Improvements relating to Displacement Measuring Devices

摘要

1,192,006. Measuring pressure electrically; pressure gauges. ELLIOTT BROS. (LONDON) Ltd. Aug. 8, 1967 [Aug. 12, 1966], No. 36174/66. Headings G1L and G1N. Deflection of a pressure capsule 1 is communicated to a differential beam 5 by a link 4 causing the beam to pivot about its end 6 and communicate movement to a detector beam 10. This beam is pivoted by cross-springs 11 at its centre and carries the input member 14 of a transducer 15 by means of which a pressure representative signal is transmitted through an amplifier 16 to a servo motor 17 driving a pointer 18 over a scale 19. The servomotor also operates to provide feedback through a gear train 20 and links 21, 23 to restore the beams 5 and 10 to their undeflected positions, whereby the arrangement operates in a null mode. In accordance with the invention, the arrangement may be operated in a second mode by actuating a mechanical clamp 24 to lock the end 9 of beam 10 against movement. By clutch means (not shown) the servomotor 17 is also disconnected from gear train 20. In this mode of operation, the feedback is inoperative and deflection of beam 5 takes place about end 7 to transmit movement to pointer 18 from the other end by way of links 21, 23 and gear train 20. According to a modification, detector beam 10 may be dispensed with and the transducer 15 and clamp 24 transferred to the end 7 of beam 5. The pick-off portion of transducer 15 may be controlled in position for the purpose of introducing corrections into the system. A second embodiment, Figs. 2 and 3 (not shown), employs two pressure capsules controlling a common detector beam. The arrangement is generally similar to Fig. 1, but includes full details of the arrangement for actuating the mechanical clamp Fig. 4 (not shown) and unclutching the servomotor 17 from the gear train. Details are also given of the arrangement for positioning the transducer to introduce corrections. Reference is made (without giving specific details) to a modification whereby this arrangement measures the difference of pressure of the two capsules.