GB417514A - Improvements in pressure gauges, particularly for indicating absolute pressure, and the like instruments - Google Patents

Abstract

417,514. Pressure gauges; recording- apparatus. SMITH & SONS (NOTTING- HAM), Ltd., S., HINE, A., and WELLER, A. G., Basford Brass Works, Nottingham. March 31, 1933, Nos. 9738/33 and 10126/34. [Classes 106 (ii) and 106 (iv).] A pressure gauge for connection to two separate sources of pressure, for example a gauge which is self-correcting for barometric pressure, comprises two sets of Bourdon tubes 10, 12 connected at their free ends to a floating yoke-bar 52 which at a point midway in its length is pivotally connected to an arm 53 of adjustable length extending from a spindle 54 for an indicating finger or pen 55, which may record on a chart 56. If one set of tubes 10 is connected at 11 to the source of pressure to be measured, and the other set 12 is sealed, the pointer 55 indicates the absolute pressure of said source. The adjustable arm 53 may comprise two parts 53<a>, 53b clamped together by a bolt 60. The chart 56 may be in the form of a drum or dial rotated by clockwork, and the tip of the pen 55 is pressed slightly against the chart by a spring 65 pressing on a pivoted limb 61<b> on which the pen is pivoted at a point 62 opposite the end of the spindle 54, an adjusting screw 63 bearing on the pen to adjust its angular position. A modification is described wherein one pressure-sensitive device is an aneroid capsule and the other a Bourdon tube, and the floating yoke-bar is arranged for movement laterally instead of endwise. In another modification, the pen is connected to one end of the yoke-bar.