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).
Instructions for replacing the diaphragms in the S.U. petrol pump.
| Identifier | ExFiles\Box 149\4\ scan0248 | |
| Date | 22th April 1937 | |
| To Hd.{Mr Hayward/Mr Huddy} 1263 Rm{William Robotham - Chief Engineer}/JBD.{John B. Dixon - Fuel Systems}1/JH.22.4.37. To Replace Diaphragms in the S.U. Petrol Pump. The two magnet bodies should be removed from the central body by undoing the 6 fixing nuts. This joint is often tight and a sharp blow on the side is usually necessary to remove it. The old diaphragm should be removed by unscrewing it when the whole assembly comes out together with 11 brass rollers (distance pieces) and springs To fit new diaphragm. (1) See the spring is in the mouth of the magnet body with the smaller coils outwards and that a fibre washer is attached to the central round pole piece also a fibre washer in the recess round the spindle in the new assembly. (2) Remove the contact breaker cover and insert the spindle of the new diaphragm down the hole in the pole piece and pressing gently to lead the thread on the spindle in to the hole in the trunnion on the contact breaker. (3) Screw the diaphragm in and insert the 11 brass rollers behind the fabric between the armature and recess in the magnet body (4) Continue to screw in the diaphragm until a position is reached that the contacts just break when the diaphragm is pressed SLOWLY & FIRMLY IN. Check this position by screwing up one further hole, on the diaphragm edge when the parts should not break when pressed in. (5) Then from this, (i.e.) the last hole at which the points will break when pressed in SLOWLY & GENTLY turn it back (unscrew) 4 holes in the diaphragm edge. This is the setting for the toggle and contact mechanism. (6) Make sure the brass rollers are still in position, press the diaphragm in and insert the forked wedge under the trunnion on the contacts these holding it back. | ||