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).
Issues and experiments related to security bolts and bolt valves for tyres.
| Identifier | ExFiles\Box 53\1\ Scan128 | |
| Date | 21th August 1923 guessed | |
| SECURITY BOLTS AND BOLT VALVES. 1. Dunlops did not, in the first instance, force on to us against R's very strong opinion, the proposal to eliminate the security bolt and bolt valve. 2. H. {Arthur M. Hanbury - Head Complaints} seems to have the idea that it is only an unsuitable security bolt or bolt valve which causes trouble. In this matter he is entirely misled, as any type of security bolt or bolt valve, was stated by Mr. Bond of the Dunlop Co. the man who actually carried out the experimentsm, to be unsatisfactory and dangerous. 3. H. {Arthur M. Hanbury - Head Complaints} has been misled in regard to the security bolt which failed being an unsuitable one, because P. had just written to us pointing out that the standard security bolt was useless on cord tyres, but the Dunlop experiments were carried out with unsuitable bolts, but with correct bolts. 4. The low pressure at which the tyres will blow off is between 12 and 20 Lbs. which certainly leaves a very wide margin, when compared with our recommended pressures. 5. The assumption is that with security bolts and bolt valves, the tubes will not fail. The Dunlop Co's experiments shew that the tube and the cover were spoilt in quite a large number of cases when security botls were used. They actually referred to us certain customers who were experiencing continual trouble with the security bolt, which was eliminated by abandoning it. | ||