This inventor holds 6 USPTO granted patents. Top assignees: Bridgestone Cycle Co., Ltd., Bridgestone Corporation. Active years: 1990-1992.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile
Location History:
- Ageo, JP (1990 - 1991)
- Urawa, JP (1992)
Company Filing History:
6 out of 37 
1 out of 5,196 
Years Active: 1990-1992
Title: Kiyofumi Hirai: Innovator in Mechanical Engineering
Introduction
Kiyofumi Hirai is a notable inventor based in Ageo, Japan, recognized for his contributions to mechanical engineering. With a total of six patents to his name, Hirai has made significant advancements in the field, particularly in the design of friction-type speed change devices and bicycle components.
Latest Patents
One of Hirai's latest inventions is a friction-type stepless speed change device. This innovative device features frictional transmission elements that consist of a pair of driving discs connected to an input shaft, along with an annular driven disc linked to an output shaft. The design allows for power transmission through wedge-engagement, generating frictional force between the driving and driven discs. The variable eccentricity of the driving discs relative to the driven disc enables a seamless speed change, enhancing the device's efficiency. Additionally, the invention includes a driving rotary unit that transmits power at an increased rotational speed and a driven rotary unit that reduces the output speed, all while minimizing the size of the frictional transmission elements.
Another significant patent by Hirai is a wheel rim designed for two-wheeled vehicles. This innovative rim features a spray-coated metallic and/or ceramic layer that covers part of the rim surface, which comes into contact with the brake shoe when braking is applied. This design enhances the durability and performance of bicycle rims.
Career Highlights
Throughout his career, Kiyofumi Hirai has worked with prominent companies, including Bridgestone Cycle Co., Ltd. and Bridgestone Corporation. His experience in these organizations has contributed to his expertise in mechanical design and innovation.
Collaborations
Hirai has collaborated with notable coworkers such as Yoshitaka Tamura and Kikuzo Takamiya, further enriching his professional journey and expanding his impact in the field of engineering.
Conclusion
Kiyofumi Hirai's inventive spirit and dedication to mechanical engineering have led to significant advancements in speed change devices and bicycle components. His contributions continue to influence the industry and inspire future innovations.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile