Adjustable dumbbell telescopic assembly and adjustable dumbbell

Abstract

The utility model relates to an adjusting dumbbell telescopic assembly which comprises a rotating rod and a telescopic rod, the rotating rod is a hollow round rod, the telescopic rod is two half-cylindrical rods which are separated in half, the telescopic rod is inserted into the rotating rod, the two ends of the rotating rod are respectively provided with a shifting piece, the shifting pieces are fixedly connected with the rotating rod, shifting protrusions are arranged on the shifting pieces, and the shifting protrusions are arranged on the rotating rod. The outer cylindrical surfaces of the two semi-cylindrical rods are respectively provided with thread grooves with opposite screwing directions, the two stirring bulges can respectively slide in the thread grooves of the two semi-cylindrical rods, each thread groove comprises a zero thread pitch section and a non-zero thread pitch section, and the zero thread pitch sections and the non-zero thread pitch sections are arranged in a staggered manner. The utility model further relates to the adjustable dumbbell. When the dumbbell is adjusted to adopt a half-weight counterweight sheet structure, the sheet falling risk is reduced, the safety of dumbbell products is improved, and meanwhile the cost is effectively controlled.

Description

Technical Field

[0001] The utility model relates to the technical field of dumbbells, in particular to an adjustable dumbbell telescopic component and an adjustable dumbbell. Background Art

[0002] Dumbbells are a common piece of fitness equipment used to increase muscle strength and endurance, improve muscle definition, and enhance body coordination. Dumbbells can be adjusted to suit individual needs, with options ranging from fixed-weight dumbbells to adjustable-weight dumbbells. Adjustable dumbbells typically allow users to change the weight of the dumbbell by adding or removing weight plates.

[0003] With the continuous development of production technology, an adjustable dumbbell has appeared in recent years that is more convenient for changing the number of weight plates. The principle is to set a dumbbell seat and two sets of weight plates. The two sets of weight plates are placed at both ends of the dumbbell seat respectively, and the grip is set between the two sets of weight plates. At the same time, a telescopic rod is set in the grip. By controlling the telescopic rod to extend or retract relative to the grip, it is possible to connect with different numbers of weight plates to achieve weight adjustment.

[0004] The Chinese utility model patent application with application number 202110166671.5 and titled “An Adjustable Dumbbell Handle Structure” discloses a dumbbell handle structure, which is provided with a first spiral shaft and a second spiral shaft, and an insert fixedly connected to a rotatable center tube. The insert cooperates with the threaded grooves on the first and second spiral shafts. When the user rotates the center tube, the insert rotates with it to move the first and second spiral shafts to achieve extension and retraction. At the same time, the document also mentions a semicircular weight plate, whose function is to refine and increase the adjustable gears of the dumbbell by designing a connection and separation transformation structure, so that the weight of the dumbbell can be changed in units of semicircular weight plates. In this solution, the above-mentioned connection and separation structure is realized by rotating the center tube to drive the cam portion on the inner part to extend and retract the card. With such a structure, the user only needs to rotate the center tube without performing other actions to achieve weight adjustment in units of semicircular weight plates.

[0005] However, such a structure also has certain problems: since the connection and separation of the semicircular weight plates are achieved by relying on the rotation of the cam, the central tube that drives the cam portion to rotate keeps rotating during the connection and separation process, and the spiral shaft that is always connected to the central tube will keep extending or retracting. However, if the weight of the semicircular weight plates is to be adjusted, the spiral shaft cannot extend into the next complete weight plate when the semicircular weight plates are separated and connected, otherwise the weight of 1.5 weight plates will be increased or decreased, resulting in functional failure.

[0006] Current adjustable dumbbells typically utilize the thickness of the weight plates to address this issue. When the user rotates the center tube one position, the screw shaft only travels half the thickness of a weight plate. When the screw shaft just barely reaches a weight plate, turning the center tube one more position moves the screw shaft into the middle of the thickness of the next weight plate, and the semicircular weight plates transition from being connected to being separated. Turning the center tube one more position further extends the screw shaft from the middle of the weight plate thickness until it is flush with the weight plate ends, and the semicircular weight plates transition from being separated to being connected.

