GB1437909A - Instrument for measurement and control of a measurable quantity - Google Patents

Abstract

1437909 Indicating measurement HAUSER VERWALTUNGS - GmbH 9 April 1974 [9 April 1973] 15755/74 Heading G1J [Also in Division H1] An instrument 10 for setting the required value and displaying the actual value of a parameter, e.g. temperature or pressure, comprises a dial gauge having means 12 for converting changes in the measured value of the parameter into rotation of a pointer spindle 11 carrying a pointer 19 movable over a dial 18 to indicate the measured value, and means 17, 21 for axially displacing the spindle 11 in proportion to its rotation, to actuate a microswitch 32. The micro-switch is mounted externally of the instrument casing 27 on a bracket 31 for easy adjustment and/or replacement. The means 12 may be electrical or, as shown, mechanical, e.g. a double layer Bourdon tube 13, 14 connected to the capillary of a thermometer. The spindle 11 has an axial threaded bore 20 which engages a normally stationary screw 21 to produce axial movement of the spindle proportional to its rotation. The screw 21 carries a set pointer 25 to indicate the control point of the instrument, i.e. the value of the parameter at which the micro-switch 32 is actuated, and carries a knob 24 in front of the centre of the cover glass 23 of the gauge for adjustment of the control point. In a modification, Fig. 3, not shown, the knob 24 is adjacent the edge of the cover glass 23 and the spindle 11 has an external screw thread (36) adjacent its rear end which engages a nut (21) rotatably mounted in the back wall (29) of the casing (27). A gear wheel (38) on the nut (21) meshes a pinion (39) on the shaft (22) of the knob 24 and carries a U-shaped set pointer (41). The pointers 19, 25 are of resilient material and each has a bifurcated end (34) Fig. 2, (not shown) by which it can be clipped to the spindle 11 or shaft 22, the bifurcated end embracing about 60% of the circumference of the spindle or shaft.