JPH04110692U - Crank extraction device - Google Patents

Abstract

(57) [Summary] [Purpose] The work of attaching and removing the crank to the bicycle crankshaft can be done easily in a short time, eliminating the need for conventional tools and reducing screw machining. [Structure] A concave hexagonal hole or hexagonal groove is provided in the center of the hexagonal head of the bolt or seat nut used to attach or remove the crank from the bicycle crankshaft. . Provide a round hole for a hex wrench in the center of the cap that supports the bolt or seat nut. Insert the bolt or seat nut into the crank hole first, then push the cap into the crank hole to secure it. Align the crankshaft with the crank hole and tighten/untighten with a single hex wrench.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This idea involves attaching the crank used to drive the bicycle to the crankshaft, or This invention relates to a crank tightening device used for removal.

0002

[Conventional technology]

There are two ways to connect the left and right cranks of a bicycle to the crankshaft: the cottered type and the crankshaft. There is a cotterless type. Clamps that use hex bolts for cotterless tightening crankshaft (bolt type) and a crankshaft with a screw at the end of the shaft and a seated nut. (shaft nut type). In both cases, up to 7.5mm from the crank surface is M22x There is a counterbore hole for the pilot hole for screw No. 1, and the bolt head or seat nut is inserted into this space. circle. The counterbore hole fits the dust cap, and the extractor ) can also be used as a screw to fit.

0003 In the former case, a pair of left and right cranks of bolt type and shaft nut type are tightened on both sides of the crankshaft. The fitting and removing methods are performed in the following order. Tightening method: A. Fit the crank onto the crankshaft. B, shaft washer and bolt Or, lightly insert the seat nut into the concave or convex thread of the crankshaft. Ha, ex Insert the 14mm hexagon hole on one side of the tractor into the hexagon of the bolt head or seat nut. , screw in until it stops. D. Hold the extractor with your left hand and use the wrench or Align the adjustable spanner (angle wrench) with the two corners of the extractor and tighten firmly. wear. E. Remove the extractor from the bolt head or seat nut. Heh, da Gently screw in the stop cap and tighten with a coin, etc. How to remove: A. Loosen the dust cap with a coin, etc. and remove it. B, Extrac. Insert the 14mm hexagonal hole on one side of the Hold the extractor and use the adjustable spanner with your right hand to tighten the bolt or nut. Loosen it and remove it by turning the extractor. C. One side of the extractor M22 x 1 Gently align the threaded part of the screw into the pilot hole of the crank to a depth of 7.5mm. Screw into. D. Screw the center of the extractor onto the crankshaft until it stops. Ho , align the monkey wrench with the two corners of the extractor and remove the crank from the crankshaft. loosen. Turn the extractor and remove it from the screw hole in the crank.

0004

[Problem that the idea aims to solve]

In the conventional proposal mentioned above, the special tool used to tighten and remove the crank A tractor is required, and since the crank made of aluminum is soft, use an M22 x 1 screw. There is a risk of the pilot hole collapsing, and once the screw thread is broken, it will be difficult to remove the crank from the crankshaft. It is very difficult to operate, and the crank becomes unusable. Also, since the crank tightening/unscrewing operation is complicated, Therefore, it is necessary to learn assembly techniques.

[0005] This idea was created to simplify the above-mentioned complicated operation and protect the crank screw. It was invented in To provide a crank tightening/unscrewing device capable of tightening/unscrewing.

[0006]

[Means to solve the problem]

In order to achieve the above purpose, the bolt-type or shaft-nut type clamp of this invention is used. The configuration of the bolt or seat nut used to attach the crank to the crankshaft should be changed to a hexagonal bolt head. A concave hexagonal groove is provided in the center of the shape, and the shaft nut is designed to match the length of the end thread of the crankshaft. Tighten the back of the nut to make a hexagonal hole in the center. When removing the crank from the dust cap, the bolt or seat nut will be supported inside the cap. Make a slot in the cylindrical part of the cap using a material such as metal that has the strength you can afford, and Provide a press-fit collar at the tip. A concave hexagonal groove in the center of the bolt head or It has a round hole that fits into the hexagonal wrench of the tightening tool that fits into the hexagonal hole in the center of the shaft nut. This is a feature of the system.

