GB104777A - Improvements in and relating to Electrically Operated Indicators. - Google Patents

Abstract

104,777. McLeod, T. April 13, 1916. Range-finders for aerial warfare comprise electrical transmitters and indicators at three stations situated at the angles of a triangle. Each transmitter varies, by the operation of an arm, the current supplied to two or more indicators which may be in the form of measuring instruments of the moving coil or core type, or of the hot wire type, or a solenoid the core of which is variably loaded in accordance with its position in the coil. Each angle of a triangle is provided with the apparatus shown in Fig. 3; this consists of a transmitter T and an observation board B provided with three indicators for indicating the angles through which observation tubes u at the three stations are turned. from a vertical plane, and an indicator for indicating the angle through which the tube u at that station is turned from a horizontal plane. In the arrangement shown in Fig. 1 an arm p carrying contacts c, e<1> is adapted to be rotated about a spindle n by the operation of a tube o. The contact e is adapted to pass over nine sets of contacts s each of which is connected to a resistance r, while the contact e' is adapted to pass over a contact range t connected to a resistance r<1>. The resistance r is connected to three digits " indicators b connected in series with a battery h; while the resistance r<1> is connected to three " tens " indicators c connected in series with the battery h. Each set of contacts s is equal in length to "one of the contacts of the range t so that with the arrangement shown any number up to 90 may be indicated by the combined reading of an indicator c and an indicator b. In the modification shown in Fig. 2 the contact arms p<1>, p<2> are connected by gearing. The receiver may consist of two segmental strips carrying figures and connected to the moving coils of the instruments. The figures are moved, by varying values of current, opposite apertures placed side by side. In the modification shown in Fig. 5, the core w of a solenoid v is attached to a moving dial j and is provided with a stepped base x. The lower part of the core is contained in a casing y into which weights k of different values fit, so that as the ccre rises these weights are successively taken up by the base x.