GB2329222A

GB2329222A - Pump dispenser

Info

Publication number: GB2329222A
Application number: GB9705656A
Authority: GB
Inventors: David Grant Barnett
Original assignee: Brightwell Dispensers Ltd
Current assignee: Brightwell Dispensers Ltd
Priority date: 1997-03-19
Filing date: 1997-03-19
Publication date: 1999-03-17
Also published as: GB9705656D0

Abstract

An inlet plate 5, having flow passages 6 and non-return inlet valves 9, 10, extends across a container neck 7. A resilient tubular body 1, closed at one end by the inlet valve plate 5, has formed at the other end an end wall 2 having an outlet opening 3 which cooperates with an outlet valve 12 supported on a substantially rigid valve stem 11 extending from the inlet valve plate 5, when the resilient body 1 is in an unstressed state. When the resilient body 1 is squeezed, the inlet valves 9,10 are sealed against the inlet plate 5 and the outlet opening 3 moves away from the outlet valve 12, allowing a quantity of fluid to be dispensed. The inlet valve may be flexible or rigid.

Description

PUMP The present invention relates to pumps, and is particularly concerned with the provision of a simple, low-cost pump assembly for use in dispensing fluid materials from a container.

Hitherto, fluids have been dispensed from containers using positive displacement pumping devices, a dispenser normally comprising a fluid reservoir and a pumping device. When the material in the reservoir is exhausted, the reservoir is refilled or replaced, and dispensing continues using the same pumping apparatus.

An objective of the present invention is to provide a low-cost disposable pumping apparatus suitable for use in a dispenser, the pumping apparatus being permanently attached to a reservoir of fluid so that when the fluid reservoir is empty, the reservoir and the pump are both replaced. By replacing the pump each time a full reservoir is fitted, problems of blockage in the pumping apparatus due to a build-up of deposits within the ducting in the pump are avoided. When the pump is used to dispense a cleaning product such as washroom soap, replacement of the pump at each refill of the dispenser will also limit the opportunity for bacteria to breed in the soap present in the pump, resulting in improved hygiene.

According to the present invention, a pumping arrangement suitable for use in a dispenser having a fluid reservoir comprises an inlet plate shaped so as to fit over an opening in the reservoir and substantially close the opening, the inlet plate having one or more flow passages therethrough and an inlet valve member being so arranged as to allow fluid to flow out of the reservoir through the flow passages but to prevent any return flow, the pump further comprising a resilient tubular body closed at one end by the inlet valve plate and formed at the other end with an end wall having an outlet opening therein, the outlet opening cooperating, in the unstressed state of the flexible body, with an outlet valve member supported on a substantially rigid valve stem extending from the inlet valve plate.

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings, in which: Figure 1 is a longitudinal sectional view of a pumping apparatus; and Figure 2 is a longitudinal sectional view of an alternative arrangement of the inlet and outlet valve members.

Referring now to Figure 1, the pump comprises a substantially tubular body 1 formed from a resilient material which may be a natural or synthetic material. At the lower end of the pump, as seen in the Figure, the tubular body 1 is closed by an end wall 2 which has a central outlet opening 3 communicating with a depending outlet spout 4.

The upper end of the tubular body 1 is closed by an inlet plate 5, through which flow passages 6 penetrate. The inlet plate 5 is held against the open end of a container neck 7, and the tubular body 1 is held against the inlet plate 5, by a retaining collar 8. In an alternative embodiment (not shown) the retaining collar 8 may be a screw-threaded cap engaging a complementary thread on the container neck 7.

The inlet plate 5 is formed with a central opening, to receive a generally tubular body 9 of an inlet valve member. The inlet valve member comprises a body 9 and a generally disc-shaped flange 10, the flange 10 being positioned adjacent the underside of the inlet plate 5 so as to cover the lower ends of the flow passages 6. The inlet valve member is formed from flexible material such as natural or synthetic rubber, plastics material, or the like.

Received in a tubular bore in the body 9 of the inlet valve member is the upper end of a substantially rigid valve stem 11. The valve stem 11 extend substantially coaxially within the tubular body 1, and at the lower end of the valve stem an enlarged outlet valve member 12 is positioned. In the arrangement shown, the valve member 12 and the stem 11 are integrally formed, the length of the valve stem being such that in the assembled position the valve member 12 is seated against the outlet opening 3 formed in the end wall 2 of the tubular body 1 of the pump.

In operation, the pump is attached to a reservoir containing a liquid or gel or other fluid product to be dispensed. The pump is arranged in a generally vertical orientation, with the inlet plate 5 at the upper end.

