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).
Endurance test for a Lucas windscreen wiper, model SW.4 No.733666.
| Identifier | ExFiles\Box 167\5\ img205 | |
| Date | 2nd September 1937 | |
| To: R.C. from Rm{William Robotham - Chief Engineer}/RC.{R. Childs} c.c. Rm.{William Robotham - Chief Engineer} Originally:RD. Rm{William Robotham - Chief Engineer}/RC.{R. Childs}17/WH.2.9.37. Handwritten: R.C. Presumably this will be followed up with lucas. Rm{William Robotham - Chief Engineer} Re Endurance Test on Lucas Windscreen Wiper SW.4. No.733666. The above unit was mounted on a "mock up" windscreen, and operated under normal working conditions. Using a 12 volt battery the blades oscillated at the rate of 40 per minute: the current consumption being 2 amperes. The working temperature of the motor is 78°c, with an armature speed of 3,640 R.P.M. From the commencement of the test a jerky movement in the blades was apparent, this movement increased and eventually caused failure. This was not due to loose wiper blade fixing screws but to wear on the spindle: the means used to lock the blade to the operating spindle is crude, as the location relies on a screw bottoming on a plain round spindle. Wear on the motor crankpin also accentuated this cause of failure. The unit failed after 394 hours running. The plating of the blades is not good enough, as, although not subjected to moisture, they show signs of rust at the end of the test. Except for the few mechanical weaknesses and a rather noisy gearing, the performance of the unit is satisfactory. It is to be noted that a similar unit fitted to 3.B.IV was reported very quiet in comparison with previous wipers. Rm{William Robotham - Chief Engineer}/RC.{R. Childs} | ||