GB188775A - Improved apparatus for testing magnetos sparking blocks and the like - Google Patents

Abstract

188,775. Davis, E. J. Aug. 17, 1921. Detecting faults. - A portable device for testing magnetos, sparking-blocks, and the like by means of a visible spark-gap, particularly adapted for testing ignition systems of internal-combustion engines using low-tension magnetos, is provided with a movable pole-piece co-operating with a fixed pole-piece and operated by the make-andbreak mechanism of the system tested to make and break the visible spark gap on the device. the device being applied to the mechanism by means of an insulated handle without adaptation of the mechanism and without temporary or permanent connection of the device to the mechanism. In the form shown, the device comprises a fixed pole 1 mounted in an insulating sleeve 5 in a metal shank 2 provided with an insulating handle 3, a movable pole 10 being pivoted in bearings 9 on the shank 2 and being normally pressed in contact with the pole 1 by a spring 11. Terminals 2<1>, 7 are provided connected to the poles 10, 1 respectively. In testing an ignition system, the device is held so that the pole 10 is rocked into and out of contact with the pole 1 by the magneto rocker arm or other part of the make-and-break mechanism of the system, the contact being broken preferably when the maximum pressure is being generated by the magneto. The condition of the magneto and sparking-block are investigated by observing the nature of the sparks produced between the poles 10, 1 when the terminal 7 is connected to the magneto lead and the terminal 2<1> to the magneto frame or to the insulated pole of the sparking- block according as the magneto or sparking-block is being tested, the earthed pole of the sparking- block being kept out of contact with the insulated role in the latter case.