Dumbbell piece and dumbbell comprising same, and processing method for dumbbell pieces
By employing a flexible main body design and infusion channel technology, the problems of fixed dumbbell weight and sagging have been solved, achieving safety and diverse training methods for dumbbell plates and meeting users' personalized needs.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- WUYI KUPAO SPORTS GOODS CO LTD
- Filing Date
- 2025-01-04
- Publication Date
- 2026-06-25
AI Technical Summary
Existing dumbbell products have a fixed weight that cannot be adjusted, and they also suffer from sagging issues, lack aesthetic appeal, and fail to meet the personalized needs of different users.
It adopts a flexible main body design, forming elastic dumbbell plates through filling channels and inflation. It is sealed by combining rigid positioning plugs and flexible fixing plugs. The dumbbell plates can adjust weight and deformation to adapt to the dumbbell bar, and are integrally molded using a slush molding process.
The dumbbell plates offer both safety and diverse workout options. The weight can be adjusted as needed to prevent injury, and the stable structure prevents wobbling, providing a variety of workout methods.
Smart Images
Figure CN2025070626_25062026_PF_FP_ABST
Abstract
Description
A dumbbell plate, a dumbbell, and a method for processing the dumbbell plate. Technical Field
[0001] This invention belongs to the field of fitness equipment technology, specifically referring to a dumbbell plate, a dumbbell, and a method for processing the dumbbell. Background Technology
[0002] With the continuous improvement of people's living standards, the desire for fitness and health is also growing stronger, requiring the use of various fitness equipment. Fitness equipment is often categorized by the number of training functions, into two main types: single-function and multi-functional. Dumbbells, as a type of fitness equipment, are widely used. Currently, most dumbbells on the market are made of pure metal, with different weight specifications to meet different training requirements. Some products also allow for weight changes by replacing different dumbbell plates, thus meeting the actual needs of trainees. With the evolution of dumbbell products, and considering the actual needs of users, some dumbbells are now designed with soft materials or have a plastic or rubber layer covering cast iron dumbbells. This changes the external softness to avoid injury to the body or surrounding equipment during exercise. Furthermore, the internal filling can be replaced as needed to adapt to the unique needs of male or female exercisers.
[0003] For example, Chinese patent CN202310187472.1 discloses a soft dumbbell, which includes a dumbbell body and a handle. The handle has a rigid inner core, and a grip is provided around the rigid inner core. Large-diameter joints are provided at both ends of the grip. The dumbbell body is a hollow airbag structure with an injection hole on its outer wall. An end plug is inlaid in the injection hole, and an air nozzle module is located inside the center of the end plug. A through hole is provided in the fixing groove, which is connected to the through hole through the air nozzle module. The rigid inner core is thermoplastically coated to fit the grip, and anti-slip protrusions prevent the two from slipping after the combination. The dumbbell body is fed internally through the end plug, and the injection hole is sealed after feeding, achieving solid support. Furthermore, tapered tie rods are provided on both sides of the rigid inner core, extending into the dumbbell body. This effectively improves the internal horizontal axial strength of the dumbbell body while ensuring the flexibility of the outer periphery, preventing the dumbbell body from sagging and collapsing at both ends. This product offers relatively flexible dumbbells, providing a better user experience. Even if the dumbbells accidentally slip and fall onto the user's feet, they won't cause significant injury, and it also reduces the risk of damage to the ground. However, this product also has some drawbacks: the weight is factory-set, and users cannot adjust the weight; furthermore, the sagging on both sides cannot be prevented, only reduced, resulting in a less aesthetically pleasing product. Summary of the Invention
[0004] The purpose of this invention is to provide a dumbbell plate and dumbbell that are safe to use and have flexibility.
