GB190214124A - Improved Apparatus for Detecting and Localizing Underground Metallic Lodes. - Google Patents

Abstract

14,124. Daft, L., and Williams, A. June 21. Prospecting.-Electric impulses are sent into the earth at the electrodes K, L from an inductor A. Exploring-electrodes are joined to a detector or resonator, Fig. 3. The character and intensity of the impulses received will be modified when the exploring-electrodes are earthed near to a conducting-mass, and this change will be audible at the resonator. By shifting the exploring-electrodes the conducting-mass can be located. The inductor A consists of a soft-iron core c, provided with an adjustable armature b. The primary and secondary (which is in sections) are in two parts, and switches B, G are used for connecting the parts as required. The primary circuit contains a contact-breaker, as shown at D and in Figs. 2<1>, 6<1>, and 8<1>. A sparkgap, either H or I, is inserted in the secondary circuit, condensers being placed in parallel with the gap. The number of condensers can be varied by turning the attached but insulated quadrants v, w, to cover the studs t<1> ... u<1> each connected to a condenser coating. A rotary contact-breaker O is connected across the electrodes K, L if required. The contact-breaker D contains two sets of movable contacts in the primary circuit, which may be placed in series or in parallel, or only one used. The vibrating armature of a contactbreaker, independently actuated by the battery h, carries a rod k which strikes the arm 7 and so moves the rod 8 away from the screw 9, thus breaking the primary circuit. The other contact is similarly operated by the armature on the other side of the electromagnet g. In another form of contact-breaker, shown in Fig. 2<1>, the motor a' imparts a vertical reciprocating motion to a rod h<1> carrying a contact k<1>, against which the contact m<1> is pressed by a spring x'. As the contact k<1> moves upwards, a disc abuts against the adjustable stop, and the circuit is broken till the contact k moves down again. A slight rotation is given to the lower contact m<1> by the pawl w<1> actuating the ratchet v<1> at every upward movement. The lower contact in another form, Fig. 6<1>, is the rim of a disc 15<1> mounted in a forked lever 16<1> and turned by the fixed pawl 18<1>. As shown in Fig. 8<1>, the lower contact is pressed up by the spring 28<1>, and the upper contact 24<1> has several concave surfaces shaped to fit the rim of the disc. The resonator, Fig. 3, consists of a tympanum 30 carrying a bobbin of wire, in two parts, which may be connected singly or in series or parallel by the sliding switch 48, moving over the end of a central actuating-magnet 35, with which are associated six bar-magnets 27 having a common pole-piece 28.