Folding bicycle rear fork

Abstract

The invention discloses a folding bicycle rear fork, which adopts a frame and a rear fork hinged, and a reset spring is arranged on the hinge shaft. The upper end of the rear fork is locked with the frame, and the pedal linkage locking mechanism is unlocked. Under the action of the reset spring, an automatic and easy-to-use folding function is realized: parking - stepping on the pedal - triggering the rear fork to be unlocked - the spring twists the rear fork to reset to the center of the sector - the clamp clamps the rear wheel to stick to the ground - the vehicle moves backward - the rear wheel is stored and stuck by the protruding part - the upper arm of the spring lifts the wedge-shaped part - the seat tube is unlocked and lowered to realize automatic storage. It is ensured that the operation of the folding bicycle can be smoothly completed without bending the body while standing.

Description

Technical Field

[0001] The invention relates to a folding bicycle frame structure, in particular to an automatically folding bicycle rear fork. Background Art

[0002] Many folding bicycles currently on the market require manual manipulation of the various folding mechanisms in a strict, sequential order to open and close the multiple folding joints, a cumbersome process. For example, to lock the seat tube, a slot is typically cut in the top of the frame's center tube to create an expansion joint. A tie is then placed around the tube end, creating a quick-release handle to adjust and unlock the seat tube. This slotting reduces the strength of the tube where strength is most needed, making it a poor technical solution. Furthermore, existing longitudinally folding bicycles require manual or foot manipulation of the rear wheel to fold, a cumbersome and inconvenient process. This makes it difficult for most people to master the folding technique, resulting in a suboptimal user experience. Summary of the Invention

[0003] The present invention aims to provide a folding bicycle that can be folded and unfolded without removing both hands from the handlebars or seat. The present invention employs a hinged connection between the frame and rear fork, allowing the rear wheel to be folded longitudinally and stored beneath the frame, while the rear fork moves within this rotating sector.

[0004] The present invention provides a return spring on the hinge shaft. The upper end of the rear fork abuts against the abutment on the middle tube and is locked, restricting its disengagement to the upper closed position, which is the upper point of the sector. When the rear fork rotates below the frame, it reaches the lower point of the sector.

[0005] The invention provides a trigger pedal arranged behind the rear wheel axle to link the closing and locking mechanism. Stepping on the pedal triggers the locking mechanism to unlock.

[0006] The present invention realizes four functions under the action of a return spring and a rear fork. The folding process is triggered by one foot. After the rear fork is unlocked, the return spring twists the rear fork to rotate, realizing the following functions: 1. The rear fork is reset and rotated; 2. The rotation of the rear fork is linked with the seat tube lock; 3. The rotation of the rear fork stops the rear wheel; 4. The rear fork automatically resets after the rear wheel is released.

[0007] Function 1 of the present invention is that the frame and the rear fork are hinged. The upper end of the rear fork is locked against the abutment on the middle tube, restricting it from disengaging to the upper closed position. When the locking mechanism is opened, the rear fork can be rotated along the hinge axis to the folded storage position. One spring cantilever is connected to the frame, and the other cantilever is fixed to the rear fork. The spring is a torsion spring. When the rear fork is twisted to the upper closed position of the sector or to the lower storage position of the sector, the rear fork, i.e. the rear wheel, can stay in the central area of ​​the sector under the reset action of the spring after being released, thereby realizing the positioning function. The rear fork rotates around the axis to achieve the unfolded or folded state.

[0008] Function 2 of the present invention is that the upper cantilever arm of the spring is fixed to the wedge. Rotation of the rear fork drives the wedge up and down, locking and releasing the seat tube. When the rear fork rotates to the upper closed position, the upper cantilever arm of the spring pulls downward, forcing the wedge downward into a wedged and locked position, securing the seat tube and ensuring a safe riding condition.

[0009] When the rear fork of the present invention rotates to the storage state, the cantilever on the spring is pushed upward, and the wedge moves upward to relax and unlock. After unlocking, the seat tube can be inserted downward for storage, thereby limiting the rotation of the rear wheel.

