GB2181790A - Manually operated pump - Google Patents

Abstract

The pump includes pressure means, for example a piston (1) slidable in a cylinder (2), in communication with a chamber (44) containing a conical flexible valve member (7). An inlet valve seat (80) cooperates with one side of the valve member in the region of the periphery thereof, and an outlet valve seat (81) cooperates with the other side of the valve member in a central region thereof. In an alternative embodiment (Fig. 12, not shown) the piston and cylinder arrangement is replaced by a resilient bulb, and the container of the material to be pumped is attached directly via a screw-cap to the pump inlet. <IMAGE>

Description

SPECIFICATION Improvements in or relating to pumps This invention relates to pumps and is particularly concerned with pumps which are suitable for dispensing liquids, creams, gels, highly viscous material and pasty materials.

It is an object of the invention to provide a pump which is particularly suitable for use in such dispensers. Pumps of known dispensers include a relatively large number of moving parts, and hence are not only expensive but are subject to malfunctions. In accordance with this aspect of the invention it is therefore an object to provide a pump which does not suffer from these disadvantages.

From this aspect the invention consists in a pump comprising pressure means, in communication with a chamber containing a flexible valve member, a first valve seat in said chamber cooperating with one side of the valve member in the region of the periphery thereof and a second valve seat cooperating with the other side of said valve member in a central region thereof.

Preferably said valve member cooperates with said first valve seat to constitute an inlet valve for the pump, while the valve member cooperates with said second valve seat to provide an outlet valve for the pump.

Preferably the valve member is circuiar and generally conical. Preferably the second valve seat is annular, and relatively small, and cooperates with the exterior conical surface of the valve member in the central region thereof. Preferably the first valve seat is annular, and relatively large, and cooperates with a flat annular peripheral part of the valve member on the side opposite to the apex thereof.

Preferably the pump consists of synthetic resin material, and all parts are capable of being produced by injection moulding, preferably with little or no finishing operations.

In one embodiment of the invention the pressure means comprises a piston slideable in a cylinder, and in another embodiment the pressure means comprises a manually compressible bulb.

Two embodiments of the invention will now be described with reference to the accompanying diagrammatic drawings in which; Figure 1 is a perspective view of a dispenser incorporating a pump in accordance with the invention, with the cover open and the cartridge removed; Figure 2 is a perspective view of the dispenser illustrated in Figure 1 showing a cartridge being inserted; Figure 3 is a perspective view of the dispenser illustrated in Figures 1 and 2 with the cover closed; Figure 4 is an enlarged part-sectional side view of the dispenser illustrated in Figures 1 to 3 taken on the line IV--IV shown in Figure 5, looking in the direction of the arrows; Figure 5 is a rear view of the dispenser as illustrated in Figure 4;; Figure 6 is a sectional side view of the dispenser illustrated in Figures 4 and 5 taken on the line VI--VI of Figure 5, looking in the direction of the arrows; Figure 7 is an underneath plan view of the dispenser illustrated in Figures 4, 5 and 6; Figure 8 is a cross-sectional view of the dispenser illustrated in Figures 4 to 7 taken on the lineVIll-VIll of Figure 5, looking in the direction of the arrows; Figure 9 is an enlarged sectional view of the lower part of the dispenser illustrated in Figures 4 to 8; Figure 10 is a scrap section taking on the line X-X of Figure 9, looking in the direction of the arrows; Figure 11 is a scrap section taken on the line Xl-Xl of Figure 9; and Figure 12 is an enlarged sectional view of the lower part of a dispenser including a modified form of pump.

The dispenser illustrated includes a back plate 21 capable of being secured to a wall, for exmaple by means of screws passing through holes 22 and slots 23, or by means of adhesive pads 51. The back plate 21 is provided with moulded sockets 52 capable of receiving hinge pins 53 on a cover 24. The back plate 21 is moulded with a forwardly projecting portion 54 which forms a recess 55 at the rear of the back plate.

This recess accommodates a conduit 25 which leads from an upper connector 56 to a lower connector 57.

The upper connector 56 is inserted in an elbow 58 at the top end of a dip tube 88. To provide a seal between the elbow 58 and the connector 56, the connector has an annular recess accommodating an O-ring 59.

The lower connector 57 is provided with an inlet 60 (Figure 9) which, for the purposes of a dispenser in accordance with the present invention, is closed by means of a suitable plug. The lower connector 57 is also provided with an outlet 61 which leads to a pump mechanism 26 located in the vicinity of the bottom of the dispenser. The pump is operable by means of a pivotal operating plate 27 and is provided with a delivery extension 9. The pump mechanism is contained within a cylindrical extension 96 which is moulded integrally with the back plate 21. It includes a cylinder 2 which is retained within the extension 96 by a tubular portion 91 (Fig. 9) of the delivery extension 9.This tubular portion 91 passes through a hole in the wall of the cylindrical extension 96 and into the outlet passage 44 of the pump mechanism. It can also be seen from Figure 9 that the cylinder 2 has a protrusion 40 and the delivery extension 9 has a matching protrusion 42. Both these protrusions are accommodated in a recess formed in the end of the wall of the cylindrical extension 96.

