Cam mechnism and weight-adjustable barbell

Abstract

A cam mechanism configured to hitch a weight plate includes a bearing layer, a first wear-resistant layer arranged on one side of the bearing layer, and a second wear-resistant layer arranged on another side of the bearing layer. The second wear-resistant layer is configured to reduce wear of the weight plate in response to the weight plate being in contact with the cam mechanism. A weight-adjustable barbell includes: a barbell rod assembly including two transmission shafts, a plurality of weight plates, and a plurality of the above cam mechanisms sleeved on the two transmission shafts and configured for hitching the plurality of weight plates.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This is a continuation of patent application Ser. No. 17 / 981,875 filed on Nov. 7, 2022, which claims priority benefits to Chinese Patent Application No. 2022112858770 filed on Oct. 20, 2022, the contents of which are both incorporated herein by reference.FIELD OF TECHNOLOGY

[0002] The present disclosure relates to the field of weightlifting equipment, and in particular to a cam mechanism and a weight-adjustable barbell.BACKGROUND

[0003] In weightlifting, the number of weight plates is often adjusted to adjust the load on a barbell, thereby meeting different training objectives. For training barbells, it is usually necessary to manually add or remove weight plates. Tt is inconvenient as it requires repeatedly assembling and disassembling the weight plates manually to increase or decrease the weight. During barbell training, the weight plates are usually disassembled frequently and repeatedly. Friction between two adjacent weight plates can cause wear, and safety problems may occur during use, mounting or disassembling of the weight plates. Furthermore, since the weight plates on the barbell are often used and replaced, the wear between the weight plates may lead to risks of unstable mounting or even cause plates to fall off. In addition, the weight plates of the barbell are centrally placed. It is necessary to carry and mount the weight plates. In the mounting process, there is a risk of the weight plates falling, which may injury people or damage the floor, making the weight adjusting process inconvenient. Moreover, due to the large size of the barbell, placing it will occupy considerable space, resulting in storage difficulties.SUMMARY

[0004] The first aspect of the present disclosure provides a cam mechanism configured for hitching a weight plate. The cam mechanism includes a bearing layer, a first wear-resistant layer arranged on one side of the bearing layer, and a second wear-resistant layer arranged on another side of the bearing layer. The second wear-resistant layer is configured to reduce wear of the weight plate in response to the weight plate being in contact with the cam mechanism.

[0005] The second aspect of the present disclosure provides a weight-adjustable barbell, which includes: a barbell rod assembly including two transmission shafts, a plurality of weight plates, and a plurality of the above cam mechanisms sleeved on the two transmission shafts and configured for hitching the plurality of weight plates.BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The drawings of the specification that constitutes a part of the present application are configured to provide a further understanding of the present disclosure. The exemplary embodiments of the present disclosure and the description thereof are configured to explain the present disclosure, and do not constitute an improper limitation of the present disclosure.

[0007] FIG. 1 is a perspective view of an embodiment.

[0008] FIG. 2 is an exploded perspective view of one side of a barbell rod assembly according to an embodiment.

[0009] FIG. 3 is a perspective view of a weight plate according to an embodiment.

[0010] FIG. 4 is a perspective view of a rear side of a cam mechanism according to an embodiment.

[0011] FIG. 5 is a perspective view respectively showing a front side and a rear side of a cam mechanism according to an embodiment.

[0012] FIG. 6 is a perspective view of a cam mechanism and a weight plate in a hitching state and a non-hitching state according to an embodiment.

[0013] FIG. 7 is a perspective view of two cam mechanisms mounted together according to an embodiment.

[0014] FIG. 8 is a perspective view of a weight plate hitched between two cam mechanisms according to an embodiment.

[0015] FIG. 9 is a perspective view of an adjusting wheel disc and a first bearing fixing base according to an embodiment.

[0016] FIG. 10 is an exploded view of a folding base according to an embodiment.

[0017] FIG. 11 is a plan view showing gear adjustment of six cam mechanisms on a single side of a barbell according to an embodiment.DETAILED DESCRIPTION OF THE EMBODIMENTS

[0018] The present disclosure is described in detail below with reference to the accompanying drawings and embodiments. Each example is provided to explain the present disclosure instead of limiting the present disclosure. In fact, those skilled in the art will appreciate that modifications and variations may be made in the present disclosure without departing from the scope or spirit of the present disclosure. For example, features shown or described as one part of one embodiment may be applied to another embodiment to generate yet another embodiment. Therefore, it is expected that the present disclosure includes such modifications and variations that fall within the scope of the appended claims and their equivalents.

