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).
Graph of efficiency versus input load for a 20-25 HP back axle brake lever, for both single and six-lever systems.
| Identifier | ExFiles\Box 102\3\ scan0157 | |
| Date | 24th March 1909 guessed | |
| MFA PERCENTAGE EFFICIENCY INPUT LOAD - LBS EFFICIENCY LINE FOR ONE LEVER EFFICIENCY LINE FOR SIX LEVERS EFFICIENCY OF 20-25 H.P. BACK AXLE BRAKE LEVER Nᵒ G 53637 ABOVE 75 LBS. LOAD THE EFFICIENCY IS CONSTANT AND EQUALS 97.6 % THE 3 PIN JOINTS IN THIS LEVER ALL DIFFER FROM EACH OTHER. THE CO-EFFICIENT OF FRICTION FOR THE CENTRAL AND MOST HEAVILY LOADED PIN JOINT HAS BEEN FOUND TO BE 0.261 AND HAD ALL JOINTS BEEN SIMILAR THE EFFICIENCY WOULD HAVE BEEN 96% WHICH AGREES CLOSELY WITH THE ABOVE. EFFICIENCY AT "PULL OF SPRING LOAD" = 95% " " NORMAL WORKING LOADS = 97.6% | ||