide plate. Specifically, when adjusting the weight by rotating the grip, the grip is ensured to rotate to the correct position, thereby guaranteeing the guide sleeve's proper positioning. This allows the guide sleeve to reliably mount the dumbbell plates, preventing partial mounting or even the dumbbell plates falling off. Furthermore, by setting a prism-shaped connecting rod and its corresponding guide sleeve, this invention ensures the translational stability of the guide sleeve and reduces the impact of circumferential rotation. This prevents unstable engagement between the gear transmission assembly and the tooth groove due to circumferential rotation, and avoids even mutual tooth jamming. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the grip assembly of the present invention;

[0019] Figure 3 This is a schematic diagram showing the assembly position of the gear guide plate of the present invention;

[0020] Figure 4 This is a schematic diagram showing the fit between the guide sleeve and the gear transmission assembly of the present invention;

[0021] Figure 5 This is a schematic diagram of the structure of the gear guide plate of the present invention;

[0022] Figure 6This is a schematic diagram illustrating the fit between the grip, guide sleeve, and connecting rod of the present invention.

[0023] Figure 7 This is a schematic diagram of the internal structure of the hanger of the present invention;

[0024] Figure 8 This is a schematic diagram of the engagement of the meshing gear and the gear transmission assembly of the present invention;

[0025] Figure 9 This is a schematic diagram of the transmission gear structure of the present invention;

[0026] Figure 10 This is a schematic diagram of the dumbbell plate of the present invention;

[0027] Figure 11 This is a schematic diagram of the unlocking disk of the present invention;

[0028] Figure 12 This is a schematic diagram illustrating the usage state of the present invention. Detailed Implementation

[0029] The present invention will now be described in further detail with reference to the accompanying drawings.

[0030] The following description is intended to disclose the invention so that those skilled in the art can implement it. The preferred embodiments described below are merely examples, and other obvious modifications will be apparent to those skilled in the art. The basic principles of the invention defined in the following description can be used in other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0031] Those skilled in the art should understand that, in the disclosure of this invention, the terms "longitudinal," "lateral," "upper," "lower," "left," "right," "front," "rear," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or position based on the orientation or positional relationship shown in the accompanying drawings. They are merely simplified descriptions for the convenience of describing this invention and do not indicate or imply that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the above terms should not be construed as limitations on this invention.

[0032] As attached Figure 1-12An adjustable dumbbell is shown, including a grip assembly 1.1 and a weight assembly. The weight assembly includes dumbbell plates 9. The grip assembly 1.1 includes a connecting rod 3 and a grip 1.1. Hangers 5 are provided at both ends of the connecting rod 3. Each hanger 5 has a mounting cavity 5.1 for mounting the dumbbell plates 9. The grip 1.1 rotatably engages with the hangers 5. The grip 1.1 is sleeved on the outside of the connecting rod 3. The connecting rod 3 is prismatic. Guide sleeves 4, movable into the mounting cavity 5.1, are movably sleeved at both ends of the connecting rod 3. The guide sleeves 4 have toothed grooves 4.1 along their length. A gear transmission assembly 6 is provided inside the hanger 5. The gear transmission assembly 6 meshes with the toothed grooves 4.1 to drive the guide sleeves 4 to translate along the connecting rod 3. The end of .1 is provided with a rotating part 1.2, and the rotating part 1.2 is provided with a meshing gear 1.3 that meshes with the gear transmission group 6. The rotating part 1.2 is also fixed with a gear guide plate 2. The gear guide plate 2 is provided with multiple guide grooves 2.1. A guide member 2.2 is provided between two adjacent guide grooves 2.1. The guide member 2.2 is provided with a guide surface 2.3. The hanger 5 is provided with a positioning component 7. The positioning component 7 includes a positioning member 7.2. The positioning member 7.2 elastically presses the gear guide plate 2. When the positioning member 7.2 is pressed on the guide surface 2.3, it has a tendency to slide toward either guide groove 2.1 on both sides of the guide surface 2.3, and drives the gear guide plate 2 to rotate so that the positioning member 7.2 is located in the guide groove 2.1.