[0007] However, this structure presents a serious safety hazard: because the spiral shaft, when inserted into the furthest weight plate and connected to the semicircular weight plate, only extends to half the thickness of the weight plate, it is easy to imagine that the weight plate is very likely to fall off in this situation. Moreover, if the weight plate is thin, and there are errors in the thickness of the weight plate itself or between the weight plates, due to the cumulative errors, it is very likely that the spiral shaft will not be able to ensure that it extends to half the thickness of the weight plate after rotating one gear, causing the entire structure to fail and the risk of weight plate falling off is huge. Utility Model Content

[0008] In view of the defects of the existing technology, the technical problem to be solved by the present invention is to provide an adjustable dumbbell telescopic component and an adjustable dumbbell. When the adjustable dumbbell adopts a half-weight counterweight plate structure, the risk of plate falling is reduced, the safety of the dumbbell product is improved, and the cost is effectively controlled.

[0009] In order to solve the above technical problems, the present invention proposes the following technical solutions:

[0010] A dumbbell telescopic adjustment assembly includes a rotating rod and a telescopic rod. The rotating rod is a hollow round rod, and the telescopic rod is two semi-cylindrical rods separated in half. The telescopic rod is inserted into the rotating rod. A toggle piece is respectively provided at each end of the rotating rod. The toggle piece is fixedly connected to the rotating rod, and a toggle protrusion is provided on the toggle piece. Thread grooves with opposite rotation directions are respectively provided on the outer cylindrical surfaces of the two semi-cylindrical rods. The two toggle protrusions can slide in the thread grooves of the two semi-cylindrical rods respectively. The thread groove includes a zero thread pitch section and a non-zero thread pitch section. The zero thread pitch section and the non-zero thread pitch section are staggered.

[0011] As described in the background art, since the user's rotation of the rotating rod must be continuous, the movement of the telescopic rod caused by the toggle member is also continuous. However, due to the use of a half-weight counterweight structure, the correct movement of the telescopic rod should be intermittent rather than continuous.

[0012] To improve safety, a common approach is to continuously improve the accuracy of the weight plate's thickness, assembly, and telescopic mechanism, ensuring that when the user turns the lever, the telescopic shaft extends or retracts by half the thickness of the weight plate. The difficulty with this approach is that when the weight plate is thinner, the margin for error becomes smaller, and the margin for error becomes smaller. Continuously increasing precision requirements can lead to a sharp increase in costs.

[0013] Another common approach to improving safety is to install a clutch between the telescopic rod and the rotating rod, changing the movement of the telescopic rod from continuous to intermittent. The difficulty with this approach is that the rotating rod and the telescopic rod fit tightly together, making adding a clutch between them difficult and costly.

[0014] The design of the present invention avoids the need for precision enhancement to improve safety, while also avoiding the need for a complex clutch device between the telescopic rod and the rotating rod, effectively achieving the dual goals of improving safety and controlling costs. The principle is that the thread groove is designed with two groove sections: a zero-pitch section and a non-zero-pitch section. When the toggle protrusion slides in the non-zero-pitch section, the telescopic rod extends and retracts normally. However, when the toggle protrusion slides in the zero-pitch section, since the thread pitch of this groove section is zero, the toggle protrusion is equivalent to only a planar rotation without axial movement, and the telescopic rod does not extend or retract, thus achieving the correct intermittent movement. Changing the thread groove shape reduces processing costs and effectively controls the overall cost of dumbbell products.

[0015] As a first embodiment of the toggle projection, the toggle projection is a spherical projection. Due to the special shape of the thread groove, the shape of the thread groove changes abruptly at the junction of the zero-pitch segment and the non-zero-pitch segment, and the direction of movement of the toggle projection changes significantly. Therefore, the toggle projection needs to be designed into a rounded spherical shape to avoid interference and affect the user's shifting feel.

[0016] Furthermore, the toggle protrusion is a ball, which is embedded in the toggle member and can roll. Changing the fixed toggle protrusion into a rolling sphere can further improve the smoothness of the gear shift.

