Speed change cable adjusting mechanism of front derailleur of bicycle

Abstract

The invention provides a bicycle front derailleur shift cable adjusting mechanism, which relates to the technical field of bicycles, and comprises a front derailleur main body fixed on a frame, a front derailleur inner connecting piece, a front derailleur outer connecting piece and a front derailleur bracket, wherein the front derailleur inner connecting piece and the front derailleur outer connecting piece are connected with the front derailleur main body through movable joints to form a multi-link structure; a fine adjustment connecting piece capable of freely rotating is arranged on the front shifting outer connecting piece and used for fixing a shift cable, the front shifting outer connecting piece is spirally connected with an adjusting screw, and the end part of the screw is in contact with the fine adjustment connecting piece; the fine adjustment connecting piece can be directly pushed to rotate relative to the front shifting outer connecting piece by screwing or unscrewing the adjusting screw, so that the tightness degree of the speed change cable is accurately and directly adjusted. The adjusting function is highly integrated on the front shifting motion connecting rod, the problems of adjustment delay, operation inconvenience and the like existing in a traditional line pipe fine adjustment mode are solved, more sensitive and accurate line tension adjustment is achieved, the gear shifting accuracy and reliability of the front shifting are effectively improved, the structure is compact, and operation is convenient.

Description

Technical Field

[0001] This invention relates to the field of bicycle technology, and in particular to a bicycle front derailleur shifter cable adjustment mechanism. Background Technology

[0002] The derailleur is a core component in a bicycle drivetrain used for switching gears and shifting gears. The front derailleur (or simply "front derailleur") is mounted on the seatpost or front derailleur lugs. Its function is to move the chain between different chainrings via the chain guide plate when the rider operates the shifters or levers. A typical front derailleur usually consists of a main body for mounting to the frame, a movable chain guide plate bracket, and a linkage mechanism connecting the two. One end of the shift cable is connected to the shifters / levers, and the other end is fixed to a connector on the front derailleur. When the shift cable is tightened or released, the tension in the cable overcomes or works in conjunction with the return spring (usually a torsion spring) inside the derailleur, driving the linkage mechanism to move, thereby causing the chain guide plate to shift laterally, completing the shifting action. The tension of the shift cable is a key factor affecting the accuracy of front derailleur shifting. Too loose cable tension can cause delayed or incomplete upshifting, resulting in chain friction with the chain guide plate or even preventing the chain from shifting at all; too tight cable tension can cause uneven downshifting or abnormal noise. After bicycle assembly or long-term use, cable tension often changes due to cable stretching, component wear, or temperature variations, thus requiring a convenient adjustment mechanism.

[0003] In existing technologies, the shift cable adjustment mechanism is usually located on the fine-tuning knob at the end of the cable tube, or integrated into the fixed interface between the front derailleur and the frame. These adjustment methods have some drawbacks: for example, the adjustment mechanism integrated into the frame interface may be limited by space, have a short adjustment stroke, and be inconvenient to operate tools during adjustment; while the fine-tuning knob at the end of the cable tube may experience decreased adjustment sensitivity or indirect adjustment transmission due to factors such as cable tube aging or bending. Summary of the Invention

[0004] The purpose of this invention is to provide a bicycle front derailleur cable adjustment mechanism to solve the technical problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A bicycle front derailleur cable adjustment mechanism includes a front derailleur body, a front derailleur outer connector, and a front derailleur bracket. The front derailleur body is fixed to a corresponding mounting position on the frame, serving as a fixed support. The front derailleur outer connector is rotatably connected to the front derailleur body via a pin. The front derailleur outer connector is provided with a fine-tuning connector and an adjusting screw. The fine-tuning connector can rotate freely on the front derailleur outer connector and has a groove for fixing the derailleur cable. The adjusting screw is screwed onto the front derailleur outer connector, with its end contacting the fine-tuning connector. Tightening the screw... Alternatively, loosening the adjusting screw can push the fine-tuning connector to rotate relative to the outer front derailleur connector, thereby adjusting the tension of the derailleur cable; it also includes an inner front derailleur connector and a torsion spring. The front derailleur body, inner front derailleur connector, outer front derailleur connector, and front derailleur bracket are connected by multiple movable joints to form a four-bar or compound linkage structure; the front derailleur bracket is used to support and guide the chain, and the front derailleur torsion spring is located on the movable joint connecting the inner front derailleur connector and the front derailleur bracket, and acts on the inner front derailleur connector and the front derailleur bracket to provide elastic force for their recovery.

