Yes,they can be very frustrating to build…they have very fine tolerances,just a couple of thou out can make them tighten up.
The only info I have found so far is from loudspeaker manufacturers Celestion’s website who mention a rival company ‘British Rola’
……….another loudspeaker manufacturer was making similar product. This was the British Rola Company, an offshoot of the Rola Company of Cleveland, Ohio, U.S.A., which began in 1934 at Minerva Road, Park Royal, London NW10.…………….
British Rola Limited was registered during 1938 as electrical and general engineers, toolmakers and stampers, and when World War Two broke out they opened up a dispersal factory at Bideford in Devon, in the former garage of Messrs Elliot and Sons. Production for the war effort grew apace with the manufacture of the R.A.F. B3 Vacuum Pump, several thousands of which were produced. These were followed into production by the Rotol Airscrew Feathering Pump, four of which were fitted to all British multi-engined bombers. The final product was the Integral Hydraulic Pump BH Mark IV, and all these items contributed in no small measure to the Forces’ need for reliable battle equipment.
Sign In
