Patent GB-190526590-A (GB)
Title: Apparatus for Generating and Utilizing High Tension Alternating Currents for the Ignition of Explosive Mixtures in Internal Combustion Engines.
Inventor: PONTOIS LEON JULES LE
Filed: 1905-12-20
Granted: 1906-12-20
Abstract: 26,590. Le Pontois, J. L. Dec. 20. Gas and like engines, igniting in. A partly selfexciting inductor alternator, driven by the engine shaft, supplies current to a step-up transformer, which is connected to the sparking-plugs through a cam-operated current-distributor. The parts are arranged as a unitary structure within a non- magnetic waterproof casing 1, Fig. 1. Bearings 2, 3, supported on the webs 91, carry a shaft 4 passing through the casing and driven by the engine shaft. An armature 6 of insulated soft iron laminµ is clamped. upon the shaft 4 so as to form an inductor rotor. With the object of obtaining a magnetic path of varying reluctance when the armature rotates, the periphery of the rotor is cut away n two parts, forming poles, Fig. 2. Within the casing are secured two annular permanent magnets 11, 12, Figs. 1 and 2, with their similar main poles facing each other and having consequent poles N, S. The magnets consist of hardened steel ribbon wound in the form of a helix. Between the polarized zones of the permanent magnets, and in magnetic contact therewith, are fastened to the casing laminated magnetic polar projections 14, 15, partly surrounding the rotating inductor arid provided each with two unequal teeth 16, 17 and 16<1>, 17<1>, Fig. 2, the laminµ being held to the casing by means of dovetailed brass disks 19. Upon the diametricallyopposite teeth 17, 17<1> are wound coils 20 to form opposite poles and arranged to be connected in parallel. By reason of the peculiar shape of the rotor during the rotation of the inductor, the magnetic flux circulating through the coils 20 suddenly reaches a maximum, giving a high-peak wave of current for a short angular movement of the inductor, and then the magnetic flux dies off, and finally increases slowly to a maximum, giving a small current, the resulting action of all the .induced currents upon the permanent magnets tending to increase their magnetic density. The peculiar disposition of the circular pole-pieces reduces the magnetic leakage, when the inductor is stationary, to a minimum. The current generated in the coils 20 may be led directly to the sparking- plugs, or it may be transformed into high-tension current after being interrupted by a circuit-breaker, which consists of a slide 22, Figs. 1 and 3, adapted to reciprocate vertically, and carrying a stem piece 27, to the lower end of which is secured an iridium contact-piece 28 making contact with a similar piece 36 mounted upon a spring - held light copper plunger 35. The lower part of the plunger dips in mercury in the cup 33, which is provided with a terminal 41, Fig. 3. By twisting the notched cap 34, held in position by the spring 39, the relative position of the contacts may be changed. The slide 22 is reciprocated by two cams 29, 30 on the shaft 4 engaging rollers 24, 25 carried by the slide 22. The rotating cam 29 moves the slide with its contact into engagement with the lower spring-held contact at the time that the current generated in the coils 20 is a maximum, and at this moment the contact is again rapidly broken by the action of the cam 30 in raising the slide. The circuit-breaker is located in an extension of the casing which is partly filled with oil or glycerine covering the contacts. The arrangement of the circuits is shown diagrammatically in Fig. 7, the condenser 87 being connected across the circuit-breaker, and the current from the coils 20 passing to the primary winding 88 of a transformer, the secondary winding 89 of which supplies current to a current distributor. The four-way distributor, Fig. 4, consists of a spindle 49, driven through helical gearing by the main shaft. The upper end of the spindle is furnished with a head 50, embedded in a cylinder of insulating- material; in the upper end of which is similarly mounted a terminal bead 52, to which is attached a light steel arm 53, Fig. 6, carrying a thin platinum leaf. This. nearly engages, as it rotates, with four circular fixed contacts 57, mounted upon insulating-projections 56 in an annular chamber 55. A cover 58, held in position by springs 66, Fig. 4, has embedded in its centre a terminal socket 59, receiving a plug 64 leading to one of the secondary terminals of the transformer. A contact-pin 61 in the socket 59 rests upon a ball in a recess in the upper part of the head 52, a spring 63 securing good electric contact. Plugs 65 passing through the upper cover serve to connect the four fixed contacts to the sparking-plugs. For altering the time of sparking, the shaft 4 is provided with two diametrically-opposite helical cam-openings 67. A sleeve 68, loosely mounted on the shaft, is also provided with two similar inclined helical camopenings 69. The gear 5 is integral with the sleeve 68, the rotary movement of which is imparted to the shaft 4 by a pin through the four helical openings referred to. A collar 70, Fig. 1, carrying the pin and longitudinally slidable upon the sleeve 68, is provided with V-shaped grooves receiving conical rollers 73, Fig. 6, supported in a yoke 74 secured upon the shaft 75, so that the collar 70 and pin can be moved longitudinally by means of a handle.