CN221698927U - Oval tooth dish variable speed bicycle front poking - Google Patents

Abstract

An oval tooth disc speed-changing bicycle front plectrum relates to the technical field of bicycles and comprises a groove-shaped poking claw, a guide sprocket, a rotating block, a fixed block, a limit bolt, a wire drawing fixed bolt, a rotating block upper rotating shaft, a bracket upper rotating shaft, a rotating block lower rotating shaft, a bracket lower rotating shaft and a torsion spring; the utility model solves the defect that the chain is easy to fall when the elliptic toothed disc adopts the traditional forward shifting, solves the problems of chain blocking and difficult speed shifting when the elliptic toothed disc adopts the traditional forward shifting, and when the pedal runs to the highest point or the lowest point after the elliptic toothed disc is matched with the forward shifting of the utility model, the pedal is easier and more labor-saving than the traditional bicycle, and can quickly pass through the area difficult to pedal after the pedal is easier in the difficult-to-force area, thereby improving the pedal frequency, further improving the speed of the bicycle and preventing the rider from feeling the muscle ache of the thigh.

Description

A front derailleur for a bicycle with an elliptical toothed disc

Technical Field

The utility model relates to the technical field of bicycles, in particular to an elliptical toothed disc speed-changing bicycle front derailleur.

Background Art

In the Chinese utility model patent for a bicycle equipped with a labor-saving module, which has been authorized by the inventor and has the authorization announcement number CN219728463U, an elliptical chainring bicycle is disclosed, which records a technical solution for modifying an ordinary bicycle by adding a labor-saving module and an elliptical chainring, thereby solving the problem that it is difficult to exert force when the pedals of ordinary bicycles are at the highest or lowest point, and also solves the shortcomings of elliptical chainring bicycles that the pedaling is sometimes light and sometimes heavy, the chain is sometimes loose and sometimes tight, and the chain is easy to fall off.

However, this technical solution is only applicable to bicycles with a single elliptical chainring, and cannot be used on speed-changing bicycles with multiple elliptical chainrings.

When a speed-changing bicycle with multiple elliptical chainrings uses an ordinary front derailleur for shifting, the chain is prone to falling off, and the gear shifting becomes stuck and difficult. The reasons are analyzed as follows: As shown in Figure 6, the phenomenon of the chain falling off mainly occurs when the long axis of the elliptical chainring 19 is perpendicular to the ground, the force section chain 18 is meshed with the teeth at the semi-long axis end of the elliptical chainring 19, and the elliptical chainring 19 rotates further. The first reason is that when the chain 18 is meshed with the teeth at the semi-long axis end of the elliptical chainring 19, the distance between the tooth tip that the elliptical chainring is to mesh with and the chain is greater than the distance between the tooth tip that the circular chainring 20 is to mesh with and the chain, and the distance increases. The second is that the chain and the tooth tip of the elliptical tooth plate are not in the same plane as soon as possible, whether the speed-changing bicycle is an elliptical tooth plate 19 or a circular tooth plate 20, the chain and the tooth plate cannot always be in the same plane, as shown in Figure 7, because the flywheel of the speed-changing bicycle has multiple discs, when the rear derailleur swings, the chain switches on the multiple discs of the flywheel, and the chain sometimes tilts inwards and sometimes tilts outwards, causing the chain and the tooth plate to form an angle, and the chain and the tooth plate are not in the same plane; the third is that when encountering a bumpy road, the chain shakes. When the force section chain meshes with the tooth tip of the semi-major axis end of the elliptical tooth plate, because the chain and the tooth plate are not in the same plane, and the distance between the tooth tips of the chain and the elliptical tooth plate to be meshed in sequence is greater than the distance between the tooth tips of the circular tooth plate with the same number of teeth to be meshed in sequence, when the chain shakes on a bumpy road, the elliptical tooth plate is more likely to drop the chain than the circular tooth plate. Analysis of the reasons why the chain is prone to getting stuck when using a traditional front derailleur to switch chainrings on an elliptical chainring bicycle: The phenomenon of easy jamming mainly occurs when the short axis of the elliptical chainring is perpendicular to the ground, the power section chain meshes with the teeth at the semi-short axis end of the elliptical chainring, and the chain is shifting speed from a chainring with fewer teeth to a chainring with more teeth. The reason is that when the short axis of the elliptical chainring is perpendicular to or nearly perpendicular to the ground, the power section chain meshes with the teeth near the semi-short axis end of the chainring. If the speed is changed at this time, the chain is hung on the pin at the semi-short axis end of the chainring with more teeth. As the effective radius of the chainring gradually increases, the distance between the tip of the tooth that the elliptical chainring is about to mesh with and the chain becomes smaller than the distance between the tip of the tooth that the circular chainring with the same number of teeth is about to mesh with and the chain. That is, as the distance between the tooth tips of the chainring that are about to engage and the chain becomes smaller, the chain is prone to rubbing against the tooth tips of the chainring when changing speed, especially when the chain shakes on bumpy roads, the chain is more likely to scratch against the tooth tips. That is, an elliptical chainring is more likely to get stuck when using a traditional front derailleur for shifting than a round chainring.