[0005] The objective of this invention is achieved as follows:
[0006] A dumbbell plate includes a flexible body with a through hole in the center and an injection channel on the side of the flexible body, connecting the inner cavity of the flexible body to the outside. A fixed plug can seal the injection channel and form a closed filling space. Filler can enter the filling space through the injection channel. The inner cavity of the flexible body can be inflated through the injection channel, keeping the filling space in an expanded state. The injection channel includes a positioning plug with a channel for installing the fixed plug in the center. The positioning plug is tightly connected to the flexible body to form a whole. The hardness of the positioning plug is greater than that of the flexible body, and the positioning plug is preferably made of a hard material.
[0007] Preferably, the flexible body is integrally formed with a skirt, which covers the outside of the positioning plug. The skirt has an opening or gap, allowing filler and gas to pass through the positioning plug and the skirt into the inner cavity of the flexible body.
[0008] Preferably, the fixing plug is a flexible component, and the side of the fixing plug is provided with an annular protrusion. The fixing plug enters the injection channel and is in a sealed state. The annular protrusion deforms and fits tightly against the inner wall of the injection channel.
[0009] Preferably, the inner side of the fixed plug is provided with a blind hole, which provides space for the fixed plug to deform inward. The annular convex edge deforms and forces the blind hole to shrink or partially close. The diameter of the annular convex edge is larger than that of the injection channel. When the fixed plug is pushed into the injection channel, the annular convex edge tilts in the direction of entry.
[0010] Preferably, the lower diameter of the annular protrusion is larger than the upper diameter of the annular protrusion.
[0011] Preferably, the flexible body is ring-shaped when inflated, and the outer surface of the flexible body is a continuous arc shape when inflated.
[0012] A dumbbell includes the aforementioned dumbbell plates and a dumbbell bar. The dumbbell bar has threaded sections at both ends, each threaded section can hold at least two dumbbell plates, and a stop block has an internal thread in the middle that mates with the threaded sections. The stop block is threadedly connected to the threaded sections and abuts against the rear of the dumbbell plates.
[0013] Preferably, in the inflated state, the inner diameter of the central through-hole of the dumbbell plate is larger than the maximum outer diameter of the threaded section; when the stop block is tightened, the dumbbell plate deforms laterally, the inner diameter of the central through-hole of the dumbbell plate decreases, and the dumbbell plate abuts against the outer surface of the threaded section. A stop plate is provided on the side of the threaded section of the dumbbell bar, and the dumbbell plate abuts against the stop plate.
[0014] A method for processing dumbbell plates, the dumbbell plate processing steps are as follows: First, a core is set in the middle of the slush mold, a positioning plug is fitted on the core, and thermoplastic material is placed in the slush mold and heat-melted together with the core to form a flexible body;
[0015] The second step is to remove the shaped flexible body. The temperature of the removed flexible body is greater than 50 degrees Celsius. After the flexible body is removed from the slush mold, the shaped plug is quickly inserted into the positioning plug.
[0016] The third step is to pry out the shaping plug after the flexible body has cooled down, and then use the filling machine to fill the flexible body with filler through the channel of the positioning plug.
[0017] The fourth step is to inflate the flexible body by using the positioning plug until it bulges; then push the fixing plug into the positioning plug; the fixing plug and the shaping plug have the same shape and material.
[0018] The shaped plug has a through hole in the middle.
[0019] Before injecting the filler, the injection channel is punctured through the injection site to ensure that the injection channel is unobstructed.
[0020] The outstanding and beneficial technical effects of this invention compared to the prior art are:
[0021] This invention uses a flexible body as the main part of the dumbbell plate. A filler is poured into the flexible body, and then inflated to form an elastic dumbbell plate. Preferably, the dumbbell plate is ring-shaped, allowing the user to either slip the plate onto a dumbbell bar or hold it for load training. Since the entire dumbbell plate is an inflatable flexible component, its safety is ensured. Even if the dumbbell plate falls on the user's body or feet from a height, it will not cause excessive injury. Users can choose one or more dumbbell plates for moderate training according to their needs, providing more training options.