[0010] Function 3 of the present invention is the provision of a frame stopper on the bicycle frame. A fork stopper is also provided on the rear fork. The brake cable, which passes through the stopper, is positioned above the outer diameter of the articulated shaft. When the rear fork rotates clockwise out of the upper closed position, the arc distance between the frame stopper and the fork stopper increases, tightening the brake cable in the rear wheel caliper and clamping the rear wheel. Because the rear wheel is stuck to the ground, the bicycle can be manually pulled backward, and the wheel can be smoothly folded into its stowed position.

[0011] Function 4 of the present invention is that when the rear wheel rotates to the storage position, that is, the lower point of the sector, the tire interferes with the raised piece below the five-way bracket. The raised piece is embedded in the interference point of the tire, and the tire is compressed. Since the connection line between the center point of the rear wheel and the hinge axis passes over the raised piece below the five-way bracket and reaches the upper area, the rebound force of the tire enables the rear wheel to be positioned in the storage position, limiting the reset of the rear fork. At this time, the pedal is reversed to the front of the rear wheel axle. When the foot steps on the pedal, because the fulcrum of the wheel contacting the ground is located behind the pedal, the pedaling force causes the rear fork to start rotating counterclockwise, triggering the rear wheel to escape the restriction of the raised piece. The rear fork rotates to the center of the sector. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a front view of an embodiment of a folding bicycle rear fork of the present invention;

[0013] Figure 2 This is a partial enlarged view of a tube cross section of an embodiment of a folding bicycle rear fork of the present invention;

[0014] Figure 3 This is a schematic diagram of folding and storing a rear fork of a foldable bicycle according to an embodiment of the present invention;

[0015] Figure 4 This is a spring diagram of a folding bicycle rear fork embodiment of the present invention;

[0016] Figure 5 This is a schematic diagram of the folding process of a folding bicycle rear fork embodiment of the present invention;

[0017] Figure 6 This is a view of a wedge-shaped member of an embodiment of a folding bicycle rear fork of the present invention;

[0018] Figure 7This is a schematic diagram of a folding bicycle rear fork embodiment of the present invention, in which the rear wheel is restrained;

[0019] Figure 8 This is an embodiment of a folding bicycle rear fork of the present invention Figure 1 A partial enlarged view of the cross section of the wedge;

[0020] Figure 9 This is an embodiment of a folding bicycle rear fork of the present invention Figure 3 A partial enlarged view of

[0021] Figure 10 This is an enlarged view of the pedal of a folding bicycle rear fork embodiment of the present invention;

[0022] Among them: 1. Frame; 2. Rear fork; 3. Articulated shaft; 4. Spring; 5. Center tube; 6. Seat tube; 7. Wedge; 8. Lock hook; 9. Clamp; 10. Frame stopper; 11. Fork stopper; 12. Protrusion; 13. Pedal; 14. Stopper. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0024] Implementation example Figure 1-2 As shown, a folding bicycle rear fork, see the view with part of the rear hinged plate on the frame removed, and the cross-sectional view of the middle tube (5). A locking hook (8) is provided between the resisting member (14) and the rear fork (2). The locking hook (8) can hook the resisting member (14) and the rear fork (2) to prevent them from being separated. The locking hook (8) is hingedly mounted on the rear fork (2) and is connected to the pedal (13) mounted on the rear end of the rear fork (2) by a cable. For example, Figure 10 As shown, the pedal (13) is fixed to the rear fork (2), and the fixing method includes hinge. The pedal (13) can only move slightly, and the amount of slight movement by the foot is only enough to trigger the lock hook (8) to unlock. When the foot steps on the pedal (13), the lock hook (8) is disengaged, the locking mechanism is unlocked, and the rear fork (2) begins to rotate.

