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).
Letter from Donald Sessions & Company Ltd. concerning the performance and modification of four-wheel jacks.
| Identifier | ExFiles\Box 26\3\ Scan135 | |
| Date | 26th February 1932 | |
| x5117 DWS FOURWHEEL JACKS CHAIRMAN S. E.{Mr Elliott - Chief Engineer} STEVENS MANAGING DIRECTOR DONALD SESSIONS DIRECTORS WILFRED SESSIONS WALTER SESSIONS DONALD SESSIONS & COMPANY LTD. 906 HARROW RD., WILLESDEN, LONDON, N.W.10 TELEPHONE WILLESDEN 1270 TELEGRAMS "TOGGLE, HARLES" CABLEGRAMS "TOGGLE, LONDON" February, 26th, 1932. Messrs.Rolls-Royce, Ltd Derby. [STAMP: RECEIVED 27 FEB 1932] LIP Dear Sirs, For the attention of Mr.Lidsey. With reference to the writer's recent visit to Derby in connection with D.W.S.Permanent Jacks. It is quite clear that the difficulty in raising the car at the start has occured through a misunderstanding in connection with lifting from rim level and flat tyre level, the difference in height being sufficient to experience undue effort on the handle. From our tests it is evident that the Jacks are capable of lifting the car efficiently from the 19" rim and at full lift providing for a clearance of approximately 1.¼" under a fully inflated tyre. We are now putting through three more Jacks which will have screws of finer pitched thread, this we think will effectively reduce the starting torque on the handle, and at the same time automatically lower the gear. We are returning to you a modified handle for temporary use until the new Jacks are ready. This handle should only be used when lifting the wheel from flat tyre level. We understand that you are perfectly satisfied with the behaviour, strength and design of the Jacks themselves after tests and we are confident we shall be able to overcome the handle difficulty in a completely satisfactory manner. In the event of our Jacks being standardized the main anchorage bed will be modified to avoid slots in the upper face of the Jack which you point out now fill with water. Continued. | ||