JPH0594088U - Plate to prevent the chain from being caught in the bicycle - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] To align the free end of thick, high-strength and durable resin material with the tip side of each drive gear tip with different diameter and number of teeth. As a result, when the drive gear is shifted, the slack side chain is prevented from rolling up in the direction of the chain stay while meshing with the gear before shifting, thereby improving safety. [Structure] Incorporation of a bicycle chain in which a plurality of speed change gears having different diameters are coaxially overlapped with each other in a drive side gear, which meshes with an endless chain In the prevention plate, the plate is made of a thick resin material, and the respective end faces approaching the gears are arranged so as to be parallel to the side faces of the gears. As a result, compared with metal ones, it can be made thicker without increasing the weight, has no shake during running and has high strength and durability,
Moreover, no unpleasant noise is generated.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to the improvement of an anti-bite plate of an endless chain wound between a drive shaft gear and a driven shaft gear in order to transmit the driving force of a crank shaft in a bicycle to a rear wheel hub. Not only does it prevent running hazards due to stopping the rotation of the axle and stopping the rotation of the rear wheels, and also eliminates damage to the bicycle drive and chain stays of the frame, it also improves the strength and durability of the plate itself. By doing so, it is intended to further improve traveling safety.

[0002]

[Prior Art]

 The use of chains as power transmission means for bicycles is extremely advantageous in terms of durability, and is widely used in practical vehicles, light vehicles, sports vehicles, etc., especially in mountain bikes and sports vehicles. In this case, in order to change the speed by changing the drive gear ratio, the number of crankshaft gears and rear wheel side freewheel driven gears in the above-mentioned hanger must be multiple, and the diameter of each gear must be increased or decreased in order. Many of the different configurations are used. In this case, the chain length is set to an extra length and a constant tension is always applied by the tension mechanism of the rear derailleur.

In particular, mountain bikes are required to have a large tire width in order to ensure sufficient running stability to withstand uneven bumps and rough roads in the mountains, and to reduce power loss during running. In order to achieve this, it is also desired to create a short rear center. Furthermore, when there are multiple shift gears, the chain line between the drive gear and the driven gear cannot be significantly displaced in order to ensure sufficient shift performance, and therefore the position of the drive gear must be within a certain range. As a result of internal restrictions, 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, the slack side portion of the chain becomes difficult to be easily separated from the gear before the gear shift when the drive gear is shifted, and the slack side portion of the chain is changed to the rear gear as the drive gear rotates. The derailleur tends to be wound up upward in the rotational direction of the drive gear against the tension force, and as a result, it is often caught between the drive gear and the chain stay.

In such a case, the rotation of the crankshaft may suddenly stop, and in some cases, an accident may occur such that the chain is cut off, which makes it extremely dangerous to drive. There is also a risk of damage to the gears of the drive part and chain stays in the frame. Therefore, recently, the tip of the metal plate is bent at a right angle so that it runs along the side of the chain slack side near the tooth tips of multiple drive gears with different numbers of teeth, and the tip corresponds to the slack side of the chain. The present inventors have developed a chain stopper adapted to run along the side surface of each drive gear (Japanese Utility Model Application No. 3-51447).

[0006]

[Problems to be solved by the device]

 However, since the above-mentioned Japanese Utility Model Laid-Open No. 3-51447 uses a metal plate, it is likely to cause lateral vibration during traveling, which may make an unpleasant sound when it comes into contact with the drive gear, or when the gear or chain is used. It often deforms due to repeated contact. This is remarkable in the mountain bikes mentioned above, especially those accompanied by severe vehicle body vibrations. For this reason, increasing the plate thickness of the above-mentioned metal plate has also been studied, but it is not realized because the weight is rather increased.

[0007]

[Means for Solving the Problems]

 Therefore, the present invention is to improve the above-mentioned conventional chain stopper made by processing a metal plate so as to improve the strength and durability without increasing the weight. Specifically, it is meshed with an endless chain. However, in a drive-side gear in which a plurality of speed change gears having different diameters are coaxially overlapped, a chain wrap-around prevention plate that is fitted to the inner side surface of the respective gears near the chain slack side has a thick wall. The present invention relates to a chain entanglement prevention plate for a bicycle, which is made of a resin material and has its respective end faces approaching each gear arranged parallel to the side faces of the gear.

Further, according to the present invention, the respective end faces approaching the respective gears are arranged so as to be parallel to the side faces of the gears, respectively, and the gears are provided in the parallel portions of the respective end faces near the drive shaft. It also relates to the chain's entanglement prevention plate for bicycles, which is formed with a relief groove that protrudes to the side to avoid the engagement protrusion.

Further, the present invention is such that a thick plate is screwed to the bottom surface of the hanger lug, and the screwed side of the plate is curved in a concave shape in the longitudinal direction, and the curved surface is curved. It also relates to a chain entanglement prevention plate for a bicycle, which has a screw hole formed in the part and is screwed to the bottom of the hanger lug.

[0010]

[Action]

 While the bicycle is traveling, when the slack side chain is in mesh with the gear before gear shifting when shifting the drive gear, and when trying to move up in the chain stay direction as the gear rotates, , It is pressed against the side surface of the end face of the thick resin stopper, which is forcibly disengaged from the drive gear and prevented from rising further. Then, the tension of the rear derailleur returns to the original position.