[0025] The seat tube (6) is smaller than the diameter of the middle tube (5) and is relatively loosely sleeved in the middle tube (5). The upper opening of the middle tube (5) is punched with a trumpet mouth that bulges outward, that is, the tube mouth is concave outward. The curvature of the concave inner surface matches the curvature of the outer surface of the wedge tongue of the wedge (7). The curvature of the inner surface of the wedge tongue of the wedge (7) matches the outer curvature of the seat tube (6). A wedge (7) is provided at the upper opening of the middle tube (5) to replace the traditional quick release. The wedge (7) is screwed to the spring (4). The rear fork (2) rotates to drive and control the locking and release of the seat tube (6).

[0026] The frame (1) is hinged to the rear fork (2), and a spring (4) is provided on the hinge shaft (3). The abutment (14) is drilled in the upper and lower directions, and the hole diameter is larger than the spring diameter. The upper arm of the spring (4) passes through the abutment (14) and the end of the upper arm is fixed to the wedge-shaped member (7). A through pipe is welded on the rear fork (2), and the lower arm of the spring (4) passes through the through pipe.

[0027] Implementation example Figure 3 As shown, the resisting member (14) is fixed to the rear side of the upper section of the middle tube (5). The resisting member (14) can be made of elastic material, so that the bicycle has a shock-absorbing function.

[0028] Implementation example Figure 4 As shown, the spring (4) is a torsion spring, which is sleeved on the hinge shaft, and the schematic diagram of the state of the lower arm of the spring in three twisted positions.

[0029] Implementation example Figure 5 As shown, one cantilever of the spring (4) is connected to the frame (1), and the other cantilever is connected to the rear fork (2). The reset action of the spring causes the rear fork (2) to rotate to the central area between unfolding and folding, that is, automatically stay in the center of the sector.

[0030] Implementation example Figure 6 、 Figure 2 As shown in the outer shape of the wedge-shaped member (7), a threaded hole is provided at the rear upper end thereof for screwing the spring (4).

[0031] Implementation example Figure 7 、 Figure 9 As shown, the rear wheel is mounted on the rear fork (2), and a protrusion (12) is provided in the area below the line connecting the center point of the rear wheel and the center point of the hinge shaft (3). When the rear fork (2) rotates to the storage position, the protrusion (12) is embedded in the tire interference position, and the tire is compressed and pushed forward by the protrusion (12). The rebound force of the tire causes the wheel to have an upward force, which allows the rear wheel to be stuck under the frame, thereby limiting the reset of the rear fork (2). The protrusion (12) is welded to the position of the five-way pipe on the frame. The protrusion includes a bump, a spring or a magnetic attraction.

[0032] like Figure 8 As shown, the wedge-shaped member (7) is an enlarged cross-sectional view. The lower portion of the wedge-shaped member (7) is in a wedge shape that is wide at the top and narrow at the bottom. The rear fork (2) rotates in conjunction with the wedge-shaped member (7) to move up and down. When the wedge-shaped member (7) moves downward and is inserted into the gap between the middle tube (5) and the seat tube (6), the seat tube (6) can be locked.

[0033] like Figure 9 、 Figure 3As shown, the frame (1) is hinged to the rear fork (2), and a spring (4) is provided on the hinge shaft (3). A frame stopper (10) is welded to the frame. A fork stopper (11) is welded to the rear fork. The brake line passing through the stopper passes above the outer diameter of the hinge shaft. When the rear fork rotates clockwise, the arc between the two stoppers increases, the brake line is tightened, and the rear wheel is clamped by the clamp (9). Because the rear wheel sticks to the ground, the bicycle is pulled back by hand, and the wheel is smoothly folded into the storage state. When the rear fork (2) is rotated to the upper closed position, the rear wheel is released by the clamp (9).

[0034] When the rear fork (2) is in the central area of ​​the sector, the rear wheel is in a clamped state. As long as the bicycle moves forward, the rear fork (2) can continue to rotate counterclockwise, and then press the seat cushion to the ground with the right hand, and the rear fork (2) will turn to the upper closed position, completing the frame unfolded riding state; if the bicycle moves backward, the rear fork (2) continues to rotate clockwise, and press the seat cushion to the ground with the right hand, and the rear wheel will turn to the storage position.