[0019] In the description of the present disclosure, orientation or position relationships indicated by terms “longitudinal”, “transverse”, “upper”, “lower”, “front”, “rear”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom” and the like are orientation or position relationships shown in the drawings, and these terms are merely for facilitating description of the present disclosure, but not for requiring that the present disclosure must be constructed and operated in a specific orientation, and thus, these terms cannot be understood as a limitation to the present disclosure. As used in the present disclosure, the terms “connected”, “connection” and “set” should be understood in a broad sense, for example, they may be fixed connection or detachable connection, they may be direct connection or indirect connection through an intermediate part; or they may be wired connection and wireless connection, or may be connection through a wireless communication signal. For those of ordinary skill in the art, the specific meanings of the terms may be understood according to the specific conditions.

[0020] The accompanying drawings show one or more examples of the present disclosure. The detailed description uses reference numerals and letters to refer to the features in the accompanying drawings. Similar numeral references in the drawings and description have been configured to refer to the similar parts in the present disclosure. As used herein, the terms “first”, “second” and “third” are used interchangeably to distinguish one component from another component, and are not intended to indicate the position or importance of individual components.Embodiment 1

[0021] According to FIG. 1 to FIG. 10, according to the embodiments of the present disclosure, a weight-adjustable barbell is provided. The weight-adjustable barbell includes a barbell rod assembly 1, and six pairs of weight plates 2 able to be hitched on two sides of the barbell rod assembly. Each of two ends of the barbell rod assembly 1 include a transmission shaft 11. Six cam mechanisms 12 are sequentially sleeved on each of the transmission shafts 11 and are configured to be hitched with the weight plates 2. Specifically, a shaft section, on which the cam mechanisms 12 are mounted, of each transmission shaft 11 has a polygonal cross section; the center of each cam mechanism 12 has a mounting hole 128; the cross section of the mounting hole 128 is matched with the cross section of the shafting section of the corresponding transmission shaft 11. The polygonal structures can limit rotation between the transmission shafts 11 and the cam mechanisms 12. Each cam mechanism 12 is provided with at least one pair of hitching parts 120 and at least one pair of avoidance parts 121. Each pair of hitching parts 120 are symmetrically arranged about the center of the corresponding cam mechanism 12. Each pair of avoidance parts 121 are symmetrically arranged about the center of the corresponding cam mechanism 12. When the hitching parts 120 and the weight plates 2 are hitched, the weight plates are hitched on the transmission shafts 11 through the cam mechanisms 12. Each pair of cam mechanisms 12 has several hitching parts 120 and avoidance parts 121 with different angles. When different cam mechanisms 12 are sequentially sleeved on the transmission shafts 11, different numbers of weight plates 2 can be hitched by rotating at different angles, thereby realizing weight adjustment.

[0022] Each cam mechanism 12 includes a bearing layer 122. The bearing layer 122 is made of a galvanized iron plate. Each cam mechanism 12 is configured to be hitched with one weight plate 2. A wear-resistant layer 123 is respectively arranged on each of two sides of each bearing layer 122. The wear-resistant layers 123 are made of plastic. When friction occurs between the wear-resistant layers 123 and the weight plates 2, the surfaces of the weight plates 2 are not damaged. A connecting neck 125 is fixedly connected to or integrally formed at a center position of the wear-resistant layer 123 on one side of each bearing layer 122. A polygonal connecting protrusion 126 is arranged at a free end of each connecting neck 125. A connecting groove 127 with a shape and a size matched with those of the connecting protrusion 126 is formed in the wear-resistant layer 123 on the other side of each bearing layer 122. The connecting protrusion 126 at the free end of the connecting neck 125 of one cam mechanism 12 is connected to the connecting groove 127 of the other cam mechanism 12. The two adjacent cam mechanisms 12 are separated by the connecting neck 125 to form a mounting space for mounting a corresponding weight plate 2.