A removabie cartridge 28 is capable of being inserted in the dispenser when the cover 24 is in the open position, as illustrated in Figures 1 and 2. The cartridge is provided with a cap 29 accommodating the elbow 58. It is to be understood that the dip tube extends to the bottom of the cartridge 28. The cartridge rests on two flat supports 90 (FigureS), which project from, and are moulded integrally with, the back plate 21.

The cover 24 is held closed by two moulded catches 65 and 66 which fit over the top edge of the back plate 21. They are shaped in such a way that the cover is locked in position automaticaliy when it is moved to the closed position. Two push rods 67 and 68 are provided in the recess 55 on each side of the conduit 25. When the push rods are raised, they contact the undersides of respective spring leaves 69 and 70. These in turn life the catches 65 and 66 to release the cover. The spring leaves 69 and 70 are provided to return the push rods to their lowermost positions since they consist of lightweight material and may otherwise stick in their guides. Further they prevent the push rods from falling out if the dispenser should be inverted with the cover open.

The push rods may be raised by means of a key 71 (Figures 4 and 5) capable of being inserted at the bottom of the back plate. This key has two legs 72 and 73 which respectively contact the lower ends of the push rods 67 and 68. The key can be in the form of a captive element, or it can be made removable.

Two sight holes, one of which is show at 74, are provided in the cover to enable the contents of the container to be seen against ambient light. The cover is also provided with a step 75, at the rear of the base thereof, to conceal the hinge arrangement 52/53 and also to provide a finger point to facilitate operation of the pump by squeezing against the operating plate 27. If the key 71 is in the form of a captive element, the lower portion 76 will normally be removed so that the step 75 also conceals the remainder of the key.

As can be seen particularly from Figure 2, a dispenser in accordance with the invention enables the cartridge to be inserted without the necessity for inverting it, as in known dispensers having a pump horizontally arranged at the base thereof.

The pump used in the dispenser illustrated is shown in particular detail in Figures 9,10 and 11. It includes a piston 1 slideable in a cylinder 2. The piston 1 is provided with an annular groove 77 in which is located a sealing ring 4. The piston is urged to the right in Figure 9 by means of a spring 6 which surrounds the cylinder 2 and bears at one end against the end of the cylindrical extension 96, and at the other end against a disc 41 on an extension 87 of the piston 1. The piston 1 is prevented from coming out of the cylinder by means of a key 8. The disc 41 is provided with a semi-cylindrical projection 78 which is designed to cooperate with the operating plate 27. The key 8 also ensures that the semi-cylindrical portion 78 remains horizontal for correct cooperation with the operating plate 27.

An end cap 3 is fitted in the cylinder 2, and an airtight seal is formed by means of a sealing ring 5.

The end cap 3 includes a skirt 79, the inner end of which forms an inlet valve seat 80. This seat cooperates with a valve member 7 which is moulded in an elastomeric material such as a fluorinated elastomer as sold under the trade name Viton. As can be seen from Figure 9, the valve member is generally conical and it constitutes a combined inlet and outlet valve member. As already stated, one side of the valve member 7 cooperates in the region of the periphery thereof with the seat 80 to constitute the inlet valve. In addition a portion of the valve member on the other side, in the region of the apex of the cone, cooperates with a valve seat 81 to constitute the outlet valve. The valve seat 81 is formed on a part 95 of the moulding integral with the cylinder 2 cantilevered from one side of the cylinder wall and having a right-angled duct forming the outlet passage 44.Free communication between the cylinder space 82 and the valve chamber 83 is thus provided.

The unstressed shape of the valve member7 is approximately a cone with a 90 degree apex, and it is deflected to the shape shown in Figure 9 when the valve cap 3 is put into position. This deflection provides a pre-loading on the valve member, producing effective seals at 80 and 81. In this connection it is to be noted that the valve seat 81 is shaped to correspond to the cone angle of the valve member 7. The cap 3 also includes a central extension 84 which protects the valve member7 from damage if excessive pressure is applied to the righthand side of it by operation of the pump.

As already stated, the interior 82 of the cylinder 2, and the valve chamber 83, are in free communication with each other. When the piston 1 is withdrawn in the cylinder under the action of the spring 6, a depression is created which causes the outer edges of the valve member 7 to move away from the annular seat 80. As a result the material to be dispensed is drawn into the chamber 83 through openings 43 in the end cap 3. It is to be understood that the depression in the valve chamber 83 is communicated through the conduit 25 and the dip tube 88 to the interior of the container 28 so that, when a new container is first inserted in the dispenser, repeated operation of the operating plate 27 will be required to draw the material to be dispensed up the dip tube and down the conduit 25 to the valve chamber 83.However, once the various passages are full of the material, only a single operation of the operating plate 27 will be required to dispense the material.

