US3084873A - Liquid dispenser - Google Patents

Description

1963 D. F. CORSETTE 3084'873 LIQUID DISPENSER Filed March 28, 1960 INVENTOR i4 Jazqylas Zbrseflg ATTORNEY5 United States Patent LIQUID DISPENSER Douglas E. Corsette, Los Angeles, Calif., assignor to The Drackett Company, Cincinnati, ()hio, a corporation of Ohio Filed Mar. 28, 160, Ser. No. 17,822 1 Claim. (Cl. 239-637) The invention relates to new and improved plastic dispensers of the reciprocating piston type for discharging liquids from portable containers in the form of a fine spray or mist.

'It has long been the practice to employ, for the dispensing of liquids from small containers, hand actuated pumps formed of moldable plastic material comprising, in assembled relation, a stationary unit including a barrel or cylinder for direct association with the container, and a reciprocable unit including a plunger or piston reciprocable in the stationary unit to effect discharge of the container contents, and having at its upper end a discharge head from which the fluid is expelled.

It is an object of the invention to effect substantial simplification of such dispensers and of methods of making and assembling the same by (1) reducing the number of component parts in each of the basic units of the dispenser, (2) altering the structural relationship of the parts to facilitate the formation during the casting operation of the necessary fluid passages, and (3) assembling component parts without the use of bonding agents.

In the application of the invention to dispensers functioning to discharge fluids in the form of a fine spray or mist, and in which the discharge head and plunger are separately formed, it is an object to provide at the interface between the discharge head and plunger the swirl passages and spin chamber which impart rotation to the fluid in order to form fine droplets which readily disperse in air at the point of discharge.

More specifically, an object of the invention is the provision of swirl passages and spin chamber on that external surface of the plunger on which the discharge head seats, whereby molding can be effected quite simply and without the use of complex collapsible mold parts.

The invention is preferably, although not necessarily, applied to dispensers of the character described having means for temporarily locking the stationary and reciprocable units together in a position in which the dispenser is completely sealed, thereby preventing leakage of liquid from the container during shipping, even though the container be inverted. The invention is accordingly illustrated in the accompanying drawings in conjunction with such dispensers.

Further objects and features of the invention will be apparent from the following description, taken in connection with the accompanying drawings, in which FIGURE 1 is an enlarged longitudinal sectional view of a dispenser of the type described illustrating the application thereto of the inventive principle;

FIGURE 2 is a front elevation of the upper end of the discharge head of the dispenser shown in FIGURE 1;

FIGURE 3 is an elevationof the upper end of the plunger or piston portion 'of the reciprocable unit shown in FIGURE 1, and

FIGURE 4 is a view in plan of FIGURE 3.

To promote an understanding of the invention, reference will now be made to the preferred embodiment thereof illustrated in the accompanying drawings, and specific language will be used to describe the same. It will nevertheless be appreciated that no limitation of the scope of the invention is thereby intended, such further modifications and alterations being contemplated as would normally occur to one skilled in the art to which the invention relates.

Referring first to FIGURE 1, the dispenser there illustrated includes a stationary unit which may be molded in one piece to provide a barrel or cylinder 12 from which a suction tube 13 depends and, at the upper end of the barrel 12, a collar portion 14, noting that throughout the following description the dispenser will be assumed to occupy the upright position in 'which it is normally used.

The upper end of the barrel 12 is preferably slotted at circumferentially spaced points, as indicated at 18, for the purpose of preventing the formation of an airlock in the barrel 12 above the piston, to permit ingress to the container of air in order to replace discharge liquid, and to allow drainage into the container of liquid which may pass the piston and which would otherwise be trapped in the upper portion of barrel 12.

A radial annular flange 2.0, formed on the collar portion 14, provides a seat for container cap 21. Cap 21 is apertured to receive collar portion 14 and is internally threaded as shown at 22 for cooperative engagement with external threads formed on the neck of the container; a gasket 24 may be positioned beneath flange 24 The collar portion 14 is further provided at its upper end with an internally threaded sleeve portion 25, and an annular lip 30 which is formed by deformation of sleeve portion .25 after assembly of the container cap 21 thereon, in order to lock the cap on the collar portion 14.

