This John Browning design was produced as the Colt Model 1903 and by Fabrique Nationale as the Browning M1903. The Colt Model 1903 was offered in two versions, which actually used different calibers. The Colt Model 1903 Pocket Hammerless was chambered in .32 ACP, while the Colt Model 1903 Pocket Hammer was chambered in .38 ACP.
John Browning was granted US Patent 747585 on December 22nd, 1903. He applied for this patent on April 3rd, 1902.
John Browning Patent 747585, Colt Model 1903 and FN Browning M1903 Drawings: