GB2153661A

GB2153661A - Swimming pool cleaner

Info

Publication number: GB2153661A
Application number: GB08502992A
Authority: GB
Inventors: Helge Jochen Schneider; Dieter Hans Frieder Kallenbach
Original assignee: COXWOLD Pty Ltd
Current assignee: COXWOLD Pty Ltd
Priority date: 1984-02-07
Filing date: 1985-02-06
Publication date: 1985-08-29
Also published as: ES540189A0; AU3847985A; FR2559190A1; DE3504226A1; ES8602195A1; FR2559190B1; GB8502992D0

Abstract

A swimming pool cleaner comprises a body 5 supported on a base 1 carried by tracks 2, which are driven by a mechanism comprising a swash plate 6 and drive rods 13, 14, the swash plate being moved by passage of water through casing 7 on operation of the swimming pool filter unit pump, which is connected thereto. <IMAGE>

Description

SPECIFICATION Swimming pool cleaner This invention relates to swimming pool cleaners which operate off the suction generated in a normal domestic pool filter system. More particularly the invention relates to cleaners which enable a continuous unrestricted flow of water to pass from the pool through the machine to drive the latter and on to the pump and filter for the swimming pool cleaner.

Several types of swimming pool cleaners particularly for use in domestic swimming pools have been proposed and used. As far as the applicant is aware only two of these types operate on the flow induced by the pump of the water filtration plant for the pool.

One of these types uses an interruption in the flow to the pump to cause impulsive step by step movement of the cleaner over the submerged surface which it is to clean. The other type of cleaner utilises a turbine carrying an out of balance weight and rotation of this weight is used to cause a step by step movement of the cleaner. This is effected by permitting the force generated as the weight is rotated to move the cleaner in one direction but restraining the movement which would otherwise occur in the opposite direction while maintaining the cleaner against the surface to be cleaned by the reduced pressure induced by filter unit pump.

The object of this invention is to provide a swimming pool cleaner which has a continuous movement over a submerged surface caused by the flow of water to the pump of the filtration plant for the pool.

According to this invention there is provided a swimming pool cleaner comprising a body supported on a base carried by a pair of tracks, the body housing a drive mechanism for the tracks in the form of a swash plate assembly having a casing with a divider plate extending radially from a central spherical mounting for a swash plate and located in a slot in the swash plate, part spherical seats for the mounting and an outlet communicating with the interior of the casing on either side of the divider plate, a passage in the body around the casing connecting the outlet from the casing to a coupling connectable to a flexible hose, an opening through the base communicating with the inlet to the casing and the spherical mounting having a radially projecting drive rod extending out of the casing to form a member of the drive mechanism for the tracks.

Further features of the invention provide for the inlet and outlet to the casing are interchangeable through a slide gate controlling a pair of openings through the base and the inlet to the passage around the casing.

The invention also provides for the divider plate to be hollow and form a guide for a slide projecting radially from the spherical mounting at substantially right angles to the drive rod. The slide will preferably have an antifriction bearing mounted on the free end thereof engaged in an enlarged outer part to the divider plate, thereof engaged in an enlarged outer part to the divider plate.

Still further features of this invention provide for the tracks to be carried by end rollers, for the drive to include a belt extending between pulleys connected to at least one of the rollers on one side of the body and a rotatable member mounted to be driven by the drive rod and for the rollers on opposite sides of the body to be connected through shafts coupled together through lost motion couplings.

Yet another feature of this invention provides for the shafts each to carry a series of radially extending blades at least the tips of which are flexible and extend beyond the outer periphery of the tracks around the rollers.

The invention also provides means for automatically reciprocating the gate between its terminal position.

A preferred embodiment of the invention is described below by way of example with reference to the accompanying drawings in which: Figure lisa part side elevation of the cleaner, Figure 2 a view showing the slide and guide arrangement, Figure 3 a part sectional end elevation, Figure 4 a view from beneath the swash plate drive mechanism, Figures 5 to 8 are details of components of the particular form of the invention described.

As shown the swimming pool cleaner consists of a base indicated generally at 1. The base 1 is carried by a pair of caterpillar-type tracks 2 one extending down each side of the base 1. The tracks 2 are mounted on rollers 3 supported on shafts 4 rotatable in suitable bearings (not shown) supported from the base 1.

On the base 1 is mounted a body 5 having a swash plate assembly. The latter consists of the swash plate 6 movable in the casing 7. A central spherical mounting 8 carries the radially extending plate 6 and the casing 7 has inlet and outlet openings 9 and 10 through the bottom thereof.

