10

15

FLUID PUMP ADAPTOR

The present invention relates to a fluid pump adaptor, and more particularly to a fluid pump adaptor 20 for use in pumping fluid from a container such as a drum.

One form of fluid pump previously used for emptying drums has a threaded collar with a tube which is adapted to extend into the drum. The threaded collar is screwed

25 into a plug hole in the drum. Generally, fluid pumps of this type comprise a mechanical or hand operated type pump which is arranged to pump fluid out of the drum and to supply replacement air into the drum to compensate for the extracted fluid.

30 U.S. patent 3880179 describes a fluid pumping system. In this system an inert gas is pumped into the drum at one location which enables a powdery substance in the drum to be pushed out of the drum through a riser tube positioned at a second location. The disadvantage

35 of this system is that it requires two plug holes in the drum and the apparatus used is a two piece apparatus which is cumbersome.

The object of the present invention is to provide a pump which has no moving parts and which is inexpensive to manufacture.

According to a first aspect of the present invention there is provided a fluid pump adaptor arranged to be fitted to an opening in an otherwise closed container containing a fluid, said pump adaptor comprising a body having a first fluid passage which extends therethrough and is arranged to extend into the container and below the level of the fluid inside the container, and a second fluid passage extending through the body and opening into the interior of the container, through which said second fluid passage a pressurized fluid from a source of pressurized fluid external of the fluid pump adaptor may be delivered into the container, said pressurized fluid forcing the level of the fluid inside the container downwardly as fluid passes upwardly through the first fluid passage and out of the container. The fluid in the container would typically be a liquid, and the pressurized fluid typically a gas, e.g. air.

Preferably, the body of the fluid pump has attachment means to sealingly engage the fluid pump with the container and is advantageously shaped for receipt in a plughole of the container. Preferably, the attachment means comprises a peripheral thread on the body of the fluid pump adapted to engage with a threaded plug hole in the container to thereby enable the pump to be secured to the container.

Preferably, the connection between the container and the thread on the body is made fluid tight by the provision of a seal. Preferably the seal is an O-ring.

Preferably, means is provided for connecting the second passage externally of the container to a source of compressed air. Such means may be externally upstanding from the body and be adapted for attachment to a fluid conduit coupled to the source of pressurized fluid.

Preferably, a device is associated with the second passage to control the pressure of pressurized fluid delivered to the container. This device may include means to limit the pressure of the fluid. Preferably, the first passage communicates externally of the container with either a U-shaped outlet pipe or a hose. Means may be provided on said body to interchangeably attach such an outlet or hose.

According to a second aspect of the present invention there is provided a fluid pump adaptor arranged to be fitted to a closed container containing a fluid, said pump adaptor comprising a body having first and second fluid passages extending therethrough, attachment means to sealingly engage the body of the fluid pump adaptor with respect to an opening in the container with both said first and second fluid passages opening into the interior of the container, a tube attached to the body for providing an extension of the first fluid passage internal of the container, which tube extends below the level of the fluid inside the container, and connection means upstanding from the body for connecting the second fluid passage with a source of pressurized fluid so that pressurized fluid may be delivered into the container through the second fluid passage, said pressurized fluid when delivered into the container through said second passage forcing the level of the fluid inside the container downwardly as fluid passes upwardly through said tube and the first fluid passage and out of the container. An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which:-

Figure 1 is a partial cross-sectional side view of a drum fitted with a fluid pump adaptor according to an embodiment of the present invention; and

Figure 2 is an enlarged view of the fluid pump shown in Figure 1.

Figure 1 illustrates a fluid pump adaptor 10 secured to a drum 12. Drum 12 is typically a 44 gallon drum containing oil, diesel or any other liquid. The fluid pump adaptor 10 comprises a body or plug 14 with a peripheral thread 16. The thread 16 enables the fluid pump adaptor 10 to be screwed into a corresponding threaded plug hole 18 in the upper wall 20 of the drum 12. The interface between the plug hole 18 and the body 14 is made fluid tight by an 0-ring seal 19 which is retained against a shoulder 21 of the body 14 and abuts the exterior of wall 20 about plug hole 18.

Extending through the body 14 are first and second fluid passages 22, 24. The diameter of the second fluid passage 24 is smaller than the diameter of the first fluid passage 22. Coaxial with the first fluid passage 22 and extending into the drum 12 is a tube 26. Tube 26 may be either integrally formed with the body 14 or otherwise connected to the body 14 to provide an extension of fluid passage 22, i.e. a continuous passageway through the first passage 22 and the tube 26. The distal end 28 of tube 26 is positioned adjacent the bottom wall 30 of the drum 12, below the level of fluid in the drum.

Attached to the body 14 external of the drum 12 is a connection pipe 32. In communication with second passage 24 connection pipe 32 carries a nipple 33 for connection of pipe 32 via a hose to a source of pressurized fluid (not shown). A regulator 36 on the connector pipe 32 regulates the flow of fluid through the connector pipe 32 and thereby the pressure in the drum 12. Regulator 36 may include a filter to prevent the flow of oil or water through the connector pipe 32. A pressure relief valve 37 is also provided to stop the flow of fluid through the regulator 36 before the pressure in the drum exceeds a predetermined pressure. The pressure relief valve 37 would typically be set for example at 35 Pa.

When the connector pipe 32 is connected to a source of pressurized air, for example an air compressor or air tank, and regulator 36 is opened, pressurized air flows into the drum 12 through the second passage 24. The pressurized air forces the level of the liquid inside the drum 12 to move downwardly thereby causing a column of liquid inside the pipe 26 to be driven upwardly through the pipe 26 and out of the drum 12 through first passage 12. Preferably, attached to body 14 external of the drum 12 and coaxial with the first passage 22 is a short pipe 38. This short pipe 38 is arranged to enable interchangeable connection with a U-shaped outlet pipe fitted with an on/off valve or a hose fitted with a nozzle. This enables the liquid which is pumped out of the drum 12 to be directly pumped into a fuel tank or other container.

As 44 gallon drums and other similar containers are not reinforced to sustain high internal pressures (i.e. pressures above 35kPa [S.p.s.i.]) it was not previously recognised that it was possible to use a flow of pressurized fluid to pump out the contents of these types of containers. However, the device of the present invention takes advantage of the large surface area of the liquid inside the drum and as such only a small force on the surface of the liquid is required to obtain a good flow rate of liquid out of the drum. In one experiment using pressurized air at 17.5kPa (2 p.s.i.), it was found that medium grade motor oil could be delivered at a flow rate of 12 litres per minute.

The invention is particularly advantageous because the pump adaptor of the present invention may be formed as an integral one piece unit, has no moving parts and can be manufactured substantially cheaper than existing pump assemblies used for similar purposes. As the pressure of the air used to drive the fluid out of the container is relatively low, a variety of air sources can

be used. Even the air in a spare tyre can be used to operate the fluid pump. The low pressure required by the present invention also means that a simple O-ring seal is sufficient to seal the connection between the pump body and the drum. Furthermore, the present invention requires use of only one plug hole in the 44 gallon drum or container as opposed to the two plug holes required by the device described in U.S. patent 3880179.

The embodiment has been described by way of example only and modifications are possible within the scope of the invention.