In order to solve the above problems, the inventor has designed and developed an elliptical chainring speed-changing bicycle front derailleur. The front derailleur not only solves the above-mentioned multiple shortcomings of the elliptical chainring when using a traditional front derailleur to switch the chainring, but also integrates the technical principle of the inventor's authorized patent (authorization announcement number: CN219728463U), and further realizes the technical features of the patent with authorization announcement number CN219728463U, that is, it solves the shortcoming of the elliptical chainring bicycle using a traditional front derailleur when pedaling.

Utility Model Content

The utility model aims to provide an elliptical chainring speed-changing bicycle front derailleur to solve the problems of easy chain drop, speed-changing jam and speed-changing difficulty in the elliptical chainring speed-changing bicycle.

In order to achieve the above purpose, the utility model adopts the following technical solutions:

A front derailleur for a bicycle with an elliptical toothed disc speed change comprises a grooved shifter claw, a guide sprocket, a rotating block, a fixed block, a limiting bolt, a wire drawing fixing bolt, an upper rotating shaft of the rotating block, a bracket, an upper rotating shaft of the bracket, a lower rotating shaft of the rotating block, and a torsion spring; the guide sprocket is installed on the left side of the grooved shifter claw; the rotating block and the fixed block are rotatably installed together through the upper rotating shaft of the rotating block; the lower side of the rotating block is hinged to the grooved shifter claw through the lower rotating shaft of the rotating block; the wire drawing fixing bolt is screwed into a threaded hole on the rotating block; the limiting bolt is screwed into a threaded hole on the fixed block; the upper end of the bracket is hinged to the fixed block through the upper rotating shaft of the bracket, and the lower end is hinged to the grooved shifter claw through the lower rotating shaft of the bracket; a torsion spring is installed on the lower rotating shaft of the bracket.

The above-mentioned elliptical chainring speed-changing bicycle front derailleur is provided with a threaded hole on the fixing block, and the threaded hole is used to install the front derailleur fixing bolt.

The above-mentioned elliptical chainring speed-changing bicycle front derailleur, when the elliptical chainring speed-changing bicycle front derailleur is installed on a bicycle, the highest meshing point between the guide sprocket and the chain is on or above the horizontal line where the highest point of the circular trajectory formed by the semi-major axis endpoints when the elliptical chainring is rotated is located.

The utility model has the following advantages:

The utility model solves the disadvantage of easy chain falling off of the traditional front derailleur when the elliptical chainring is used, and solves the problems of chain jamming and difficult speed change when the elliptical chainring is used for speed change with the traditional front derailleur. After the elliptical chainring and the front derailleur of the utility model are used in combination, when the pedal is operated to the highest point or the lowest point, pedaling is easier and more labor-saving than a traditional bicycle. After pedaling becomes easier in the interval where it is difficult to exert force, the rider can quickly pass through the difficult pedaling area, thereby increasing the pedaling frequency, further improving the vehicle speed, and the rider will not feel sore thigh muscles.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic front view of the utility model;

FIG2 is a schematic top view of the utility model;

Fig. 3 is a cross-sectional view along the line A-A;

FIG4 is a schematic rear view of the utility model;

FIG5 is a schematic diagram of the installation of the front derailleur on a bicycle;