[0017] As a second embodiment of the toggle protrusion, the toggle protrusion is a threaded protrusion, the length of the threaded protrusion extending along the axis of the telescopic rod does not exceed the thickness of the toggle member along the axis of the telescopic rod, and the groove width of the zero thread pitch section is not less than the length of the threaded protrusion extending along the axis of the telescopic rod. The toggle protrusion can also be a threaded protrusion, in which case the length of the threaded protrusion is smaller and cooperates with the groove section with non-zero thread pitch. Such a threaded protrusion slides normally in the non-zero thread pitch section. When the threaded protrusion enters the groove section with zero thread pitch, due to the larger width of the groove section, the entire threaded protrusion can enter the groove section and then the groove section rotates with the threaded protrusion, and the threaded shaft does not extend or retract during the entire process. The advantage of the threaded protrusion is that it fits tightly with the groove section with non-zero thread pitch, and the telescopic accuracy of the telescopic rod is high.

[0018] Furthermore, the projected angle of the telescopic rod's central angle corresponding to the zero-pitch segment is equal to the projected angle of the telescopic rod's central angle corresponding to the non-zero-pitch segment on a radial cross-section of the telescopic rod. This design ensures that the angle of rotation for each gear is consistent, improving the user experience and facilitating the design of the weight display device.

[0019] Furthermore, the outer surfaces of the two semi-cylindrical rods are respectively provided with two or more thread grooves, and the number of the toggle protrusions is twice the number of the thread grooves of a single semi-cylindrical rod.

[0020] Furthermore, the two semi-cylindrical rods are each provided with a full cylinder at different ends to form an insertion head. This structure ensures that the telescopic rod can fully fit into the center hole when extended into the farthest weight plate, further reducing the risk of the plate falling off.

[0021] Furthermore, the adjustable dumbbell telescopic assembly includes guide rods. The two semi-cylindrical rods are each provided with a guide groove at the central axis, into which the guide rods are mounted. Because the telescopic shaft has a special thread, its movement is complex and varied. The arrangement of the guide rods and guide grooves ensures the reliability of the telescopic shaft's movement.

[0022] The present invention also provides an adjustment dumbbell, including a placement rack, a weight plate group and a grip assembly, there are two weight plate groups and both are provided with a center hole, the two weight plate groups are respectively arranged at the two ends of the placement rack, the grip assembly is installed between the two weight plate groups and passes through the center hole, the grip assembly includes the adjustment dumbbell telescopic assembly and the weight plate connecting assembly as described above, the weight plate connecting assembly includes an end seat assembly, a counterweight plate and an intermittent connector, there are two end seat assemblies and are respectively connected to the weight plate group, the two ends of the rotating rod are mounted in the end seat assembly and can rotate around the center axis, the intermittent connector is fixedly connected to the rotating rod, when the rotating rod rotates and the toggle protrusion slides in the zero thread pitch section of the thread groove, the intermittent connector connects the counterweight plate and the end seat assembly and the telescopic shaft does not change relative to the center hole position; when the rotating rod rotates and the toggle protrusion slides in the non-zero thread pitch section of the thread groove, the intermittent connector causes the counterweight plate and the end seat assembly to separate and the telescopic shaft extends or retracts relative to the center hole position. The principle of the adjustment dumbbell product is as described above and will not be repeated.

[0023] Furthermore, it also includes an adjustable dumbbell weight display device, the weight display device includes a driving member and a display member, the driving member is fixedly connected to the rotating rod, and the display member is transmission-connected to the driving member.

[0024] In summary, such an adjustable dumbbell telescopic assembly and an adjustable dumbbell can effectively reduce the risk of weight plate falling when the adjusting dumbbell adopts a half-weight counterweight plate structure, thereby improving the safety of the dumbbell product and effectively controlling costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The utility model is further described in detail below with reference to the accompanying drawings and specific implementation methods.

[0026] Figure 1 is a schematic diagram of a dumbbell explosion according to the embodiment;

[0027] Figure 2 is an enlarged schematic diagram of the spiral groove structure of the embodiment;

[0028] Figure 3 is a schematic structural diagram of the toggle member of the embodiment;

[0029] Figure 4 is another structural schematic diagram of the toggle member of the embodiment;

[0030] Figure 5 Schematic diagram of radial projection of the central angle of the zero thread pitch segment and the non-zero thread pitch segment of the embodiment;

[0031] Figure 6 is a schematic diagram of the position of the guide rod in the embodiment;

[0032] Figure 7is a schematic diagram of the positions of the toggle member and the telescopic rod in the dumbbell according to the embodiment;

