A weight plate adapter

Abstract

With the gradual entry of fitness equipment into households, especially strength training equipment, dumbbells, barbells, kettlebells, and hammer bells in these strength training exercises are self-contained systems, each with its own counterweight, which is poorly compatible with each other and has almost zero shared parts. The present invention relates to a weight plate adapter, comprising an upper gripping portion and a mounting portion; the gripping portion comprises: a top handle and a support arm fixedly connected to the bottom of the grip; the mounting portion comprises: a vertical arm fixedly connected to the support arm at the top, and a screw rod fixedly arranged at the bottom of the vertical arm for mounting the weight plate. The present invention can directly convert the weight plates of barbells and dumbbells into kettlebells. Buying one set can turn it into two sets of fitness equipment. It does not need to take up a large space. It is just a simple handle that can utilize conventional weight plates. As long as there are weight plates of different specifications, you can have kettlebells of corresponding weights for exercise, which perfectly solves the disadvantages of high cost and large volume of multiple weight accessories for multiple training equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of fitness equipment, and in particular to a weight plate converter for fitness. Background Art

[0002] With rising health awareness, fitness equipment is gradually entering homes. This is particularly true for strength training equipment, which requires minimal space. Dumbbells, barbells, kettlebells, and hammerbells are the preferred choice for their compact size and wide application. Strength training improves physical fitness and enhances functional performance, serving as a foundation for bodybuilding and professional athletic training. In recent years, the ownership of fitness equipment in homes has steadily increased, with not only gyms becoming more fully equipped, but also the availability of fitness equipment in homes increasing year by year.

[0003] However, in these strength training exercises, dumbbells, barbells, kettlebells, and hammerbells are self-contained and cannot be used interchangeably. In particular, their respective weights are incompatible with each other, with almost no shared features. Without a single piece of equipment to increase compatibility, it's essential to purchase everything, which takes up a lot of space. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a weight plate adapter with multiple functions and small footprint.

[0005] A weight plate adapter includes an upper grip portion and a mounting portion fixedly connected to the grip portion; the grip portion includes a top handle and a support arm fixedly connected to the bottom of the handle; the mounting portion includes a vertical arm fixedly connected to the support arm at the top, and a screw fixedly mounted at the bottom of the vertical arm for mounting a weight plate, the axis of the screw being perpendicular to the vertical axis of the vertical arm. Furthermore, the screw is also fitted with a lower nut for fastening the weight plate.

[0006] Furthermore, the vertical arm includes an upper vertical arm and a lower vertical arm, and the upper vertical arm and the lower vertical arm are fixedly connected by screws. The top of the upper vertical arm is fixedly connected to the support arm, and the screw rod is fixedly connected to the bottom of the lower vertical arm.

[0007] Furthermore, the upper hanging arm is horizontally provided with two upper screw holes, and the lower hanging arm is provided with two lower screw holes corresponding to the two upper screw holes.

[0008] Furthermore, the upper screw holes are arranged in three groups vertically.

[0009] Furthermore, the support arm and the vertical arm are fixedly connected by a limiting screw, a vertical arm top plate is provided on the top of the vertical arm, a vertical arm positioning hole is provided on the vertical arm top plate, and a support arm positioning hole is provided on the support arm. The limiting screw includes a screw rod and an upper nut, and the screw rod passes through the vertical arm positioning hole, the support arm positioning hole and the upper nut from bottom to top in sequence and is threadedly connected.

[0010] Furthermore, the screw rod includes a nut, a lower screw rod, and an upper screw rod connected in sequence, and the upper screw rod is adapted to the upper nut; the radial end face of the lower screw rod is non-circular, and the radial cross-sections of the vertical arm positioning hole and the support arm positioning hole are adapted to the radial end face of the lower screw rod.

[0011] Furthermore, the radial end face of the lower screw rod is square, and the radial cross-sections of the vertical arm positioning hole and the support arm positioning hole are square and matched with the radial end face of the lower screw rod.

