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).
Stress on throttle return springs for the Phantom III and 30 HP models.
| Identifier | ExFiles\Box 7\4\ X 608 Carburetter-page13 | |
| Date | 23th December 1937 | |
| To By.{R.W. Bailey - Chief Engineer} c. to EX/Scott. c. to Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux} Handwritten: 608 also 308 Rm{William Robotham - Chief Engineer}/GR.{George Ratcliffe}10/JH.23.12.37. PHANTOM III & 30 H.P. Throttle return springs. With reference to Rm{William Robotham - Chief Engineer}/GWH.{George W. Hancock - Head Chateauroux}3/EH.14.12.37. We certainly agree that the Phantom III spring is overstressed i.e. maximum of 116,000 lbs.sq.in. The proposed new spring E.88488 has a maximum stress of 65,500 lbs.sq.in. A standardisation sheet for the latter was issued and completed 26.8.37. With regard to the 30 H.P. throttle spring E.58851 we do not agree that this spring is overstressed as our tests show a maximus of 64,500 lbs.sq.in. i.e. when used with the correct links E.60822 and E.51877. However, we give below an alternative spring which gives a slight increase in load with less stress. Present Spring. Alternative. E.58851. EB.3429. Link E.60822 2 links E.51877 Link E.51877 Full open 3.350" / 7 lbs. 3.750"/9 1/4 lbs. Closed 2.560/3 lbs. 2.900"/4 lbs. Max. stress 64,500 lbs.sq.in. Max stress 58,000 lbs.sq.in. Rm{William Robotham - Chief Engineer}/GR.{George Ratcliffe} | ||