[0033] Figure 8 is a schematic diagram of a dumbbell explosion according to the embodiment;

[0034] Among them, the grip assembly-1, the rotating rod-11, the telescopic rod-12, the semi-cylindrical rod-121, the weight plate connecting assembly-13, the end seat assembly-131, the counterweight plate-132, the discontinuous connecting piece-133, the thread groove-2, the zero thread pitch segment-21, the non-zero thread pitch segment-22, the insertion head-23, the guide groove-24, the toggle member-3, the toggle protrusion-31, the spherical protrusion-311, the thread protrusion-312, the guide rod-4, the placement rack-5, the weight plate group-6, the center hole-61, the weight display device-7. The driving member-71, the display member-72, the projection plane-f, the zero thread pitch segment projection-f1, the non-zero thread pitch segment projection-f2, and the semi-cylindrical rod center projection-fo. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0036] A dumbbell telescopic adjustment assembly includes a rotating rod 11 and a telescopic rod 12. The rotating rod 11 is a hollow round rod, and the telescopic rod 12 is two semi-cylindrical rods 121 separated in half. The telescopic rod 12 is inserted into the rotating rod 11. A toggle member 3 is respectively provided at both ends of the rotating rod 11. The toggle member 3 is fixedly connected to the rotating rod 11. A toggle protrusion 31 is provided on the toggle member 3. Thread grooves 2 with opposite rotation directions are respectively provided on the outer cylindrical surfaces of the two semi-cylindrical rods 121. The two toggle protrusions 31 can respectively slide in the thread grooves 2 of the two semi-cylindrical rods 121. The thread groove 2 includes a zero thread pitch section 21 and a non-zero thread pitch section 22. The zero thread pitch section 21 and the non-zero thread pitch section 22 are staggered.

[0037] As described in the background art, since the user's rotation of the rotating rod 11 must be continuous, the movement of the telescopic rod 12 caused by the toggle member 3 is also continuous. However, due to the use of a half-weight counterweight structure, the correct movement of the telescopic rod 12 should be intermittent rather than continuous.

[0038] To improve safety, a common approach is to continuously improve the accuracy of the weight plate's thickness, assembly, and telescopic mechanism, ensuring that when the user turns the lever, the telescopic shaft extends or retracts by half the thickness of the weight plate. The difficulty with this approach is that when the weight plate is thinner, the margin for error becomes smaller, and the margin for error becomes smaller. Continuously increasing precision requirements can lead to a sharp increase in costs.

[0039] Another common approach to improving safety is to install a clutch device between the telescopic rod 12 and the rotating rod 11, changing the movement of the telescopic rod 12 from continuous to intermittent. The difficulty with this approach is that the rotating rod 11 and the telescopic rod 12 fit tightly together, making adding a clutch device between them difficult and costly.

[0040] The design of the present invention avoids the need for precision enhancement to improve safety, while also avoiding the need for a complex clutch device between the telescopic rod 12 and the rotating rod 11, effectively achieving the dual goals of improving safety and controlling costs. The principle is that the thread groove 2 is designed to have two groove sections: a zero-pitch section 21 and a non-zero-pitch section 22. When the toggle protrusion 31 slides in the non-zero-pitch section 22, the telescopic rod 12 extends and retracts normally. However, when the toggle protrusion 31 slides in the zero-pitch section 21, because the thread pitch of this groove section is zero, the toggle protrusion 31 is equivalent to only a planar rotation without axial movement, and the telescopic rod 12 does not extend or retract, thus achieving a correct intermittent movement mode. Changing the shape of the thread groove 2 reduces processing costs and effectively controls the overall cost of the dumbbell product.

[0041] As a first embodiment of the toggle protrusion 31, the toggle protrusion 31 is a spherical protrusion 311. Due to the special shape of the thread groove 2, the shape of the thread groove 2 changes abruptly at the junction of the zero-pitch segment 21 and the non-zero-pitch segment 22, causing a significant change in the direction of movement of the toggle protrusion 31. Therefore, the toggle protrusion 31 needs to be designed into a rounded spherical shape to avoid interference and affect the user's shifting feel.

[0042] Furthermore, the toggle protrusion 31 is a ball, which is embedded in the toggle member 3 and can roll. Changing the fixed toggle protrusion 31 into a rolling sphere can further improve the smoothness of the gear shift.

