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).
Decision to use Bensport direct-acting brakes over servo, hydraulic, or vacuum-assisted types.
| Identifier | ExFiles\Box 84\2\ scan0005 | |
| Date | 1st October 1932 | |
| HS.{Lord Ernest Hives - Chair} FROM R.{Sir Henry Royce} X206 R4/M.10.32. C. to SG.{Arthur F. Sidgreaves - MD} WOR.{Arthur Wormald - General Works Manager} DA.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} BY.{R.W. Bailey - Chief Engineer} BENSPORT BRAKES. ------------------ We are more than pleased that we have settled to make the Bensport brakes direct acting. We fear the servo might give less even results, and be a little too dangerously powerful in the control of a strong or nervous person. We have learnt that hydraulic brakes of the Lockheed type, if any part of the system is in the proximity of heat (not exhaust pipe) or the brake drums become heated, generate vapour, and render the brakes inoperative. We know that vacuum assisted brakes might not prove reliable in the case of mountain work through the engine stopping, so that we think the system of direct acting brakes eliminating all the friction losses possible, and automatically adjustable, promises to be the safest and best for this car. It will be noted that our standard mechanism inside the brake drum is about as good as we know how to make it, and probably has much less friction than the general run of this part of the system. --------- Since writing the above we have received HS{Lord Ernest Hives - Chair}' telephone message on this subject, to which we reply. (1) We should not expect success unless the whole system of levers is arranged for unassisted application - i.e. exactly the right leverage, freedom from friction, and self adjusting. (2) For a week I have worried over the schemes that we might naturally use, and have come to the conclusion that we cannot get a good schem by our ordinary devices as they stand and the system I have suggested is simpler, freer from friction, and permits of the best possible results. We hope to send a description on Monday. (3) As there are many cars of similar type, nearly all of which use unassisted direct operated brakes, we think it would be better and cheaper to judge from these rather than our temporary arrangement made from what I think, parts of which are unsuitable even when fitted in the best possible proportions. Therefore before losing faith in our programme, get all the comparisons within our reach. R.{Sir Henry Royce} | ||