[0007]

[Effect]

Therefore, if the crank is a bolt type, there is a shaft washer and bolt, and if the crank is a nut type. Insert the seat nut first and secure the dust cap first to secure the bolt head. Hexagonal wrench 1, a tool that fits into the concave hexagonal groove in the center of the shaft nut or the hexagonal groove in the center of the shaft nut. With this book, you can tighten and tighten the crank onto the crankshaft.

[0008]

【Example】

Hereinafter, this invention will be explained in detail based on the illustrated embodiments. As shown in FIG. Bolts 3 and shaft washers 4 or seat nuts that fix the crank 2 to the crankshaft 1 6 and a dust cap 8 fixed to the crank 2.

[0009] In addition, the bolt 3 has a concave hexagonal groove 5 in the center of the head, or the center of the seat nut 6 It has a hexagonal hole 7 in it. 6 in the center of the dust cap 8 fixed to the crank 2. Has a round hole 9 into which a square wrench can be inserted, and a long hole used for attaching or removing the cap. It is said that a square hole 10 is provided.

0010 This invention consists of the above structure, and the operation method will be explained step by step from installation. If so, insert the bolt 3 and shaft washer 4 or seat nut into the threaded hole 11 of the crank 2. Insert 6. Until the press-fit spring 13 of the dust cap 8 is inserted into the pilot hole 12 of the crank. Push in with your fingers to secure it, and insert the inner square hole of crank 2 into the square taper of crankshaft 1. and insert the hex wrench from round hole 9 into concave hexagon hole 5 or hexagon groove 7. Turn the hex wrench to secure the crank to crankshaft 1. On the other hand, as shown above, If you want to remove crank 2 fixed to rank shaft 1, just reverse the above steps. However, the dust cap 8 fixed to the crank 2 and the bolt and shaft washer or seat nut There is no need to remove the kit if it is used with the same bolt type or shaft nut type.

[0011]

[Effect of the idea]

As described above, according to this invention, the threaded part of the crank is protected, so it can be used as many times as needed. The crank can be replaced, and there is no need for an extractor, a special tool for extraction. . Also, there is no need to learn assembly techniques, and anyone can easily and quickly install it with just a hex wrench. It has the advantage that the crank can be tightened and removed from the crankshaft.

0012 Also, with bolt type, the hexagon on the outside of the bolt head is not necessarily required. A commercially available cap with a round bolt head and a concave hexagonal groove in the center of the head. It can also be used with top bolts (hexagonal socket bolts), and the dust cap can be used with bolts. Or it can be used to support the seat nut, so it can be fixed by press fitting, and it can be fixed under the crank screw. Since only a groove is required in the part, there is an advantage that thread cutting of the crank can be omitted.

[Brief explanation of drawings]

FIG. 1 is a front view and a side view of a bolt and a shaft washer or seat nut for fixing a crank to a crankshaft according to an embodiment of the invention.

FIG. 2 is a front view and a side view of a dust cap that supports a bolt or seat nut.

FIG. 3 is a side view of a crankshaft (shaft nut type), a seat nut and a dust cap installed inside the crank.

[Explanation of symbols]

1 crankshaft 2 crank 3 bolt
4 Shaft washer 6 Nut with seat 8 Dust cap

Claims (1)

[Scope of utility model registration request] Claim 1: In the bolt type and shaft nut type crankshafts for mounting the bicycle crank, the bolt used for tightening and tightening the crank has a concave hexagonal groove or hexagonal hole in the center of the hexagonal head of the seat nut. to accomplish. Further, a crank extraction device is characterized in that a slot is made in the cylindrical portion of the cap, a press-fit collar is provided at the tip, and a rectangular hole with a round hole is provided in the center of the head of the cap.