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).
Test report and commentary on a car jack manufactured by Tangyes.
| Identifier | ExFiles\Box 52\4\ Scan040 | |
| Date | 9th October 1930 | |
| By. {R.W. Bailey - Chief Engineer} from Hs {Lord Ernest Hives - Chair} /AJL. E. {Mr Elliott - Chief Engineer} Roy. {Sir Henry Royce} X4491 HS {Lord Ernest Hives - Chair} /AJL1/AD9.10.30. JACK MADE BY TANGYES. We are returning to you the jack for your examination and comments. We have tested the jack by lifting up one side of a P.II. car, through the total range of the mechanical lift, 50 times. (N.B. The lateral movement of a point on the axle underneath the spring clip is .750" relative to a point on the ground for this range of lift; the jack has to accommodate this side thrust by slack in threads or by bending). After completing this test is was found that the inner thread had tightened up badly in one place; examination of the thread does not reveal the cause, it is difficult to see it clearly at the point where it is tight because it is about half way up the long inner thread. The threads appear to be rather too close a fit for the job, possibly the failure is due to foreign matter. The jack was examined after 25 lifts had been completed and it was found that the bevel pinion and wheel were badly marked. These were a very rough job in the first place; they were trimmed up before the test was continued. We should insist on these parts being a better job, the bevel wheel teeth were left just as they were cast. This jack has several features which are an improvement on the Dunlop jack, these are (1) Two bearings for the pinion, one ball bearing and one plain bearing. (2) Ball bearing thrust race below the bevel wheel. (3) All threads are enclosed. It would be improved further by using the type of handle fixing recently incorporated in the Dunlop jack to enable the jack to be placed in position with the handle fixed to the jack. HS {Lord Ernest Hives - Chair} /AJL. | ||