[0033] The above technical solution enables reliable adjustment and shifting of the adjustable dumbbell. When adjusting the weight by rotating the grip 1.1, it ensures that the grip 1.1 rotates to the correct position, thereby guaranteeing that the guide sleeve 4 moves into place and reliably mounts the dumbbell plate 9. This avoids a partial mounting state, where the guide sleeve 4 is not fully extended but still lifts the dumbbell plate 9, thus preventing the dumbbell plate 9 from falling off due to incomplete adjustment. By setting a prism-shaped connecting rod 3 and its cooperating guide sleeve 4, this invention ensures the translational stability of the guide sleeve 4 and reduces the impact of circumferential rotation. Specifically, it avoids unstable engagement between the gear transmission assembly 6 and the tooth groove 4.1 due to circumferential rotation, preventing even jamming or tooth collisions. Furthermore, the use of the gear transmission assembly 6 to drive the guide sleeve 4 ensures the accuracy of its movement.

[0034] Based on the above, to ensure reliable cooperation between the positioning component 7.2 and the gear guide plate 2, inclined sliding surfaces 2.4 are provided on both sides of the guide component 2.2, and a guide surface 2.3 is located between the two sliding surfaces 2.4. The guide surface 2.3 is arc-shaped, and the two edges of the guide surface 2.3 smoothly transition with the sliding surface 2.4. This ensures that when the guide surface 2.3 of the gear guide plate 2 moves to a state of pressure against the positioning component 7.2, it can slide smoothly. This ensures that the guide groove of the gear guide plate 2 rotates to the position opposite to the positioning component 7.2, avoiding the phenomenon of the gear guide plate 2 getting stuck or not rotating into place.

[0035] It is worth mentioning that the multiple guide grooves 2.1 of the present invention are evenly distributed in a ring on the side of the gear guide plate 2, and the gear guide plate 2 is detachably engaged with the rotating part 1.2. The multiple evenly distributed guide grooves 2.1 can easily rotate with the rotating part 1.2 and reliably engage with the positioning component 7. At the same time, the detachable gear guide plate 2 facilitates maintenance and installation, reduces production costs, and is especially convenient for replacement after wear and tear from long-term use.

[0036] To ensure that the gear guide plate 2 rotates into position, the hanger 5 of this invention is provided with multiple positioning components 7 corresponding to the guide groove 2.1, and the contact surface between the positioning component 7.2 and the gear guide plate 2 is an arc surface. Specifically, the positioning component 7 includes a positioning seat 7.1, the positioning component 7.2 is movably disposed within the positioning seat 7.1, and the positioning seat 7.1 is also provided with a compression spring 7.3 for pressing the positioning component 7.2. The compression spring 7.3 ensures reliable pressing between the positioning component 7.2 and the gear guide plate 2, thereby ensuring the accuracy of gear shifting of the adjustable dumbbell. The multiple positioning components 7 provided simultaneously can provide sufficient driving force for the gear guide plate 2, especially when the guide plate 2.2 rotates to be aligned with the positioning component 7.2, thereby forcing the gear guide plate 2 to continue rotating, ensuring that the positioning component 7.2 can be reliably positioned within the positioning groove.

[0037] The guide sleeve 4 of the present invention is provided with a sliding hole 4.2 that matches the connecting rod 3, and the guide sleeve 4 fits into the connecting rod 3. The prism-shaped connecting rod 3 and the guide sleeve 4 that cooperate with it can ensure the stability of the guide sleeve 4 during movement. That is, the guide sleeve 4 is limited by the prism, thereby preventing the circumferential rotation of the guide sleeve 4. In other words, while ensuring the stability of the lateral movement of the guide sleeve 4, the circumferential rotation of the guide sleeve 4 can also be prevented, thus providing a guarantee for the reliable shifting of the adjustable dumbbell.

[0038] It should be noted that the gear transmission assembly 6 of the present invention includes a transmission gear 6.1, which includes a drive gear 6.2 and a driven gear 6.11 and an intermediate gear 6.12 coaxially fixed. The driven gear 6.11 meshes with the meshing gear 1.3, the intermediate gear 6.12 meshes with the drive gear 6.2, and the drive gear 6.2 meshes with the tooth groove 4.1. Preferably, to ensure that the gear transmission assembly 6 can reliably drive the guide sleeve 4 and avoid interference and jamming, intermediate gears 6.12 are fixed on both sides of the driven gear 6.11. Each intermediate gear 6.12 meshes with a corresponding drive gear 6.2. The outer side of the guide sleeve 4 is provided with tooth grooves 4.1 that mesh with the corresponding drive gears 6.2. The movement of the guide sleeve 4 by the cooperation of the two drive gears 6.2 and the corresponding tooth grooves 4.1 can avoid the interference and jamming phenomenon caused by the shaking of the guide sleeve 4 when a single drive gear 6.2 drives the guide sleeve 4. That is, the stability of the force on both sides of the guide sleeve 4 can be ensured by the double row of drive gears 6.2. Preferably, the meshing gear 1.3 and the driven gear 6.11 are both helical gears, and the axis of the meshing gear 1.3 is perpendicular to the axis of the driven gear 6.11. The axis of the meshing gear 1.3 is parallel to the axis of the guide sleeve 4. The meshing teeth and driven teeth in the form of helical gears can change the transmission direction while ensuring rotation, and can effectively avoid reversal, that is, avoid the gear transmission group 6 from reversing due to the dumbbell plate 9 pressing the guide sleeve 4.

