JP2541980Y2 - Chain entrainment prevention plate for bicycles - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an anti-jam plate for an endless chain wound between a drive shaft gear and a driven shaft gear for transmitting a driving force of a crankshaft of a bicycle to a rear wheel hub. Prevents the danger of running by stopping the hanger shaft rotation due to the biting of the chain and stopping the rear wheel rotation, and not only eliminates damage to the chain stay and other parts of the bicycle drive unit and frame, but also the strength of the plate itself. The purpose of the present invention is to further improve running safety by improving vehicle durability.

[0002]

2. Description of the Related Art The use of a chain as a power transmission means of a bicycle is widely used in practical vehicles, light vehicles, sports vehicles, etc., since it is extremely advantageous in terms of durability. In the case of a sports car, etc., in order to change the gear ratio by changing the drive gear ratio, the number of each of the crankshaft gear in the hanger and the driven gear of the rear freewheel is made plural, and the diameter of each gear is sequentially reduced. In many cases, a large or small configuration is used. In this case, the length of the chain is set excessively, and a constant tension is constantly applied by a tension mechanism of a rear derailleur.

[0003] In particular, mountain bikes are required to have a large tire width in order to secure sufficient running stability to withstand uneven roads and running on rough roads in the mountains, and to reduce power loss during running. Therefore, it is also desired to make a short rear center. Further, when there are a plurality of transmission gears, the chain line between the driving gear and the driven gear cannot be largely shifted in order to sufficiently secure the shifting performance, so that the position of the driving gear naturally falls within a certain range. As a result, the clearance between the drive gear and the chain stay of the frame must be designed to be equal to or less than the width of the chain.

In such a structure, when the drive gear is shifted, the slack side portion of the chain is not easily disengaged from the gear before the gear shift, and the slack side portion of the chain becomes rearward with the rotation of the drive gear. The drive gear is likely to be wound upward in the rotational direction of the drive gear against the tension force of the derailleur, and as a result, it often bites between the drive gear and the chain stay.

[0005] In such a case, the rotation of the crankshaft is suddenly stopped, and in some cases, an accident in which the running becomes impossible due to a broken chain or the like may occur. There is also a danger of damage to gears and chain stays in the frame. Therefore, recently, the tip of the metal plate is bent at a right angle so as to follow the side of the chain loose side near the tooth tip of each of the plurality of drive gears having different numbers of teeth, and the tip corresponds to the loose side of the chain. A chain stopper adapted to be along the side surface of each drive gear has been developed by the present applicants (Japanese Utility Model Application No. 3-51447).

[0006]

However, in Japanese Unexamined Utility Model Publication No. Hei 3-51447, since a metal plate is used, the vehicle is liable to run out during running, and unpleasant noise comes in contact with the drive gear. It is often deformed gradually due to repeated contact with gears or chains. This is particularly remarkable in those involving severe vehicle vibration, such as the aforementioned mountain bike. For this purpose, an increase in the thickness of the above-mentioned metal plate has been considered, but this is not realized because the weight is rather increased. Further above
The stopper is secured by screwing one end to the body frame.
However, if the mounting part on the frame side is flat,
Is not easy to loosen, and the drive gear
And the chance of contact with the chain
Where fine adjustment of installation and tightening are required
Therefore, there was also a problem in terms of maintainability.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention is to improve the above-described conventional chain stopper made of a metal plate,
A drive-side gear in which a plurality of speed-change gears having different diameters are coaxially overlapped with an endless chain to improve strength and durability without increasing weight. In the chain entanglement prevention plate adapted to be attached to the inner side of each gear on the side closer to the chain loose side, the plate is made of a thick resin material, and one end is screwed to the bottom surface of the hanger lug.
Both sides of the hanger lug of the plate to be screwed
With its mounting end raised or longitudinally recessed.
Curved to make the mounting side concave, and the concave surface
Form a screw hole in the part and screw it to the bottom of the hanger lug
The present invention also relates to a plate for preventing a chain from being entangled in a bicycle , wherein each end face approaching each gear is parallel to a side surface of the gear.

Further, according to the present invention, each end face approaching each gear is arranged so as to be parallel to the side face of the gear, and a portion of the parallel face of each end face near the drive shaft is provided on the side face of the gear. The present invention also relates to a chain entanglement prevention plate for a bicycle in which a projecting escape groove is formed to avoid an engagement projection.

[0009]

[0010]

[Function] Hanger with concave part of plate
Touch the bottom of the lug, screw it in place
When it is stopped and fixed, the mounting part on the concave surface of the plate
Forcibly crush until the minute gradually becomes flat
And always keeps the reaction force in the recovery direction intact
Is done. Further, when the bicycle is traveling, the loose gear chain is engaged with the gear before shifting when the drive gear is shifted, and when the gear is about to go up in the chain stay direction with the rotation of the gear, it is attached to the side surface of the drive gear. Of the stopper end face of the thick resin, thereby being forcibly disengaged from the drive gear and prevented from further rising. Then, it returns to the original position again by the tension tension of the rear derailleur.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The specific contents of the present invention will be described below with reference to the illustrated embodiment. 1 is a hanger lug, 2 is a chain stay, 3 is a rear wheel, and 4.5.6 is the hanger lug 1 described above. A drive shaft gear (crank gear) coaxially and integrally mounted on the drive shaft X, and a driven shaft gear (free gear) 7 mounted on a drive shaft gear 5 and a hub shaft (not shown) of the rear wheel 3. (Not shown), the chain 7 is constantly tensioned in a pulling direction by a rear derailleur (not shown) attached to the rear wheel hub. The rear derailleur on the wheel side and the front derailleur (not shown) near the hanger axis allow the gears to be freely changed by changing the chain 7 to a plurality of drive gears 4.5.6 each having a different diameter. It has to be able to shift by changing the. Further, reference numeral 8 denotes an entrainment prevention plate.

