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).
The failures of Lucas Mellotone Horns and the proposed modifications.
| Identifier | ExFiles\Box 166\9\ img038 | |
| Date | 8th January 1937 | |
| C.A.P. 6066 Will you gradually get all our horns changed over WSD S/W. Rm{William Robotham - Chief Engineer}/Wst. CxIO/KW8.1.37. Lucas Mellotone Horns. Rm{William Robotham - Chief Engineer}/Wst.7/AP8137 You will doubtless be interested to hear the result of the interview I had with Mr.Thacker of Lucas' concerning the above. He first of all explained to me the causes of the failures which - as he put it - were due to the diaphragm being mounted in a zinc alloy casting and being too good a fit,so that when cold temperatures prevail contraction took place causing the diaphragm to stick. Their modifications include increasing the clearances and introducing a greased washer which prevents the diaphragm from sticking. They propose on our recommendation to change all the horns that have been supplied,by providing a floating stock of modified horns to Hd{Mr Hayward/Mr Huddy} on the one hand and Br on the other, who will change the horns on all cars as they come in. Hd{Mr Hayward/Mr Huddy} and Br are also being informed by Lucas' of the markings on the horns indicating those that have already been modified. Cx.{Major Len W. Cox - Advertising Manager} hub For progress. AP. | ||