The company's products included valves, radios, televisions and military electronics.
The younger son Frank Cossor joined the company in 1885, and eventually took over the running of the original scientific glassware company which remains to this day as Accoson, a manufacturer of sphygmomanometers.
Cossor, a go-ahead electronics firm, designed, and manufactured electronic thermionic valves, domestic radio sets and television receivers both before, and after World War II.
During the War, their work on the Chain Home radar alongside Pye and EMI brought great prestige to the company.
Cossor has designed IFF equipment for the British Aerospace Rapier missile, Shorts Blowpipe missile, Bofors RBS-70, Ericsson's Giraffe radar and the Contraves Italiana's LPD-20 air defence radar.