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).
Investigation report on tests conducted on a type 'MP' shock absorber.
| Identifier | ExFiles\Box 152\1\ scan0070 | |
| Date | 12th January 1933 | |
| TO: Mr. Watson, Mr. Pitt, Mr. Douglas, & File. FROM: Mr. W.A. Green. X832 INVESTIGATION 33.LA. {L. A. Archer} 1. 12th January, 1933. WAG/EGR ROLLS-ROYCE SHOCK ABSORBER TESTS. This investigation refers to tests on the shock absorber type "MP" which was submitted to Messrs. Rolls-Royce for test and was returned by them, together with their criticisms contained in their letter of August 11th, 1931. The shock absorber, when received; was dismantled and the working chamber drilled and tapped to take our indicator connections. It was also fitted with a special recuperating chamber with the top half cut away to allow of coupling up of the indicator connections. For the purpose of our tests it was mounted on a stand which carried a crankshaft from which a connecting rod could be coupled to the end of the lever arm. The crankshaft was provided with a variable throw crank pin to adjust the stroke of the shock absorber, and it could be driven by means of a series of step pulleys at a range of speeds varying from about 50 to about 600 revs. The indicator connection consisted of 1/4" gas bends so arranged that the indicator when in place was upside down, and there was no possibility of the formation of an air lock in the indicator itself, or the connections. The minimum size of the passages to the indicator was 7/32" bore. The indicator used was a Dobbie McInnes No.1 small size. The Makers state that it is suitable for speeds up to 800 revs. The indicator drum was driven from one of two pins fixed, one in the lever arm, and the other in an extension of double the length, so that a reasonable length of diagram could be got at all strokes. It should be clearly noted in connection with the attached photostats of indicator cards, that all these were taken with a piston of 1/5 of a sq. inch area, and a spring rated at 350 lbs/sq.in. per inch for a piston of 1/2 of a sq. inch area, so that a height of 1" on the cards represents a pressure of 700 lbs/sq.in. The first cards obtained showed that the air vent valves were leaking. They were of a nature to agree generally with those sent to us by Messrs. Rolls-Royce with their above mentioned letter, and showed therefore that their criticisms were justified. The writer understands that the shock absorber was carefully | ||