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).
Modifications to a gauge, including a new packing gland and a change of material from aluminium to gun-metal.
| Identifier | ExFiles\Box 44\4\ Scan147 | |
| Date | 4th December 1929 | |
| Messrs. Rolls-Royce, Ltd., Date 4.12.29. Page 2 the gauge from registering. They have accordingly introduced a packing gland joint at this point, using rubber to a certain specification as being less affected by Tetrabromide than any other substance which they have tested. They have been using this system for many months, and the writer has had it on his own car for some months now running with satisfaction. The pressure balance connection is taken out at the back and top of the gauge, and the areas are such that small quantities of Tetrabromide will not block them, and the trouble with the small capillary is accordingly overcome. In connection with the rubber used for the packing gland, this appears to swell slightly upon immersion in Tetra-bromide, but as the rubber in this case is under compression, there appears to be no harmful effect; the rubber not appearing to disintegrate. At the same time, the material of the body has had to be changed from aluminium to gun-metal, owing to the fact that Tetrabromide attacks aluminium. This change appears absolutely essential, in view of the fact that your test department is now testing our gauges for accuracy before the chassis are despatched to the body builders. | ||