[0023] Each cam mechanism 12 defines an inner cavity 129 along an axial direction of the cam mechanism 12. The inner cavity 129 includes the mounting hole 128 and the connecting groove 127 in communication with each other. A cross section of the connecting groove 127 is greater than a cross section of the mounting hole 128 to allow a step surface 130 to be formed between the connecting groove 127 and the mounting hole 128. The two wear-resistant layers 123 on each of two sides of each cam mechanism 12 can be named as a first wear-resistant layer and a second wear-resistant layer. The first wear-resistant layer is arranged on one side of the bearing layer 122 of each cam mechanism 12. The second wear-resistant layer is arranged on another side of the bearing layer 122 of each cam mechanism 12. Each connecting neck 125 includes the free end and a connecting end, the connecting end is connected to the outer surface of a corresponding second wear-resistant layer. Each inner cavity 129 runs through middle portions of the correspondingly bearing layer 122, the correspondingly first wear-resistant layer, the correspondingly second wear-resistant layer, the correspondingly connecting neck 125, and the correspondingly connecting protrusion 126. The shape of each connecting protrusion 126 is the same as the shape of the corresponding connecting groove 127, and the size of each connecting protrusion 126 is not greater than the size of the corresponding connecting groove 127. The thickness of each bearing layer 122 is greater than the thickness of each first wear-resistant layer, and the thickness of each bearing layer is greater than the thickness of each second wear-resistant layer. The connecting neck 125 includes a cylindric outer wall. The outer surface of the connecting protrusion 126 does not go beyond a side surface of the outer wall of the connecting neck 125. The cross-section of the outer wall the connecting protrusion 126 is polygonal, and the cross-section of the inner wall of the connecting groove 127 is also polygonal. Each cam mechanism 12 further defines at least one through hole 140 at a side of the inner cavity 129.

[0024] A notch 21 for the connecting neck 125 to enter is formed in the middle of each weight plate 2. A cam groove 22 that is arranged on the surface of one side of each weight plate 2 and located on the outer side of the notch 21 and has an upper opening is configured to accommodate a corresponding cam mechanism 12 and realize hitching between the corresponding cam mechanism 12 and a corresponding weight plate 2. The cross section of each cam groove 22 has a partial circle structure larger than a one-half circle, and the size of the avoidance part 121 of each cam mechanism 12 is less than the size of the opening of each cam groove 22. When each avoidance part 121 is located at the opening of the corresponding cam groove 22 and the corresponding cam mechanism 12 is lifted upwards, the corresponding cam mechanism 12 is unhitched with the corresponding weight plate 2. A maximum width of each pair of hitching parts 120 of each cam mechanism 12 is greater than a minimum width of the opening of a corresponding cam groove 22. When a pair of hitching parts 120 are located at the opening of the corresponding cam groove 22 and the corresponding cam mechanism 12 is lifted upwards, the corresponding cam mechanism 12 is hitched with a corresponding weight plate 2. A plurality of protrusions 124 are arranged on an outer surface of the wear-resistant layer 123 on one side, on which the connecting neck 125 is arranged, of each cam mechanism 12. When the connecting neck 125 of each cam mechanism 12 enters the corresponding weight plate 2 from the notch 21, the protrusions 124 are in contact with the interior of the corresponding cam groove 22 and configured to reduce friction between the corresponding bearing layer 122 and the corresponding weight plate 2. In this embodiment, the protrusions 124 are convex points, but are not limited to the convex-point structures, and may also have a structure capable of protruding out of the outer surface of each wear-resistant layer 123, such as a convex strip and a convex ring. The depth of each cam groove 22 is less than the sum of the thickness of the bearing layer 122 of the corresponding cam mechanism 12 and the thickness of the two wear-resistant layers 123 on the two sides of the corresponding bearing layer. When each cam mechanism 12 is located in the corresponding cam groove 22, one side, on which the protrusion 124 is not arranged, of the corresponding cam mechanism 12 protrudes beyond the corresponding cam groove 22, thereby reducing friction between two corresponding weight plates 2.

