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).
Analysis of different types of shock dampers, including the 'Hartford' type and single-acting variable load dampers.
| Identifier | ExFiles\Box 178\1\ img160 | |
| Date | 22th June 1926 | |
| - 6 - Hs{Lord Ernest Hives - Chair}/Rml/T22.6.26. however, varies with the angle of the scissor arms and usually gives the least restraining force at max. spring deflection and the maximum when the spring extension is greatest. It is quite clear that the "Hartford" type of shock damper directly aggra- vates the complaint for which type II shock absorbers are fitted. If sufficient friction is applied to be really effective at high speeds the low speed riding is bound to suffer. In addition the loading of these shock dampers varies widely from its initial setting due to climatic effects on the friction plates. Wear also occurs rather rapidly on the wooden bushes "a.a." allowing rattles to be set up. In more recent designs a rubber shackle takes the place of the wooden bushes, this is claimed to give superior service. It will be observed that the "Hartford" is double acting, i.e. it provides extra friction both on the compression and extension of the spring, giving an increasing load on extension throughout its entire range. (b) Single acting variable load dampers. The shortcomings of the Hartford type being realised, especially in the case of cars used chiefly as town carriages, other designs which are single acting have been evolved. These almost invariably check the rebound of the spring only. Though in some cases these "Snubbers" as they are frequently termed, may affect the low speed riding comfort less for a fixed amount of high speed damping than the double acting "Hartford" type, contd. | ||