The JoLoAr pistol was a combination of a poor-selling and unremarkable Spanish blowback semiauto pistol called the Sharpshooter and an idea by a man named Jose Lopez Arnaiz (whose name is the source of the pistol’s name). Arnaiz conceived the idea of mounting a lever (palanca in Spanish) onto a pistol slide, to allow the pistol to be charged one-handed. There is a rumor (unsubstantiated) that he was inspired by the one-armed commander of the Spanish Foreign Legion, Colonel José Millán-Astray. But whatever the inspiration, Arnaiz patented his idea, and went looking for a manufacturer.
The company he found was Hijos de Calixto Arrizabalaga, who were making the rather mundane Sharpshooter. This was a blowback pistol, which was designed without an extractor. Instead, it was equipped with a tip-up barrel for clearing malfunctions and unloading the chamber. This feature carried over to the JoLoAr, although an extractor had also been added to the design by that time. Wanting to maintain control over his idea, Arnaiz opened his own small shop where his employees would add his patented palanca to otherwise-complete JoLoAr pistols made by Arrizabalaga.
Arrizabalaga’s experiment with the Arnaiz idea worked out fairly well, really. About 30,000 JoLoAr pistols were made between the mid 1920s and early 1930s, which is probably a lot more than would have been sold as plain Sharpshooters. This example is in .45ACP; quite scarce in the United States today.