Patent GB-645310-A (GB)
Title: Improvements in or relating to liquid dispensing apparatus
IPC: B05B11/00
Filed: 1948-05-26
Abstract: 645,310. Reciprocating pumps. COLLINS, A. F. May 26, 1948, Nos. 14259/48, 27513/48, 1874/49 and 3771/49. [Class 102(i)] [Also in Group XVIII] Liquid dispensing apparatus comprises a container for the liquid, a plunger displaceable axially within the container against the influence of spring means, and an axially displaceable hollow stem carrying the plunger which opens at its lower end below the plunger and has its upper end extending through an opening in a cap or closure lid for the upper end .of the container, and being fitted externally of said cap or lid with a discharge spout, the. arrangement being such that depression of the hollow stem acts to discharge liquid from the. space between the underside of the plunger and the base of the container up through the hollow stem and through the discharge spout, the container being constructed so as to permit liquid to enter said.. space.. during upward movement, of the plunger. In one form, Fig. 2, the. apparatus .comprises a container 1 which is reduced in.diameter at its lower portion 2 and is closed by a cap 5 which is a friction fit, a plunger 3 attached to a hollow stem 4 at the top of which are spout 11 and a knob 10, and a compression spring 7. Tc dispense the liquid the knob 10 is depressed and the plunger 3 enters the portion 2, in which it is a close working fit, and liquid is thereby forced up through the stem 4; on releasing the knob 10 the spring 7 returns the plunger high enough for more liquid to flow past it into the portion 2 of the container. The amount of liquid discharged at each stroke can be adjusted by altering the position of the plunger 3 on the stem 4 by, providing a threaded fitting with lock-nuts (or without lock-. nuts if the thread is a tight fit) or a tight friction fit, and the stem may project through the plunger to engage the base 8 and limit the downward stroke. Another form, Fig. 4, also comprises a plunger 15, hollow stem 18, spout 19 and knob 24, but the container is a cylinder 13 inserted in an ordinary container 14 Holding the bulk of the liquid'which is allowed to enter the cylinder through ports 21 when the plunger is raised, or the plunger 15 may be raised above the top of the cylinder 13 to allow the'liquid to enter, or the top of the cylinder may be castellated for the same purpose. The cylinder is held in the container by tie rods 23, or extends to the cap 20, the rods, being omitted. The stem may be made up of several sections as shown, each a. push fit in the other, and the plunger may be a push fit on the stem and the spout a push fit on the stem. Alternatively a port 25 maybe formed in the base of the cylinder 13 and a flat multi-sided valve 27 located therein, leaving spaces between its straight sides and the circumference of its seat through which liquid flows by suction when the plunger is raised. In some instances a valve may be provided, in the lower end of the stem or between its ends, comprising a valve body formed with a concave tapered seating at each end, so that both ends are identical and either may be used, and a ball resting in the seating at the upper end and urged off it when liquid is forced upwards through the stem. The first Provisional Specification mentions that the valve body, may be detachably mounted in the stem by clamping screws., and axial adjustment at the valve body with respect to the stem provided by one or more openings in the stem with any of which a single threaded opening in the valve body may register.