GB2079863A - Dispenser pumps - Google Patents

Abstract

A dispenser pump is adapted to dispense lumpy products such as pickles or relishes. Non-return valves (8, 9) permitting, admission to and egress from a pumping volume formed by a cylinder (2) and hollow piston stem (1) are C-shaped flap valves to offer a maximum through- passage. The nozzle (19) of the pump is fitted with a restrictor (33) at its outlet. The aperture (30) of the restrictor is chosen to be of a diameter e.g. 7 to 10 mm that is appropriate to a particular product so that it will permit active expulsion of the product and yet prevent it dripping from the nozzle when the pump is idle. The restrictor may be rigid as shown or elastic, and the nozzle may alternatively or additionally be fitted with a check valve. The inlet (35) to the pump is covered with an outwardly flared roof (34) which is formed to help prevent "bridging" of the product in its container. <IMAGE>

Description

SPECIFICATION Dispenser pumps This invention relates to dispenser pumps.

Pumps of this general type are well known. They have a pump cylinder in which a piston works, admission of material to the cylinder being through a non-return valve, and an outlet for material from the cylinder through a hollow stem of the piston and an outlet nozzle, expulsion of material being caused by pressing the piston into the cylinder. They are used for dispensing materials such as liquids or substantially smooth semi-liquid material from a container in measured doses. In the past such materials have been sauces, detergents, cleaning gels, creams, and the like.

However, problems would be encountered if such pumps were to be used with lumpy products.

Dispensing pickles or relishes or other products containing solid particles whose size is comparable with the size of the valve aperture(s) in the pump, would frequently lead to the pump becoming jammed with the lumpy particles and to the product dripping from the pump nozzle when it is not actually in use due to the weight and viscosity of the lumpy product.

The object of the present invention is to provide a dispenser pump which can be used with lumpy products without the problems of jamming or dripping which would be associated with the use of conventional dispenser pumps for lumpy products. The pump has large through-ways and valve apertures and means to restrict the volume of lumpy product which is free to drip from the nozzle outlet when product is not being dispensed.

According to the invention a pump is provided of which a non-return valve governing entry into the pump cylinder is a flap valve which is only allowed to open in an upward direction. A valve is also usually provided at the upper end of the cylinder to govern egress of material from it; this should also be a flap valve. The flap valve(s) are constructed and positioned so as to provide apertures substantially as wide as the internal diameter of the pump body when they are open.

They are thus difficult to jam in comparison to types of valves which restrict the flow of material even in their open position. An additional advantage of the flap valves is that they may be moulded in one piece from a plastics material such as polypropylene for example. They are thus cheap and easy to produce.

In a particuiar form they consist simply of a disc surrounded by an annulus and linked to it by a hinge part. Such a valve will be referred to as a "C-shape" flap valve.

At the upper end of the upper pump body and attached to it a dispenser head is provided which serves as a means both of operating the pump and of conducting the pumped product from the upper flap valve to the dispenser head outlet, which will preferably be provided by a separable nozzle part.

A further aspect of the invention comprises the provisions of a means for reducing or eliminating the free volume of the actual outlet of the nozzle.

This is the volume in which product could reside and be free to drip from the nozzle outlet when product is not being dispensed. This means, for convenience called a check means, may take the form of the provision within the nozzle and behind its outlet of a tubular valve of flexible and resilient material, and this may be used instead of but preferably in addition to, the upper flap valve. The tubular constricted valve may be secured within the nozzle part by any suitable means for example by integral moulding, glue, snap fittings, or by the open end being held in place between a separable nozzle part and the dispenser head body, which will snap-fit together. In the latter case the nozzle part and valve may be easily removed for cleaning or renewal.

Alternatively or additionally to the valve in the nozzle part, it may have a rigid or resilient restrictor fitted at its extreme outlet, to cut down the through passage of the nozzle over only a short distance to a reduced cross-sectional area.