[0043] As a second embodiment of the toggle projection 31, the toggle projection 31 is a threaded projection 312. The length of the threaded projection 312 extending along the axis of the telescopic rod 12 does not exceed the thickness of the toggle member 3 along the axis of the telescopic rod 12, and the groove width of the zero-thread pitch segment 21 is not less than the length of the threaded projection 312 extending along the axis of the telescopic rod 12. Alternatively, the toggle projection 31 may be a threaded projection 312. In this case, the threaded projection 312 is shorter and mates with a groove segment with a non-zero thread pitch. Such a threaded projection 312 slides normally within the non-zero thread pitch segment 22. When the threaded projection 312 enters the zero-thread pitch groove segment, due to the larger width of the groove segment, the entire threaded projection 312 can enter the groove segment, and the groove segment then rotates with the threaded projection 312, without the threaded shaft extending or contracting during the entire process. The advantage of the threaded projection 312 is that it mates tightly with the non-zero thread pitch groove segment, resulting in high telescopic precision for the telescopic rod 12.

[0044] like Figure 5 As shown, the zero-pitch segment 21 and the non-zero-pitch segment 22 are radially projected onto a radial projection plane f, resulting in arc segments f1 and f2 of equal length and a projection fo of the center of the semi-cylindrical rod. This indicates that the central angle of the telescopic rod 12 corresponding to the zero-pitch segment 21 and the central angle of the telescopic rod 12 corresponding to the non-zero-pitch segment 22 are equal when projected onto a radial cross-section of the telescopic rod 12. This design ensures that the angle of rotation for each gear is consistent, improving the user experience and facilitating the design of the weight display device 7.

[0045] Furthermore, the outer surfaces of the two semi-cylindrical rods 121 are respectively provided with two or more thread grooves 2, and the number of the toggle protrusions 31 is twice the number of the thread grooves 2 of a single semi-cylindrical rod 121. Setting multiple toggle structures can improve the reliability of the toggle and the telescopic accuracy.

[0046] Furthermore, the two semi-cylindrical rods 121 are respectively provided with a complete cylinder at different ends to form an insertion head 23. Such a structure can ensure that the telescopic rod 12 can fully cooperate with the center hole 61 when extending into the farthest weight plate, further reducing the risk of falling plates.

[0047] Furthermore, the dumbbell telescopic adjustment assembly further includes a guide rod 4. The two semi-cylindrical rods 121 are each provided with a guide groove 24 at the central axis thereof, and the guide rod 4 is mounted in the guide groove 24. Because the telescopic shaft has a special thread, its movement is complex and varied. The provision of the guide rod 4 and the guide groove 24 ensures the reliability of the telescopic shaft's movement.

[0048] The utility model also provides an adjustment dumbbell, including a placement rack 5, a weight plate group 6 and a grip assembly 1, the weight plate group 6 has two and each is provided with a center hole 61, the two weight plate groups 6 are respectively arranged at both ends of the placement rack 5, the grip assembly 1 is installed between the two weight plate groups 6 and passes through the center hole 61, the grip assembly 1 includes the above-mentioned adjustment dumbbell telescopic assembly and the weight plate connecting assembly 13, the weight plate connecting assembly 13 includes an end seat assembly 131, a weight plate 132 and an intermittent connector 133, the end seat assembly 131 has two and is respectively connected to the weight plate group 6, the two ends of the rotating rod 11 The end bracket is mounted in the end seat assembly 131 and can rotate around the central axis. The discontinuous connector 133 is fixedly connected to the rotating rod 11. When the rotating rod rotates and the toggle protrusion 31 slides in the zero thread pitch section 21 of the thread groove 2, the discontinuous connector 133 connects the weight plate 132 and the end seat assembly 131 and the position of the telescopic shaft relative to the center hole 61 does not change. When the rotating rod rotates and the toggle protrusion 31 slides in the non-zero thread pitch section 22 of the thread groove 2, the discontinuous connector 133 separates the weight plate 132 and the end seat assembly 131 and the telescopic shaft extends or retracts relative to the center hole 61. The principle of adjusting the dumbbell product is as described above and will not be repeated here.

