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).
Page from 'The Autocar' magazine discussing an electric timing set and a new accumulator for lighting and starting.
| Identifier | ExFiles\Box 138\2\ scan0032 | |
| Date | 28th November 1924 | |
| 1098 THE AUTOCAR, November 28th, 1924. An Electric Timing Set. Two bell coils, taken from an ordinary house bell, complete with the armature thereof, serve to trip the watch starting mechanism. The latter is made so that effective working is assured even with the smallest amount of current, and upon this feature reliability largely depends. If we make sure of the apparatus working with the smallest possible current—say 1 volt and no perceptible ampèrage—it will most certainly work when in circuit with the accumulator. Hence the reason for the very long operating arms which insure the merest hair pull on the magnet tripping the mechanism. Fig. 2. A simple type of contact maker which has proved very successful. lock spring provides the force necessary for starting and stopping the watch, while the other units of main importance are a two-way switch, a spring-clip housing into which the watch is slipped, and by which it is firmly held, and the electric connections to the accumulator. How the Apparatus Works. The working of the apparatus will become obvious as we follow out just what happens. Suppose we are timing a motor vehicle up a hill. Two wires are run from one pair of terminals to the bottom of the hill where the contact maker is fixed, and two other wires are run from another pair of terminals to the contact maker at the top of the hill. All is ready, both tapes set, leaving the circuits open, and the two-way switch is in the left-hand position. The vehicle breaks the tape at the bottom of the hill, thus closing the one circuit. The armature is attracted by the electro-magnet and disengages with the pivoted arm, which, at once flies down. This releases the long arm, which, under the influence of the lock spring, starts the watch. The operator now moves the two-way switch over to the right-hand position, and resets the instrument by raising the pivoted arm until it is again held up by the armature. As the vehicle makes contact at the top of the hill precisely the same thing happens over again, and the watch is stopped, and the time taken. Before the next ascent the watch hand must be returned to zero by tripping the apparatus by hand. Following out the electric connections—which can be made in a variety of ways—it will be observed that the circuit is from the electro-magnet coils to the armature, thence by contact to the pivoted arm, and from the hinge thereof to the two-way switch. This is simply to avoid wastage of electricity and the possibility of burning out the coils, the latter being thrown out of circuit the instant they have done their work. Hints on Construction. The mechanism should be as solidly constructed as possible, and mounted on a good hard board which will not bend. If integral with the accumulator box, the floor of the box should be provided with felt which will take a good grip of the earth. My special apparatus, now the property of the East Lothian M.C.C., is made mainly of brass, and the minor parts are finished in black and red, so that the apparatus looks very smart and business-like. The wires do not, of course, show, but are carried through to the underside of the board. The contact makers need no description. Fig. 2 shows the type that I have long used in connection with electric photography. and, though crude, it is absolutely reliable, and can be carried in one’s pocket, and takes only a very few minutes to make. Fig. 3 is the obvious type of contact maker for hill-climbs and similar events to which flags are carried. Fig. 3. An alternative type of contact maker for use at hill-climbs The demand for electric timing apparatus is, in these days, great, and for testing purposes such a set is invaluable to the motorist. A stop-watch, used by hand, is only a rough guide. It falls short when it comes to measuring a car’s speed over a short distance. LIGHTING AND STARTING. A New Accumulator for which Specially Strong Claims are Put Forward. ALREADY there are many makes of accumulators on the market, and the advent of another battery would indicate that it should have special claims for the attention of motorists, in order to be successful. Oldham and Sons, Ltd., Denton, Manchester, make such claims for the batteries which they are now introducing. Previously this firm has specialised in the manufacture of electric lamps for miners, and, having mastered the mechanical requirements of such a lamp, they then found that ordinary lead storage batteries were not sufficiently reliable for a service which requires that every underground failure of a lamp shall be reported. Experiments were commenced, and eventually a lead-plate accumulator was evolved which will give at least ten hours’ light, and may be dropped, or thrown at a wall, for instance, with impunity. Such a battery, it follows, should be admirable for motor car use, and from the miner's lamp type the Oldham car lighting and starting batteries have been evolved. The chief features of these batteries are the peculiar construction of grid, consisting of a staggered rib formation which allows the active material to take the form of a continuous sheet from top to bottom of the plate, and the special composition and preparation of the paste itself, which combines a sufficient degree of porosity to allow the maximum permissible action of the electrolyte, at the same time retaining such cohesion as to give the plate a strong and lasting structure. Batteries are being made for every standard car equipment, and they are produced throughout at the Denton works from the raw materials. We can vouch for the fact that rigid inspection and exhaustive laboratory tests are applied throughout the processes of manufacture which we observed in all its stages. B 18 25 | ||