From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Press cuttings from 'Motor' and 'The Export Trader' describing the Servais straight-through silencer.
| Identifier | ExFiles\Box 152\3\ scan0218 | |
| Date | 16th June 1936 | |
| Servais DURRANT'S PRESS CUTTINGS St. {Capt. P. R. Strong} Andrew's House, 32 to 34 Holborn Viaduct, and 3 St. {Capt. P. R. Strong} Andrew Street, Holborn Circus, E.C.1. Telephone: CENTRAL 3149 (Two Lines). Motor 7-15 Rosebery Avenue, E.C. Cutting from issue dated......16 JUN 1936.........193 Striking Demonstrations of a New Silencer A PARTY of journalists and technical people gathered at the Savoy Hotel last Wednesday to witness demonstrations of the Servais silencer which is described in this issue. In the first test a pistol was fired with a startling report. A little Servais silencer, about 6 ins. long, was then clipped to the barrel, and the ensuing shot was barely audible above the noise of ordinary conversation. Then a miniature petrol engine was started with the lusty clatter of its type, and this was reduced to a gentle splutter, much like a water tap running, so soon as the small Servais silencer was attached. Equally striking results were obtained with full-size silencers on actual cars, complete silence being maintained at high engine speeds. The EXPORT TRADER DORSET HOUSE, STAMFORD STREET, LONDON, S.E.1. PUBLISHED MONTHLY We have pleasure in sending you an extract from our issue of ......................... which we hope will prove of interest. THE EDITOR STRAIGHT-THROUGH SILENCER SERVAIS SERVICES, LTD., a firm in London, are now manufacturing a silencer known as the Servais, which is designed to eliminate noise without producing back pressure. In principle the silencer consists of a sheet of expanded metal formed into a spiral, the space between the convolutions being packed with steel wool. A welded sheet-steel cylinder encloses the whole and is finished with stub pipes at each end. As the inner passage is built up of expanded metal there is really no central tube. The inside is elastic and flexible and is in full contact with the gases. As exhaust gases come out of the pipe into the silencer their impulses are absorbed, and as a result of friction with the expanded metal the direct egress of the gas is slightly resisted, a state of minor turbulence being set up. There is actually no appreciable restriction of flow, but the unchecked impulse of each exhaust stroke is split up. Back pressure is reduced as compared with an ordinary baffle-type of silencer and the silence of the exhaust is noticeably improved. THE TRADER PUBLISHING CO., LTD. | ||