The stationary and reciprocable units of the dispenser may be formed of any moldable plastic materials, preferably materials commonly designated thermoplastics, for instance, polyethylene and polypropylene. Excellent results are achieved by the use of a polyethylene sold under the trademark Super Dylan by Koppers Company, Inc.,

of Pittsburgh, Pennsylvania. Vinyl chloride acetate is also highly effective, and in general, any plastic material subject to hot or cold flow, capable of being molded, and readily deformed after molding in response to heat and/ or pressure may be employed.

The reciprocable unit of the dispenser comprises a plunger 35 and a dependent hollow piston 36, the piston 'being enlarged in diameter at its lower end to fit snugly -At its upper end, the plunger 35 is preferably tapered upwardly to provide a conical portion 38.

A discharge head 37, preferably cast separately, from thermoplastic resins of the type hereinbefore described, is recessed in ternally for reception with a snug fit on the upper end of the cylindrical portion of the plunger 35 and on the ta pered portion 38 thereof. Orientation of head 37 and plunger 35 is established, and relative rotation of the head and plunger is prevented by a rib 43 projecting from conical portion 38 of plunger 35 into a conforming slot 44 in head 37. Assembly of the head 37 on the plunger 35 is effected by applying endwise pressure to force the head downwardly on the plunger until it assumes the position shown, in which annular beads 39' on the plunger seat in' coacting annular grooves in the interior of the head, the

head yielding sufiiciently to pass it over the beads. The head and plunger, thus assembled, are fitted together sufficiently tightly to prevent egress of fluid therebetween.

The tapered portion 38 of the plunger 35 terminates short of the upper end of the head 37, providing a cavity 70, into which passage 41 opens. A stud 71, projecting downwardly from the finger rest portion 73 of the head into cavity 70 serves as a retainer for the ball valve 45.

Received within piston 36 and seated in the lower end of barrel :12 is a coil compression spring 52, acting to urge the reciprocable unit upwardly. Ball valve 55', seating by gravity in the lower end of barrel 12, acts as a check valve to prevent drainage of liquid downwardly from the barrel 12. Preferably the seat 56 for ball valve 55 forms an angle of at least 45 with the axis of the dispenser to minimize the possibility of wedging of the valve in its seat.

Spring 52 is formed with convolutions st) of reduced diameter, preferably adjacent each end, as shown, to provide reversibility. In the position which the parts occupy in FIGURE 1, the reciprocable unit being fully depressed, the ball valve 55 is engaged by the adjacent small convolutions 60 of spring 52 to hold the valve tightly against its seat, thus preventing fiow of liquid into the barrel and outwardly through passages 40 and 41 when the dispenser is inverted.

An externally threaded portion 42 of plunger 35 coacts with internally threaded sleeve portion 25 on barrel 12 to hold the plunger in fully depressed position. When the plunger is thus screwed down, as shown in FIGURE 1, coacting inclined surfaces 62 on the plunger 35 and barrel are pressed together to form a seal preventing discharge of liquid from the container through the slots 18 and externally of the plunger. Since movement of liquid upwardly into the lower end of the barrel 12 and the plunger 35 is prevented in the fully depressed position of the plunger by direct engagement of the convolutions 60 of the spring 52 with the ball valve 55, leakage of liquid is prevented during handling and shipping, this being of particular importance when toxic liquids, such as insecticides, are used.

It will be appreciated that in order to render the dispenser operative, it is only necessary to unscrew the plunger 35 from the barrel, whereupon the plunger is raised by spring 52. Liquid may then be forced upwardly Within the plunger 35 by finger pressure on the upper surface of the head to reciprocate the plunger in barrel 12 in the usual manner.