[0007] Based on the above technical solutions, the present invention also provides the following optional technical solutions:

[0008] In one alternative: the fine-tuning connector is mounted on top of the front derailleur outer connector via a fine-tuning pin, and a bushing is provided between it and the front derailleur outer connector. The fine-tuning connector has a protrusion on its side wall, and a fine-tuning screw seat is provided on the side wall of the front derailleur outer connector opposite to the protrusion. The adjusting screw passes through the fine-tuning screw seat, and one end of it contacts the protrusion. A fine-tuning shim is installed between the fine-tuning screw seat and the adjusting screw.

[0009] In one alternative: the movable joint between the outer front derailleur connector and the front derailleur bracket is a hollow short rivet, and the movable joint between the front derailleur bracket and the inner front derailleur connector is a hollow long rivet.

[0010] In one alternative: one side of the front derailleur body has an arc surface that matches the structure of the mounting position of the frame. The arc surface has a locking hole, a locking screw is connected in the locking hole, and a front derailleur fixing block is provided between the locking screw and the arc surface of the front derailleur body.

[0011] By adopting the above technical solution, the present invention has the following beneficial effects:

[0012] This invention integrates the fine-tuning connector and adjusting screw onto the front derailleur's movement linkage (front derailleur external connector). The movement of the adjusting screw directly acts on the fine-tuning connector that fixes the shift cable, avoiding the adjustment lag and wear caused by the long and curved cable path of traditional cable fine-tuning knobs. This makes cable tension adjustment more direct, sensitive, and precise. The adjusting screw is located on the front derailleur body and is usually easy to operate with common tools (such as an Allen wrench), allowing users to quickly fine-tune before and after riding. Since the adjustment point is directly located on the drive linkage, the adjusted cable tension can be stably transmitted to the entire four-bar / compound linkage mechanism, effectively improving the accuracy and reliability of shifting and reducing chain friction. The fine-tuning mechanism of this invention is simple and efficient to adjust and can be used regardless of whether the shifters / shifters have a fine-tuning structure. Furthermore, when the shifters / shifters do not have a fine-tuning structure, there is no need to add a fine-tuning structure to the cable; the front derailleur has its own fine-tuning structure, allowing workers to quickly and easily adjust the shifting accuracy during assembly and debugging. Attached Figure Description

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

[0014] Figure 1 This is a schematic diagram of one perspective of the bicycle front derailleur shift cable adjustment mechanism in this invention.

[0015] Figure 2 This is a schematic diagram of another perspective of the bicycle front derailleur shifter cable adjustment mechanism in this invention.

[0016] Figure 3 This is a schematic diagram of the front derailleur external connector structure in this invention.

[0017] Figure 4 This is an exploded view of the front derailleur external connector in this invention.

[0018] Figure 5 This is a schematic diagram of the connection structure between the front derailleur body and the inner connecting member of the front derailleur in this invention.

[0019] Figure 6 This is a schematic diagram of the connection structure between the front derailleur outer connector and the front derailleur bracket in this invention.

[0020] Reference numerals in the attached drawings: Front derailleur body 100, front derailleur fixing block 110, locking screw 120, front derailleur inner connector 200, front derailleur outer connector 300, pin shaft 310, fine-tuning screw seat 320, fine-tuning pin 330, bushing 340, front derailleur bracket 400, fine-tuning connector 500, protrusion 510, adjusting screw 600, fine-tuning shim 610, movable joint 700, front derailleur torsion spring 800, shift cable 900. Detailed Implementation

[0021] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The left, right, up, and down positions of the various components shown in the attached diagram are just one arrangement method; the specific positions should be set according to specific needs.