[0011]

【Example】

 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 a drive shaft X of the hanger lug 1. A drive shaft gear (crank gear) coaxially and integrally attached to the drive shaft gear, and a driven shaft gear (free gear) 7 (not shown) attached to the drive shaft gear 5 and the hub shaft (not shown) of the rear wheel 3. The chain 7 is an endless chain that is stretched between the rear wheel side and the rear wheel hub side, and the rear derailleur (not shown) attached to the rear wheel hub constantly applies tension in the pulling direction. By using the rear derailleur and the front derailleur (not shown) near the hanger shaft, it is possible to freely change the gear ratio by replacing the chain 7 with multiple drive gears 4.5.6, each of which has a different diameter. Ete is made to be able to shift. In addition, 8 indicates the entanglement prevention plate.

The entanglement prevention plate 8 is made of plastic or another thick resin material (preferably containing glass fiber). The base portion 8a is fixedly attached to the hanger lug 1, and at the free end side, The three drive gears with different diameters are attached so that they come close to the tooth tips of the drive gears and are parallel to the side faces of the drive gears. The tips 8b. 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 surface 8b. 8d. 8f at each intermediate portion, that is, each end surface 8b. 8d. 8f, in a portion near the drive shaft X in the parallel portion, the engaging protrusions 4a. 4a. Protruded from the side surfaces of the drive gears 4 and 5 in order to smooth the speed change operation by switching the chain 7 between the drive gears. Escape groove 8c for avoiding 5a. 8e is formed.

Further, a lightening hole 8g is formed on the free end side of the roll-in prevention plate 8, and a mounting hole 8h larger than the diameter of the screw 10 mounted on the hanger lug 1 is formed in the base portion 8a. However, the end face 8b. 8d. The base portion 8a is aligned and pressed against the bottom surface of the hanger lug 1 so that 8f is located on the tip side surface of each drive gear 4.5.6, and is fixed by tightening the screw 10 via the metal plate 9. The adjustment of the mounting position at that time can be easily performed only by shifting the entrainment prevention plate 8 with the screw 10 loosened.

Further, the metal plate 9 is increased in frictional resistance by a method such as forming a large number of sharp projections on its mounting surface, and this surface is pressed against the base portion 8a of the entanglement prevention plate 8. By hitting, the tips of the protrusions can bite into the resin plate, which makes the attachment stronger and more durable.

[0016]

[Effect of the device]

 As described above, the present invention is provided on the inner side surface of each drive gear, which is meshed with an endless chain and has a plurality of transmission gears of different diameters, which are coaxially overlapped with each other. A chain entrainment prevention plate adapted to be made of a thick resin material, and the end faces approaching each gear are arranged parallel to the side faces of the gear. Therefore, while the bicycle is running, when the slack side chain engages with the gear before shifting during gear shifting, and when trying to move up in the chain stay direction as the gear rotates, the It pushes against the end face part (stopper part) along with it, and it is forcibly disengaged from the drive gear, preventing further rise, and biting into the narrow gap between the gear and chain stay. Nde prevents to or stops the rotation abruptly stops the rotation of the crankshaft, or the rear wheels, the running safety is ensured, moreover a risk damaging the chain stay portion of the drive portion and the frame body is eliminated.

Not only that, but the strength and durability of the plate itself can be improved to further improve the traveling safety, and the thickness can be secured without increasing the weight compared to the metal one, There is no runout of the plate on the free end side during running, so that repeated chain contact does not cause deformation or damage, or generation of unpleasant noise.

Further, the respective end faces approaching the respective gears are arranged so as to be parallel to the side faces of the gears, and the portions of the respective parallel portions which are close to the drive shaft are projected to the gear side surface. If an escape groove is formed to avoid engagement protrusions, avoid this even if engagement protrusions are formed on the side surface of the drive gear in order to facilitate the shifting operation by switching chains between the drive gears. Therefore, the original function as the roll-in prevention plate is not impaired.

In addition, the thick roll-in prevention plate is screwed to the bottom surface of the hanger lug, and the mounting end is raised or the screwed side of the base plate is curved in a concave shape in the length direction. In addition, if a screw hole is formed in the curved part and it is screwed to the bottom of the hanger lug, the plate can be forcibly deformed by the screw, and as a result, it is always attached by the reaction force in the restoring direction. Will become stronger.

[Brief description of 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 roll-in prevention plate and is viewed from the bottom side of the bicycle.

FIG. 2 is a bottom view of an essential part showing a state where the chain winding prevention plate of FIG. 1 is attached.

FIG. 3 is a side view of a main portion showing a state in which the chain winding prevention plate of FIG. 1 is attached.

[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 Entrainment prevention plate 8a Base part 8b End face part 8c Escape groove 8d End face part 8e Escape groove 8f End face 8g Lightening hole 8h Mounting hole 9 Metal plate 10 Screw

Claims (3)

[Scope of utility model registration request] 1. A chain adapted to be meshed with an endless chain so that a plurality of speed-changing gears having different diameters are coaxially overlapped with each other, and the respective gears of a drive-side gear are fitted to the inner side surface of the respective gears on the loose side of the chain. The entanglement prevention plate of the bicycle, wherein the plate is made of a thick resin material, and the end faces approaching the gears are arranged so as to be parallel to the side faces of the gears. plate. 2. An end face approaching each gear is arranged so as to be parallel to a side face of the gear, and a portion of each parallel portion near the drive shaft is projected to the gear side face. The chain winding prevention plate for a bicycle according to claim 1, wherein the escape groove is formed to avoid the landing protrusion. 3. The thick plate is screwed to the bottom surface of the hanger lug, and the screwed side of the plate is raised at its mounting end or curved in a concave shape in the lengthwise direction. 2. The chain entanglement prevention plate for a bicycle according to claim 1, wherein the chain is a concave surface, and a screw hole is formed in the concave surface portion so as to be screwed to the bottom surface of the hanger lug.