GB303987A - Improvements in indicating and measuring instruments - Google Patents

Abstract

303,987. Paulin, J. G. Dec. 6, 1927. Barometers.-Comprises a particular construction of barometer of the type in which the elasticity of a spring system or the like is used to balance the pressure exerted upon the vacuum box and in which the movements of the latter are indicated by a zero pointer connected to the member through a gearing device. The vacuum box 2 is connected to the under side of a frame member 1 and has attached to it by means of a nut 17 one shank of a. bent leaf spring 18 the upper shank of which is clamped in an interstice in a bar 20. This bar bears against two stop screws 21 and is provided with a projecting. arm 22 the end of which is connected by a screw 23 to a base plate. The leaf spring 18 is designed to relieve the vacuum box of the normal atmospheric pressure. The leaf spring is provided with two laterally projecting laps 24 to which are atttached the lower ends of two helical springs 26 the upper ends of which are secured to a yoke 25 rigidly connected with a nut 13 adapted to be adjusted by a micrometer screw 12 Journaled at the lower end in a fixed bearing 27. The nut is kept from rotation by a forked member 15 engaging a guide 16', the screw 12 being rotated to adjust the tension of the comparatively weak springs 26 which can be made of very hard material. The lower shank of the leaf spring 18 is provided with an angularly bent extension 18<1> forming a tongue 30 located between two stops 29 which limit the movement of the diaphragm box, and two projections 7<1> to which are attached vertical bands or strings 6, 6 connected by horizontal bands 5, 5 to arms on a floating spindle 3 the ends of which are supported on tensioned springs 32 the spindle carrying a pointer 8. In use, when a change of pressure occurs, the diaphragm box is restored to its initial position by operating the screw 12, a pointer 28 moving over a dial 9<1> and the pointer 8 being restored to zero.