Brief Summary of the Invention
This invention relates to a device for displacing an article in a liquid, in particular a swimming pool cleaner.
According to the invention there is provided a displacing device for displacing an article in a liquid, which includes
a hollow housing which defines a chamber;
a connection means for connecting the housing to a source of pressurised liquid for delivering pressurised liquid into the chamber;
a plurality of outlet openings defined in the housing for permitting the flow of liquid out of the chamber; and
a closing means for periodically closing the outlets so that at least one is open and the or each other outlet is closed, in a substantially random manner.
The outlets may be connected to components, such as turbines which convert liquid flow to mechanical movement, or to jet defining members.
The closing means may comprise at least one ball or other object within the housing, which is displaced, in a substantially random manner, into closing engagement with the entrance to one of the outlet openings (or more if there is more than one ball).
The outlet openings may be arranged in groups, there being at least one ball for each group. It will be understood that with each group there will be at least one less ball than there are outlet openings in that group. Further, a valve arrangement may be provided to supply the pressurised liquid alternately to the various groups. The valve arrangement may be movable to supply the liquid to the groups in a cyclical manner. The valve arrangement may include a slidable and rotatable member.
In addition a displacing means may be provided to displace the or each ball from the outlet opening(s) in a particular group with which it/they are engaged, when the valve arrangement stops supplying liquid to that particular group of outlet openings.
In a preferred embodiment, which has jet defining members, some of the jet defining members may face in a forward direction and some in a backward direction. Further, the jet defining members may be angled so as to provide a sideways thrust component in addition to a forward or backward component.
Brief Description of the Drawing
The invention is now described, by way of an example, with reference to the accompanying drawing, which shows schematically a displacing device in accordance with the invention.
Detailed Description
Referring to the drawing, a device for displacing a swimming pool cleaner is designated generally by reference numeral 10. The device 10 has a hollow housing 12 that has a connecting portion 14 at one end whereby it may be connected to a source of pressurized water (not shown). Further, the housing 12 has a cylindrical wall 16 with two end walls 18 and 20. The connecting portion projects from the end wall 20.
The connecting portion 14 is centrally located and is aligned with a tube 22 that is slidable towards and away from the connecting portion 14. The tube 22 is axially connected to a further tube 24 at its end remote from the connecting portion 14, so that the tube 22 is rotatable relative to the tube 24. As is clear from the drawing, the further tube 24 extends through an opening in the end wall 18 and is slidable therein.
The interior of the housing 12 is divided into three chambers by two annular partitions 26 and 28. Thus, there is a first chamber 30 which is located between the partition 28 and the end wall 20, a chamber 32 between the partitions 26 and 28 and a chamber 34 between the partition 26 and the end wall 18.
An aperture 36 is provided in the cylindrical wall 16, in the region of the chamber 30, through which water may flow to perform a cleaning function. Four jet nozzles 38, 40, 42 and 44 are fast with the cylindrical wall 16, about openings 46, 48, 50 and 52, respectively. As will be noted from the drawing, the nozzles 38 and 40 communicate with the chamber 32 and are directed in a backward direction, and the nozzles 42 and 44 communicate with the chamber 34 and are directed in a forward direction. All of the nozzles 38 to 44 are angled so that water issuing therefrom will exert a thrust on the housing 12 which has both a sideways component and a forward or backward component.
Within the chamber 32 there is a ball 54 and within the chamber 34 there is a ball 56. The ball 54 seats in either the opening 46 or the opening 48 and the ball 56 seats in either the opening 50 or 52.
The tube 22 has outlet orifices 58 through which water flows into either the chamber 34 or the chamber 32, depending on the position of the tube 22 which is displaced back and forth by the tube 24. The tube 24, in turn, is displaced backwards and forwards by a unit 60 which is shown in dotted lines and which does not form part of the present invention. The unit 60 is operated by water flow, which is supplied to it via the tube 24. A suitable unit is described in our co-pending application filed at the same time as this application and entitled "A Fluid Operalbe Engine".
The tube 22 has at its free end, i.e. its end closest to the wall 20, a turbine wheel 62. It will be appreciated that when the tube 22 is at the limit of its stroke at which it is closest to the connecting portion 14, water flowing past the turbine wheel 62 will cause it to rotate, thereby rotating the tube 22. As the tube 22 is rotated slightly with each stroke, the relative orientation of the orifices 58 with reference to the openings 46 to 52 varies thereby inhibiting a particular pattern.
It will further be appreciated that when the tube 22 is in such a position that the orifices 58 communicate with the chamber 34, water flows through these orifices 58 and into the chamber 34. Depending on the position of the ball 56 at the time when flow begins, either the opening 50 or the opening 52 will be blocked. Thus, water will then issue either through the jet 42 or 44. When the tube 22 is displaced from left to right, when looking at the drawing, the orifices 58 will then pass into communication with the chamber 32 and the ball 54 will block either the opening 46 or 48 so that water issues either through the jet 38 or the jet 40. When water is being supplied to the chamber 32, the ball 56 will no longer be held in seating engagement with the opening 42 or 44 that it had closed, and it will move to some position in the chamber 34. Thus, as the tube 22 moves back and forth, rotating slightly with each stroke, the balls 54 and 56 close the openings 46 to 52 in a substantially random manner. Thus, although the device 10 experiences an alternate forward and backward thrust, it also experiences a substantially random sideways thrust. Thus, the device 10 is moved forwards and backwards in a predetermined manner and randomly in a sideways manner.
In order to ensure that the balls 54 and 56 are dislodged, pins 64 are provided that are fast with the tube 22 and which dislodge the balls 54 and 56 upon movement of the tube 22.
It will be appreciated that the invention provides a device whereby a pool cleaner may be displaced, which is cheap to manufacture, is reliable in operation and which moves in a predetermined but nonetheless random manner.