John Kay (spinning frame) a spinning machine embodying the ideas which they had been developing. Arkwright patented it 1769 without mentioning Kay, his "workman". Kay learned of this patent from another Nottingham inventor, James Hargreaves, and told Hargreaves that it was he, Kay, who was the real inventor. Arkwright accused Kay of revealing the design to Hargreaves, and the two fell out. Kay left Arkwright's Nottingham house, where he had been living, ending their relationship. Kay subsequently accused Arkwright of stealing his work tools, and Arkwright made a counter-charge . The spinning machine as constructed in Nottingham by Kay and Arkwright was powered by
Spinning jenny "Jenny" in the machine's name is that a daughter (or his wife) named Jenny knocked over one of their own spinning wheels. The device kept working as normal, with the spindle now pointed upright. Hargreaves realized there was no particular reason the spindles had to be horizontal, as they always had been, and he could place them vertically in a row. The name is variously said to derive from this tale. The Registers of Church Kirk show that Hargreaves had several daughters, but none named Jenny (neither was his wife). A more likely explanation of the name is that 'Jenny'