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).
Technical comparison between the S.S. Jaguar bonnet hinge and the Widney concealed hinge.
| Identifier | ExFiles\Box 126\5\ scan0040 | |
| Date | 26th May 1938 | |
| To Dg. & Ms. From RHO/SB.{Mr Bull/Mr Bannister} c. to By.{R.W. Bailey - Chief Engineer} & (Rm.{William Robotham - Chief Engineer}) c. to G.{Mr Griffiths - Chief Accountant / Mr Gnapp} & Ox. STEADMAN See me (handwritten) 1070 (handwritten) RHO/SB.{Mr Bull/Mr Bannister}1/MJ.26.5.38. CONCEALED BONNET HINGE. The bonnet fitted to the S.S. Jaguar has been examined as instructed in Sg.{Arthur F. Sidgreaves - MD}10/M.7.2.38, and whilst the concealed hinge fitted to this car is not of the Widney type there is little difference as regards appearance when the bonnet in each case is in the closed position, the external proportions being almost identical. It is considered that the Widney hinge is the more satisfactory because the Jaguar hinge in the open position relies upon the Chromium moulding to act as a stop whereas the Widney hinge incorporates a positive internal stop. The Moulding in question is anchored to the scuttle and radiator to prevent rotation, but when the bonnet is opened hard against the stop considerable deflection of the radiator shell and hinge occurs and the hard bearing of the painted bonnet edge against the Chromium moulding will no doubt result in damage to both surfaces after some service. The Jaguar type hinge although of inferior design necessitates only a single bend in the top plate and could therefore be produced with the existing Factory Tool equipment. The Widney hinge however, whilst of superior design, requires a double bend that cannot be produced at these Works unless special equipment is installed. It is not considered that the Jaguar type hinge design would be suitable for R.R. production on account of general flimsy construction and the damage which may occur to the external surfaces in use as previously explained. It cannot be stated whether any special form of rust preventative treatment is adopted but as a matter of interest, the Rover Company have found it necessary to tin the edges of steel bonnets in order to prevent corrosion. The Jaguar bonnet is produced from .044 thick material and appears to be free from ripples although the dull metallic finish may hide such irregularities of surface finish. Attached hereto is a sketch showing the relative construction of the S.S. Jaguar and Widney hinge. Bannister. | ||