Patent GB-498112-A (GB)
Title: Improvements in gyroscopic fluid flow meters
IPC: G01F1/38
Filed: 1938-01-27
Abstract: 498,112. Electric signalling systems ; follow-up devices ; speedometers ; gyroscopic apparatus. STOVER, E. F. Jan. 27, 1938, No. 2666. [Class 40 (i)] [Also in Groups XIX and XX] A fluid-flow meter comprises a gyroscope the frame and wheel of which are adapted to be rotated at proportional speeds about two axes at right-angles to each other, the speed of rotation being controlled by the pressure sensitive member so that the force due to the torque of the gyroscope about the third axis balances the force of the pressure sensitive member. The force due to the pressure sensitive member varies as the square of the rate of flow and the force due to the torque of the gyroscope varies as the square of the speed of rotation, so that the speed of rotation is a measure of the rate of flow. As shown, the frame 40 of the gyroscope with the whole of the mechanism within it, rotates on a vertical axis A in adjustable bearings on the fixed frame 10 which also carries the driving motor 54. A cylindrical casing 52 pivoted on a horizontal axis C in frame 10 has a horizontal spindle 61 at rightangles to axis C carrying a pair of gyro wheels 62, the spindle being rotated by a bevel pinion 81 engaging a bevel wheel 82 on a sleeve 44 fixed to the stationary frame 10. Rotation of the frame 40 and wheels produces torque about axis C which, by means of thrust bar 103 and lever 95, lifts a rod 30 connected to the pressure sensitive device. The centre of gravity of casing 52 and its contents is adjusted along the B axis by adjustable bushes 66 carrying the bearings of spindle 61 and along the A axis by adjustable sleeves 75, 76 so that the centre of gravity lies at the point of intersection of the axes. Further, the moments of inertia of casing 52 about the A and B axes are equalized by adjustment of sleeves 75, 76. The rod 30 which rotates with the gyroscope frame is connected by a thrust bearing 89 to a rod 87 fixed to a diaphragm 23 in a differential pressure device 20 connected to the conduit in which flow is to be measured, the weight of rods 87, 30 and the diaphragm being counterbalanced by a weighted lever 110. The weight 115 is adjustable to compensate for deviations from the square law relationship between pressure and fluid flow. Pressure urges rod 30 downwardly and closes contacts 120 in the circuit of motor 54 but when the speed of the gyroscope is such that the torque about axis C balances the pressure, the contacts 120 re-open. The frame 40 of the gyro drives through worm gear 128, a shaft 126 the speed of which is measured to give indications of rate of flow, revolutions of shaft 126 being counted at 125 to indicate total fiow. An arm 136 loosely carried on shaft 126 is driven clockwise by the shaft by the action of worm wheel 146 on worm shaft 142 mounted on the arm. A disc 130 driven by constant speed motor 132 drives a friction wheel 135 mounted on arm 136 and rotating the worm shaft 142 in such a direction that arm 136 rotates counterclockwise. The resultant angular position of the arm and pointer 148 gives an indication of the speed of shaft 126 which is read off on scale 147 and is recorded on a chart 150 also rotated by the constant speed motor. Remote signalling. Cam 161 on shaft 126 intermittently closes contacts at a rate depending on its speed, the impulses being repeated by magnet 167 which steps a worm shaft 172. The shaft moves a pointer 174 and friction wheel 176 across a disc 177 rotated at constant speed so that rotation of the friction wheel by the disc moves the pointer in the opposite direction. A scale and recording chart are provided as in the local indicating and recording mechanism. Modification, Figs. 2 and 3 (not shown). The rod 30 instead of controlling the circuit of the driving motor operates a clutch connecting the frame of the gyroscope to a driven shaft.