Patent GB-983520-A (GB)
Title: Basic liquid flow meter and interchangeable compensating means therefor
IPC: G01F15/02
Filed: 1962-07-12
Abstract: 983, 520. Liquid flow meters. A. J. GRANBERG, July 12, 1962 [Feb. 26, 1962], No. 26815/62. Heading G1R. In a compensated liquid flow meter including a basic meter having a casing, a soluble shaft, a flow register and compensating means therefor the compensating means comprises a transmission means connecting the shaft to the register and including an intermittently activated cam follower activated by a cam driven by the shaft. In the arrangement shown in Figs. 1, 2, 3 and 5 rotary components of a position displacement type meter 1 drive, by means of a shaft 9 through gearing contained in a housing 13 and a shaft 15, a rotatable counting register 17. A single lobed cam 19 is secured to the shaft 9 below a base plate of a housing 23 for planetary transmission comprising a sun wheel 25, planet wheels 27 and an enclosing gear 29 carrying a hollow shaft 31 projecting upwardly through a bush 32 in the housing 23. The shaft 15 to the register 17 is secured to the hollow shaft 31. The housing 23 is provided with two rings 33, 34. The upper ring 33 is surrounded by an overriding unidirectional clutch 35, Fig. 4 (not shown), and a lower ring 34 with a unidirectional clutch 37 which is operative in the opposite direction to rotation of clutch 35. The lower clutch 37 is connected through an arm 49, links 51 and arm 53, journalled on a fixed pivot 55, to an arm 57 also journalled on pivot 55 and secured to arm 53 and which, at its free end, bears against a cam 19. The arm 49 is anchored to the casing 13 by a spring 69 and an adjustable stop 61 bears against arm 53. The rotation of shaft 9 and hence cam 19 deflects the follower 59 and, through the linkage, clutch 37 and the planetary gearing, imparts a counterclockwise rotation to the shaft 15 in addition to the normal action of the planetary gearing, the amount of additional counterclockwise rotation being determined by the adjustment of the position stop 61. The upper overriding clutch 35 is adapted to impart an intermittent rotary movement to the planetary gear as in housing 23 and hence register 17 by any one of a variety of compensating means which respond to some change in the metered liquid. One such compensating means responds to the liquid temperature change with respect to a reference temperature and has a temperature sensitive capsule 75, filled with a suitable volatile liquid, placed in the meter casing 3 and connected by a small diameter tube 77 to a bellows 79 in a housing 81. Opposed to the bellows 79 is a second bellows 83 filled with a volatile liquid to compensate for ambient atmospheric temperature and pressure changes. Alteration in the liquid temperature causes a pressure change in capsule 75 to alter the length of bellows 79 to rotate a bellcrank 85 resiliently coupled by a compression spring 89 to the bellows 83. The rotation of the bell-crank 85 will vary the position of contact between a boss 91 thereon and a stub 99 on crank arm 95, pivoted about a pin 97 and connected through a link 93 to the arm 49 and the upper clutch 35, to vary the distance the arm 95 will be permitted to move in a clockwise direction about the pivot 97. The arm 95 is movable against a spring 100. To correct for the different temperature-value relationships of liquids of different density or gravity the angularity between the arm 95 and its cam follower 101, independently journalled on pivot 97, is altered. An upstanding bracket on the cam follower 101 is urged counterclockwise with respect to the arm 95 by a spring 105 and a bracket 109 on the arm 95 carries a threaded shaft 111 bearing against the bracket 103, which shaft 111 can be adjusted by a knob 121 and gears 115, 113 to vary the angle between the cam follower 101 and arm 95. The temperature-responsive element just described may be rendered inoperative by a cam 127, operated by a knob 131, bearing against an extension of the arm 49 of the upper clutch 35. A gravity compensator may be substituted for the temperature sensitive element when the specific gravities of the liquid passing through the flowmeter are not constant. The gravity compensator comprises a float chamber 141, Fig. 6, connected in a conduit leading to or from the meter. A perforated guard 143 provided in the chamber 141 has a float 145 therein secured to a shaft 147. At one end of the shaft 147 is a pin clutch 151 engaging a spiral spring 153 on a stub shaft 155 provided with a worm gear 157 adjustable by a worm 159 for compensating for the float weight. The opposite end of the shaft 147 is connected by a second pin clutch 161 to a coaxial shaft 163 connected by a link 177 to a bell-crank 179 which engages one end of the bellows transmitting element 183 connected by tubing to the bellows 79 shown in Fig.2. In an alternative device for transmitting motion from the shaft 147, Figs. 8, 9 (not shown), for very high pressure liquids, the link 177 is replaced by a permanent magnet acting on a similar magnet secured to the shaft of an electrical synchronous motor position transmitter which transmits a signal to a synchronous receiving element and through a cam provided thereon acting on a cam follower engages a stub 99 on the arm 95, Fig.2. In a further specific gravity compensator, Figs. 10-13 (not shown), the arm 149 of the float 145 is attached to a magnet armature movable vertically within a pair of like windings mounted on laminated cores which partially rotate a disc and through a cam and rod operate on the stud 99 of the arm 95, Fig.2.