FIG6 is a comparison of the distance between the tooth tip and the chain of an elliptical chainring and a circular chainring;

FIG7 is a top view of the chain and the crankset position;

The numbers in the figure represent: 1. grooved shifter claw, 2. guide sprocket, 3. rotating block, 4. fixed block, 5. front derailleur fixing bolt, 6. limit bolt, 7. drawing fixing bolt, 8. rotating block upper shaft, 9. bracket, 10. bracket upper shaft, 11. rotating block lower shaft, 12. bracket lower shaft, 13. torsion spring, 14. front derailleur handle, 15. drawing, 16. front derailleur fixing frame, 17. rear derailleur, 18. chain, 19. oval chainring, 20. round chainring.

DETAILED DESCRIPTION

The utility model is further described below in conjunction with the accompanying drawings and embodiments.

The utility model discloses an elliptical chainring-shifting bicycle front derailleur, as shown in FIG5 , wherein the front derailleur is mounted on a bicycle frame via a front derailleur fixing frame 16, a rear derailleur 17 is mounted below a bicycle flywheel, and a front derailleur turning handle 14 is mounted on a handlebar of the bicycle. When speed change is required, the front derailleur turning handle 14 is rotated, a wire drawing 15 pulls the front derailleur, and then a chain 18 is driven to switch between multiple chainrings of an elliptical chainring 19.

The utility model discloses an elliptical toothed disc speed-changing bicycle front derailleur, which is provided with a grooved claw 1, a guide sprocket 2, a rotating block 3, a fixed block 4, and a bracket 9. The guide sprocket 2 is installed on the left side of the grooved claw 1. The rotating block 3 and the fixed block 4 are rotatably installed together through the rotating block upper shaft 8. The lower part of the rotating block 3 is hinged with the grooved claw 1 through the rotating block lower shaft 11. The upper end of the bracket 9 is hinged with the fixed block 4 through the bracket upper shaft 10, and the lower end is hinged with the grooved claw 1 through the bracket lower shaft 12. The lower shaft 12 is installed on the bracket 9. On the grooved pusher claw 1, a torsion spring 13 is installed on the lower rotating shaft 12 of the bracket; a threaded hole is provided at the upper end of the rotating block 3, and a wire drawing fixing bolt 7 cooperates with the threaded hole. Tightening the wire drawing fixing bolt 7 is used to press and fix one end of the wire drawing 15; a limiting bolt 6 is provided on the fixing block, and two limiting bolts 6 are provided, and their lower ends are in contact with the top of the side plate on one side of the bracket 9. By adjusting the height positions of the two limiting bolts 6 respectively, the position of the bracket 9 can be limited, so as to ensure that the position of the chain 18 is in the middle position of the groove of the grooved pusher claw 1 during installation.

When the wire drawing 15 pulls the rotating block 3, the rotating block 3 rotates around the rotating shaft 8 on the rotating block, and the lower end of the rotating block 3 moves, thereby driving the grooved claw 1 to move to move the chain 18; when it is necessary to shift the chain 18 in the reverse direction, the front shift handle 14 is moved in the reverse direction, the wire drawing 15 is released, and under the torsion of the torsion spring 13, the bracket 9 is caused to rotate around the rotating shaft 10 on the bracket, thereby driving the grooved claw 1 to move in the reverse direction to shift the chain 18.

The utility model of an elliptical chainring speed-changing bicycle front derailleur, when installed on a bicycle, has the highest meshing point of the guide sprocket 2 and the chain 18 on or above the horizontal line where the highest point of the circular track formed by the semi-major axis endpoints when rotating the elliptical chainring 19 is located. The above-mentioned elliptical chainring 19 refers to the one with the longest major axis among multiple elliptical chainrings, so that all elliptical chainrings 19 can be guaranteed to meet the installation requirements. The principle of the above-mentioned installation technical requirements is the same as the principle of the Chinese utility model patent of the inventor's authorization announcement number: CN219728463U, title: A bicycle with a labor-saving module installed, which is to overcome the shortcomings of the elliptical chainring bicycle that is light or heavy when pedaling and easy to drop the chain.