Having as check means such a restrictor has the effect of causing the retention within the nozzle of lumpy products, and enables the elimination of the resilient sleeve valve mentioned earlier. The restrictor being fitted to the nozzle outlet in the factory or by the user (but usually the former) and being selected from a range of restrictors having orifices of sizes, usually within the range of 4 mm to 12 mm, but most commonly 7 to 10 mm, designed to be effective for given products or sizes of lumps, allows a wide range of lumpy products to be handled by a dispenser of which all other parts may be uniform over that range.

The nozzle part which has already been mentioned may have two important features. The first is that the whole of the delivery side of the head may be separable so that nozzle parts of different lengths may be provided with a singlesize moulding of the body of the head. This allows either the manufacturer or the user (usually the former) to select any one of a range of sideways "throws" when product is dispensed from the head, in accordance with the girth of the container with which the pump is going to be used.

The second is that any one of the range of length of spouts may be used with any one of a range of restrictors further to increase the range of applicability of the pump.

In yet another feature of the invention, for handling highly viscous or non-fluent products, the foot of the tube which passes to the base of the container may be fitted with a downwardly outwardly flaring outer surface roofing over its inlet. We find that this greatly decreases the tendency of such products to bridge and thereby form a permanent funnel-like depression which offers a path through which air, not product, is drawn up by the pump.

A particular embodiment of the invention will now be described with reference to the accompanying drawings in which: Figure 1 is a cross sectional view of an embodiment of the pump fitted with a restrictor, Figure 2 is a cross sectional view of the delivery spout of a pump fitted with a tubular valve, Figure 3 is a perspective view of a tubular valve, Figure 4 is a face view of a C-shape flap valve, and Figure 5 is a section through a nozzle outlet showing another form of restrictor.

The pump described has an upper pump body 1 which is a sliding but sealable fit inside a lower pump body 2. The seal 3 anaiogous to a piston head is in this embodiment moulded integrally with the upper pump body 1. A threaded retaining collet 4 is provided which engages threadedly with the pump body 1 and both cooperates with a projection 5 on its outer surface to secure the pump to a container and interferes with the projection 6 on the lower part of the upper pump body 1 so as to limit its upward movement resulting from the upward bias imparted to it by a spring 7. The lower and upper pump bodies 1, 2 are each provided at their lower and upper ends respectively with C-shape flap valves 8, 9. The C-shape flap valves are prevented from opening in a downward direction by local constriction 10, 11 in the internal diameters of the pump body parts.The flap valves are each integrally moulded from polypropylene and each have an outer ring 12, and inner flap 1 3 and an interconnecting and integral film hinge 14 which is thinner than the ring and flat. The lower flap valve is retained by the spring 7 holding its outer ring against the ledge formed by the constriction 10. At the upper end of the upper pump body and engaged with it by a snap engagement there is provided a dispenser head 15 which by means of a projection 1 6 retains the outer ring of the upper C-shape flap valve 9 against the end of the upper pump body 1 which is fittingly located in a recess in the dispenser head 15. The dispenser head 15 is also provided with a projecting handle 1 7 and an internal passageway 18 to conduct the pumped product from the upper C-section flap valve 9 to the dispenser head outlet.

A nozzle spout 19 is separably connected to the dispenser head 1 5 by a snap fit connection.

Annular projections 20 on the outer periphery of the nozzle end piece 21 engage with corresponding annular depressions 22 in the internal periphery of the dispenser head end 23.

At the lower point of the nozzle spout 1 9 there is a rib 32 which fits into a cut back recess in the end of the head 1 5 to assure a correct, downward, direction for the nozzle outlet 30 of the spout A set of nozzle spouts 1 9 may be available either to the manufacturer or to the user, these being of different length to deliver the product to a greater or lesser distance from the axis of the body 1. Selection of the appropriate one will usually be done by the manufacture before sending out the pump.

Within the nozzle 30 a restrictor 33 is snapfitted by a rib and groove similar to 20, 22. The orifice of the restrictor is of a diameter selected with a view to preventing dripping of a specific lumpy product or range of products with which the dispenser is to be used. Examples are diameters of orifice are 7 mm and 10 mm.

As for the provision of a range of spout lengths, the provision of a number of restrictor orifices from which a choice can be made either by the manufacturer or by the user allows simple adaptation of the dispenser as a whole to efficiency in its intended use.