[0023] In one embodiment, such as Figures 1-6 As shown, a bicycle front derailleur cable adjustment mechanism includes a front derailleur body 100, a front derailleur outer connector 300, and a front derailleur bracket 400. The front derailleur body 100 is fixed to the corresponding mounting position on the frame as a fixed support. The front derailleur outer connector 300 is rotatably connected to the front derailleur body 100 via a pin 310. The front derailleur outer connector 300 is provided with a fine-tuning connector 500 and an adjusting screw 600. The fine-tuning connector 500 can rotate freely on the front derailleur outer connector 300 and has a groove for fixing the derailleur cable 900. The adjusting screw 600 is screwed onto the front derailleur outer connector 300, and its end contacts the fine-tuning connector 500. By tightening or... Loosening the adjusting screw 600 allows the fine-tuning connector 500 to rotate relative to the front derailleur outer connector 300, thereby adjusting the tension of the derailleur cable 900. The system also includes a front derailleur inner connector 200 and a front derailleur torsion spring 800. The front derailleur body 100, front derailleur inner connector 200, front derailleur outer connector 300, and front derailleur bracket 400 are connected by multiple movable joints 700 to form a four-bar or compound linkage structure. The front derailleur bracket 400 supports and guides the chain. The front derailleur torsion spring 800 is located on the movable joint 700 connecting the front derailleur inner connector 200 and the front derailleur bracket 400, and acts on the front derailleur inner connector 200 and the front derailleur bracket 400, providing a restoring elastic force.

[0024] In this embodiment of the invention, the front derailleur body 100 is fixed to the corresponding mounting position on the frame as a fixed support. The shift cable 900 passes through the cable conduit and is led out. At the same time, the cable conduit is supported on the cable conduit fulcrum of the frame. Then, the shift cable 900 is pressed into the cable groove on the front derailleur bracket 400, thus completing the initial installation and locking of the shift cable 900. When upshifting, the shift cable 900 is tightened, and the shift cable 900 pulls the fine-tuning connector 500. The fine-tuning connector 500 drives the front derailleur outer connector 300 to rotate around the movable joint 700 between it and the front derailleur body 100. At the same time, the front derailleur bracket 400 swings around the connection between it and the front derailleur outer connector 300 and the front derailleur inner connector 200. The front derailleur bracket 400 also drives the front derailleur inner connector 200 to rotate around the movable joint 700 between it and the front derailleur body 100. Thus, the upshifting action is completed. When downshifting, the shift cable 900 is released, and the front derailleur torsion spring 8... Under the elastic force of 00, the inner connector 200 of the front derailleur rotates around the movable joint 700 between itself and the main body 100 of the front derailleur. The bracket 400 of the front derailleur rotates and swings around the connection between itself, the outer connector 300 of the front derailleur, and the inner connector 200 of the front derailleur. The bracket 400 of the front derailleur drives the outer connector 300 of the front derailleur to rotate. The outer connector 300 of the front derailleur acts on the fine-tuning connector 500 to make it rotate. At this point, the downshifting action is completed. When trying to press the lever of the shifter to shift gears, the shifting accuracy may be poor, causing the bracket 400 of the front derailleur to rub against the chain, or even making it impossible to shift up or down. In this case, it is necessary to adjust the tension of the shift cable 900. This can be done by tightening or loosening the adjusting screw 600. The adjusting screw 600 pushes the fine-tuning connector 500 to rotate relative to the outer connector 300 of the front derailleur, thereby adjusting the tension of the shift cable 900.

[0025] In one embodiment, such as Figures 1-6 As shown, the fine-tuning connector 500 is mounted on top of the front derailleur outer connector 300 via a fine-tuning pin 330, and a bushing 340 is provided between it and the front derailleur outer connector 300. The fine-tuning connector 500 has a protrusion 510 on its side wall, and a fine-tuning screw seat 320 is provided on the side wall of the front derailleur outer connector 300 opposite to the protrusion 510. The adjusting screw 600 passes through the fine-tuning screw seat 320, with one end contacting the protrusion 510. A fine-tuning shim 610 is installed between 320 and the adjusting screw 600. In this embodiment of the invention, the adjusting screw 600 is a Phillips head screw. Tightening the adjusting screw 600 causes it to move toward or away from the protrusion 510 through its cooperation with the fine-tuning screw seat 320, thereby applying a knob force relative to the pin 310 to the protrusion 510. The fine-tuning connector 500 rotates relative to the pin 310 to adjust the tightness of the gear cable 900.