[0012] Furthermore, there is more than one vertical arm positioning hole.

[0013] Furthermore, the four vertical arm positioning holes partially overlap to form an adjustable vertical arm positioning hole. The four vertical arm positioning holes form a linear array, with the linear array direction perpendicular to the vertical arm axis and parallel to the axis of the screw. The adjustable vertical arm positioning holes are generally prismatic, with right angles at both ends of the major axis and two sets of corresponding segmented positioning teeth at each end of the minor axis. Furthermore, the dimensions of the screw and upper screw meet the national standard for dumbbell screws, and the upper and lower nuts are compatible with these locking heads.

[0014] Furthermore, the gripping portion is trapezoidal, L-shaped or C-shaped; when the gripping portion is trapezoidal, the handle is the long side of the trapezoid, and the support arm is the short side of the trapezoid; when the gripping portion is L-shaped, the handle is the vertical upper side of the L, the support arm is the horizontal lower end of the L, the axis of the handle is parallel to the axis of the vertical arm, and the top end of the handle is also provided with a spherical end to prevent loosening; when the gripping portion is C-shaped, the handle and the support arm are respectively the two free ends of the C-shape.

[0015] The positive effects of the present invention are as follows:

[0016] The present invention can directly convert the weight plates of barbells and dumbbells into kettlebells. Buying one set can turn it into two sets of fitness equipment without taking up a large space. Just a simple handle can be used to utilize the conventional weight plates, turning a single set of equipment into two strength fitness equipment. Grab the handle with your hands and use the support arm, support arm and screw rod to lift the weight plates, which is a kettlebell. If you need a large weight, you can hang a large weight plate (such as 20kg). If you need a small weight, you can hang a small (0.5kg) dumbbell weight plate. As long as you have weight plates of different specifications, you can have a kettlebell of the corresponding weight for exercise. One set of equipment can achieve the effect of two or more sets of equipment, and the adapter is small in size and takes up very little space. Not only does it add new functions to existing equipment, but it is also cheap and takes up little space. It perfectly solves the disadvantages of multiple training equipment and multiple weight accessories with high cost and large size.

[0017] The weight plate can be fixed by adding a nut to the screw rod, which makes it more convenient to use and prevents the weight plate from falling off. The swinging motion during training can be larger and it is convenient to take and put.

[0018] The upper and lower drop arms can accommodate weight stacks of varying outer diameters. Larger diameter weight stacks can be adjusted to lengthen the upper and lower drop arms, while smaller diameters can be adjusted to lengthen the lower and upper drop arms. This not only improves aesthetics, but also brings the center of gravity of the weight stack closer to the center of the handlebar, making it more comfortable to use and more consistent with the mechanics of the setup, optimizing for better protection against injuries.

[0019] Use screws to connect the upper and lower pendant arms. The inner wall of the screw hole is threaded, so you can tighten it directly with the screws. The two-row setting makes the connection between the upper and lower pendant arms more stable, avoiding the risk of the upper and lower pendant arms rotating when fixed with a single screw.

[0020] The three rows of screw holes on the upper arm accommodate weight plates of varying diameters, bringing the center of gravity of the weight plate closer to the center of the handle. This reduces the distance between the center of gravity of the weight plate and the center of the handle, which in turn reduces torque, making the kettlebell more compact and closer to the shape and load-bearing structure of a regular kettlebell. This further optimizes the mechanics of the kettlebell and prevents sports injuries.

[0021] The support arm and the top plate of the upper drop arm are connected by set screws, making the entire structure removable and easier to use. The set screws are fastened with nuts, allowing the drop arm to be bent by stamping, resulting in a simpler and more economical manufacturing process for the entire grip. The set screw connection is more secure and less prone to loosening, can withstand impacts from all directions, and can be disassembled for other uses, achieving maximum utilization.

