GB699835A - Improvements in hydrostatic levels - Google Patents

Abstract

699,835. Levels. SCHMIDT, C. E. April 27, 1951, No. 9954/51. Class 97 (ii). A level comprises a liquid reservoir 10, Fig. 1, a tube 25a having one end communicating with the liquid 14 in the reservoir, a distant level reading sight 35 at the other end of the tube and a normally closed valve which is opened when a scriber 36 is used to scribe and mark. The transparent tube 35 provided with a datum mark 37 at a fixed distance above the scriber 36 is held by a rubber insert 49, Fig. 4, within the boss 48 of a portion 38 of a transparent valve casing. When the scriber 36, which is attached to a diaphragm 46 rigidly fixed at its edge in the portion 38, is pressed inwardly, its rear end opens a spring pressed valve 41 contained within a second portion 39 of the valve casing. A reinforcing tube and clamp 33a connect the end of tube 25a to a boss 33 on the portion 39. The reservoir 10 comprising heads 11, 12 and a transparent drum 13 is rotatably carried on a flanged base 26 by a bushed bearing, the outer surface of which is provided with a standard pipe thread which normally receives a handle but may be used for supporting the base. A bolt 15, which holds the parts 11, 12, 13 together is bored at 22, one end thereof communicating with a passage 23 whose outer end removably receives an L-shaped connector to which one end of the transparent tube 25a is clamped whilst the other end of bore 22 terminates in an opening 24 at the geometric centre of the drum 13. The drum 13 is more than half filled with liquid 14 and has a closable vent valve 18. After use, the reservoir 10 is employed as a reel on which the tube 25a is wound, a knob 19 being provided on the head 12. The end of tube 25a is passed through one of several openings 57 and the valve casing and detached sight 35 laid on head 12 so that a cover 52 secured by lugs 54 engaging posts 51, 58 may be placed thereover, a spring in the cover 52 bearing on the end of bolt 15. A hanger may be provided on the base 26 for supporting the reservoir, when in use, from a nail.