In a second embodiment seen in Figure 2, step 24 formed in the nozzle spout and another step 25 formed in the internal surface of dispenser head end piece form a recess when the nozzle spout is snapped into the dispenser head outlet. The recess is used to entrap the open end of a tubular constricted flap valve 27 whose open end has been folded outwardly and rearwardly to lie parallel to the remainder of the open end material and to be located in the recess and further held there by the nozzle end piece projection and the step 25. The tubular constricted flap valve 27 is such that its constricted end 29 is positioned adjacent to the nozzle aperture 30 so as to cut down the free volume behind the nozzle from which the product can slowly drip. The tubular constricted flap valve and the nozzle may thus be easily removed for cleaning or replacement.It is possible for the invention to work with either or both the constricted flap valve 27 and/or the upper C-section flap valve 9.

The pump is further provided with a conventional tube 31 fitted to a projection on the lower pump body 2 and cut to a suitable length. In a further aspect of the invention a flared pedestal 34 may be fitted to the bottom of the tube. It has a castellated foot 35 positioned on the bottom of the container. Product to be dispensed is sucked through the gaps in the castellation.

We find that the provision of such a pedestal assists the extraction of viscous or non-fluent products, which if the conventional straight-ended tube is used tend to form a funnel-like depression around that end so that air, not product, is sucked up by the pump. For reasons which are not entirely clear, the provision of an outwardly flaring "roof appear largely to prevent that problem.

Furthermore, an alternative or additional nozzle restrictor, provided at the nozzle outlet, may be of an elastic material which enlarges to allow the passage of large particles but contracts to prevent drip. Examples are a simple elastic sleeve or the restrictor seen in Figure 5. This is an essentially hemispherical rubber moulding 36 with an equatorial flange 37 with a returned bead 38.

The flange and bead are trapped between nozzle spout part 19' and a nozzle outlet piece 39 which may be permanently secured together e.g. by ultrasonic welding. An outlet aperture 30 is of a.

small diameter in the relaxed condition of the restrictor, say 3 or 4 mm diameter, but will allow passage of comparatively large lumps, say up to 12 mm, when they are being positively expelled by the action of the pump.

The provision of the restrictor 33 or 36 or of the valve 27 has the effect of cutting down or, in the case of the restrictors which are preferred to the valve, eliminating the volume lying behind the extreme cutletof the nozzle in which product could reside and from which it could slowly emerge and drip during the time between active strokes of the pump. The valve or restrictor with an aperture chosen to be appropriate to a product will retain that product during that idle time but will not prevent expulsion of product during the active stroke of the pump.

Claims (11)

1. A dispenser pump for use in dispensing lumpy products wherein a non-return valve for admitting product into the pump cylinder is a flap valve, and check means are provided in an outlet nozzle of the pump to reduce or eliminate the volume behind the outlet of the nozzle from which the product could drip from that outlet when the pump is idle.

2. A dispenser pump according to claim 1 wherein there is a second non-return valve at the head of the hollow stem of the pump and this is also a flap valve.

3. A dispenser pump according to claim 1 or claim 2 wherein the flap valve(s) is or are a plate of plastics material surrounded by an annulus of such material and joined to it by a hinge connection.

4. A dispenser pump according to any one of the preceding claims wherein the check means is a valve mounted in the spout of the nozzle part behind the outlet.

5. A dispenser pump according to any one of claims 1 to 3 wherein the check means is a restrictor mounted at the outlet of the nozzle.

6. A dispenser pump according to claim 5 wherein the restrictor is rigid.

7. A dispenser pump according to claim 5 wherein the restrictor is elastic.

8. A dispenser pump according to claim 5, claim 6 or claim 7 wherein the outlet aperture of the restrictor has a diameter or a diameter in the relaxed state of 4 to 10 mm.

9. A dispenser pump according to any one of the preceding claims wherein the nozzle part is a member discrete from the head of the hollow stem of the piston.

10. A dispenser pump according to any one of the preceding claims wherein an inlet for product into the cylinder is covered by a downwardly outwardly flaring roof.

11. Dispenser pumps substantially as herein described with reference to and as illustrated in the accompanying drawings.