The entanglement prevention plate 8 is made of a plastic or other thick resin material (more preferably containing glass fiber). The base 8a is attached to the hanger lug 1 and fixed thereto. The three drive gears 4.5.6 are attached so as to be close to the tooth tips of the drive gears 4.5.6 and to be parallel to the side surfaces thereof. Each tip 8b. Corresponds to being arranged in a large one. 8d. 8f is formed in a stepped shape, and is attached with its tip facing the loose side of the drive chain 7.

Further, the end faces 8b. 8d. 8f, that is, each end face 8b. 8d. In the portion near the drive shaft X in the parallel portion of 8f, in order to smoothly perform the shifting operation by changing the chain 7 between the drive gears,
Engagement projections 4a.
Relief groove 8c to avoid 5a. 8e are formed.

Further, a lightening hole 8g is formed on the free end side of the entanglement preventing plate 8, and a base 8a is formed.
Is formed with a mounting hole 8h larger than the diameter of the screw 10 mounted on the hanger lug 1. Thus, the end face 8b. 8d. The base 8a is aligned and pressed against the bottom surface of the hanger lug 1 so that 8f is positioned on the tip side surface of each drive gear 4.5.6, and is fixed by tightening the screws 10 via the metal plate 9. In this case, the adjustment of the mounting position is performed with the screw
Can be easily performed simply by shifting

The frictional resistance is increased by, for example, forming a large number of sharpened projections on the mounting surface of the metal plate 9, and this surface is pressed against the base 8 a of the entrainment preventing plate 8. By doing so, the tips of the projections can bite into the resin plate, so that the mounting can be made more robust and more durable.

[0016]

According to the present invention, as described above, in the drive-side gear which is meshed with the endless chain and in which a plurality of transmission gears having different diameters are coaxially stacked, the respective gears are closer to the chain loose side. In a chain entanglement prevention plate adapted to be attached to the inner surface, the plate is made of a thick resin material, and one end is attached to a bottom surface of the hanger lug.
Screwed and screwed plate c
There is a bumper lug facing side, with its mounting end raised
Or curved concavely in the length direction to make the mounting side concave.
And a screw hole is formed in the concave part
With screwed to the bottom surface of the grayed, the respective end faces approaching each gear, for it is made by along so as to be parallel each to the side surface of the gear, the negative plate
Until the mounting part that has been
Forcibly crushed, and always contained a reaction force in the recovery direction
Hanger lug bottom with uneven surface while keeping the state as it is
Can be loosened due to use over time as it is firmly attached to the surface
Does not occur. Further, when the bicycle is running, the loose side chain is engaged with the gear before the gear shift, and when the gear is going to go up in the direction of the chain stay with the rotation of the gear, the end face (stopper) attached to the side surface of the drive gear. Part), thereby being forcibly disengaged from the drive gear and prevented from further ascending, biting into the narrow gap between the gear and the chain stay to rapidly stop the rotation of the crankshaft, or There is no need to stop the rotation of the wheels, so that running safety is ensured, and there is no risk of damage to the drive parts and the chain stays of the frame body.

In addition, the strength and durability of the plate itself can be improved, and the safety of traveling can be further improved. In addition, the thickness can be secured without increasing the weight as compared with a metal plate. There is no plate deflection on the free end side during running, and therefore, even if there is repeated contact with the chain, deformation, damage, or generation of unpleasant noise does not occur.

Further, each end surface approaching each gear is arranged so as to be parallel to the side surface of the gear, and a portion of each parallel portion near the drive shaft is projected from the gear side surface. In the case where a relief groove is formed to avoid the protrusion, in order to make the speed change operation by changing the chain between the drive gears smooth, it is possible to avoid this even if an engagement protrusion is formed on the side surface of the drive gear, The original function as the entanglement preventing plate is not impaired.

[0019]

[Brief description of the drawings]

FIG. 1 is a perspective view of a main part of a bicycle according to an embodiment of the present invention, which is provided with a chain entrainment preventing plate, as viewed from the bottom side of the bicycle.

FIG. 2 is a bottom view of a main part showing an attached state of a chain entanglement prevention plate of FIG. 1;

FIG. 3 is a side view of a main part showing an attached state of a chain entanglement prevention plate of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Hanger lug 2 Chain stay 3 Rear wheel 4 Drive shaft gear 4a Engagement protrusion 5 Drive shaft gear 5a Engagement protrusion 6 Drive shaft gear 7 Chain 8 Entrapment prevention plate 8a Base 8b End face 8c Escape groove 8d End face 8e Escape groove 8f End face 8g Lightening hole 8h Mounting hole 9 Metal plate 10 Screw

Claims (2)

(57) [Scope of request for utility model registration] 1. A chain in which a plurality of transmission gears having different diameters, which are meshed with an endless chain, are coaxially stacked on a drive side gear and attached to the inner side surface of each gear closer to the chain loose side. In the entrainment prevention plate, the plate is made of a thick resin material, and one end is screwed to the bottom surface of the hanger lug, and the mounting end of the hanger lug facing side of the screwed plate is raised, or The mounting side is concavely curved in the longitudinal direction, and a screw hole is formed in the concave part and screwed to the bottom of the hanger lug, and each end face approaching each gear is attached to the side of the gear. A chain wrap prevention plate for a bicycle that is arranged so as to be parallel to each other. 2. An end surface approaching each gear is arranged so as to be parallel to a side surface of the gear, and a portion of each parallel portion near the drive shaft is projected from the side surface of the gear. 2. A chain entanglement prevention plate for a bicycle according to claim 1, wherein an escape groove is formed to avoid the attachment projection.