GB122094A - Improvements in Pressure Gauge Legs. - Google Patents

Abstract

122,094. Paulin, J. B. April 4, 1918. Pitot-tube apparatus.-The differential pressuregauge constituting the measuring-instrument of the log comprises a casing 1, Fig. 1<a>, containing a rheostat and a series of pressure-sensitive diaphragm boxes 2 connected to a Pitot tube 3, the interior of the casing communicating by a pipe 19 with a casing 20, provided with a static pressure tube 21 and preferably partly filled with oil 22, a float 23, and valve-cone 230 preventing liquid from entering the casing 1. The end segments of the rheostat are connected up with a battery 12 and regulating-resistance 13. The expansion of the boxes 2 allows a spring to turn a cam disk 9 carrying a contact spring 10, the shape of the cam being so chosen that the ship's speed may be indicated by an ammeter or voltmeter 24. In a modification, the casing 1 is divided into two compartments by a diaphragm, the Pitot and static-pressure tubes each communicating with one compartment. The circuits may be as shown in Fig. 3 or Fig. 4, an auxiliary rheostat being provided in the latter case, its contact 140 being moved simultaneously with the contact 10 in order to keep the total resistance constant. The casing may be filled with liquid and provided with a second set 26, Fig. 5, of diaphragm boxes communicating with the static pressure tube, the liquid thus acting as the intermediary through which the two pressures balance; a rod 4 operated by the boxes 2 is connected to a lever 29 which operates a rod 31 carrying brushes 36 in contact with rheostat segments 38.