Yamaha Hatsudoki Kabushiki Kaisha

Sunstar Engineering Pte. Ltd.

Yuya Okuda

Yuki Murayama

Satoshi Kubota

Masafumi Shimizu

Provided is a strong and lightweight sprocket. A sprocket according to one aspect of the present invention comprises: attachment holesformed at equal intervals in the circumferential direction; a plurality of sprocket teethprovided to the outer periphery; first openingsformed into substantially triangular shapes of which two corners each face an attachment holeand the remaining corner is positioned toward the outer periphery; and second openingsthat are formed into substantially triangular shapes of which one corner faces an attachment holeand the remaining two corners are positioned toward the outer periphery, and that, with the first openings, demarcate first crossbarswith which driving force and load reaction force align and second crossbarswith which driving force and load reaction force conflict.

Sprocket

A handle includes handle grips and a handle pipe including an attachment portion, a first grip portion, a second grip portion, a first bent portion between the attachment portion and the first grip portion, and a second bent portion between the attachment portion and the second grip portion. The first grip portion includes a first overlapping region overlapping a first handle grip and a first non-overlapping region not overlapping the first handle grip. The second grip portion includes a second overlapping region overlapping a second handle grip and a second non-overlapping region not overlapping the second handle grip. The first and second non-overlapping regions each include a thick portion having a thickness larger than, or equal to, a thickness of the attachment portion. The first and second overlapping regions each include a thin portion having a thickness smaller than the thickness of the thick portion.

Growing community of inventors

Iwata, Japan

Yuya Okuda