[0022] The infusion channel of this invention consists of a tightly connected flexible body skirt and a positioning plug. The skirt covers the outer edge of the positioning plug, and the tight connection prevents air leakage between the positioning plug and the flexible body. The positioning plug is made of a rigid material, and the rigid material positioning plug can be directly sealed by a flexible fixing plug. The flexible fixing plug deforms within the positioning plug and seals the infusion channel. Preferably, the flexible body and the positioning plug are integrally molded using a slush molding process. The skirt of the flexible body may seal the channel where the positioning plug is located within the flexible body, affecting the entry of the filler into the flexible body and also affecting the inflation of the flexible body. Therefore, before injecting the filler, it is necessary to confirm the unobstructedness of the infusion channel by insertion, which can be achieved by puncturing the infusion channel through the injection nozzle.
[0023] In this invention, the inner diameter of the through hole in the middle of the dumbbell plate is larger than the outer diameter of the threaded section. Therefore, the user can easily put the dumbbell plate on the dumbbell bar. When the user tightens the stop block, the dumbbell plate deforms under the push of the stop block, and the inner diameter of the through hole in the middle of the dumbbell plate decreases, so that the dumbbell plate can be effectively placed on the dumbbell bar. The installed dumbbell plate does not wobble and the structure is stable.
[0024] After the slush molding process is completed, the hot flexible body is removed and the shaping plug is quickly inserted into the positioning plug. Then, the flexible body is allowed to cool down naturally. Under the action of thermal expansion and contraction, the positioning plug is shaped into the optimal state to match the shaping plug. This allows for the replacement of the fixed plug with the same material and shape. The shaping plug forms a channel for the pre-shaped positioning plug, which enables the fixed plug and positioning plug to achieve an effective seal. This ensures that the inflated dumbbell plate remains fully inflated for a long time without air or filler leakage. Attached Figure Description
[0025] Figure 1 is a schematic diagram of the dumbbell plate structure of the present invention;
[0026] Figure 2 is a schematic diagram of the internal structure of the dumbbell plate of the present invention;
[0027] Figure 3 is an enlarged structural diagram of point A in Figure 2;
[0028] Figure 4 is a schematic diagram of the structure of the fixed plug of the present invention;
[0029] Figure 5 is a schematic diagram of the internal structure of the fixed plug of the present invention;
[0030] Figure 6 is a schematic diagram of the dumbbell structure of the present invention;
[0031] Figure 7 is a schematic diagram of the internal structure of a dumbbell in the uncompressed state of the dumbbell plate of the present invention;
[0032] Figure 8 is an enlarged structural diagram of point B in Figure 7;
[0033] Figure 9 is a schematic diagram of the internal structure of a dumbbell in the compressed state of the dumbbell plate of the present invention;
[0034] Figure 10 is an enlarged structural diagram of point C in Figure 9.
[0035] In the diagram: 1-Flexible body; 1a-Filling space; 11-Through hole; 12-Skirt; 121-Gap; 13-Positioning plug;
[0036] 14-Injection channel; 19-Filling material; 2-Fixing plug; 21-Annular flange; 22-Blind hole; 3-Dumbbell bar;
[0037] 31-Baffle; 32-Threaded section; 4-Stop block; L-Gap between dumbbell plate and threaded section. Detailed Implementation
[0038] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, as shown in Figures 1-10:
[0039] A dumbbell plate includes a flexible body 1 with a through hole 11 in the center and an injection channel 14 on the side of the flexible body 1, connecting the inner cavity of the flexible body to the outside. A fixed plug 2 seals the injection channel 14, forming a closed filling space 1a. Filler 19 enters the filling space 1a through the injection channel 14. The dumbbell plate should not be completely filled with filler, as this would negate its flexibility; excessive filler could cause the flexible body to explode and break during de-inflation. The filler can be common weighting materials such as sand, iron filings, rubber, or liquids. Manufacturers can fill the flexible body 1 with different weights of filler 19 according to actual requirements, ensuring the filling space is not completely filled. The weight of a single dumbbell plate can be freely controlled within the range of 0.5-5 kg. The inner cavity of the flexible body 1 can be inflated through the injection channel 14, keeping the filling space in an expanded state. In the inflated state, the filler within the filling space can flow under gravity. Users can use the dumbbell plates individually or assemble them into dumbbells as described below. The specific exercise method is up to the user. The individual dumbbell plates are continuous, preferably ring-shaped, and the flexible body has a continuous arc shape when inflated, providing a good grip experience. The soft rubber material also provides a non-slip effect, ensuring a comfortable grip. Users can also thread the dumbbell plates onto elastic bands for weight training, with various specific exercise methods available.
