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).
Analysis and recommendations for improving fuse holder and clip design based on heating and handling tests.
| Identifier | ExFiles\Box 166\7\ img098 | |
| Date | 18th October 1938 | |
| -3- Rm{William Robotham - Chief Engineer}/RC.{R. Childs}7/JH.18.10.38. higher rate of cooling of the circular section, in the middle portion. The test proved that less heat is produced with the larger contact area of the flat end, but much more when the exposed portion of the fuse is also flat, instead of being round. Since, however, fuse elements cannot conveniently be other than all flat or all circular form the only possible improvements seem to be in the direction of - (a) Larger fuse holder for the armature position. (b) The use of steel clips. (c) The use of a heavier gauge strip on the carrier and clips. These tests prove the advantage of the steel clip with respect to heating and of a slight advantage to be obtained by the use of a thicker gauge strip say 26 S.W.G. on the fuse carrier. There are however two faults, the steel clips being used - (1) The fuse is held so firmly by the clips that due to insufficient means of gripping the fuse carrier with the fingers, it is extremely hard to remove. (2) Unless the carrier strip is of a thicker gauge, in pulling out the carrier, there is a danger of dragging and damaging the strip holding the wire. The steel clip for the armature fuse is already in production and we consider it quite satisfactory from an electrical point of view, however, in view of the reasons stated above we recommend that the carrier is made so as to provide a better grip for fingers, when removing, also that the strip for holding the wire be increased to 26 S.W.G. Rm{William Robotham - Chief Engineer}/RC.{R. Childs} | ||