[0026] In one embodiment, such as Figures 1-6As shown, the movable joint 700 between the outer front derailleur connector 300 and the front derailleur bracket 400 is a hollow short rivet, and the movable joint 700 between the front derailleur bracket 400 and the inner front derailleur connector 200 is a hollow long rivet; the hollow long rivet and the hollow short rivet are fitted with the holes in the front derailleur bracket 400 or the inner front derailleur connector 200 with clearance, so that the inner front derailleur connector 200 and the front derailleur bracket 400 can rotate within a certain clearance.

[0027] In one embodiment, such as Figures 1-6 As shown, one side of the front derailleur body 100 has an arc surface, which matches the structure of the frame mounting position. The arc surface has a locking hole, and a locking screw 120 is connected in the locking hole. A front derailleur fixing block 110 is provided between the locking screw 120 and the arc surface of the front derailleur body 100. In this embodiment of the invention, the arc surface of the front derailleur fixing block 110 is placed at the frame mounting position. The locking screw 120 passes through the front derailleur fixing block 110 and the frame mounting hole, and is finally locked onto the front derailleur body 100. The setting of the front derailleur fixing block 110 can increase the locking force of the locking screw 120 and improve the connection strength between the front derailleur body 100 and the frame mounting position.

[0028] The above embodiment provides a bicycle front derailleur cable adjustment mechanism, the working principle of which is as follows:

[0029] First, the front derailleur body 100 is securely installed on the designated position on the frame using the locking screw 120 and the front derailleur fixing block 110, serving as the fixed base for the entire mechanism. After supporting the external shift cable conduit on the frame cable conduit fulcrum, the shift cable 900 is led out and pressed and fixed in the cable groove located on the front derailleur bracket 400, completing the initial installation.

[0030] The moving part of the mechanism consists of a front derailleur body 100, an inner front derailleur connector 200, an outer front derailleur connector 300, and a front derailleur bracket 400, which are connected by multiple movable joints 700 (such as hollow short rivets and hollow long rivets) to form a four-bar linkage. A front derailleur torsion spring 800 is installed on the movable joint 700 connecting the inner front derailleur connector 200 and the front derailleur bracket 400 to provide restoring force for downshifting (releasing tension).

[0031] When the rider operates the shifters / shifters to upshift (e.g., from a smaller chainring to a larger chainring), the shift cable 900 is tightened. The tension in the shift cable 900 acts on the fine-tuning connector 500, causing the fine-tuning connector 500 to rotate around its fine-tuning pin 330.

[0032] The fine-tuning connector 500 is connected to the outer connector 300 of the front derailleur, thereby pulling the outer connector 300 to rotate around the pin 310 that connects it to the front derailleur body 100. The movement of the outer connector 300 is transmitted through a linkage mechanism, driving the front derailleur bracket 400 to swing forward around its connection with the outer connector 300 and the inner connector 200, pushing the chain to shift to a larger chainring. At the same time, the front derailleur bracket 400 drives the inner connector 200 to rotate around its connection with the front derailleur body 100, completing the entire upshifting action.

[0033] When downshifting (e.g., from a large chainring to a small chainring), the shifter / manual shifter releases tension on the shift cable 900. At this time, the compressed front derailleur torsion spring 800 releases its elasticity, pushing the inner front derailleur connector 200 to rotate around its connection point with the front derailleur body 100. The rotation of the inner front derailleur connector 200 causes the front derailleur bracket 400 to swing back to its original position around its connection point with both the outer and inner front derailleur connectors 300 and 200. This return movement of the bracket 400 further causes the outer front derailleur connector 300 to rotate around the pin 310, which in turn pushes the fine-tuning connector 500 to rotate, keeping the shift cable 900 in a moderately slack state, allowing the chain to downshift smoothly.

