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).
Article from 'The Autocar' magazine detailing the stringent tests and construction of the new four-cylinder Peel-Conner Magneto.
| Identifier | ExFiles\Box 4\5\ 05-page260 | |
| Date | 8th February 1924 | |
| 254 THE AUTOCAR, February 8th, 1924. ENSURING THE VITAL SPARK. Stringent Tests and Minute Attention to Details Designed to Give the New Four-cylinder Peel-Conner Magneto an Exceptionally Long Life. Particular care has been taken in the construction of the magneto to render it smooth, as regards the exterior, to facilitate cleaning. The studs and channels to take the high tension wires on the distributor end of the magneto have been arranged so that the channels are sunk in the cover, while the driving end plate is arranged to provide an extra stiff support for the bearing. A BRITISH firm, the Peel-Conner Telephone Works, of Coventry, has lately produced a magneto of more or less orthodox design, but one which has reliability and durability as its chief objects, regardless of the manufacturing cost. The new instrument at present is constructed only for four-cylinder engines, and is slightly more bulky than the usual modern types. Its cost also is higher. The Peel-Conner magneto, on the other hand, is constructed with the idea that it shall never need attention; that it shall be self-lubricating; and that it shall be entirely durable, both from the mechanical and the electrical points of view. The makers have carried out exceedingly stringent tests of the instrument, one example of which has been run for 1,300 hours at 3,000 revolutions per minute, and thereafter for 320 hours at 1,500 revolutions per minute, the magneto being at the time contained in an asbestos-lined box with the interior temperature maintained at 180° F.{Mr Friese} The machine has been stopped at night, and the box filled with wet rags, with the idea that, as the instrument cooled off, it would draw into its interior moisture which might be calculated to cause trouble either in the bearings, the insulation, or the contact breaker bush. At the end of this test the only part that showed any wear and tear was the contact breaker itself. This magneto has produced about 468 million sparks, and the contact breaker shoe has travelled about 9,250 miles on its cam. The total run would represent several years of use on the average touring car, or with an average top gear ratio some sixty thousand miles. General Construction. In its general lines the construction of the magneto follows standard practice. A laminated H section armature built up with gun-metal ends is wound with the usual primary and secondary wires, and rotates on ball bearings in a tunnel formed between silicon iron pole pieces with extension horns to prevent plug fouling, attached to tungsten steel magnets, ahe assembly being mounted on a gun-metal baseplate. The end plate of the instrument adjacent to the driving coupling is also of gun-metal, and built very solidly with the object of standing up to possible misalignments of the magneto driving couplings, and also to provide a stout abutment against which a tool can be used if necessary to detach the coupling from the armature spindle. Closing in the contact breaker end of the magneto is an aluminium casting into which are spigoted and bolted gun-metal cages carrying the ball races of the armature spindle below and the distributor gear wheel above, the hollow spindle of the distributor gear wheel being supported on two ball races, as shown in the sketch. Component parts of the new Peel-Conner magneto. (1) The distributor cover, which is built up with insulated centre. (2) Driving end plate which is provided with an oil reserve wheel. (3) Distributor brush holder. (4) A steel ring is shrunk on the contact breaker taper socket at the end of the armature spindle to prevent the latter from slipping if the taper holding plug is screwed up too hard. (5) Contact studs in the distributor cover are sunk below the surface to avoid possibility of breakage. (6) The cam ring. c 18 | ||