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).
Improved design for the Hobson Petrol Gauge featuring a new air seal.
| Identifier | ExFiles\Box 44\2\ Scan179 | |
| Date | 14th July 1928 | |
| To D.A. from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} C. to BY.{R.W. Bailey - Chief Engineer} 4036 Hs{Lord Ernest Hives - Chair}/RmL/LG14.7.28. HOBSON PETROL GAUGE. With further reference to this instrument. We are glad to say that Messrs. Hobson have now discovered an arrangement whereby they can ensure that the gauge is not blown no matter what the air venting of the tank may be. This device consists of fitting an air seal which comes into operation at the extreme top of the tank. This seal is connected to the top of the glass tube containing the indicating liquids in the gauge so that when 20 gallons have been registered any further pressure is balanced out equally at the top and bottom of the column of fluid. This, incidentally, enables the overall length of the gauge to be shortened by 2¼" thereby overcoming the difficulty of installation on the instrument board and will enable us to enlarge the scale somewhat if we find it desirable, because now the petrol in the side filler does not have to be allowed for on the glass tube. Therefore the question of the venting of the tank, which we previously mentioned, does not now arise. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||