Piston Pump Actuated Diaphragm Pump for Spraying Liquids

Heretofore, aerosol-type dispensers have been employed for dispensing various types of liquids such as paint, air freshener, hair spray, and the like. However, the use of aerosol-type dispensers has become less popular of late due to the reported breakdown of the ozone layer in the atmosphere caused by the propellants used in the aerosols.

To overcome the hazardous condition caused by aerosol-type dispensers, the use of pumps as the discharge assistant is becoming more prevalent. The conventional dispensing pump includes a dip tube extending into the container of fluid to be dispensed and a plunger or piston assembly and outlet nozzle mounted on the container closure, whereby the reciprocation of the plunger causes a measured amount of fluid to be drawn through the dip tube and dispensed through the nozzle.

While the use of conventional pumps has been satisfactory for avoiding hazardous aerosols, they have not been universally accepted by the general public due in large measure by the pumps' lack of versatility for dispensing different types of fluids. More particularly, a pump provided for dispensing paint from one container cannot be employed for dispensing a different colored paint from another container without first spending a considerable amount of time cleaning the pump assembly.

After considerable research and experimentation, the dispenser of the present invention has been devised to overcome the disadvantages of conventional dispensing pumps, and comprises, essentially, a motor actuated piston pump assembly mounted in a housing which is detachably connected to a container closure having a diaphragm pump-spray nozzle assembly mounted thereon. The piston pump actuates the diaphragm pump-spray nozzle assembly for dispensing fluid from the container. The piston pump and diaphragm pump are constructed and arranged so that the piston pump does not become contaminated by the fluid being dispensed and, therefore, can be detachably connected to other containers having similarly mounted diaphragm pump-spray nozzle assemblies whereby various types of fluids, such as paint, air freshener, water, hair spray, and the like can be successively dispensed.

FIG. 1 is an exploded view of the pump dispenser of the present invention;

FIG. 2 is a side elevational view, partially in section, showing the piston pump assembly;

FIG. 2a is a fragmentary, side elevational view, partially in section, showing the drive components for the piston pump;

FIG. 3 is a view taken along line 3--3 of FIG. 2;

FIG. 4 is a view taken along line 4--4 of FIG. 2a;

FIG. 5 is a view taken along line 5--5 of FIG. 2 showing the piston mid-way in its stroke;

FIG. 6 is a top plan view of the container closure;

and

FIGS. 7a and 7b are fragmentary, side elevational views showing the suction and pumping strokes, respectively, of the piston and diaphragm pumps.

Referring to the drawings, and more particularly to FIG. 1 thereof, the dispenser assembly of the present invention comprises a motor actuated piston pump assembly 1, and a diaphragm-spray nozzle assembly 2, the diaphragm-spray nozzle assembly being mounted within a closure or cap 3 of a container 4, the piston pump assembly 1 being detachably connected to the closure 3, to be described more fully hereinafter.

The details of the construction of the piston pump assembly 1 are shown in FIGS. 2, 2a and 5 wherein a housing 1a is provided, the housing wall being configured to facilitate being gripped by the operator. The bottom wall 1b of the housing is formed with an annular recess 1c for receiving the neck 3a of the closure 3, a threaded portion 1d being formed in the recess cooperating with a threaded portion 3b on the closure neck, whereby the housing 1a is detachably connected to the closure 3. The bottom wall 1b of the housing is also provided with a bore 1e forming a cylinder for a piston 1f having a piston rod lg. Reciprocatory movement is imparted to the piston rod 1g by an eccentric 1h rotatably mounted in an elliptical aperture 1i provided in the piston rod. The eccentric 1h forms the hub portion of a ring gear 1j having internal teeth 1k meshing with a drive pinion 1L driven by an electric motor 1m, the pinion extending through a slot 1n provided in the piston rod. The components are supported in the housing 1a by a vertically extending wall 1o having its lower edge inserted between a pair of spaced, upwardly extending lugs or ears 1p integral with the bottom wall of the housing, and the upper edge of the wall 1o being inserted between a pair of depending lugs 1q integral with the top wall of the housing. The eccentric 1h and associated ring gear 1j are rotatably mounted on a stub shaft 1r secured to and extending outwardly from the wall 1o. As will be seen in FIGS. 2a and 4, the upper portion of the piston rod 1g is guided during its reciprocatory movement by a bifurcated member 1s extending outwardly from the wall 1o for guiding the lateral edges and one face of the piston rod, the opposite face of the piston rod being guided by a pair of depending lugs 1t integral with the top wall of the housing. The motor 1m is energized by a plurality of batteries 1u mounted in the housing, the circuit between the batteries and motor being controlled by a switch 1v (FIG. 3) actuated by a button 1w mounted on the side wall of the housing 1a. While a battery energized d.c. motor has been shown and described, it will be appreciated by those skilled in the art that an a.c. motor could also be employed to be connected to the standard 110 V a.c. circuit.