The utility model discloses an elliptical chainring speed-changing bicycle front derailleur. When the front derailleur is installed on a bicycle, the installation height of the front derailleur is adjusted so that the highest point of a guide sprocket 2 is on or above the horizontal line where the highest point of a circular track formed by the semi-major axis end point of the largest chainring is located when the elliptical chainring is rotated. The front derailleur cable is released and the front derailleur is rotated so that the guide sprocket 2 and the elliptical chainring with the least number of teeth are in the same plane.

The utility model discloses an elliptical chain disc speed-changing bicycle front derailleur, which solves the disadvantage of easy chain falling of the traditional front derailleur of the elliptical chain disc: when the front derailleur of the utility model is installed, the guide sprocket 2 and the elliptical chain disc 19 are in the same plane, so the chain 18 connecting the guide sprocket and the elliptical chain disc is also in the same plane as the elliptical chain disc. Even when the chain disc plates are switched during riding, the guide sprocket is always in the same plane as one of the multiple discs. That is, the chain tilting phenomenon existing when the elliptical chain disc adopts the traditional front derailleur is eliminated, and even when the chain shakes on a bumpy road, the chain between the guide sprocket and the elliptical chain disc is not easy to fall off.

Although the chain between the guide sprocket 2 and the flywheel is not in the same plane as the guide sprocket, the guide sprocket is round, which is the same as the situation when the chain and the chainwheel are not in the same plane when a round chainring is used with a traditional front derailleur, so the chance of the chain falling off is small.

The utility model discloses an elliptical chainring-shift bicycle front derailleur, which solves the disadvantage of chain jamming during speed change existing in the traditional front derailleur of the elliptical chainring: the chain between the elliptical chainring-shift plate pin and the guide sprocket 2 is raised in height due to the joint action of the plate pin and the guide sprocket, thereby increasing the distance between the chain and the tooth tips of the chainrings that are to be meshed in sequence, so that the chain and the tooth tips of the chainrings are no longer scratched during speed change, thereby solving the problem of chain jamming during speed change existing in the traditional front derailleur of the elliptical chainring.

Traditional bicycle front derailleurs are divided into four categories, namely, top swing front derailleur, bottom swing front derailleur, push-type front derailleur, and direct-mount front derailleur. The above text takes the bottom swing front derailleur as an example for illustration and explanation. For top swing front derailleur, push-type front derailleur, and direct-mount front derailleur, no matter which traditional front derailleur is the same or similar to the present utility model in structure, it is within the protection scope of the present utility model.

Claims (3)

1. An oval tooth dish variable speed bicycle front plectrum which characterized in that: the device comprises a groove-type pusher dog (1), a guide sprocket (2), a rotating block (3), a fixed block (4), a limit bolt (6), a wire drawing fixed bolt (7), a rotating block upper rotating shaft (8), a bracket (9), a bracket upper rotating shaft (10), a rotating block lower rotating shaft (11), a bracket lower rotating shaft (12) and a torsion spring (13); the left side of the groove-shaped pusher dog (1) is provided with a guide chain wheel (2); the rotating block (3) and the fixed block (4) are rotatably arranged together through a rotating shaft (8) on the rotating block; the lower part of the rotating block (3) is hinged with the groove-shaped pusher dog (1) through a rotating block lower rotating shaft (11); the wire drawing fixing bolt (7) is screwed in a threaded hole on the rotating block (3); the limit bolt (6) is screwed in a threaded hole on the fixed block (4); the upper end of the bracket (9) is hinged with the fixed block (4) through a bracket upper rotating shaft (10), and the lower end of the bracket is hinged with the groove-shaped pusher dog (1) through a bracket lower rotating shaft (12); a torsion spring (13) is arranged on the lower rotating shaft (12) of the bracket.

2. An oval dental disk speed change bicycle front derailleur according to claim 1, characterized in that: the fixing block (4) is provided with a threaded hole, and the threaded hole is provided with a front pulling fixing bolt (5).

3. An oval dental disk speed change bicycle front derailleur according to claim 1, characterized in that: when the oval chain wheel speed change bicycle is arranged on a bicycle, the highest meshing point of the guide chain wheel (2) and the chain (18) is on or above the horizontal line where the highest point of the circular track formed by the semi-long axis end points is located when the oval chain wheel (19) is rotated.