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).
Continued report on the specifications and conclusions regarding a Michelin 'Fast' jack.
| Identifier | ExFiles\Box 26\3\ Scan037 | |
| Date | 28th September 1927 guessed | |
| contd :- -2- Maximum jack height ................ 8.5" Hand adjustment .................... 4.0" Mechanical lift .................... 5.5" Total .............................. 18.0" i.e. max. height available before mechanical lift = 12.5" max. required 10.5". (The max. height required is 16" based on .5" clearance between the tyre and a level road, this measurement of course should be increased by 1.5" to allow for soft roads and camber etc. the additional height (*1.5") required however can only be obtained by increasing the mechanical lift and not the initial height). Conclusions. The Michelin 'Fast' jack, while not able to meet all possible requirements on the 40/50 HP. chassis as shewn above, is not impossible. It will serve its purpose in most cases of flat tyres which occur if the maximum initial obtainable height is made use of. The lift required for a deflated tyre is approx. .75 to 1" less than that for a bare rim giving slightly better results than indicated in the above figures. We are bound to get complaints, however, and a jack that will meet all needs should be found. Hs.{Lord Ernest Hives - Chair} | ||