Chain sprocket crank for bicycles

Abstract

The utility model provides a chain wheel crank for bicycle relates to bicycle accessory technical field, including the chain wheel spare for connecting the frame, the chain wheel spare is installed with detachable crank spare one side away from the frame, the crank spare one side away from the chain wheel spare is rotatably connected with the pedal spare, the pedal spare includes pedal body, and the pedal body one side is open and forms the storage cavity, compared with the prior art, the utility model discloses the setting realizes palm fixed function through rubber band, elastic rope and locking piece, when the specific operation, the user pulls rubber band and makes it from the storage cavity to stretch out, elastic rope is stretched and is fixed by locking piece when this time, after the palm of the rider inserts the clearance between pedal body and rubber band, loosens rubber band, and the retraction of elastic rope will drive rubber band reset, thereby clamping palm completes locking, reduces the equipment purchase cost and the later period maintenance cost, and the convenience of use has been improved simultaneously.

Description

Technical Field

[0001] This utility model relates to the field of bicycle parts technology, and in particular to a bicycle chain crank. Background Technology

[0002] As one of the most important means of transportation in human history, the bicycle has undergone significant technological changes since its invention in the early 19th century, evolving from wooden structures to metal alloys and then to composite materials. Modern bicycles have formed a complete industrial system, covering multiple sub-sectors such as commuting, sports, and racing. Its core transmission system consists of components such as sprockets, cranks, chains, and freewheels. Among these, the sprocket-crank assembly, as the central hub of power transmission, directly determines riding efficiency and comfort. In traditional bicycle components, the sprocket (also called the chainring) typically consists of multiple gears fixed to the crank arm and connected to the rear freewheel via the chain to achieve gear shifting. The crank assembly, including the left and right crank arms, spindle, and pedals, is a key component for power transmission. However, existing sprocket-crank systems have certain drawbacks: when using these systems, especially during high-frequency pedaling, the rider's foot is prone to slipping between the pedals, reducing pedaling frequency and bicycle speed. Current systems rely on specialized clipless shoes and locking pedals to lock the rider's foot, resulting in higher initial and maintenance costs. Utility Model Content

[0003] To address the shortcomings of the existing technology, this utility model proposes a sprocket crank for bicycles.

[0004] The technical solution of this utility model is implemented as follows: A bicycle sprocket crank includes a sprocket assembly for connecting to a frame. A detachable crank assembly is mounted on the side of the sprocket assembly away from the frame. A pedal assembly is rotatably connected to the side of the crank assembly away from the sprocket assembly. The pedal assembly includes a pedal body. One side of the pedal body is open to form a storage cavity, and the other side forms two through holes communicating with the storage cavity. A movable rubber band is installed inside the storage cavity. Two elastic cords are symmetrically mounted on one side of the rubber band. The free ends of the two elastic cords pass through the through holes. A detachable limiting member is mounted on the free ends of the elastic cords. The through holes are located between the limiting member and the rubber band.

[0005] Preferably, the limiting member includes two symmetrically arranged side plates, two arc-shaped tubes are symmetrically rotatably connected between the two side plates, and a detachable screw ring is screwed between the two arc-shaped tubes.

[0006] Preferably, the inner walls of both arc-shaped tubes are fixedly connected with limiting rods, and the free ends of the limiting rods protrude outward to form sharp protrusions.

[0007] Preferably, the crank assembly includes a crank body, one end of which is fixedly connected to a first connector and the other end of which is fixedly connected to a second connector.

[0008] Preferably, the sprocket component includes a sprocket body, one side of which is recessed to form a connecting groove, and one side of the second connector is protruding and fixedly connected to a connecting pipe, the connecting pipe being detachably connected to the connecting groove.

[0009] Preferably, the surface of the foot pedal body is coated with a reflective coating, which makes the device easier to observe and improves the device's visibility at night.

[0010] Compared with the prior art, the present invention has the following beneficial effects: 1. This utility model achieves foot fixation through the design of a rubber band, elastic cord, and locking mechanism. In operation, the user pulls the rubber band to extend it from the storage cavity. At this time, the elastic cord is stretched and fixed by the locking mechanism. When the rider's foot is inserted into the gap between the pedal body and the rubber band, the rubber band is released. The recoil force of the elastic cord will drive the rubber band to return to its original position, thereby clamping the foot and locking it. This avoids the need for traditional cycling shoes to be used with dedicated pedals, reduces equipment purchase costs and subsequent maintenance costs, and improves ease of use.