[0025] After six cam mechanisms 12 are respectively sleeved on the transmission shaft 11 on each side, a first bearing fixing base 13 and a second shaft fixing base 14 are respectively arranged on each of two end parts of the transmission shaft 11. Each first bearing fixing base 13 and each second bearing fixing base 14 are respectively mounted on the corresponding transmission shaft 11 through a bearing. Each transmission shaft 11 may rotate relative to the corresponding first bearing fixing base 13 and the corresponding second bearing fixing base 14. An adjusting wheel disc 15 is arranged on an inner side of each first bearing fixing base. Each adjusting wheel disc 15 is sleeved on the corresponding transmission shaft 11 in a non-rotatable manner. Seven limiting grooves 151 are arranged on the edge of each adjusting wheel disc 15 uniformly at equal angles. Correspondingly, an adjusting block sliding groove 131 is formed at the top of each first bearing fixing base 13. A first spring 132 is mounted in each adjusting block sliding groove 131. An upper part of each first spring 132 abuts against a corresponding adjusting block 133 for being in clamping connection with a corresponding limiting groove 151. When an end part of each adjusting block 133 is pressed and a corresponding adjusting block 133 presses a corresponding first spring 132 tightly, the corresponding adjusting block 133 relieves clamping connection with a corresponding limiting groove 151, and the corresponding adjusting wheel disc 15 may rotate relative to the corresponding first bearing fixing base 13, that is, the corresponding transmission shaft 11 may rotate relative to the corresponding first bearing fixing base 13 for weight adjustment. When each adjusting block 133 is loosened, each adjusting block 133 moves upwards under the action of the corresponding first spring 132, and the corresponding adjusting block 133 is in clamping connection with the corresponding limiting groove 151; and at this time, the corresponding transmission shaft 11 cannot rotate relative to the corresponding first bearing fixing base 13, that is, weight adjustment cannot be performed. This effectively avoids falling of the weight plates 2 caused by relative rotation of the transmission shafts 11 during use. Two ball placing holes 134 are formed on the inner side of the first bearing fixing base 13. A spring 135 is mounted in each of the ball placing holes 134. An outer side of each of the second springs 135 abuts against a corresponding balls 136. Correspondingly, seven positioning holes 152 are formed in each adjusting wheel disc 15 at equal angles along a circumferential direction and respectively correspond seven adjusting gears of each adjusting wheel disc 15. The two ball placing holes 134 are opposite to two of the positioning holes 152. When each gear is rotated, the two balls 136 are respectively located in two positioning holes 152, and at this time, there will be a limiting sound from the balls, thereby facilitating a user to confirm that a gear has been adjusted.

[0026] A handwheel disc 16 is arranged on an outer side of each second bearing fixing base 14. Each handwheel disc 16 is sleeved on the corresponding transmission shaft 11 in a non-rotatable manner, the corresponding transmission shaft 11 can be rotated synchronously when each handwheel disc 16 is rotated, and the mass can be adjusted by rotating each handwheel 16. The outer circumference of each handwheel disc 16 is provided with seven weight scales that respectively correspond to seven gears of the corresponding adjusting wheel disc 15. Correspondingly, an outer circumferential surface of each second bearing fixing base 14 is provided with weight displaying holes. When the weight scales on each handwheel disc 16 are opposite to the weight displaying holes, the weight of the barbell at this time can be displayed. Upper end parts of each first bearing fixing base 13 and the corresponding second bearing fixing base 14 are fixedly connected through a bridge block 17, thereby ensuring the position synchronization of each first bearing fixing base 13 and the corresponding second bearing fixing base 14. Two sides of the barbell rod assembly 1 have symmetrical structures, a handle 18 is fixedly connected between the transmission shafts 11 on the two sides in a non-rotatable manner, and the transmission shafts 11 on the two sides of the barbell rod assembly 1 are fixedly connected, thereby realizing synchronous rotation of the transmission shafts 11 on the two sides. The handle 18 includes a straight handle and a bending handle, thereby achieving the training purposes of different users or at different use stages.Embodiment 2

[0027] A manufacturing method of a weight-adjustable barbell includes the following specific steps.

[0028] S1: the number of gears is set as N, and the rotating angle at each gear is set as α=(360 / N) °.

[0029] S2: the number of cam mechanisms 12 is set as (7−1)*2=12, and the number of the cam mechanisms 12 on a single side of the barbell is 6, and a diameter of each of the cam mechanisms 12 is as same as a size of a cam groove 22 on a weight plate 2.

[0030] S3: an opening is formed in an upper part of the cam groove 22 on the surface of each of the weight plate 2.