[0022] By setting the radial cross-section of the lower screw of the limit screw to a non-circular shape and aligning the positioning holes of the support arm and the hammer arm with this shape, the vertical arm and the support arm are locked together, preventing the combination from rotating relative to each other. This prevents the combination from twisting when subjected to external forces or inertia, not only improving safety and preventing sprains, but also effectively transmitting radial inertial forces, and effectively transmitting force when the combination is used in self-spinning mode.

[0023] The radial cross-section of the lower screw is square, allowing the drop arm to rotate 90° relative to the support arm, which in turn rotates the weight stack 90°. This creates a 90-degree angle between the grip surface and the weight stack surface. This creates two different gripping positions for the palm and the weight stack, increasing the number of gripping positions available to the exerciser. These two gripping positions target different muscle groups, especially when the weight stack is circling the body and passing under the hips. These two gripping positions activate two different muscle groups, making them more suitable for strength training, more targeted, and more practical.

[0024] Multiple hanging arm positioning holes can be set on the top plate of the hanging arm, which can be freely adjusted according to different weights, postures, muscle groups to be trained, and personal preferences. It has stronger applicability and wider use.

[0025] The four vertical arm positioning holes are overlapped to form a pair of serrated edges and a pair of right-angled edges. This is mainly to accommodate different weight plate thicknesses and to ensure that the center of gravity of different weight plates is always aligned vertically with the center of the handle. Different weight plates have different diameters and thicknesses, so it is necessary to adjust the center of gravity. Therefore, the linear array of multiple vertical arm positioning holes is parallel to the screw axis and is located in the same plane in the vertical state. This makes the alignment of the center of gravity of the weight plate and the center of the handle more scientific and rigorous, increasing the user experience while increasing the professionalism and rigor of the equipment.

[0026] This device involves two threaded connections, one is the upper screw and the other is the screw. Not only are the threads the same, but they are also the same as the threads of the dumbbell and the screw. In this way, the upper and lower nuts can be used interchangeably with the locking heads of the dumbbell and the screw, increasing the versatility of the device.

[0027] When the handle is horizontal, one end is connected to the support arm to form a C shape, and the two ends are connected to the support arm to form an inverted trapezoid, which is now in the dumbbell state; when the handle is vertical, in order to keep the axis of the handle parallel to the axis of the hanging arm, and to keep the axis of the handle coincident with the center of the weight plate, the bottom of the handle is connected to one end of the support arm through a sloped body, so that the handle and the support arm are L-shaped as a whole, which is in the hammerbell state. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Attachment Figure 1 This is a schematic diagram of the front structure of the present invention in use;

[0029] Attachment Figure 2 This is a side structural diagram of the present invention in use;

[0030] Attachment Figure 3 This is a schematic diagram of the front structure of the present invention;

[0031] Attachment Figure 4 This is a schematic diagram of the structure of the limiting screw of the present invention;

[0032] Attachment Figure 5 This is a bottom view of the structure of the positioning hole of the vertical arm of the present invention;

[0033] Attachment Figure 6 This is a bottom view of the support arm positioning hole structure of the present invention;

[0034] Attachment Figure 7 This is a schematic diagram of the upward-looking structure of adjusting the positioning hole of the vertical arm of the present invention;

[0035] Attachment Figure 8This is a schematic diagram of the side structure of the vertical arm of the present invention;

[0036] Attachment Figure 9 This is a schematic diagram of the side structure of the present invention in the state of use after rotation;

[0037] Attachment Figure 10 This is a schematic diagram of the L-shaped handle structure of the present invention;

[0038] In the attached Figure 1-10 Middle: 1 handle, 2 support arm, 21 support arm positioning hole, 3 vertical arm, 4 screw rod, 5 lower nut, 6 limit screw, 31 upper vertical arm, 32 lower vertical arm, 33 vertical arm top plate, 311 upper screw hole, 321 lower screw hole, 331 vertical arm positioning hole, 332 adjusting vertical arm positioning hole, 333 split positioning tooth, 61 screw rod, 611 nut, 612 lower screw rod, 613 upper screw rod, 62 upper nut. DETAILED DESCRIPTION

