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 overview of the Philbrin Coil Ignition system, detailing its components, features, and operation.
| Identifier | ExFiles\Box 37\1\ scan 138 | |
| Date | 8th November 1922 guessed | |
| Philbrin Coil Ignition THE "Philbrin" Apparatus represents the very latest in coil ignition construction, and has the following special features:— - Single or high-frequency spark at will. - Instantaneous make and break at all speeds. - Contact points self-correcting for wear. - Steel-sheathed die-pressed condenser, eliminating all troubles. - Electrically synchronised double sparking if required. - High-frequency spark, giving 60,000 sparks per minute, ensures ignition under adverse circumstances. By means of the "Philbrin" a powerful spark is obtained at all speeds, giving a degree of flexibility otherwise unobtainable. The great assistance to starting rendered by the high-frequency spark reduces the strain on the accumulator and starting motor to a minimum. The engine, when warm, will frequently start on the switch. The number of different models now available is sufficient to enable sets to be fitted to any standard type of motor car or commercial vehicle. IGNITER.—The "Philbrin" igniter consists of a cast iron contact-maker base, which houses the contact mechanism and condenser, the upper part is enclosed by the distributor cap, which clips on with detachable spring clips, thus giving immediate accessibility to all parts. The contact maker is of special construction, providing for an instantaneous break at all speeds. The contact plunger P is depressed by means of the cam, and makes contact with the lower contact point C, the last part of this motion compressing the spring S. The cam being shaped to admit of the instantaneous release of the springs, two contact points fly suddenly apart, producing a perfectly clean break. The lower contact point C is free to turn, which equalises all wear. It will be seen that the ideal "straight line" contact is realised in this design. Fig. I. Igniter with Magneto replacement mounting. Fig. II. Illustrating action of Contact maker. The high tension distributor is of the jump-spark type, containing no brushes or wearing parts. Attention is directed to the particularly neat terminal, the principle of which can be understood from the view of the terminal in Fig. II. When considering installing the "Philbrin," three types of igniter are available:— (I.) With magneto replacement mounting (Fig. I.), fits clockwise or counter-clockwise. (II.) Vertical igniter (clockwise). (III.) Vertical igniter (counter-clockwise). The magneto replacement mounting enables the "Philbrin" igniter to immediately replace any standard magneto on the same platform with a minimum of labour and expense. The rotations of the vertical igniters are taken from the direction of rotation when looking down on the distributor. Vertical igniters are used when the engine has been built for coil ignition, and in consequence, provides for a suitable support and drive without the necessity for a special mounting. Full details of installation particulars can always be obtained on request, and if the make and year of car be given, the appropriate set can usually be selected immediately. COIL.—The "Philbrin" coil is of smooth, neat appearance, and is absolutely proof against damp and all troubles arising therefrom. DUPLEX SWITCH The "Duplex" Switch provides:— (I.) A two-pole battery switch. (II.) A selector switch, controlling single or high-frequency spark. The battery switch provides for the use of a spare battery if desired. The selector switch is a special device and calls for a more detailed explanation. Referring to Fig. IV., it will be seen that alternate positions, "Start," "Run," are provided. In the "Start" position the current through the coil operates a trembler contained in the switch and a continuous stream of sparks is produced and is distributed by the high-tension distributor, quite independently of the contact-maker mechanism. In the "Run" position the current is controlled by the contact maker and the set runs on "single spark" in the ordinary way. The delightfully easy starting which can be obtained by turning on the high frequency spark will be appreciated by everyone. The two systems being quite independent, a double security against breakdown is provided. The selector switch is provided with a pawl and ratchet and will not turn backwards. At each half-turn of the switch the direction of the current through the system is completely reversed. Fig. III. Coil. Fig. IV. "Duplex" Switch. | ||