Patent GB-849501-A (GB)
Title: Improvements relating to impulse-duration telemetering systems
IPC: G01F1/37
Filed: 1957-02-19
Abstract: 849,501. Integrating- and recording-apparatus. BRISTOL CO. Feb. 19, 1957 [Feb. 24, 1956], No. 5578/57. Class 106 (4). [Also in Group XXXVIII] In a telemetering system, the duration of impulses repeated at a constant frequency bears a predetermined non-proportional relationship to the magnitude of the variable being measured, the non-proportionality resulting, at least in part, from a component of constant duration included in each impulse, and a first quantity derived from the impulses is algebraically added to a second quantity of such value that the effect on the first quantity of said components of constant duration is cancelled out. As shown, Fig. 1, in a system for telemetering the rate and volume of fluid flow in a pipe line 10, the pressures on either side of an orifice plate 11 are applied to a manometer element 14 which actuates a spindle 18 angularly to deflect an arm 19 to an extent dependent on the rate of flow. A rider (not shown) at the end of the arm 19 is disposed between a flat rocker-plate 21 and a flat circular plate 20, which is continuously rotated at a uniform speed by a motor 23, so that the rider, during a part of each revolution, the length of which part depends on the position of the rider, is engaged by a flat cam 28 which has a leading edge 29, and a spiral trailing edge 30 designed to impart a square-root law to its functioning, and which is fixed to the plate 20. Volume measurement.-During the period of engagement of the rider and the cam 28, the rocker plate 21 is deflected with its shaft 24 and an arm 31 to open contacts 33, 34, thus interrupting the supply of D.C. from a source 42 to the winding of a relay 78, Fig. 4, in an integrating unit 60, which in turn interrupts the rotation, by a motor 72 through gearing, of a sun-wheel 66 of a differential gearing device 64. A second sun-wheel 65 in device 64 is continuously rotated through gearing by a motor 71 at a speed designed to cancel out the effect of the rotation of the sun-wheel 66 during that part of each revolution of plate 20, shown as angle C in Fig. 3, which represents a constant component of each impulse from source 42. The output of device 64 is, therefore, proportional to the rate of flow, and is arranged to drive an integrating train 75, through a lost-motion coupling 76, to register total volume. In a modification (not shown) the integrating device 60 comprises a single constant speed motor which continuously drives sun-wheel 65, and is connected through a clutch and gearing to drive sun-wheel 66 by the periodic energization of an electromagnet within device 60. Rate of flow measurement.-The impulses from source 42 also energize an electromagnet 37, Fig. 1, and a constant-speed motor 36 drives alternately, according to whether the electromagnet 37 is energized or not, and in opposite directions, two spindles 38, 39, which carry impeller members 40, 41, and on which are rotatably mounted lever arms 44, 45, respectively. A variation of the ratio of energization to de-energization of the electromagnet 37 lengthens the excursion of one of the impellers 40, 41, which drives its associated lever arm and thence through gearing, deflects a recording arm 50. Specification 453,571 is referred to.