[0039] As attached Figure 1 、 2 As shown in Figures 3, 5 and 6, a weight plate adapter of the present invention includes a gripping portion at the top and a mounting portion fixedly connected to the gripping portion; the gripping portion includes: a handle 1 at the top and a support arm 2 fixedly connected to the bottom of the handle 1; the mounting portion includes: a vertical arm 3 fixedly connected to the support arm 2 at the top, a screw rod 4 fixedly arranged at the bottom of the vertical arm 3 for mounting the weight plate, and the axis of the screw rod 4 is perpendicular to the vertical axis of the vertical arm 3. As shown in the attached figure Figure 2 As shown, the screw rod 4 is also provided with a lower nut 5 for fastening the weight plate. Figure 1 、 2 As shown in FIG3 , the hanging arm 3 includes an upper hanging arm 31 and a lower hanging arm 32, and the upper hanging arm 31 and the lower hanging arm 32 are fixedly connected by screws. The top of the upper hanging arm 31 is fixedly connected to the support arm 2, and the screw rod 4 is fixedly connected to the bottom of the lower hanging arm 32. Figure 1 、 2 As shown in FIG3 , the upper hanging arm 31 is horizontally provided with two upper screw holes 311, and the lower hanging arm 32 is provided with two lower screw holes 321 corresponding to the two upper screw holes 311. Figure 1 、 3 As shown, the upper screw holes 311 are in three groups and arranged vertically.

[0040] Grab the handle 1 and use the support arm 2, drop arm 3, and screw 4 to lift the weight stack, creating a kettlebell. For heavier loads, attach a large weight stack (e.g., 20 kg); for lighter loads, attach a small (0.5 kg) dumbbell weight stack. Install the lower nut 5 (locking head) on the screw 4 to secure the weight stack.

[0041] The arrangement of the upper hanging arm 31 and the lower hanging arm 32 can accommodate weight plates of different outer diameters. A large diameter weight plate can adjust the hanging arm 3 to be longer, while a small diameter weight plate can adjust the length of the hanging arm 3. This can bring the center of gravity of the weight plate closer to the center of the handle 1, making it more comfortable to use.

[0042] Use countersunk screws to connect the upper and lower arms 31 and 32. The inner walls of the upper and lower screw holes 311 and 321 are threaded, so they can be tightened directly with the screws. The two rows of screws provide a more stable connection between the upper and lower arms 31 and 32, avoiding the risk of rotation when a single screw is used. If a single screw is used, the upper and lower arms 31 and 32 must also be provided with corresponding concave and convex points or corresponding concave and convex grooves. This concave and convex structure increases the thickness of the arm and is not user-friendly, but it can be used. Using countersunk screws directly is more reasonable.

[0043] The three rows of screw holes 311 are provided on the upper vertical arm 31 mainly to accommodate weight plates of different diameters, so that the center of gravity of the weight plate and the center of the handle 1 are closer, reducing the distance between the center of gravity of the weight and the center of the handle 1, that is, reducing the torque, and being closer to the appearance and force structure of an ordinary kettlebell.

[0044] As attached Figure 1-3 As shown, the support arm 2 and the vertical arm 3 are fixedly connected by a limit screw 6. The top of the vertical arm 3 is provided with a vertical arm top plate 33, and the vertical arm top plate 33 is provided with a vertical arm positioning hole 331. The support arm 2 is provided with a support arm positioning hole 21. The limit screw 6 includes a screw rod 61 and an upper nut 62. The screw rod 61 passes through the vertical arm positioning hole 331, the support arm positioning hole 21 and the upper nut 62 from bottom to top in sequence and is threadedly connected. As shown in the attached figure Figure 1-4 As shown, the screw rod 61 includes a nut 611, a lower screw rod 612, and an upper screw rod 613 connected in sequence, and the upper screw rod 613 is adapted to the upper nut 62; the radial end face of the lower screw rod 612 is non-circular, and the radial cross-sections of the vertical arm positioning hole 331 and the support arm positioning hole 21 are adapted to the radial end face of the lower screw rod 612.

