GB377939A - Liquid measuring device with twin-piston - Google Patents

Abstract

377,939. Delivering measured quantities of liquids. FABRIK EXPLOSIONS - SICHERER GEFASSE SALZKOTTEN GES., Salzkotten, Westphalia, Germany. Jan. 27, 1931, No. 2639. Convention date, Jan. 30, 1930. Void [Published under Sect. 91 of the Acts]. [Class 106 (v).] In liquid measuring apparatus of the piston and cylinder type the piston is formed double and encloses a space 4 in communication with the atmosphere, into which leakage past the piston flows and may be indicated. Fig. 3 shows a form in which the leakage flows into the space below two separate measuring cylinders with interconnected pistons and is indicated in a sight glass 47. The transparent measuring cylinder 1, Fig. 1, is provided with a double piston 2, 3 comprising cup leathers clamped to a piston body 5 forming between them the cavity 4 in communication with the hollow piston rod 11b by passages 11. The upper and lower chambers of the cylinder 1 are alternately connected with the supply duct 16 and the outlet duct 17 by a four-way valve 7. Any liquid leaking through the cup leathers runs off through the hollow piston rod. Alternatively the leakage may escape through a small hole or groove arranged in the side of the cylinder 1 level with the top of the lower piston 3 when in its upper position. The cavity 4 between the pistons may be filled with liquid of a colour different from the liquid being measured, or with a liquid for preserving the leather e.g. glycerine, castor oil &c., and communicate with a stand-pipe 53, Fig. 4, having at its upper end a sight glass 54 level with a sight glass 60 interposed in the outlet duct 16 and having an overflow pipe 62. A duct 55 controlled by a cock 57 allows of the removal of any air accumulating below the upper piston 2. Any leakage is indicated by rise or fall of level in the sight glass 54. Fig. 3 shows a form having pistons 33, 34 operating in separate cylinders and connected by a lever 42 and rods 40, 41. The space 4 communicates with the outside by a pipe 23, sight glass 47 and overflow pipe 51. A small bore 30 in the overflow pipe allows slight leakage to escape directly but considerable leakage is indicated in the sight glass. In this modification the valve 7 may be operated automatically by the increase of pressure in the measuring chamber when the piston reaches the end of its stroke. Adjustable abutments 43, 44 limit the stroke of the pistons which are guided by ribbed members 29 working in tubes 36 on the cylinder covers. The invention may be applied to apparatus having horizontal cylinders and to arrangements of measuring cylinders in a circle, the pistons being moved in succession by rotating driving mechanism which also operates the reversing valves.