Patent GB-202330-A (GB)
Title: Improvements in systems for measuring quantity or like variations
IPC: G01N7/04
Filed: 1923-08-14
Abstract: 202,330. Roucka, E. Aug. 14, 1923. Tell-tale apparatus.-For indicating the variations of a physical value such as the volume of a gas, means are provided for holding a member, movable in accordance with the variations, in its indicating position for an interval of time, during which interval the member co-operates with means actuated by auxiliary power to produce impulses of an augiliary energy. The Figure shows a system used in connection with a gas analysing apparatus in which the position of the arm 84 is periodically recorded at a distant station by a recorder 154 moved synchronously with a shaft controlling the operations of the analysing apparatus. A cylinder 18 containing liquid, communicates through a pipe 28 with a measuring gas container 30 and an auxiliary gas container 32. The cylinder contains a piston 20 which is reciprocated through connecting-rods 16 and crank discs 8, 10 by a synchronous motor 2. The gas container 30 is connected through a liquid check valve 36 to the source of gaseous mixture to be analysed. The valve 36 is connected by a pipe 44 through a check valve 46 to an automatic valve 52, 56, 58 and through a pipe 60 to an absorption vessel 62. The automatic valve is also connected to the gas space of the vessel 62 by a pipe 54. The gas space of the vessel 62 is connected by a pipe 68 to a nozzle 70 which communicates with the interior of an inverted bell 74 floating in a liquid in a container 72. The bell 74 is attached to one end of a flexible connector 82, which passes over a pulley 80 carried by a shaft 76, the other end of the connector carrying a counter-weight. In operation, as the piston 20 rises the gaseous mixture to be tested is drawn through the pipe 42 and valve 36 into the container 30, 32. As the piston descends the liquid rises and forces the gas from the containers 30, 32 through the valves 36, 46 and the valve 52, 56, 58 into the atmosphere when the level of the liquid is below the valve 52, 56, 58. The gas space of the vessel 62 is also in communication with the atmosphere, so that the bell 74 falls to its zero position. When, however, the liquid is above the valve, the gases pass through the pipe 60 into the absorbing-liquid 64. The non-absorbed gas is conducted into the bell 74, which rises as the volume of gas increases, and so rotates the counter balanced arm 84 carried by the shaft 76. As the piston approaches its lowest position, the pumping-liquid enters the enlarged end 180 of the cylinder 18, so as to hold temporarily the belf 74 in the position assumed by it at the end of the pumping stroke. The crank disc 10 has a cam notch 100 of length corresponding to the interval during which the bell is held stationary - The disc 10 oscillates a lever 92 which is carried by a shaft 94, and operates a V-shaped member 96, the base portion 98 of which has an inclined edge 99. The portion 98 engages the arm 84. which in turn is forced against a pivoted U- shaped member 106. A U-shaped member 101 is pivoted on the shaft 94, and is loosely connected to the member 96 by clips 104. The purpose of this member is to hold the arm 84 against movement as it is engaged by the inclined edge of the member 96. The member 106 oscillates the lever 110 to close momentarily a circuit between the strips 116, 120. The position of the impulse in the time interval is determined by the position of the arm 84 relative to the inclined edge 99 of the member 98. The impulse produced energizes the receiving-magnets 168, to force a pen 156 into engagement with a recording- strip 158. The pen 156 is carried by a lever 154 which is oscillated by a cam 148 rotated by a synchronous motor 144.