[0049] Furthermore, it also includes an adjustable dumbbell weight display device 7, which includes a driving member 71 and a display member 72. The driving member 71 is fixedly connected to the rotating rod, and the display member 72 is transmission-connected to the driving member 71.

[0050] In summary, such an adjustable dumbbell telescopic assembly and an adjustable dumbbell can effectively reduce the risk of weight plate falling when the dumbbell adopts a half-weight weight plate structure, thereby improving the safety of the dumbbell product and effectively controlling the cost.

[0051] In short, the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. An adjustable dumbbell telescopic assembly, comprising a rotating rod and a telescopic rod, wherein the rotating rod is a hollow round rod, and the telescopic rod is two semi-cylindrical rods separated in half, the telescopic rod being inserted into the rotating rod, and a toggle member being provided at each end of the rotating rod, the toggle member being fixedly connected to the rotating rod, the toggle member being provided with a toggle protrusion, and the outer cylindrical surfaces of the two semi-cylindrical rods being provided with thread grooves of opposite rotation directions, the two toggle protrusions being able to slide in the thread grooves of the two semi-cylindrical rods, respectively, and characterized in that: The thread groove includes a zero thread pitch segment and a non-zero thread pitch segment, and the zero thread pitch segment and the non-zero thread pitch segment are arranged alternately.

2. The adjustable dumbbell telescopic assembly according to claim 1, characterized in that: The dialing protrusion is a spherical protrusion.

3. The adjustable dumbbell telescopic assembly according to claim 1, characterized in that: The toggle protrusion is a ball, which is embedded in the toggle piece and can roll.

4. The adjustable dumbbell telescopic assembly according to claim 1, characterized in that: The toggle protrusion is a threaded protrusion, the length of the threaded protrusion extending along the axis of the telescopic rod does not exceed the thickness of the toggle member along the axis of the telescopic rod, and the groove width of the zero thread pitch section is not less than the length of the threaded protrusion extending along the axis of the telescopic rod.

5. The adjustable dumbbell telescopic assembly according to any one of claims 1 to 4, characterized in that: The projection angle of the central angle of the telescopic rod corresponding to the zero thread pitch section is equal to the projection angle of the central angle of the telescopic rod corresponding to the non-zero thread pitch section on the radial cross section of the telescopic rod.

6. The adjustable dumbbell telescopic assembly according to claim 5, characterized in that: Two or more thread grooves are respectively provided on the outer cylindrical surfaces of the two semi-cylindrical rods, and the number of the shifting protrusions is twice the number of the thread grooves of a single semi-cylindrical rod.

7. The adjustable dumbbell telescopic assembly according to claim 6, characterized in that: The two semi-cylindrical rods are respectively provided with a complete cylinder at different ends to form an insertion head.

8. The adjustable dumbbell telescopic assembly according to claim 7, characterized in that: It also includes a guide rod, and the two semi-cylindrical rods are respectively provided with a guide groove at the central axis, and the guide rod is installed in the guide groove.

9. An adjustable dumbbell comprising a rack, a weight plate group, and a grip assembly, wherein the weight plate groups are two and each has a center hole, the two weight plate groups are respectively disposed at both ends of the rack, the grip assembly is mounted between the two weight plate groups and passes through the center hole, and is characterized in that: The grip assembly includes the adjustable dumbbell telescopic assembly and the weight plate connection assembly according to any one of claims 1 to 8, the weight plate connection assembly includes an end seat assembly, a weight plate and an intermittent connector, there are two end seat assemblies and they are respectively connected to the weight plate group, the two ends of the rotating rod are mounted in the end seat assembly and can rotate around the central axis, the intermittent connector is fixedly connected to the rotating rod, - When the rotating rod rotates to drive the protrusion to slide in the zero-thread pitch section of the thread groove, the discontinuous connector connects the weight plate and the end seat assembly and the position of the telescopic shaft relative to the center hole does not change; -When the rotating rod rotates to drive the protrusion to slide in the non-zero thread pitch section of the thread groove, the discontinuous connection piece causes the weight plate and the end seat assembly to separate and the telescopic shaft to extend or retract relative to the center hole.

10. The adjustable dumbbell according to claim 9, characterized in that: It also includes a weight display device, which includes a driving member and a display member. The driving member is fixedly connected to the rotating rod, and the display member is transmission-connected to the driving member.

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