GB659602A - Stopper for flask - Google Patents

Abstract

659,602. Stoppers. RANE, L. Aug. 23, 1949, No. 21897. Convention date, Sept. 1, 1948. '[Class 125(iii)] [Also in Group VI] A flask stopper has a tapered body of soft vulcanized rubber or the like with a duct 20 extending therethrough in an axial direction with its outer end 26 flared to form a substantially conical valve seating; a valve member 30 which has a head 32 shaped to seat in the valve seating and a dependent shank 34 which enters the duct and has radial projections 36 towards the inner end which bear against the duct wall, the arrangement being such that when the stopper is wedged in the mouth 12 of the flask with the valve closed contraction of the duct causes the valve to be gripped and held in the closed position until the pressure in the flask exceeds the external pressure whereupon there is a. sufficient relative resilient yield between the parts to permit escape of gas &c. from the flask. Preferably the stopper has an integral skirt 14 of considerable length to embrace the bottle mouth, and a concentric rib 18 on the top with an inner diameter substantially equal to the maximum diameter of the stopper. The duct 20 has a constriction 28, immediately below the conical part 26, in which the shank 34 of the valve 30 fits loosely. The valve may have a finger tab 38. A number of holes 22, 24 also extend through the stopper, each having an upper conically flared orifice 40 and a constricted portion 42, and each hole is fitted with a soft rubber plug 44 having a conical end 46 to seat in the orifice 40, a shank 48 to fit in the portion 42, an enlarged lower end 50, and an axial bore 52 extending from the lower end to near the upper end. The duct 20 may be continued downwardly by a tubular extension 60 provided with small holes 62. A vent tube 64 is usually fitted into one of the holes 22, 24. The stopper may form part of a blood transfusion &c. apparatus, the flask being filled and inverted, the valve 30 removed and a tube thrust in the outer end of duct 20. The extension 60 acts as a strainer. An air vent is provided by thrusting a hollow needle through one of the slugs 44 into the bore 52, the punctured plug being replaced after use. When the flask is heated to sterilize it and its contents the internal pressure lifts the valve 32 to permit escape of gas &c. the valve then being held on its seat by the elasticity of the parts, and later by the outer pressure when the inner, pressure drops. In the example shown in Fig. 3, the duct 20 extends through the stopper, but holes 70, 72 stop short of the top leaving integral diaphragms 74, 76. The vacuum in the flask forms slight depressions at 74, 76 indicating where the needle should be thrust and these parts preferably contain a high percentage of rubber gum so that they are self-sealing and may be punctured a number of times.