[0045] The support arm 2 and the top plate 33 of the upper vertical arm 31 are connected by a set screw 6, which is tightened by an upper nut 62. This allows the vertical arm 3 to be bent by stamping. The set screw 6 provides a more secure connection and prevents loosening. The lower screw 612 of the set screw 6 is configured with a non-circular radial cross-section, and the support arm positioning hole 21 and the hammer arm positioning hole 331 are adapted to this. This combination can lock the vertical arm 3 and support arm 2 together, preventing the combined components from rotating relative to each other.

[0046] As attached Figure 4 、 5As shown in FIG. 6 , the radial end face of the lower screw rod 612 is a square, and the radial cross-sections of the vertical arm positioning hole 331 and the support arm positioning hole 21 are square and matched with the radial end face of the lower screw rod 612 .

[0047] The radial cross-section of the lower screw rod 612 is square, so that the hanging arm 3 can rotate 90 degrees relative to the supporting arm 2, and the weight plate can also rotate 90 degrees, so that the surface where the grip portion is located forms a 90-degree angle with the surface where the weight plate is located. In this case, the palm gripping posture and the weight plate will form two different situations.

[0048] As attached Figure 7 、 8 As shown, there are more than one vertical arm positioning hole 331. As shown in Appendix 7, there are four vertical arm positioning holes 331, which partially overlap to form an adjustable vertical arm positioning hole 332. The four vertical arm positioning holes 331 form a linear array, with the linear array direction perpendicular to the axis of the vertical arm 3 and parallel to the axis of the screw rod 4. The adjustable vertical arm positioning hole 332 is generally prismatic, with the two ends of the long axis at right angles and two sets of corresponding segmented positioning teeth 333 formed at the two ends of the short axis. Multiple vertical arm positioning holes 331 can be provided on the vertical arm top plate 33. When four vertical arm positioning holes 331 are overlapped, an adjustable vertical arm positioning hole 332 is formed, forming an adjustable vertical arm positioning hole with one pair of serrated edges and one pair of right-angled edges. When there are four vertical arm positioning holes 331, three sets of corresponding segmented positioning teeth 333 are formed in the adjustable vertical arm positioning hole 332, corresponding to the positions of the four limit screws 6, corresponding to four different thicknesses of counterweight plates. As can be inferred from this, a linear arrangement of several vertical arm positioning holes 331 that do not completely overlap will result in different positions for the limit screws 6, corresponding to different weight plate thicknesses. For less demanding use, only the weight plates can be replaced without adjusting the vertical arm positioning holes 331. In other words, a single vertical arm positioning hole 331 is sufficient for daily use.

[0049] It should be noted that the linear arrangement of the plurality of vertical arm positioning holes 331 can be equidistant or partially equidistant. Therefore, when equidistant, the segmented positioning teeth 333 are of equal size, while when unequal, they are of different sizes. However, corresponding sets of segmented positioning teeth 333 are of equal size. Because the adjustable vertical arm positioning hole 332 is formed by overlapping two or more vertical arm positioning holes 331, each set of segmented positioning teeth 333 has a vertical arm positioning hole 331 on both sides.

[0050] As attached Figure 1-4As shown in Figures 9 and 10, the sizes of the screw rod 4 and the upper screw rod 613 conform to the national standard for dumbbell screws, and the upper nut 62 and lower nut 5 are compatible with them. This device involves two threaded connections and fastenings, one for the upper screw rod and the other for the lower screw rod. The threads of the two are not only the same, but also the same as the threads of the dumbbell and the screw. In this way, the upper and lower nuts can be used interchangeably with the locks of the dumbbell and the screw. The lock is a common name in the field of fitness equipment and refers to a large nut that is turned by hand. Tightening it to compress the counterweight and loosening it to remove the counterweight.