[0039] It is worth mentioning that, based on the above, the hanger 5 of the present invention is provided with a fixed seat 5.6, the fixed seat 5.6 is provided with two opposing support plates 5.7, the gear transmission group 6 is rotatably disposed between the two opposing support plates 5.7, and the fixed seat 5.6 is provided with a telescopic hole 5.8, the guide sleeve 4 is laterally movable in the telescopic hole 5.8. The support plates 5.7 can provide stable support for the gear transmission group 6, and the telescopic hole 5.8 can support and limit the sliding of the guide sleeve 4, reducing radial sway.

[0040] To improve the reliability of the adjustable dumbbell during use and prevent accidental rotation, the present invention also includes an unlocking disc 8 and a locking assembly on the hanger 5 for locking the grip bar 1.1. The locking assembly includes a locking groove 5.9 and a locking block 10. The locking groove 5.9 is formed on the hanger 5, and the locking block 10 is slidably disposed in the locking groove 5.9. A locking spring for pressing the locking block 10 is provided in the locking groove 5.9. The rotating part 1.2 is provided with an anti-rotation groove 1.4 that engages with the locking block 10. The unlocking disc is provided with an unlocking element 8.1 corresponding to the locking block 10. When the positioning element 7.2 is located in the guide groove 2.1, the locking block 10 is aligned with the anti-rotation groove 1.4. When the hanger 5 is placed in the unlocking disc 8, the unlocking element 8.1 lifts the locking block 10, so that the locking assembly is in the unlocked state. At this time, the grip bar 1.1 can be rotated to drive the gear 6.2 transmission group 6 to rotate, thereby driving the guide sleeve 4 to move and adjust the dumbbell. When the adjustable dumbbell is lifted from the unlocking plate 8, the unlocking part 8.1 separates from the locking block 10. Under the action of the locking spring, the locking block 10 is inserted into the anti-rotation groove 1.4, thereby locking the grip bar 1.1 assembly 1 and preventing the adjustable dumbbell from rotating accidentally during exercise, thus improving safety. That is, the user can only unlock the locking block 10 to adjust the weight when the adjustable dumbbell is placed on the unlocking plate 8.

[0041] It is worth mentioning that the hanging device 5 of the present invention is detachably provided with a fixed shell 5.2, and the grip 1.1 movably passes through the fixed shell 5.2 and extends into the hanging device 5. At this time, the rotating part 1.2 at the end of the grip 1.1 is rotatably positioned between the fixed shell 5.2 and the hanging device 5, ensuring reliable rotational engagement while preventing axial lateral displacement of the grip 1.1. At the same time, the meshing gear 1.3 of the present invention can be detachably fixed to the rotating part 1.2, which facilitates assembly and replacement after long-term wear.

[0042] The hanging device 5 of the present invention includes two opposing mounting plates 5.3, with a support member 5.4 positioned between the two mounting plates 5.3. The dumbbell plate 9 has a corresponding slot 9.1 on the support member 5.4, and a hanging hole 9.2 in the middle of the dumbbell plate 9 that mates with the guide sleeve 4. The support member 5.4 also has an auxiliary stop 5.5 for separating the dumbbell plate 9, ensuring the accuracy of the dumbbell plate 9 when inserted into the hanging cavity 5.1. The support member 5.4 is positioned along the length of the guide rod, and the guide sleeve 4 protrudes from the side of the support member 5.4, with its length greater than the width between the two mounting plates 5.3. By positioning the support member 5.4 along the length of the guide rod, the guide rod can be concealed within the support member 5.4, reducing exposure and minimizing the possibility of debris entering between the guide rod and the guide sleeve 4, thus preventing jamming. The protrusion of the guide sleeve 4 from the side of the support member 5.4 ensures the reliability of the dumbbell plate 9 hanging on the guide sleeve 4, preventing slippage.

