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 showing the efficiency of a 20-25 HP back axle brake lever under different loads.
| Identifier | ExFiles\Box 92\4\ scan0038 | |
| Date | 21th December 1934 guessed | |
| EFFICIENCY LINE FOR ONE LEVER EFFICIENCY LINE FOR SIX LEVERS EFFICIENCY OF 20 - 25 H.P. BACK AXLE BRAKE LEVER Nº G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 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% EFFICIENCY AT NORMAL WORKING LOADS = 97.6% Y-AXIS: PERCENTAGE EFFICIENCY X-AXIS: INPUT LOAD - LBS | ||