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).
Potential modifications to a measurement instrument, comparing it to the Askania model.
| Identifier | ExFiles\Box 138\2\ scan0172 | |
| Date | 13th September 1938 guessed | |
| - 6 - compared with the Askania. Accordingly we have to consider to what extent the instrument may be modified, and to intimate the degree in which we can accept increased size and weight as the legitimate price for more refined measurements. We note that the handle of the instrument increases the overall length by at least six inches, and that in any case it is scarcely practicable to employ this when the vibrograph is used in other than the horizontal plane. The only other function performed by the handle is to house the control switch, which could presumably be arranged elsewhere, and accordingly a useful reduction in overall dimensions could be achieved by reshaping the instrument body for easier handling and dispensing with this appendage. We presume that this could be done without entailing any re-arrangement of the instrument. A second point in this connection which would require attention is the extension of the stylus away from the instrument body. We recommend that it should project in a suitable tube or guide for at least a length corresponding to that of the Askania - i.e. 4". It would be interesting to know whether this could be done without sacrificing the capacity of the instrument to follow high accelerations. At present the stylus mechanism projects from a point close to the forward edge on the underside of the body so that the provision of an extension in this direction again would call for no serious modification in the layout. However the ideal arrangement from our point of view would be to follow the Askania design completely and provide the stylus extension from the front of the body, but it is appreciated that this would involve the complete revision of the design, and producing a virtually new instrument. Finally we find that the spring loading, which required 8 lbs. to bring the recording arm to the centre of the film is a little tiresome. If this loading is not entirely/to withstand the highest accelerations met in practice it would be convenient to reduce the figure, since the occasions when the vibrograph XXXX XXXXXXXXXX is used horizontally under its own weight from only a proportional amount of its usage. Lr{Mr Ellor}/HWS. | ||