Referring to FIGS. 1, 7a and 7b, the diaphragm-spray nozzle assembly 2 comprises a cylindrical housing 2a having its bottom edge 2b seated on the upper surface 3c of the cap 3 within the neck portion 3a. An aperture 3d is provided within the cap 3 for receiving a depending tubular boss 2c integrally connected to the top wall 2d of the cylindrical housing 2a. The upper end of a dip tube 2e is inserted within and integrally connected to the boss 2c, the upper edge 2f of the dip tube 2e providing a seat for a ball check valve 2g contained within the tubular boss 2c. An orifice 2h is formed through the top wall 2d of the cylindrical housing 2a and communicates with the interior of the boss 2c, a spider 2i being provided at the inner end of the orifice to prevent the check valve 2g from closing the orifice 2 h during the suction stroke, to be described hereinafter. The top wall 2d of the cylindrical housing 2a is formed with a concave surface 2j and a thin, flexible membrane disc forming a diaphragm 2k is integrally connected along its peripheral edge to the top wall 2d of the cylindrical housing 2a as at 2L, to thereby provide a chamber 2m between the diaphragm 2k and the concave surface 2j.

To complete the structure of the spray-nozzle assembly, the cylindrical housing 2a has an integral, tubular stem 2n extending radially outwardly from the side wall thereof, the stem 2n having a bore 2o communicating with the chamber 2m. The outer end of the stem 2n has an orifice plate 2p threaded thereon which cooperates with a serrated outlet valve 2q slidably mounted in the end of the stem to thereby form a nozzle. The outer end of the bore 2o provides a seat for the outlet valve 2q during the suction stroke, as shown in FIG. 7a, and the serrated head portion 2r of the valve allows fluid to spray through the orifice plate 2p during the discharge stroke as shown in FIG. 2b. In order to accommodate the radially extending stem 2n, the outer wall of the cap 3 and the wall of the cap neck 3a are provided with cut-out portions 3e and 3f, respectively, as shown in FIG. 6.

As will be seen in FIGS. 7a and 7b, the closure or cap 3 is provided with internal threads 3g which cooperate with threads 4a on the top portion of the container 4, and a rubber ring seal 3h is mounted between the upper edge of the container 4 and the bottom surface of the cap, the seal 3h extending radially inwardly to cover a plurality of vent apertures 3i provided in the cap 3.

To assemble the components of the dispenser of the present invention, the seal 3h is placed on the top edge of the container 4 containing the fluid to be dispensed. The closure 3 is then threaded onto the container 4 and the diaphragm spray-nozzle assembly 2 is inserted into the neck portion 3a of the closure. The piston pump assembly 1 is then threaded onto the neck portion 3a of the closure, thereby hermetically sealing the diaphragm 2k along its peripheral edge 2b to the housing 2a.

In the operation of the dispenser, the operator presses the switch button 1w closing the electrical circuit to energize the motor 1m which in turn will cause the piston 1f to reciprocate via the drive pinion 1L, ring gear 1j, and eccentric 1i. During the upward movement of the piston 1f, the diaphragm 2k is drawn upwardly, as shown in FIG. 7a, creating a vacuum in chamber 2m, thereby causing fluid from the container 4 to flow upwardly in the direction of the arrows through the dip tube 2e into the chamber 2m, the spider 2i preventing the check valve 2g from closing the orifice 2h, while the outlet valve 2q is drawn inwardly to the closed position. During the downward movement of the piston 1f, as shown in FIG. 7b, air trapped within the cylinder 1e forces the diaphragm 2k downwardly causing the fluid to be discharged from the chamber 2m outwardly through the stem 2n and the spray nozzle. The increased pressure within the chamber 2m causes the check valve 2g to be moved to the closed position while the outlet valve 2q is moved to the open position.

When assembled, it will be noted that a slight clearance 3j is provided between the upper edge of the closure wall and the lower surface of the housing bottom wall 1b, whereby the top surface of the closure 3 will be at atmospheric pressure which will cause the seal 3h to move to the open position to open the vent holes 3i to thereby prevent a vacuum build-up in the container 4. It will also be noted that the piston 1f includes axially spaced, oppositely extending lip portions 1x which cooperate with the cylinder wall 1e and notches 1y and 1z formed in the cylinder wall at each end thereof to thereby control the build-up of pressure in the cylinder and the release thereof during the reciprocation of the piston 1f. In this connection, as the piston 1f moves to the end of its downward stroke (FIG. 7b), the lower lip 1x approaches the lower notch 1z allowing the trapped compressed air to escape past the lower and upper lips 1x to the atmosphere. On the upward stroke, the upper lip seals the piston against the cylinder wall creating a vacuum on the diaphragm 2k causing the fluid to flow into chamber 2m. As the piston 1f approaches the upper end of its stroke (FIG. 7a), the upper lip of the piston approaches notch 1y thereby venting the cylinder to the atmosphere whereby the vacuum imposed on the diaphragm is relieved therefrom.

After dispensing the required amount of fluid from the container 4, the diaphragm-pump spray nozzle assembly 2 can be cleared of fluid which might harden in time, such as paint, by merely turning the container 4 upside down and depressing the switch button 1w until clear air is dispensed through the orifice plate 2p. The diaphragm pump spray nozzle assembly 2 can remain assembled to the closure 3 and container 4 for future use, while the piston pump assembly 1 can be detached from the closure 3 and used on another container having a similarly mounted diaphragm pump-spray nozzle assembly.

It is to be understood that the form of the invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size and arrangement of parts may be resorted to, without departing from the spirit of the invention or scope of the subjoined claims.