[0040] The injection channel includes a positioning plug 13, which has a channel for installing a fixing plug in the middle. The positioning plug 13 is tightly connected to the flexible body 1 to form an integral unit. The hardness of the positioning plug 13 is greater than that of the flexible body 1. The positioning plug 13 is hard under normal conditions, so the flexible fixing plug 2 can seal the channel in the middle of the positioning plug. Preferably, the positioning plug 13 and the flexible body 1 are heat-fused into an integral unit during the manufacturing process. The flexible body is integrally formed with a skirt 12, which covers the outside of the positioning plug 13. The skirt 12 has an opening or gap 121, allowing filler and gas to pass through the positioning plug and the skirt into the inner cavity of the flexible body.
[0041] The fixed plug 2 is a flexible component. The side of the fixed plug 2 is provided with an annular protrusion 21. The fixed plug 2 enters the injection channel and is in a sealed state. The annular protrusion 21 deforms and fits tightly on the inner wall of the injection channel 14.
[0042] The inner side of the fixed plug 2 is provided with a blind hole 22, which provides space for the fixed plug to deform inward. The annular convex edge 21 deforms and forces the inner diameter of the blind hole 22 to decrease or partially close. As shown in Figure 3, the diameter of the annular convex edge is larger than that of the injection channel. When the fixed plug 2 is pushed into the injection channel 14, the annular convex edge 21 tilts in the direction of entry. The tilted annular convex edge has a better sealing effect and also prevents the fixed plug from falling out of the injection channel.
[0043] The lower diameter of the annular flange is larger than the upper diameter of the annular flange. The purpose of this structure is that when the fixed plug is inserted into the injection channel, the entire fixed plug enters the injection channel, and the upper diameter of the annular flange is smaller. The blind hole at this position will not be completely closed. Workers can insert a tool into the blind hole to pry out the plug and replace the fixed plug.
[0044] A dumbbell includes dumbbell plates and a dumbbell bar 3. Both ends of the dumbbell bar 3 are provided with threaded sections 32, each threaded section 32 capable of holding at least two dumbbell plates. A stop block 4 has an internal thread in its center that mates with the threaded sections 32. The stop block 4 is threadedly connected to the threaded sections 32 and abuts against the rear of the dumbbell plates. Users can place an appropriate number of dumbbell plates on the dumbbell bar according to their actual needs to achieve the desired training effect.