To dispense a quantity of fluid, the tubular body 1 is deformed inwardly either by squeezing the walls of the tubular body 1 manually, or by a displacer element contacting the tubular body 1 to displace the walls of the tubular body 1 radially inwardly.

The radial compression of the tubular body 1 increases the internal pressure within the tubular body 1, and this pressure increase has two main effects. Firstly, the flange 10 of the inlet valve is pressed against the underside of the inlet plate 5, and effectively seals the flow passages 6 to prevent any fluid flowing into the reservoir. The increased pressure also deforms the end wall 2 in a generally downward direction, so that the outlet opening 3 is moved away from the valve member 12 and the fluid within the tubular body 1 can escape through the spout 4. A quantity of fluid is thus dispensed when the tubular body 1 is squeezed. Once fluid has exited through spout 4, the pressure within the body 1 decreases and the end wall 2 returns to its original position with the openings 3 closed by valve member 12.

When the tubular body 1 is released, its natural resilience tends to return it to its original tubular configuration. This will cause the outlet opening 3 in the end wall 2 to be firmly seated against the valve member 12, and a reduced pressure will be formed within the tubular body 1. This reduced pressure will deform the flexible flange 10 of the inlet valve member downwardly, opening the flow passages 6 and allowing fluid to flow into the tubular body 1 from the reservoir. The pump is then ready for the next dispensing operation.

In an alternative embodiment, shown in Figure 2, the valve stem 11 is a substantially rigid element, fixed in the inlet plate 5 directly.

The inlet valve is constituted by a substantially rigid disc which is mounted for limited axial movement on the valve stem 11, and is positioned adjacent the underside of the inlet plate 5. The axial movement of the valve disc 13 is such that its normal position is slightly spaced from the inlet plate 5, but when the tubular body 1 is squeezed to dispense a quantity of fluid, the valve disc 13 is urged upwardly by the increased pressure within the tubular body 1, and effectively seals the flow passages 6 in the inlet plate 5. At the lower end of the valve stem 11 shown in Figure 2, the valve stem is stepped down to a reduced diameter, and a generally annular valve member 14 is attached to the reduced-diameter valve stem section.

The valve stem may be made of substantially rigid plastics material, and may be attached to the inlet plate 5 by bonding, or by a snap-engagement formation.

Claims

1. A pumping arrangement suitable for use in a dispenser having a fluid reservoir comprises an inlet plate shaped so as to fit over an opening in the reservoir and substantially close the opening, the inlet plate having one or more flow passages therethrough and an inlet valve member being so arranged as to allow fluid to flow out of the reservoir through the flow passages but to prevent any return flow, the pump further comprising a resilient tubular body closed at one end by the inlet valve plate and formed at the other end with an end wall having an outlet opening therein, the outlet opening cooperating, in an unstressed state of the resilient body, with an outlet valve member supported on a substantially rigid valve stem extending from the inlet valve plate.

2. A pumping arrangement as claimed in claim 1, wherein an outlet spout is formed externally of the end wall of the resilient housing and cooperating with the outlet.

3. A pumping arrangement as claimed in claim 1 or 2, wherein the resilient body is held against the inlet plate by a retaining collar.

4. A pumping arrangement as claimed in claim 1 or 2, wherein the resilient body is held against the inlet plate by a screw-threaded cap.

5. A pumping arrangement as claimed in any preceding claim, wherein the inlet valve member is formed from flexible material.

6. A pumping arrangement as claimed in any one of claims 1 to 4, wherein the inlet valve member comprises a substantially rigid member movable towards and away from the inlet plate.

7. A pumping arrangement as claimed in claim 6 wherein the inlet valve member is normally in a position spaced from the inlet plate.

8. A pumping arrangement as claimed in any preceding claim, wherein the outlet valve member is enlarged relative to the valve stem.

9. A pumping arrangement as claimed in any preceding claim, wherein the outlet valve member is positioned within the resilient body.

10. A pumping arrangement as claimed in any preceding claim, wherein the outlet valve member is formed as a separate member to the valve stem.

11. A pumping arrangement as claimed in any preceding claim, wherein the outlet valve member is seated against the outlet opening in an unstressed state of the resilient body.

12. A pumping arrangement as claimed against any preceding claim, wherein the outlet opening is moved away from the outlet opening in a stressed state of the resilient body.

13. A pumping arrangement as claimed in claim 12, wherein the outlet opening is moved temporarily away from the outlet opening in a stressed state of the resilient body.

14. A pumping arrangement substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.