During operation of the pump, any load reaction from deflecting the valve member 7 reinforces the seal between the righthand side of the valve member and the valve seat 81. When the piston is moved to the left against the action of the spring 6, the pressure in the cylinder 2 is increased and the peripheral portion of the valve member 7 is forced against the valve seat 80. The pressure builds upon the righthand face of the valve member 7 and deflects the central conical portion away from the delivery seat 81. The contents of the valve chamber 83 are thus forced into the outlet passage 44 and through the passage 85 in the delivery extension 9.

Thus the material to be dispensed will travel aiong the passage 85 to the nozzle 46.

If it is necessary to vary the amount of material ejected in each operation, the piston stroke may be limited by one or more collars sprung over the piston rod.

Figure 12 of the accompanying drawings shows a dispenser including a modified form of pump in accordance with the invention. The dispenser housing includes a back plate 21 and a cover 24 generally similar to those illustrated in Figures 1-9.

It also includes a similar operating plate 27.

However in this modification the material to be dispensed is contained in a container 101 having a neck 102 which is externally threaded. The pump in this instance is formed integrally with a cap 103 designed to cooperate with the threads on the neck 102. The screw cap 103 incorporates a cylindrical extension 104 leading to an annular inlet valve seat 105. The pump also includes a valve chamber 106 provided with a circular outlet valve seat 107. The valve chamber 106 contains a valve member 7 similar to the valve member 7 of Figure 9.

The valve chamber 106 is in communication through the outlet valve with a nozzle 108 containing an outlet passage 109.

The pump is also formed with a body 110 having a spigot 111 designed to fit into the cylindrical extension 96 of the back plate 21 in the same way as the pump illustrated in Figure 9. The pump body is also formed with an extension at the end opposite to the spigot 111, this extension including two rings 112 and 113. The ring 112 is externally threaded to receive a further ring 114, and a compressible bulb 115 is held in position on the ring 113 by means of the ring 114. The interior of the bulb is in communication with the valve chamber 106 through a passage 116.

It will be understood that the operation of the pump illustrated in Figure 12 is substantially the same as the pump illustrated in Figure 9. If the bulb 115 is compressed by manual pressure on the operating plate 27, the pressure in the valve chamber 106 will be increased, and as a result the valve member 7 will be lifted off the outlet valve seat 107. Air or material in the valve chamber will be expelled through the outlet passage 109. When the pressure on the operating plate 27 is released, the bulb 115 will return to the shape shown in the drawing, and as a result the pressure in the valve chamber 106 will be decreased, the periphery of the valve member 7 will be lifted off the inlet valve seat 105, and material from the container 101 will be drawn into the valve chamber 106.Thereafter pressure on the operating plate 27 will again compress the bulb 115, lift the centre of the valve member 7 from the outlet valve seat 107 and expel any material in the valve chamber 106 out through the outlet passage 109.

If it is required for any reason to limit use of a particular dispenser to particular cartridges, it is possible to incorporate a key system which will prevent the assembly of the dispenser with any cartridges other than those designed for the particular key. For example a plurality of holes may be provided in the back plate 27, and during assembly of the dispenser, two or more short pins, consisting for example of synthetic resin material, may be permanently secured in selected ones of the holes. Dimples may be provided in the cartridge 28 in positions corresponding to the positions of the pins. These pins constitute a key, and it is only possible to insert a cartridge having dimples in the same two key positions. If, for example, there are 8 holes provided in the back plate, this will provide 28 possible two-pin combinations. If an attempt is made to insert a cartridge without dimples, or with dimples in the wrong place, into a dispenser with the pins in position, it will be impossible to fit the connection 56 or close the cover 24.

Claims (10)

1. A pump comprising pressure means, in communication with a chamber containing a flexible valve member, a first valve seat in said chamber cooperating with one side of the valve member in the region of the periphery thereof and a second valve seat cooperating with the other side of said valve member in a central region thereof.

2. A pump according to Claim 1, wherein said valve member cooperates with said first valve seat to constitute an inlet valve for the pump, while the valve member cooperates with said second valve seat to provide an outlet valve for the pump.

3. A pump according to Claim 2, wherein the valve member is circular and generally conical.

4. A pump according to Claim 3, wherein the second valve seat is annular, and smaller than the first valve seat, and cooperates with the exterior conical surface of the valve member in the central region thereof.

5. A pump according to Claim 4, wherein the first valve seat is annular and cooperates with a flat annular peripheral part of the valve member on the side opposite to the apex thereof.

6. A pump according to any of Claims 1 to 5, wherein said pressure means comprises a piston slideable in a cylinder.

7. A pump according to any of Claims 1 to 5, wherein said pressure means comprises a manually compressible bulb.

8. A dispenser comprising a housing, a pump according to Claim 5, and a container, wherein said pump and said housing comprise respective means which cooperate to retain the pump removably in the housing, and wherein the pump includes a cap adapted to cooperate with the container to retain the container removably joined to the pump with the interior of the container in communication through the cap with the first valve seat.

9. A dispenser substantially as hereinbefore described with reference to, and as illustrated in, the accompanying diagrammatic drawings.

10. A pump substantially as hereinbefore described with reference to, and as illustrated in, Figures 9 to 11 or Fig. 12 of the accompanying diagrammatic drawings.