[0045] When inflated, the inner diameter of the central through-hole of the dumbbell plate is larger than the maximum outer diameter of the threaded section, as shown in Figure 8. When the dumbbell plate is not compressed, the gap between the dumbbell plates is L. By setting this gap, the user can easily install and remove the dumbbell plates. A baffle 31 is provided on the side of the threaded section of the dumbbell bar, and the dumbbell plates abut against the baffle 31. When a single dumbbell plate is mounted on a threaded rod and the stop block is tightened, the dumbbell plate is pressed between the stop block and the stop plate, and the dumbbell plate deforms. The inner diameter of the central through-hole of the dumbbell plate decreases, and the dumbbell plate abuts against the outer surface of the threaded section. Therefore, the flexible dumbbell plate is restricted on both sides and at the position of the through-hole, and the dumbbell plate is stably fixed and will not wobble. If two dumbbell plates are mounted on the threaded rod and the stop block is tightened, the two dumbbell plates are pressed between the stop block and the stop plate. The dumbbell plates squeeze against each other, and at the same time, the dumbbell plates deform, the inner diameter of the central through-hole of the dumbbell plate decreases, and the dumbbell plate abuts against the outer surface of the threaded section. The two sides and at the position of the through-hole of both dumbbell plates are restricted, and the dumbbell plates are stably fixed and will not wobble. Moreover, the dumbbell plates themselves are made of flexible material and have high frictional resistance, making the dumbbell structure stable when the stop block is tightened. Preferably, the baffle 31 can be integrally molded onto the dumbbell bar, or it can be a separate component, depending on the manufacturer's choice. The flexible body is preferably made of PVC, but other soft materials are also acceptable.
[0046] A method for processing dumbbell plates, comprising the following steps: First, a core is placed in the center of a slush mold, and a positioning plug is fitted onto the core. Thermoplastic material is placed in the slush mold and heat-melted together with the core to form a flexible body. The slush mold is not shown in the attached drawings. The slush mold is manufactured by an external mold manufacturer. We provide the required dimensions of the flexible body 1 to the external manufacturer, who then manufactures the product according to the actual dimensions. The core needs to be integrally formed in the slush mold, preferably located on the periphery of the mold.
[0047] The second step involves removing the shaped flexible body 1. The temperature of the removed flexible body should be above 50 degrees Celsius. After the flexible body is removed from the slush mold, the shaping plug is quickly inserted into the positioning plug 13. While the flexible body is still hot, the worker can easily insert the shaping plug into the positioning plug. After the flexible body cools, due to thermal expansion and contraction, the positioning plug is shaped to its optimal state for fitting the shaping plug. After physical contraction, the positioning plug achieves a tight fit with the shaping plug. When the shaping plug is not subjected to external force, its outer diameter is larger than the inner diameter of the positioning plug, and the shaping plug remains in a contracted deformation state when inserted into the positioning plug.
[0048] The third step involves prying out the shaped plug and using the filling machine to inject the filler into the flexible body 1 through the channel of the positioning plug. The filling machine is a non-standard machine and is outsourced equipment. This equipment is not a key point of protection in this application, therefore no attached diagram is provided. This equipment can be simply understood as a filling device with a weighing function. The worker puts the filler into the storage funnel. A filling needle is set at the bottom of the equipment. The filling needle can enter the filling channel. When the filling needle enters the filling channel, it can open the filling channel, so that the filler can enter the flexible body 1 through the discharge needle. The worker starts the switch of the filling equipment, and a certain amount of filler enters the flexible body.
[0049] The fourth step involves inflating the flexible body 1 using the positioning plug 13 until it bulges; then, the fixing plug 2 is pushed into the positioning plug 13. The fixing plug and the shaping plug have the same shape and material. Both inflation and filling utilize the channel of the positioning plug. Workers must carefully insert the positioning plug through the channel to avoid damaging its inner wall. Preferably, the outer wall of the positioning plug has a texture, which facilitates a tight connection between the positioning plug and the flexible body during the slush molding process; the internal channel of the positioning plug is also not smooth, increasing friction and promoting a tight fit between the positioning plug and the shaping plug.
[0050] The shaping plug has a through hole in the center. When the shaping plug is inserted, the entire flexible body remains at a high temperature. This through hole connects the interior of the flexible body to the outside, preventing internal expansion and uneven deformation during cooling, thus maintaining the ring shape. Alternatively, if the flexible body has a thick inner wall and is not easily deformed, the shaping plug may not have a through hole. Manufacturers decide whether to include a through hole based on their specific needs, but a shaping plug with a through hole is preferred.
[0051] The above embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.