[0031] S4: all the cam mechanisms 12 are divided into two groups, namely a group L and a group R, the two groups of cam mechanisms 12 are numbered L1, L2 . . . , L5 . . . . L6, and R1, R2 . . . , R5 . . . , R6 sequentially from one side away from a handle 18 to a side facing the handle 18, and a mounting direction is marked on each of the cam mechanisms 12.

[0032] S5: one pair of cam mechanisms 12 closest to a handle 18 is set as a first cam mechanism group, the cam mechanism 12 with the serial number L6 facing one side of the handle 18 in the L group of mechanisms 12 is taken as the first cam mechanism 12, two parts of cam sheets of the first cam mechanism 12 are cut to form a pair of avoidance parts 121, one pair of avoidance parts 121 are symmetrically arranged about a center point of each cam mechanism 12, a maximum width of the two avoidance parts 121 is less than a minimum width of the opening of each cam groove 22, and a central angle corresponding to each avoidance part 121 on a single side is (360 / 7) °.

[0033] S6: each of the cam mechanisms 12 on each side of the barbell is sequentially rotated by (360 / 7°) based on the previous cam mechanism 12, a pair of avoidance parts 121 with a central angle being (360 / 7°) are additionally arranged, and on the barbell on a single side: a pair of avoidance parts 121 with a central angle being (360 / 7°) are arranged on the first cam mechanism 12; two pairs of avoidance parts 121 with a central angle being (360 / 7°) are arranged on a second cam mechanism 12; . . . six pairs of avoidance parts 121 with a central angle being (360 / 7°) are arranged on a sixth cam mechanism 12.

[0034] S7: the two groups of cam mechanisms 12 are sleeved on the transmission shafts 11 on left and right sides of the barbell in a non-rotatable manner sequentially according to the marked mounting direction.

[0035] S8: each cam mechanism 12 is inserted into a corresponding cam groove 22 of a corresponding weight plate 2 along an opening of the corresponding cam groove 22, the transmission shafts 11 on the two sides of the handle 18 are rotated synchronously to rotate each of the cam mechanisms 12, (N−1) weight plates 2 are respectively hitched on the two sides of the barbell when the cam mechanisms are rotated to the Nth gear. For example, when a first gear is in the initial state, the weight at this time is the weight of the barbell rod assembly 1, and one wight plate 2 is respectively hitched on the two sides of the barbell when the cam mechanism is rotated to a second gear.

[0036] Further, in S4, the cam mechanisms 12 may also be numbered from one side close to the handle 18 to one side away from the handle 18; in S5, one cam mechanism 12 on one side farthest away from the handle 18 may be taken as the first cam mechanism, cutting is performed sequentially towards a direction close to the handle 18; and the difference between the two steps only lies in the sequence direction of sequentially hitching the weight plates 2, and the setting method is completely the same.

[0037] As shown in FIG. 11 which is a plan view of a rotating state of a cam mechanism on one side of a barbell rod assembly 1 in a cam groove 22, L1 to L6 are respectively the serial number of each cam mechanism 12 from one side away from the handle 18 to one side close to the handle 18, and the columns D1 to D7 respectively represent the rotating state of each cam mechanism 12 in the cam groove 22. In this embodiment, the number of the barbell adjusting gears is set to be 7, and the number of the cam mechanisms 12 arranged on one side of the barbell rod assembly 1 is 6. As shown in the figure, the column D1 is the state where each cam mechanism 12 is initially mounted on the barbell rod assembly 1, and the weight plate is not hitched on each cam mechanism 12 at this time. When the barbell rod assembly is rotated to the second gear, the cam mechanism with the serial number L6 is hitched with the weight plate, others are not hitched, and the total weight of the barbell is the weight of the barbell rod assembly at this time. From the second column to the seventh column, when the cam mechanism 12 on the barbell rod assembly is sequentially rotated by adding one gear, one cam mechanism 12 is added to be hitched with the weight plate. As shown in the column D3 which is the matching situation in the third-gear state, the cam mechanisms 12 with the serial numbers being L6 and L5 are respectively hitched with the weight plates.Embodiment 3

