GB798683A - Improvements in or relating to fluid dispensing devices - Google Patents

Abstract

798,683. Dispensing measured quantities. WARD, L. T. Nov. 30, 1954 [Aug. 16, 1954, Aug. 16, 1954, Aug. 16, 1954], No. 34714/54. Class 106(5) [Also in Group XXVIII] A valve for dispensing a measured quantity of liquid 11, Fig. 1, from a pressurized container 10 comprises a valve body 14, a chamber 20, Fig. 2, within the valve body and having an inlet orifice 43 and an outlet orifice 24, and a valve operating member 16 which controls the orifices 24 and 43 to dispense a measured quantity. When the member 16 is in the position shown in Fig. 2, the liquid 11, which may be an insecticide, germicide, cosmetic, medicine or drug incorporating a quantity of low boiling point liquid propellant, rises in the tube 15 and flows through the orifice 43 into the chamber 20, a duct 36, ports 37 and an annular space 21. When the member 16 is depressed against the action of a spring 34 the liquid escapes by way of a port 25, a duct 24 and a discharge orifice 19 while the inlet orifice 43 is closed by a resilient sealing member 32. The sealing member 32 may be replaced by two axially spaced sealing rings while an upper sealing member 26 may be replaced by one having a quadrant shaped cross section. Fig. 6 shows a modified construction in which a reservoir chamber 51 is in communication through a port 43a with the interior of a dip tube 15 and hence with the substance in the container: the reservoir chamber 51 is accordingly filled with such substance. Upon downward movement of the plunger 16 against the action of spring 34a, a bulbous region 49 passes over port 43a to cut off communication between the reservoir chamber 51 and the container and and thereafter to establish communication between the chamber 51 and the annular space between the bore of the dip tube 15 and the outer surface of the lower section 48 of the plunger 16 lying above the region 49. Further downward movement of the plunger 16 causes the port 25 to become uncovered below the lowermost surface of the sealing ring 26a so that fluid communication is established between the reservoir chamber 51 and the discharge orifice by way of port 43a, port 25 and bore 24 to allow the contents of the reservoir chamber to discharge. In a further embodiment, Fig. 9, the valve actuating member 16 has a section 21 which is a loose fit within the bore 65 of the valve body 14. The reservoir chamber is constituted by the space within the bore 65 of the valve body 14 above a collar 69 and becomes filled with the substance to be dispensed through the dip tube 15. Upon actuation of the valve member 16, portion 67 enters the bore of a collar 69 and causes complete cut off of any liquid communication between the interior of the container and the reservoir chamber whilst still permitting the passage of propellent gas or vapour. The port 25 in the upper section 22 of the valve operating member 16 becomes uncovered by its downward movement past the lower surface of the sealing ring 26a whereby the reservoir chamber is placed in communication with the bore 24 and the stem 22 of the valve operating member and hence the discharge orifice of the operating knob (not shown). The release of the contents of the reservoir chamber is assisted by the continued supply of pressure gas or vapour through the narrow annular gap between the cylinder 67 and the bore of the collar 69. Continued downward movement of the valve member 16 brings a truncated conical surface between cylinders 66 and 67 into engagement with the upper end of the collar 69 to completely cut off the supply of gas and liquid from the interior of the main container. Fig. 14 shows an embodiment suitable for use with substances such a medicinal products where possible contamination by contact with metal surfaces is to be avoided. This embodiment is adapted for use with a glass container 10 and the valve assembly is secured in position by means of a rolledover metal cap 84. In the position shown, the valve operating member 16 provides fluid connection between the dip tube 15 and the reservoir chamber 51 through a throat 85 whereby the latter becomes filled with the quantity of the substance to be dispensed. Upon depression of the valve operating member the entry of the lower section 23 of the member through the throat 85 isolates the chamber 51 from the dip tube 15 whilst, at a later time, lowering the transverse port 25 in the upper section 22 of the valve operating member below the lower edge of the sealing ring 26b establishes a discharge path from the chamber 51 through the port 25 and the axial bore 24 of the stem 22 to an orifice in the operating knob. The spring 34 in this embodiment may be replaced by an external spring. Fig. 19 shows a construction in which the valve body 14 comprises a rigid metal member of tubular form having an outwardly projecting collar 38 below which is disposed a screw thread 13 for engagement with corresponding threads in the neck of the container. The reservoir chamber is defined by the upper end of the bore of the dip tube 15 above a constriction 99. When the member 16 is depressed the lower end 100 of the member enters into sealing engagement with the constriction 99 while port 25 is lowered until the contents of the chamber are discharged outwardly through the annular gap between the central section 21 and the inner wall of the dip tube 15. In a modification of the construction shown in Fig. 19, the lower part of the valve member 16 is arranged to slide within the upper part and is loaded by a spring so that it is pressed into engagement with the constriction 99 instead of passing therethrough. In a further modification, the lower end of the valve member 16 is provided with a circumferential groove to receive a resilient sealing member which makes engagement with the constriction.