Patent GB-710943-A (GB)
Title: Improvements in fluid-flow meters
IPC: G01F15/06
Filed: 1951-05-01
Abstract: 710,943. Indicating-apparatus. STOKOE, C. L., and MONITOR PATENT SAFETY DEVICES, Ltd. April 25, 1952 [May 1, 1951], No. 10191/51. Class 106 (4) A fluid-flow meter comprises a crank member for transmitting movement of a member located in the fluid flow path to an operating spindle projecting through the wall of a crank chamber with means for preventing leakage by the elimination of axial movement of the spindle and means for operating electric members by adjustable tappets located on an annular ring attached to the projecting portion of the spindle for operating alarm or control devices. The body of the meter b, Fig. 1, has bolted thereto a crank chamber a wherein up or down vertical movement of a link c positioned in accordance with a member in a conical tube located between fluid inlet and outlet, represents increase or decrease of flow in a pipe and is transformed into rotary movement of an operating spindle k through rack d and pinion, the pinion carrying a crank pin h working in a slot j in the flanged end of the spindle k. The pinion is mounted on a sleeve f free to rotate on a fixed hollow spindle g which houses a needle s pressed by a spring r against the flanged end of spindle k, the thrust of the spring r combined with the fluid pressure being taken by a stop plate q which forms a bearing for the pointed end of the spind'e k. The inner bearing for the spindle k is an aperture l in the cover m of the chamber a and it is rendered fluid-tight by a resilient washer o pressed by a spring n weaker than the spring x. In another embodiment, Fig. 3, a flap v attached to a spindle w in a bearing y responds to changes of flow and rotary movement is transmitted to the spindle k by a crank pin h carried by a disc z on the spindle w engaging the slot j in the flanged end of the spindle k. In order to relieve the flap spindle w from end thrust and allow it to float freely a spring loaded bridge plate a<SP>1</SP> is provided which by virtue of springs b, on pillar studs c' presses against the pointed end d' of the operating spindle k to prevent axial movement. The relative positions of the crank pin h and bridge a<SP>1</SP> are chosen so that the path of the pin h does not foul the bridge a<SP>1</SP>. A boss e' on the spindle k carries a pointer t indicating against a scale u and an annular ring f<SP>1</SP> supported by two arms g', arranged to clear the bearing bridge p between zero and full flow indication. The ring f' carries two adjustable tappets h', k', Fig. 6, co-operating with insulated rollers j', l<SP>1</SP> carried by hinged blocks, co-operating with other hinged blocks, each pair of blocks carrying various silver contact members arranged in indicating, alarm and, if desired, control circuits so that when e.g. the tappet h' actuates the roller j' to trip the blocks m<SP>1</SP>, n<SP>1</SP>, the "safety" lamp is extinguished and a predetermined low limit of flow is indicated, the blocks remaining tripped until released by depressing an arm o<SP>1</SP> to release a trip plate q'. For control purposes such as starting or stopping an electric motor at predetermined flow limits, the " make " or " break contacts may be looped into the pushbutton connection of the starter switch. Specific cations 447,809 and 553,602, [both in Group XXIX], are referred to.