[0011] 2. This utility model simplifies the maintenance process of the elastic rope by setting up side plates, arc-shaped tubes and screw rings. When in use, the free end of the elastic rope is passed through the through hole and placed between the two arc-shaped tubes. The arc-shaped tubes are clamped by screwing in the screw rings. When the elastic rope or rubber plate needs to be replaced, the components can be disassembled simply by unscrewing the screw rings, which reduces the difficulty and cost of maintenance and further enhances the practicality of the device.

[0012] 3. This utility model, through the setting of the limiting rod and the sharp protrusion, when the elastic rope is placed between two arc-shaped tubes and fixed by the screw ring, the arc-shaped tube will simultaneously drive the limiting rod to insert into the elastic rope, thereby limiting and fixing the elastic rope, making the connection between the elastic rope and the arc-shaped tube more secure, avoiding accidental separation between the arc-shaped tube and the elastic rope, making the elastic rope and rubber band clamp the person's foot more stable, and further improving the stability of the device during use. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1This is one of the perspective views of this utility model; Figure 2 This is a second perspective view of the present invention; Figure 3 This is a perspective view of the sprocket component of this utility model; Figure 4 This is one of the perspective views of the crank component of this utility model; Figure 5 This is the second perspective view of the crank component of this utility model; Figure 6 This is one of the perspective views of the foot pedal component of this utility model; Figure 7 This is the second perspective view of the foot pedal component of this utility model; Figure 8 This is a perspective view of the limiting component of this utility model; Figure 9 This is a perspective view of the limiting component of this utility model after it has been unfolded. In the diagram: 1. Foot pedal; 11. Foot pedal body; 12. Rubber belt; 13. Elastic rope; 14. Storage cavity; 15. Limiting component; 151. Side plate; 152. Arc-shaped tube; 153. Limiting rod; 154. Threaded ring; 16. Through hole; 17. Reflective coating; 2. Crank assembly; 21. Crank body; 22. First connector; 23. Second connector; 24. Connecting tube; 3. Sprocket assembly; 31. Sprocket body; 32. Connecting groove. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0016] like Figures 1-9 As shown, the present invention provides a bicycle sprocket crank, including a sprocket 3 for connecting to the frame. A detachable crank 2 is installed on the side of the sprocket 3 away from the frame. A pedal 1 is rotatably connected to the side of the crank 2 away from the sprocket 3. The pedal 1 includes a pedal body 11. One side of the pedal body 11 is open to form a storage cavity 14, and the other side forms two through holes 16. The through holes 16 communicate with the storage cavity 14, and a movable rubber belt 12 is installed inside the storage cavity 14. Two elastic ropes 13 are symmetrically installed on one side of the rubber belt 12. The free ends of the two elastic ropes 13 pass through the through holes 16. A detachable limiting member 15 is installed on the free end of the elastic rope 13. The through hole 16 is located between the limiting member 15 and the rubber belt 12.

[0017] With the above technical solution, before using the device, the sprocket 3 is connected to the frame, and then the bicycle chain is fitted onto the sprocket 3. When a person steps on the pedal body 11, the pedal body 11 drives the crank 2 to rotate, which in turn drives the sprocket 3 to rotate, causing the sprocket 3 to rotate the chain. When the person needs to fix their foot on the pedal body 11, they pull the rubber band 12, which stretches the elastic rope 13. The limiting member 15 limits the free end of the elastic rope 13. The person then places their foot between the foot pedal body 11 and the rubber band 12, releases the rubber band 12, and the elastic rope 13 rebounds, causing the rubber band 12 to move back to its original position. The rubber band 12 and the foot pedal body 11 clamp the person's foot, preventing it from accidentally falling off when the person steps on the foot pedal body 11. When the person needs to separate their foot from the foot pedal body 11, they only need to lift their foot slightly and move the foot backward on the lever to separate their foot from the rubber band 12 on the foot pedal body 11, thus completing the separation from the foot pedal body 11.

[0018] Specifically, in one embodiment, regarding the aforementioned limiting member 15, as... Figures 6-9 As shown, the limiting member 15 includes two symmetrically arranged side plates 151, and two arc-shaped tubes 152 are symmetrically rotatably connected between the two side plates 151. A detachable screw ring 154 is screwed between the two arc-shaped tubes 152.

[0019] In this embodiment, when the rubber band 12 needs to be installed, the rubber band 12 is placed in the storage cavity 14, and the free end of the elastic rope 13 is passed through the through hole 16. The free end of the elastic rope 13 is placed between the two arc-shaped tubes 152. The arc-shaped tubes 152 are rotated to rotate around the side plate 151 until the two arc-shaped tubes 152 clamp the elastic rope 13. Then, the screw ring 154 is screwed into the arc-shaped tube 152 to fix the arc-shaped tube 152 to the elastic rope 13. When the elastic rope 13 and the rubber band 12 need to be replaced, the screw ring 154 is unscrewed to separate the damaged elastic rope 13 from the arc-shaped tube 152 and replace it with a new elastic rope 13.

