GB315267A - Improvements in or relating to method of and apparatus for indicating, recording and computing certain manifestations, such as pressure involved in meters - Google Patents

Abstract

315,267. Young, A. E. July 10, 1928, [Convention date]. Proportional calculators.-A computing device comprises a linkage connecting four points Q, P, H, O in such a manner that the relation OQ = #OH Î OP is always maintained as the linkage shifts with the shifting of the points. The device is described as applied to the recording mechanism of a differential pressure gauge for a flow meter. A float 9 rests in mercury in a chamber 10 forming with a pipe 18 one leg of a U-tube the other leg 19 of which is connected with a tank 21 which is kept at a constant pressure. Points 13, 33 at the top of the chamber 10 and a similar chamber 27 are connected bv a pipe 14 to the up-stream side of an orifice meter in the conduit 16. The float 9 therefore moves in response to the up-stream pressure in the conduit and the movement is transmitted by a slotted arm 6 on a pivot 5 to an arm 3 on the same pivot. The chamber 27 is connected at the bottom by a pipe 30 to a chamber 31 and forms therewith a U-tube in which is mercury, the leg 31 being connected to the down-stream side of the orifice. The movement of a float 26 in the chamber 27 is transmitted by a slotted arm 24 mounted on a pivot 23 to an arm 4 which is thus moved correspondingly to the pressure difference on opposite sides of the orifice. Extending across and carried by the casing 1 containing the clockwork, and across the chart 2 is a slotted guide 35 the centre of which coincides with the centre of the chart. In one with the guide 35 is a slotted guide 50 at right angles to it in which moves a pin 48 passing through the corner of a square formed by two slotted arms 44, 45. A pin 42 passes through the slotted arm 44 and the slotted end 43 of the arm 4 and works in the guide 35. A pin 37 passes through the arm 45 and slotted end 38 of the arm 3 and works in the guide 35. Weighted extensions 44a are provided on the square so that the centre of gravity coincides with the pin 48 and the square is suspended at this point by a cord 51 passing over a pulley to a balance weight 53. From the property of a right-angled triangle OQ = #OHÎOP and the point Q therefore moves so that OQ changes in proportion to the square root of the product of the pressure in, and the pressure-difference on opposite sides of a constriction in a conduit. The recording pens are carried at the points 54, 55, 59 upon extensions from the points P. H. Q. Three other constructions of suitable linkages are described based upon first the geometrical figure, Fig. 8 where 0 Q H is a rightangled triangle and OQ = #OHÎOP; secondly on Fig. 10 where the lines 79 H, 79 Q, 79 P are all equal and the same relation holds; and thirdly on Fig. 12, where the point P is not in the line OH, and OP = OP' and the link PP<1> moves parallel to itself.