N.K. Chinnusamy ("Chinn") was born on July 1, 1939 in the small farming village of Nalligoundanur in the state of Tamil Nadu, Southern India.
He was the youngest of three siblings born to N.K. Kavundiappa (father) and Karuppayammal (mother).

He was the first engineer in his family and graduated from the PSG College of Technology with a B.S. in Mechanical Engineering in 1962. Upon graduation from PSG, he spent six years working as an engineer for the Tamil Nadu Public Works (PW) Department. In search of greater fulfillment and success, he made decision to move abroad. After a very brief stint in London, United Kingdom, he arrived in Chicago, IL in the Spring of 1968.

He landed a job at Ingersoll Milling Machine in Rockford, IL as a design engineer. He then spent the next twenty-two years at Ingersoll, executing design work for large, complex machine tools that Ingersoll was known for delivering to the marketplace. Over the course of his career at Ingersoll, he developed deep technical expertise in gear design and manufacturing. Still fueled by the same ambitions that brought him to the United States in 1968, he left Ingersoll in 1990 to start a brand new gear manufacturing company – Excel Gear. He led Excel Gear as president for the next 33 years, until the company was sold in 2023. He loved the work of complex product designs, spanning gear boxes to high-speed spindles. His design talents were also accompanied by a knack for troubleshooting problems on the manufacturing shop floor. Every action he took and decision he made was in service of what he thought was best for Excel Gear, all underpinned by a direct management style.

Outside of his work, he enjoyed playing golf at Sinnissippi Golf Course on the weekends (often coming back home and stating that he was "hacking it out there"), watching golf and other sports on TV, and working on this yard. He also took on a lot of repair projects at home, putting his mechanical aptitude to very productive use. In his later years, he enjoyed taking trips with his family and spending time with his grandchildren.

Chinn is survived by his wife Thilakavathy, his son Aravinth (Kavitha), his daughter
Prathiusha (Vijay), and his grandchildren Tej and Nila.

He was preceded in death by his parents and his older brothers N.K. Natarajan and N.K. Subramaniam.
He endeared himself to family, friends, co-workers, neighbors, and acquaintances through his humility, candor, and honesty.

Visitation Saturday, November 22nd, from 11:30am until time of Puja Service 1:30pm at McCauley-Sullivan Funeral Home 530 W. Boughton Rd. Bolingbrook, IL. 60440. Cremation Rites to follow Puja Service.

In lieu of flowers or gifts, please consider a donation to the Alzheimer's Association ().