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).
Combination of friction and hydraulic shock dampers for vehicles.
| Identifier | ExFiles\Box 87\3\ scan0128 | |
| Date | 2nd August 1934 | |
| To Sg.{Arthur F. Sidgreaves - MD} and WGr. from E.{Mr Elliott - Chief Engineer} c. HS.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} Combined Friction and Hydraulic Shock Dampers. As we rather anticipated, the Hartford shock dampers we added to E.R.Hall's Bentley are greatly appreciated for steadying the car at high speeds, and clearly show the benefits of a little dry friction super-imposed on the damping already provided by the hydraulics. We think this can perhaps be explained by the different characteristics of the two systems wherein the hydraulic is at a maximum at half stroke, and the dry friction obtains its maximum where stiction occurs at each end of the stroke. This rather suggests that we might advantageously modify our present dampers by combining in them some dry friction, and with such a scheme the damper control would be arranged on the dry friction and the hydraulic arranged with a characteristic which would possibly automatically increase with speed. Before however we proceed very far in considering this proposal we should be glad if the Experimental Department would confirm the advantage to be gained from it by equipping one of our own cars with the same schemes as we got out for Mr E.R.Hall's Bentley and trying different degrees of friction at different speeds. The front damper scheme as arranged will go on any Bentley, but the rear one perhaps is not suitable for any of our normal bodies, in which case we can rig up the dry friction on the existing damper itself. We should also be glad if By/NW{N. Walker - Patents} would let us know if a combination damper as suggested above has sufficient novelty to warrant patent protection. E.{Mr Elliott - Chief Engineer} | ||