Explanation:

- Option 1: John Kay invented the flying shuttle, which improved weaving efficiency but did not invent the sewing machine.

- Option 2: James Hargreaves invented the spinning jenny, which contributed to the textile industry but was unrelated to the sewing machine.

- Option 3: Elias Howe is correct. He was one of the first to patent a practical sewing machine, which greatly impacted cloth stitching and revolutionized the garment industry.

- Option 4: Henry Court is known for advancements in iron production, such as the puddling process, not sewing machines.