[0034] If inaccurate shifting occurs after prolonged use or installation (such as friction between the chain and the front derailleur bracket 400 or uneven shifting), the basic tension of the derailleur cable 900 needs fine adjustment. This function is accomplished by an independent fine-tuning subsystem: the fine-tuning connector 500 is mounted on top of the front derailleur outer connector 300 via a fine-tuning pin 330 and a bushing 340, and can rotate independently. The adjusting screw 600 spirals through the fine-tuning screw seat 320 located on the side wall of the front derailleur outer connector 300, and its end contacts the protrusion 510 on the side wall of the fine-tuning connector 500. The fine-tuning shim 610 ensures smooth adjustment.

[0035] Rotating the fine-tuning connector 500 towards the protrusion 510 causes it to rotate slightly around the fine-tuning pin 330. This rotation tightens the gear cable 900 fixed in its groove, effectively increasing the reference tension of the gear cable.

[0036] Loosen the adjusting screw 600: The screw is pulled away from the protrusion 510. Under the tension of the transmission cable 900 itself or the action of the mechanism reset, the fine-tuning connector 500 can rotate slightly in the opposite direction, thereby releasing part of the tension of the transmission cable 900 and making it loose.

[0037] In the description of this invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

Claims

1. A front derailleur gear shift wire adjusting mechanism of a bicycle, comprising a front derailleur main body, a front derailleur outer connecting member and a front derailleur bracket, the front derailleur main body is fixed on the corresponding installation position of the frame as a fixed support, characterized in that, The front derailleur outer connecting piece and the front derailleur body are connected together through a pin shaft part, the front derailleur outer connecting piece is provided with a fine adjustment connecting piece and an adjusting screw, the fine adjustment connecting piece can rotate freely on the front derailleur outer connecting piece and is provided with a wire slot for fixing a derailleur wire; The adjusting screw is screwed on the front derailleur outer connecting piece, the end thereof is in contact with the fine adjustment connecting piece, by screwing or unscrewing the adjusting screw, the fine adjustment connecting piece can be pushed to rotate relative to the front derailleur outer connecting piece, so as to adjust the tightness of the derailleur wire; The front derailleur further comprises a front derailleur inner connecting piece and a front derailleur torsion spring; The front derailleur body, the front derailleur inner connecting piece, the front derailleur outer connecting piece and the front derailleur support are connected through a plurality of movable joints to form a four-bar linkage or a compound linkage structure; The front derailleur support is used for supporting and guiding a chain, the front derailleur torsion spring is arranged on a movable joint connected by the front derailleur inner connecting piece and the front derailleur support and acts on the front derailleur inner connecting piece and the front derailleur support to provide elastic force for restoring them.

2. The bicycle front derailleur shift cable adjustment mechanism of claim 1, wherein, The fine adjustment connecting piece is installed on the top of the front derailleur outer connecting piece through a fine adjustment pin shaft and is provided with a shaft sleeve between the fine adjustment connecting piece and the front derailleur outer connecting piece, the fine adjustment connecting piece is provided with a protruding part on the side wall thereof; The front derailleur outer connecting piece is provided with a fine adjustment screw seat opposite to the protruding part on the side wall thereof, the adjusting screw passes through the fine adjustment screw seat, one end of the adjusting screw is in contact with the protruding part, and a fine adjustment gasket is arranged between the fine adjustment screw seat and the adjusting screw.

3. The bicycle front derailleur shift cable adjustment mechanism of claim 1, wherein, The movable joint between the front derailleur outer connecting piece and the front derailleur support is a hollow short rivet, and the movable joint between the front derailleur support and the front derailleur inner connecting piece is a hollow long rivet.

4. The bicycle front derailleur shift cable adjustment mechanism of claim 1, wherein, One side of the front derailleur body is provided with a curved surface, the curved surface is matched with the structure of the mounting position of a frame, the curved surface is provided with a locking hole, a locking screw is connected in the locking hole, and a front derailleur fixing block is arranged between the locking screw and the curved surface of the front derailleur body.

5. A front derailleur for a bicycle, characterized in that The derailleur wire adjusting mechanism of any one of claims 1 to 4 is included.

6. A bicycle characterized in that, The front derailleur of claim 5 is included.

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