[0038] As shown in FIG. 1 and FIG. 10, the present disclosure further discloses a folding base 3 for storing weight plates 2. The folding base 3 includes two fixed frames 31, a connecting plate 32 is arranged between the two fixed frames 31. Each of two ends of the connecting plate 32 is arranged with a rotating shaft 33 configured to hinge with an end part of each of the two fixed frames 31. The two fixed frames 31 may respectively rotate around the corresponding rotating shafts 33, and the folding base 3 is in a folded state when the two fixed frames 31 respectively rotate by 90°

[0039] The top of the other end of each of the two fixed frames 31 is respectively fixedly connected to a fixed plate 34, a bottom support 35 for placing the weight plates 2 is fixedly connected above each fixed plates 34. Limiting baffles are arranged in each of the bottom supports 35 and configured to place the weight plates 2 separately, so that the weight plates 2 are mounted on the barbell rod assembly 1 conveniently.

[0040] Each of the fixed frames 31 includes a straight rod and a bending rod, one end of each straight rod and one end of each bending rod are respectively fixed below a corresponding fixed plate 34. The other end of each bending rod is bent towards the other end of a corresponding straight rod, then is merged in parallel, and is hinged with the connecting plate 32 through a corresponding rotating shaft 33 at a corresponding end part. Bending sides of bending rods of the fixed frames 31 on two sides of the folding base 3 are mounted oppositely, and a concave area is formed between the two bending rods, so that it is convenient for a user to stand when grabbing or putting down the barbell.

[0041] Several supporting pads 36 are arranged below the folding base 3 and are respectively connected to the lower surfaces of two ends of the straight rods and the bending rods of the two fixed frames 31. When the folding base 3 is unfolded and placed on the ground, the folding base 3 may be leveled by adjusting the height of the corresponding supporting pad 36. During use, it is only necessary to unfold and flatly place the two fixed frames 31 and then adjust the flatly place the supporting pads 36; and during folding and storage, it is only necessary to fold the two fixed frames 31 for storage, thereby reducing the occupied space.

[0042] From the above description, it can be seen that the above embodiments of the present disclosure achieve the following technical effects:

[0043] 1. A plurality of cam mechanisms 12 are arranged on two sides of the barbell rod assembly 1, each of the plurality of cam mechanisms 12 is respectively provided with hitching parts and avoidance parts with different angles, a cam groove 22 matched with a corresponding cam mechanisms 12 is formed in the surface of each of the weight plates 2, the transmission shafts on two sides of the barbell rod assembly rotate synchronously, the corresponding cam mechanisms 12 hitch the weight plates 2 when the transmission shafts on the two sides rotate synchronously at a certain angle, and different numbers of weight plates 2 can be hitched by rotating different angles. This allows for adjusting weight by rotating the transmission shafts 11 and facilitates use.

[0044] 2. Rotating control of the transmission shafts 11 is realized by limiting and fixing the limiting grooves 151 of the adjusting wheel discs 15 on the transmission shafts 11, and the adjusting blocks 133 and the first springs 132 on the first bearing fixing bases 13. That is, the transmission shafts 11 can be allowed to be rotated only when the adjusting blocks 133 are pressed, thereby avoiding falling of the weight plates 2 due to rotation of the transmission shafts 11 during use.

[0045] 3. One wear-resistant layers 123 is respectively arranged on each of two sides of the bearing layer 122 of each cam mechanism 12, thereby reducing wear of the weight plates 2 when the weight plates 2 are in contact with the cam mechanisms 12 and avoiding the phenomena of inaccurate weight and unstable fixation of the weight plates 2 due to wear.

[0046] 4. Several protrusions 124 are arranged on the outer surface of the wear-resistance layer 123 on one side, on which the connecting neck 125 is arranged, of each cam mechanism 12, and are configured to reduce friction between each cam mechanism 12 and the corresponding weight plate 2.

[0047] 5. The depth of each cam groove 22 is less than the sum of the thickness of the bearing layer 122 of the corresponding cam mechanism 12 and the thickness of the wear-resistant layers 123 on the two sides of the corresponding bearing layer 122. When each cam mechanism 12 is located in the corresponding cam groove 22, friction between two of the weight plates can be reduced.

[0048] According to the manufacturing method of the barbell provided by the present disclosure, different numbers of avoidance parts are arranged on different cam mechanisms, the barbell rod assemblies are sequentially mounted on the cam mechanisms, and the weight gear of the barbell is adjusted through synchronous rotation of the cam mechanisms, thereby facilitating adjustment.