[0020] To facilitate clamping the elastic rope 13 between the two curved tubes 152, such as Figures 8-9 As shown, the inner walls of the two arc-shaped tubes 152 are fixedly connected to limit rods 153, and the free ends of the limit rods 153 protrude outward to form sharp protrusions.

[0021] In this embodiment, when the arc-shaped tube 152 clamps the elastic rope 13, the limiting rod 153 and the sharp protrusion cooperate to make the arc-shaped tube 152 clamp the elastic rope 13 more securely.

[0022] Specifically, in one embodiment, regarding the aforementioned crank component 2, as... Figure 1 , Figure 2 , Figure 4 and Figure 5 As shown, the crank assembly 2 includes a crank body 21, one end of which is fixedly connected to a first connector 22, and the other end is fixedly connected to a second connector 23.

[0023] In this embodiment, when a person steps on the foot pedal body 11, the foot pedal body 11 drives the sprocket 3 to rotate through the cooperation of the first connector 22 and the second connector 23.

[0024] Furthermore, in this utility model, regarding the aforementioned sprocket component 3, as follows: Figures 1-3 As shown, the sprocket component 3 includes a sprocket body 31, with a connecting groove 32 formed by an inward recess on one side of the sprocket body 31, and a connecting pipe 24 fixedly connected to an outward protrusion on one side of the second connector 23. The connecting pipe 24 is detachably connected to the connecting groove 32.

[0025] In this embodiment, the second connector 23 is screwed into the connecting groove 32 on the sprocket body 31, thereby connecting the crank body 21 and the sprocket body 31. When the pedal body 11 drives the crank body 21 to rotate, the crank body 21 will synchronously drive the sprocket body 31 to rotate, causing the sprocket body 31 to drive the chain to rotate. When replacing the crank body 21, the sprocket body 31 is fixed and the crank body 21 is rotated, thereby separating the connecting tube 24 from the connecting groove 32, so that the crank body 21 can be replaced.

[0026] To make the device easier for personnel to locate, such as Figure 1 , Figure 2 , Figure 6 and Figure 7 As shown, the surface of the foot pedal body 11 is coated with a reflective coating 17.

[0027] In this embodiment, when a person steps on the foot pedal body 11 at night, the reflective coating 17 makes it easier for other people to observe the device, thus improving the device's visibility at night.

[0028] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A bicycle chain crank, characterized in that: The system includes a sprocket assembly (3) for connecting to the frame. A detachable crank assembly (2) is mounted on the side of the sprocket assembly (3) away from the frame. A pedal assembly (1) is rotatably connected to the side of the crank assembly (2) away from the sprocket assembly (3). The pedal assembly (1) includes a pedal body (11). One side of the pedal body (11) is open to form a storage cavity (14), and the other side forms two through holes (16). The through holes (16) communicate with the storage cavity (14), and a movable rubber band (12) is installed inside the storage cavity (14). Two elastic ropes (13) are symmetrically installed on one side of the rubber band (12). The free ends of the two elastic ropes (13) pass through the through holes (16). A detachable limiting member (15) is installed on the free end of the elastic rope (13). The through hole (16) is located between the limiting member (15) and the rubber band (12).

2. The bicycle sprocket crank according to claim 1, characterized in that: The limiting member (15) includes two symmetrically arranged side plates (151), and two arc-shaped tubes (152) are symmetrically rotatably connected between the two side plates (151). A detachable screw ring (154) is screwed between the two arc-shaped tubes (152).

3. The bicycle sprocket crank according to claim 2, characterized in that: The inner walls of the two arc-shaped tubes (152) are fixedly connected to limit rods (153), and the free ends of the limit rods (153) protrude outward to form sharp protrusions.

4. The bicycle sprocket crank according to any one of claims 1-3, characterized in that: The crank assembly (2) includes a crank body (21), one end of which is fixedly connected to a first connector (22), and the other end is fixedly connected to a second connector (23).

5. The bicycle sprocket crank according to claim 4, characterized in that: The sprocket component (3) includes a sprocket body (31), one side of which is recessed to form a connecting groove (32), and one side of the second connector (23) is protruding and fixedly connected to a connecting pipe (24), the connecting pipe (24) and the connecting groove (32) being detachably connected.

6. The bicycle sprocket crank according to any one of claims 1-3, characterized in that: The surface of the foot pedal body (11) is coated with a reflective coating (17).

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