In a workshop where Isaac was working on his second wood carving machine, the Blodget & Leroy sewing machines were assembled and repaired. With 40 Dollars he borrowed from a friend George Zieber, to pay for parts and welding, he set to work, with their permission, on one of the Blodget & Leroy machines. He worked for eleven days and nights, scrapping and adjusting the parts he made, eating and sleeping when he could.
Isaac's invention was a long boat shaped shuttle which held a thin spool. Yards and yards of thread were wound evenly around the spool which, in the shuttle, went back and forth beneath the base of the machine. A straight long needle was held at the top by the machine with an eye at the bottom near the point. The eye was threaded with thread from a bobbin at the top of the machine. A wheel attached to the side of the machine when turned by a handle, activated the needle and shuttle. The needle went up and down looping the thread from the shuttle and making a stitch.
On the eleventh day Isaac was very despondent. Looking at the two pieces of material he had tried to sew together, the stitches had repeatedly knotted and the thread then snapped. His friend George went home to bed, Isaac sat in front of the machine, very depressed, just what was he doing wrong? A thought flashed through his mind, it was not the machine that was wrong, it was the tension of the thread. Once he had made the adjustments to correct the tension of the thread, it worked perfectly and stitched two pieces of material together, measuring an inch.. It was the first machine made and used by Isaac and the patent was applied for in September 29th 1850 in New York and granted in September 1856.
Isaac was now 40 years old. His marriage to Catherine was in name only and he and Mary Ann were living as man and wife with their eight children. There were two more but they had died when only toddlers.
With his invention Isaac thought his money worries were over but Elias Howe another inventor, accused Isaac of stealing his invention and he was going to take him to court and sue him.
Isaac was still short of money and was unable to hire a lawyer, but he let it be known that he was willing to give a third of the Singer Sewing Machine shares to any lawyer who would take on the case and win.
Edward Clarke, a solicitor accepted the challenge and won the complicated case. Elias Howe did not lose either. Once the patent had been granted, he received royalties from every sewing machine company that used the invention.
George Zieber having lent Isaac the 40 dollars he needed to get started, eventually was persuaded to sell his shares to the company for 6000 dollars and the firm became known as the Singer & Clarke Sewing Machine Company.