The reciprocable unit is retained in position in the, stationary unit by an inwardly directed annular part 66 which extends into close proximity with the plunger 35 and serves as a bearing surface for guiding the plunger during recipnocation thereof, while limiting outward movement of the plunger in response to the action of spring 52. The annular part 66 is formed after assembly of the two units, by assembling around plunger 35, a cylindrical tool, the tool being pressed downwardly against a shoulder formed at the junction :of the barrel proper with the collar portion '14 of the barrel so as to cause the material to flow inwardly.

It will be appreciated that the sequence of steps employed in swaging or deforming the stationary unit'to provide the annular lip 30 and to form the inwardly directed part 66 as described is not critical and may be reversed if desired. These steps do not ordinarily require the heating of the parts to be deformed, but where the nature of the material is such that heat is needed, it may be supplied by heating the tools employed to exert pressure on the parts.

As hereinbefore indicated, an important feature of the invention resides in the manner in which provision is made for rotating the discharging fluid as it emerges from the head, whereby droplets of fluid are dispersed in air to produce a fine mist or a spray. The achievement of effective rotation has'heretofore been a substantial factor in the expense of producing dispensers of both the pump and the pressurized types, the more common method involving'the use of small orifice disks, having whirl passages and spin chambers formed therein, separately formed and assembled, In accordance with the instant invention, rotation is imparted to the fluid at the interface of the plunger and head, eliminating the expense of producing and assembling a separate orifice disk. This feature will now be described in detail.

The external surface of the tapered portion 38 of the plunger 35 is cast, as shown more clearly in FIGURE 3, to provide a plurality of swirl passages extending circumferentially of the plunger and entering tangentially into a circular spin chamber 80, also formed in the plunger. Grooves 76, extending generally longitudinally of the plunger, afford communication between cavity 70 and swirl passages 75. It will be appreciated that the casting operation, involving formation of the described passages in the external surface only of the plunger, is quite simply performed.

Fluid rotating in the spin chamber is discharged through orifice 81 in the head 37; the orifice is positioned substantially on the axis of the chamber, the necessary orientation between the head and the plunger being establis'hed by rib 43. Fluid is thus expelled through orifice 81 as a fine jet which expands radially on leaving the orifice owing to its rotation, which is continued in the outwardly flaring discharge cones 82 and 83, of conventional design. I

Although the use of a conical interface between the plunger and head has a number of advantages, it will be appreciated that the same principles are applicable to structures in which the interface is cylindrical.

While the invention has been described in its application to a pump type sprayer, its utility with self propelled fluids in a pressurized container is obvious. In such a package, the spray head is fitted on the stem in the manner hereinbefore described, so as to provide the swirl passages and spin chamber at the interface between the stem and the head.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

In a fluid dispenser of the character described, the combination with a plunger having a fluid passage therein, a discharge head having a recess therein in which the upper end of said plunger is received, the peripheral surface of the plunger engaging the inner surface of the head recess with a tight fit, the peripheral surface of the plunger being grooved to provide at the interface between said plunger and said head a spin chamber and a plurality of swirl passages leading tangentially into said spin chamber, the plunger surface being for-med with means comprising longitudinal grooves affording communication between the said fluid passage in said plunger and said swirlpassages, said swirl passages being relatively parallel to each other and leading into said spin chamber from diametrically opposite locations with respect to said chamber, said means communicating separately with said swirl passages at locations remote from said spin chamber and producing fluid flow in opposite directions through the respective said passages, said head being provided with a discharge orifice communicating with the axis of said spin chamber.

References Cited in the file of this patent UNITED STATES PATENTS 1,162,133 Carmody Nov. 30, 1915 2,119,884 Lohse June 7, 1938 2,213,846 Meyer Sept. 3, 1940 2,362,080 Martin Nov. 7, 1944 2,693,983 Howell Nov. 9, 1954 2,702,957 Cooprider et al. Mar. 1, 1955 2,789,012 Bretz Apr. 16, 1957 2,906,461 Bretz Sept. 29, 1959 2,989,251 Abplanalp et a1 June 20, 1961

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