[0043] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention. The objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been shown and explained in the embodiments, and any modifications or variations of the embodiments of the present invention may be made without departing from the stated principles.

Claims

1. An adjustable dumbbell, comprising a grip assembly and a weight assembly, wherein the weight assembly includes dumbbell plates, the grip assembly includes a connecting rod and a grip, both ends of the connecting rod are provided with hangers, the hangers are provided with hanging cavities for hanging dumbbell plates, the grip is rotatably engaged with the hangers, and the grip is sleeved on the outside of the connecting rod, characterized in that, The connecting rod is prismatic in shape, and guide sleeves that can be moved into the mounting cavity are movably sleeved at both ends of the connecting rod. The guide sleeves are provided with toothed grooves along their length. A gear transmission assembly is provided inside the mounting fixture. The gear transmission assembly meshes with the toothed grooves to drive the guide sleeves to translate along the connecting rod. A rotating part is provided at the end of the grip rod. The rotating part is provided with a meshing gear that meshes with the gear transmission assembly. The rotating part is also fixed with a gear guide plate. The gear guide plate is provided with multiple guide grooves. A guide member is provided between two adjacent guide grooves. The guide member is provided with a guide surface. The mounting fixture is provided with a positioning assembly. The positioning assembly includes a positioning member. The positioning member elastically presses the gear guide plate. When the positioning member is pressed against the guide surface, it has a tendency to slide toward either guide groove on both sides of the guide surface and drives the gear guide plate to rotate so that the positioning member is located in the guide groove.

2. The adjustable dumbbell according to claim 1, characterized in that, The guide member has inclined sliding surfaces on both sides, and the guide surface is located between the two sliding surfaces. The guide surface is an arc surface and smoothly transitions with the sliding surfaces.

3. An adjustable dumbbell according to claim 1, characterized in that, The multiple guide grooves are evenly distributed in a ring on the side of the gear guide plate, and the gear guide plate is detachably engaged with the rotating part.

4. An adjustable dumbbell according to claim 1, characterized in that, The fixture is provided with multiple positioning components corresponding to the guide groove, and the contact surface between the positioning component and the gear guide plate is an arc surface.

5. An adjustable dumbbell according to claim 4, characterized in that, The positioning assembly includes a positioning seat, the positioning element is movably disposed within the positioning seat, and a compression spring for pressing the positioning element is also provided within the positioning seat.

6. An adjustable dumbbell according to claim 1, characterized in that, The guide sleeve is provided with a sliding hole that matches the connecting rod, and the guide sleeve fits into the connecting rod.

7. An adjustable dumbbell according to claim 1, characterized in that, The gear transmission assembly includes transmission teeth, which include a drive gear and a driven gear and an intermediate gear fixedly arranged coaxially. The driven gear meshes with the meshing gear, the intermediate gear meshes with the drive gear, and the drive gear meshes with the tooth groove.

8. An adjustable dumbbell according to claim 7, characterized in that, Both sides of the driven gear are fixed with intermediate gears, and each intermediate gear meshes with a corresponding drive gear. The outer side of the guide sleeve is provided with tooth grooves that mesh with the corresponding drive gears.

9. An adjustable dumbbell according to claim 7, characterized in that, The hanger is equipped with a fixed base, which has two opposing support plates. The gear transmission assembly is rotatably disposed between the two opposing support plates. The fixed base is also equipped with a telescopic hole, and the guide sleeve is laterally movable within the telescopic hole.

10. An adjustable dumbbell according to claim 1, characterized in that, It also includes an unlocking disc and a locking assembly mounted on the hanger for locking the grip. The locking assembly includes a locking groove and a locking block. The locking block is slidably disposed in the locking groove, and a locking spring is provided in the locking groove for pressing the locking block. The rotating part is provided with an anti-rotation groove that engages with the locking block. The unlocking disc is provided with an unlocking element corresponding to the locking block. When the positioning element is located in the guide groove, the locking block is aligned with the anti-rotation groove. When the hanger is placed in the unlocking disc, the unlocking element lifts the locking block, thus unlocking the locking assembly.

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