Ergas was a small company based in Rue Du Nord 29 2720 Tramelan in Switzerland founded in 1945

and bought by Patek in 2001. In 2001 it had only 15 staff and manufactured precision engineering and clocks. The company was liquidated in 2006. 

Ergas had only 2 patents. One was for a watch strap, the second was Swiss patent 367124 (granted in 1963 and lapsed in 1977) for an electrically rewound balance wheel movement of high quality, in 2 versions running on either 4.5volts or 110/220vac. The platform has 15 jewels and 5 hours winding reserve and rewinds once an hour. These movements were used by several high end companies, including Tiffany and Co in the US and Concord Watch Co. and were made throughout the 1960s and 70s. 

Ergas movements were also used in the Rex Mundi clock but Ergas does not appear as maker on its dial, see separate folder for this large world time clock