[0051] When the handle 1 is horizontal, the two ends connected to the support arm 2 form an inverted trapezoid, which is in the dumbbell state. Figure 1 、 3 As shown in FIG9 , the gripping portion is a trapezoid, the handle 1 is the long side of the trapezoid, and the support arm 2 is the short side of the trapezoid.

[0052] Example 1:

[0053] As attached Figure 1-4 As shown in 6-8, the radial end face of the lower screw rod 612 is selected to be a square, and the radial cross-section of the vertical arm positioning hole 331 and the support arm positioning hole 21 is selected to be a square.

[0054] When using, after selecting the required weight stack, loosen the upper nut 62, remove the screw 61 from the support arm positioning hole 21, remove the upper hanging arm 31, and according to the thickness of the weight stack, thread the lower screw rod 612 of the screw 61 into the hanging arm positioning hole 331 formed by the divided positioning teeth 333 in the adjustment hanging arm positioning hole 332. At this time, keep the vertical plane of the grip part parallel to the vertical plane of the weight stack, as shown in the figure. Figure 1 、 2 Then, the upper screw rod 613 is passed through the support arm positioning hole 21 and the upper nut 62 is tightened to fix it.

[0055] Then, according to the size of the weight plate, the lower screw hole 321 of the hanging arm 32 is aligned with the upper screw hole 311 of the appropriate upper hanging arm 31 and fixed. The hanging arm 32, the upper hanging arm 31, the hanging arm top plate 33, the handle 1 and the supporting arm 2 at this moment form an integral body.

[0056] Pass the screw rod 4 through the center hole of the weight plate and tighten it with the lower nut 5. At this time, a kettlebell is formed.

[0057] Example 2:

[0058] The difference from the first embodiment is that when changing the use state, loosen the upper nut 62 and withdraw the screw 61 from the support arm positioning hole 21 and the vertical arm positioning hole 331. Rotate the vertical arm 3 90 degrees, and then pass the screw 61 through the vertical arm positioning hole 331 and the support arm positioning hole 21 in turn and tighten them with the upper nut 62. Figure 9 As shown. At this point, a new kettlebell is formed.

[0059] Example 3:

[0060] The difference from the first embodiment is that one of the hypotenuses of the trapezoidal structure is not connected, so that the overall grip portion is C-shaped, and the handle 1 and the support arm 2 are the two free ends of the C-shape, one on the top is the handle 1, and the other on the bottom is the support arm 2.

[0061] Example 4:

[0062] As attached Figure 10 As shown, this is the use state of the hammer bell, and the handle 1 and the support arm 2 are L-shaped. When the grip is L-shaped, the handle 1 is the vertical upper side of the L, and the support arm 2 is the horizontal lower end of the L, with an italic fixed connection in the middle, and the whole is L-shaped. However, the axis of the handle 1 and the axis of the vertical arm 3 must be parallel, and the axis of the handle 1 must coincide with the center of the counterweight. It is best to match the center of gravity of the counterweight by adjusting the vertical arm positioning hole 332, so that the center of gravity of a variety of counterweight plates can be matched. A single vertical arm positioning hole can also be used. There is a spherical end at the top end to prevent loosening. This is a box of hammer bells with a round counterweight.