[0035] Example Figure 1-10 The folding action process:

[0036] Stop the car - step on the pedal - trigger the rear fork to be unlocked - the spring twists the rear fork to return to the center of the sector - the brake clamps the rear wheel and sticks it to the ground - the car moves backward - the rear wheel storage is stuck by the protrusion - the upper arm of the spring pushes up the wedge - the seat tube is unlocked and lowered for automatic storage.

[0037] Example Figure 1-9 The following describes the process of launching a ride:

[0038] Lift the seat tube - step on the pedal - the rear wheel passes over the protrusion - the spring twists the rear fork back to the center of the sector - press down the seat cushion - the rear fork is closed and locked - the seat tube is locked, and the riding state is achieved.

[0039] After dismounting, a rider typically holds the handlebars with their left hand and the seat with their right hand – the most natural and comfortable position. With this technical solution, a simple push of the foot triggers a series of automated procedures within the folding mechanism, automatically folding or unfolding the bike, making folding and unfolding fun and natural. This allows for smooth operation of the folding bike, while keeping the rider's hands in place and standing upright without bending over.

Claims

1. A folding bicycle rear fork, comprising a frame, a rear fork, a rear wheel, a hinge shaft, a spring, a seat tube, and a middle tube, characterized in that: The frame is hinged to the rear fork, a spring is arranged on the hinge shaft, one cantilever of the spring is connected to the frame, and the other cantilever is connected to the rear fork; A wedge-shaped piece is arranged on the middle tube, and the wedge-shaped piece is fixed by a spring upper cantilever; The rotation of the rear fork drives the wedge-shaped piece to move up and down, thereby locking and releasing the seat tube.

2. The folding bicycle rear fork according to claim 1, characterized in that: The spring is sleeved on the hinge shaft.

3. The foldable bicycle rear fork according to claim 1, characterized in that: The upper end of the rear fork is locked against the middle tube to prevent it from leaving the upper closed position, which is the upper point of the sector; when the locking mechanism is opened, the rear fork rotates to the bottom of the frame to be the lower point of the sector; The restoring effect of the spring causes the rear fork to rotate to the central area between unfolding and folding, that is, automatically stay in the center of the sector.

4. The foldable bicycle rear fork according to claim 3, characterized in that: A stopper is arranged on the middle tube, the upper cantilever of the spring passes through the hole of the stopper, and the spring is screwed to the wedge-shaped piece.

5. The foldable bicycle rear fork according to claim 3, characterized in that: A trigger pedal is arranged behind the rear wheel axle, which links the locking mechanism, and stepping on the pedal triggers the locking mechanism to unlock.

6. The foldable bicycle rear fork according to claim 3, characterized in that: The locking hook is installed on the rear fork and connected to the pedal by a cable. Stepping on the pedal triggers the locking mechanism to unlock.

7. The foldable bicycle rear fork according to claim 3, characterized in that: A frame stopper is welded on the frame, and a fork stopper is welded on the rear fork. The brake line passing through the stopper passes over the outer diameter of the hinge shaft. When the rear fork rotates clockwise, the arc between the two stoppers increases, the brake line is tightened, and the rear wheel is clamped by the clamp. Because the rear wheel sticks to the ground, the bicycle is pulled backward by hand, and the wheel is smoothly folded into the storage state. When the rear fork is turned to the upper closed position, the rear wheel is released by the clamp.

8. The foldable bicycle rear fork according to claim 3, characterized in that: Folding action process: Stop the car - step on the pedal - trigger the rear fork to be unlocked - the spring twists the rear fork to return to the center of the sector - the clamp clamps the rear wheel and sticks it to the ground - the car moves backwards - the rear wheel storage is stuck by the protrusion - the upper arm of the spring lifts the wedge-shaped piece - the seat tube is unlocked and lowered for automatic storage.

9. The foldable bicycle rear fork according to claim 3, characterized in that: Expand the action process: Lift the seat tube - step on the pedal - the rear wheel passes over the protrusion - the spring twists the rear fork back to the center of the sector - press down the seat cushion - the rear fork is closed and locked - the seat tube is locked, and the riding state is achieved.

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