[0049] Compared with the related art, the folding base disclosed by the present disclosure is more convenient to store, and the length after folding is only half of the original length, so that storage is facilitated. The folding mode is simple, and the operation from opening to folding is very convenient.

[0050] Compared with the related art, the weight-adjustable barbell provided by the present disclosure is more convenient in a barbell weight adjusting mode and is more stable and safer in the adjusting process.

[0051] The above is merely illustrative of the preferred embodiments of the present disclosure and is not intended to limit the present disclosure, and various changes and modifications may be made by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and scope of the present disclosure should be included within the protection scope of the present disclosure.

Claims

1. A cam mechanism configured to hitch a weight plate, the cam mechanism comprising:a bearing layer;a first wear-resistant layer arranged on one side of the bearing layer; anda second wear-resistant layer arranged on another side of the bearing layer;wherein the second wear-resistant layer is configured to reduce wear of the weight plate in response to the weight plate being in contact with the cam mechanism.

2. The cam mechanism according to claim 1, wherein the cam mechanism further comprises:a connecting neck configured to hitch the weight plate, the connecting neck comprising a connecting end and a free end, the connecting end being connected to an outer surface of the second wear-resistant layer; anda connecting protrusion arranged at the free end of the connecting neck.

3. The cam mechanism according to claim 2, wherein the connecting neck is integrally formed at the outer surface of the second wear-resistant layer.

4. The cam mechanism according to claim 2, wherein the connecting neck comprises an outer wall, and the outer wall is cylindrical.

5. The cam mechanism according to claim 4, wherein an outer surface of the connecting protrusion does not go beyond a side surface of the outer wall of the connecting neck.

6. The cam mechanism according to claim 2, wherein the cam mechanism defines an inner cavity along an axial direction of the cam mechanism, the inner cavity comprises a mounting hole and a connecting groove in communication with each other, a cross section of the connecting groove is greater than a cross section of the mounting hole to allow a step surface being formed between the connecting groove and the mounting hole;the inner cavity runs through middle portions of the bearing layer, the first wear-resistant layer, the second wear-resistant layer, the connecting neck, and the connecting protrusion; anda size of the connecting protrusion is not greater than a size of the connecting groove.

7. The cam mechanism according to claim 6, wherein a cross-section of an inner wall of the mounting hole is polygonal.

8. The cam mechanism according to claim 6, wherein a shape of the connecting protrusion is the same as a shape of the connecting groove.

9. The cam mechanism according to claim 8, wherein a cross-section of an outer wall of the connecting protrusion is polygonal, and a cross-section of an inner wall of the connecting groove also polygonal.

10. The cam mechanism according to claim 1, wherein a thickness of the bearing layer is greater than a thickness of the first wear-resistant layer, and the thickness of the bearing layer is greater than a thickness of the second wear-resistant layer.

11. The cam mechanism according to claim 1, wherein a plurality of protrusions are arranged on an outer surface of the second wear-resistance layer.

12. The cam mechanism according to claim 1, wherein the cam mechanism defines at least one pair of hitching parts and at least one pair of avoidance parts;the at least one pair of hitching parts are symmetrically arranged about a center point the cam mechanism; andthe at least one pair of avoidance parts are symmetrically arranged about the center point of the cam mechanism.

13. The cam mechanism according to claim 1, wherein the bearing layer comprises a galvanized iron plate.

14. The cam mechanism according to claim 1, wherein the first wear-resistant layer and the second wear-resistant layer are made of plastic.

15. The cam mechanism according to claim 1, wherein the cam mechanism further defines at least one through hole at a side of the inner cavity.

16. A weight-adjustable barbell, comprising:a barbell rod assembly comprising two transmission shafts;a plurality of weight plates;a plurality of cam mechanisms sleeved on the two transmission shafts and configured for hitching the plurality of weight plates, each of the plurality of cam mechanisms comprising:a bearing layer,a first wear-resistant layer arranged on one side of the bearing layer,a second wear-resistant layer arranged on another side of the bearing layer,wherein the first wear-resistant layers and the second wear-resistant layers of the plurality of cam mechanisms are configured to reduce wear of the plurality of weight plates in response to the plurality of weight plates being in contact with the plurality of cam mechanisms.

Images