Patent GB-410908-A (GB)
Title: Improvements in or relating to differential pressure gauge apparatus for measuring the flow of gases
IPC: G01F1/37
Filed: 1933-01-16
Abstract: 410,908. Pressure gauges. COMPAGNIE POUR LA FABRICATION DES COMPTEURS ET MATERIEL D'USINES A GAZ, 12, Place des Etats-Unis, Montrouge, Seine, France. Jan. 16, 1933, No. 1441. Convention date, Jan. 16, 1932. [Class 106 (ii).] Relates to apparatus for measuring the flow of gas through a pipe by using a pressuredifference device corrected for temperature and density and consists in driving the counting device by a constant speed motor operating through a variable linkage and one way drive so that one or more pivot points of the linkage is moved by an alteration in one of the variants such as pressure density and temperature. The pipes 4, 5 from either side of the constriction 3 are taken to opposite sides of the dividing wall 8 of a gravity gauge 6 of the ring type partly filled with quicksilver. The gauge is connected by a rod 9 to a lever 10 the end of which is pivoted to a slide bar 14. The lever 10 is connected at a second point 26 by a rod 15 to a second ring balance gauge 16 which is influenced by a gas tight gauge 17 comprising an inverted U-tube 18 the two ends of which enter the pipe 1 and face up and down stream respectively. A vessel 19 is joined to the bend of the U-tube 18 and a pipe 20 extending downwards from the vessel 19 is bent into a U-shape from which a small pipe 21 extends to one side of the dividing wall 22 of the gauge 16 while a small pipe 23 extends from the tube 18 to the other side of the dividing wall. The U-shaped part of the tube 20 is filled with quicksilver while above the latter and in the vessel 19 is a liquid of less specific gravity than quicksilver. The flow of gas through the tube 18 is so small that it can be neglected, the pressure difference between pipe 21, 23 corresponding to the weight of the gas in the right limb of the tube 18 and thus the movement of the gauge 16 to density. A rod 27 is joined to the guide rod 14 an arm 29 being pivoted at 28 to this rod 27. The end of arm 29 is pivoted to a connecting-rod 31 and to a guide rod 32 pivoted at the other end 33 to a guide rod 34 swinging around a fixed axis 35. The rod 34 is connected at the point 36 by a connecting rod 37 to a crank 38 driven by a constant speed electric motor 39. The rod 31 is also connected at the point 40 to a parallel guide formed by a rod 42 pivoted at 41, 44 pivoted at 45, and a link 43. The arm 44 carries a brake block 46 which engages and drives the disc 47 when the arm moves to the left. A similar brake block 48 prevents the disc moving in the opposite direction during return of the arm 44. The disc drives the counter 52 through bevel gear 49, 50 and shaft 51. The rod 32 is equal in length to the rod 34. During downward movement of rod 27, if the point 30 coincides with the point 35 it makes no movement during the rotation of the crank and the parallel motion 42, 43, 44 makes no movement. The greater the angle between rods 32, 34 the greater the movement of the part 44. According to the movement of the rod 27 the motion of the motor 39 is transmitted to the counter in varying degree up to a certain maximum. The lever 10 may be acted upon by a device to compensate for temperature.