Claims
1. A dumbbell plate characterized by: The system includes a flexible body (1), with a through hole in the middle and an injection channel (14) on the side of the flexible body (1). The injection channel connects the inner cavity of the flexible body to the outside. A fixed plug can seal the injection channel and form a closed filling space (1a). The filler (19) can enter the filling space (1a) through the injection channel (14). The system inflates the inner cavity of the flexible body (1) and keeps the filling space in an expanded state. The infusion channel (14) includes a positioning plug (13), which has a channel for installing a fixing plug (2) in the middle. The positioning plug (13) is tightly connected to the flexible body (1) to form an integral whole. The hardness of the positioning plug is greater than that of the flexible body (1).
2. The dumbbell plate of claim 1, wherein: The flexible body (1) is integrally formed with a skirt (12), which covers the outside of the positioning plug (13). The skirt (12) has an opening or gap (121) through which the filler (19) and gas can pass through the positioning plug (13) and the skirt (12) into the inner cavity of the flexible body (1).
3. The dumbbell according to claim 1 or 2, wherein: The fixed plug (2) is a flexible part. The side of the fixed plug (2) is provided with an annular protrusion (21). The fixed plug (2) enters the injection channel (14) and is in a sealed state. The annular protrusion (21) deforms and fits tightly on the inner wall of the injection channel (14).
4. The dumbbell plate of claim 3, wherein: The fixed plug (2) has a blind hole (22) on its inner side. The blind hole provides space for the fixed plug to deform inward. The annular convex edge deforms and forces the inner diameter of the blind hole to decrease or partially close. The diameter of the annular convex edge is larger than that of the injection channel. When the fixed plug is pushed into the injection channel, the annular convex edge tilts in the direction of entry.
5. The dumbbell piece of claim 1 or 2 or 4, wherein: The flexible body is ring-shaped when inflated, and its outer surface is a continuous arc shape when inflated.
6. A dumbbell characterized by: The dumbbell bar includes the dumbbell plates as described in any one of claims 1, 2 or 4, and also includes a dumbbell bar (3). The dumbbell bar (3) has threaded sections (32) at both ends, and each threaded section (32) can hold at least two dumbbell plates. The stop block (4) has an internal thread in the middle that mates with the threaded section, and the stop block (4) can be threadedly connected to the threaded section. The dumbbell bar has a stop plate (31) on the side of the threaded section, and the dumbbell plates abut against the stop plate (31) and the stop block (4).
7. The dumbbell of claim 6, wherein: When the dumbbell plate is in the inflated state, the inner diameter of the through hole in the middle of the dumbbell plate is greater than the maximum outer diameter of the threaded section; when the stop block (4) is tightened, the dumbbell plate deforms laterally, the inner diameter of the through hole in the middle of the dumbbell plate decreases, and the dumbbell plate abuts against the outer surface of the threaded section.
8. A method of manufacturing a dumbbell piece, characterized by: The dumbbell plate processing steps according to any one of claims 1, 2, 4 or 7 are as follows: First, a core is provided in the middle of the slush mold, and a positioning plug is fitted on the core. The thermoplastic material is placed in the slush mold and heat-melted together with the core to form a flexible body. The second step is to remove the shaped flexible body. The temperature of the removed flexible body is greater than 50 degrees Celsius. After the flexible body is removed from the slush mold, the shaped plug is quickly inserted into the positioning plug. The third step is to pry out the shaping plug after the flexible body has cooled down, and then use the filling machine to fill the flexible body with filler through the channel of the positioning plug. The fourth step is to inflate the flexible body by using the positioning plug until it bulges; then push the fixing plug into the positioning plug; the fixing plug and the shaping plug have the same shape and material.
9. The method of claim 8, wherein: The shaped plug has a through hole in the middle.
10. The method of claim 8, wherein: Before injecting the filler, the injection channel is punctured through the injection site to ensure that the injection channel is unobstructed.