Claims

1. A weight plate adapter, characterized in that: It includes an upper gripping portion and a mounting portion fixedly connected to the gripping portion; The gripping portion comprises: a top grip (1) and a support arm (2) fixedly connected to the bottom of the grip (1); The mounting portion comprises: a vertical arm (3) whose top is fixedly connected to the supporting arm (2); a screw rod (4) fixedly arranged at the bottom of the vertical arm (3) for mounting a counterweight plate, wherein the axis of the screw rod (4) is perpendicular to the vertical axis of the vertical arm (3); the vertical arm (3) comprises an upper vertical arm (31) and a lower vertical arm (32), and the upper vertical arm (31) and the lower vertical arm (32) are fixedly connected by screws; The support arm (2) and the vertical arm (3) are fixedly connected by a limit screw (6); a vertical arm top plate (33) is provided on the top of the vertical arm (3); the vertical arm top plate (33) is provided with a vertical arm positioning hole (331); the support arm (2) is provided with a support arm positioning hole (21); there is more than one vertical arm positioning hole (331); the vertical arm positioning holes (331) are linearly arrayed, and the direction of the linear array is perpendicular to the axis of the vertical arm (3) and parallel to the axis of the screw rod (4).

2. A weight plate adapter according to claim 1, characterized in that The screw rod (4) is also provided with a lower nut (5) for fastening the weight plate.

3. A weight plate adapter according to claim 1 or 2, characterized in that The top of the upper hanging arm (31) is fixedly connected to the supporting arm (2), and the screw rod (4) is fixedly connected to the bottom of the lower hanging arm (32).

4. A weight plate adapter according to claim 3, characterized in that The upper hanging arm (31) is horizontally provided with two upper screw holes (311), and the lower hanging arm (32) is provided with two lower screw holes (321) corresponding to the two upper screw holes (311).

5. A weight plate adapter according to claim 4, characterized in that The upper screw holes (311) are in three groups and arranged vertically.

6. A weight plate adapter according to claim 1 or 2, characterized in that: The limiting screw (6) comprises a screw rod (61) and an upper nut (62), wherein the screw rod (61) passes through the vertical arm positioning hole (331), the support arm positioning hole (21) and the upper nut (62) in sequence from bottom to top and is threadedly connected.

7. A weight plate adapter according to claim 6, characterized in that The screw rod (61) includes a nut (611), a lower screw rod (612), and an upper screw rod (613) connected in sequence, and the upper screw rod (613) is adapted to the upper nut (62); the radial end surface of the lower screw rod (612) is non-circular, and the radial cross-sections of the vertical arm positioning hole (331) and the support arm positioning hole (21) are adapted to the radial end surface of the lower screw rod (612).

8. A weight plate adapter according to claim 7, characterized in that The radial end face of the lower screw rod (612) is square, and the radial cross-sections of the vertical arm positioning hole (331) and the support arm positioning hole (21) are square and match the radial end face of the lower screw rod (612).

9. A weight plate adapter according to claim 8, characterized in that : There are four vertical arm positioning holes (331), and the four vertical arm positioning holes (331) are partially overlapped to form an adjustment vertical arm positioning hole (332); The adjusting vertical arm positioning hole (332) is prismatic in shape as a whole, with the two ends of the long axis being right angles, and two sets of corresponding segmented positioning teeth (333) being formed at the two ends of the short axis.

10. The weight plate adapter according to claim 7, characterized in that The sizes of the screw rod (4) and the upper screw rod (613) conform to the national standard for dumbbell screws, and the upper nut (62) and the lower nut (5) are lock heads adapted thereto.

11. A weight plate adapter according to claim 1 or 2, characterized in that : The gripping portion is trapezoidal, L-shaped or C-shaped; When the gripping portion is trapezoidal, the grip (1) is the long side of the trapezoid, and the support arm (2) is the short side of the trapezoid; When the grip portion is L-shaped, the grip (1) is the vertical upper side of the L, the support arm (2) is the horizontal lower end of the L, the axis of the grip (1) is parallel to the axis of the vertical arm (3), and the top end of the grip (1) is also provided with a spherical end to prevent loosening; When the gripping portion is C-shaped, the grip (1) and the support arm (2) are respectively two free ends of the C-shape.

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