The swash plate 6 is preferably made of flexible material such that while the plate is sufficiently rigid to perform its normal function it will nevertheless yield in foreign bodies which are trapped between it and the inside of the casing 7. The spherical mounting 8 is made of hard abrasive resilient material and plate 6 will be annular with its inner periphery 11 retained in a peripheral grove in the mounting 8 as indicated in Figure 5.

The opposite walls of the casing 7 against which the swash plate 6 essentially operates have apertures 12therethrough and part spherical annular seats for the spherical mounting 8 are provided around these apertures 12.

A pair of drive rods 13 and 14 extend in diametrically opposite direction from the mounting 8 one through each aperture 12.

The body 5 has a passage 15 therein which extends around the casing 7 to communicate with openings 16 and 17 through the base 1. A reciprocatable gate 18 is movable between terminal positions where it will close one of the openings 16 as well as the passage 15 adjacent that opening. Movement of the gate as described more fully below to its other terminal position will close the other opening 17 and close the passage adjacent the opening while simultaneously opening the first opening 16. As can be seen in Figure 2 the passage 15 extends around the casing 7 and the inlet and outlet openings 9 and 10 in the casing 7 are spaced apart from but located above the openings 16 and 17 through the base 1.

A divider plate 19 extends across the body 5 from the base 1 between openings 16 and 17 to the spherical mounting 8. The divider is located in a radial slot 20 provided in the swash plate 6 with a small clearance and the spherical mounting is in substantial sealing engagement with the inner end of divider plate 19 as well as with the annular seats around the apertures 12.

From the above and referring particularly to Figure 1 it will be seen that there is a pathway through opening 16 in base 1 between divider plate 19 and upstanding end of gate 18 through the inlet 9 into casing 7 out through outlet 10 and along passage 15 to an outlet 21 from the body 5. With the gate 18 in the other terminal position the pathway extends through opening 17 into the casing 7 through outlet 10 and from the casing 7 into passage 15 through inlet opening 9. Thus movement of the gate 18 between its terminal positions reverses the function of inlet 9 and outlet 10 and, if water is drawn through the casing 7 with the pathway as first described open then the swash plate will move in one direction and this direction will be reversed if the other pathway is open.

It will be understood that this reversal of movement of the swash plate reverses the direction in which the drive rods 13 and 14 revolve.

The divider plate 18 is formed as a hollow guide 22 having an enlarged outer part extending between the swash plate 6 and the body 5. A slide in the form of a rigid arm 23 extending from the spherical mounting 8 substantially at right angles to the drive rods 13 and 14 carries an antifriction bearing 24 on its free end. The bearing runs in the enlarged part of the hollow divider plate 19 and absorbs any thrust acting on the swash plate 6 enabling the latter to move freely in the casing 7.

The shafts 4 at each end of body 5 are connected together through a lost motion coupling 25 which can conveniently be of the form illustrated in Figure 6. The ends of the shafts each carry part of the coupling 25 and each carries an outwardly projecting dog 26 on a disc 27. The dogs 26 extend only a small distance around the outer periphery of the discs so that when a driven shaft 4 rotates the dog associated therewith will engage the dog on the other part of coupling 25 and drive the contiguous shaft and its associated roller in the same direction. If the direction of rotation of the driven shaft is reversed, that shaft 4 will complete almost a complete revolution before the coupling dogs again engage to drive the driver roller 3 in the new direction.

This will result in the track 2 on one side of the base moving for a period of time while that on the other is stationary and consequently the base 1 will turn in a plane parallel to the surface on which it rests until the tracks 2 are drawn in unison to move the base 1 in one longitudinal direction. Reversal of rotation of the shaft will cause a turn in the oppposite direction before the body reverses its direction of travel.

The base 1 is arranged to be in fairly close contact with the surface to be cleaned and to ensure that a limited opening is available for water to be drawn under the machine. This is effected by having the tracks 2 mounted to support the base 1 only a small distance above the surface on which the cleaner is to operate. The tracks 2 are also mounted close to the sides of the base 1 to further restrain the ingress of water under the machine. The belt drive is illustrated as extending to only one roller 3 and associated shaft 4 but it could also extend to both rollers on one side of the base 1.

Means are also provided at each end of the machine to close the space between the base 1 and the surface to be cleaned. This means consists of flexible blades 28 arranged in a symmetrical series around the shafts connecting the end rollers 3. The ends of the body 5 have arcuately shaped recesses 29 extending across the ends. As rollers 3 rotate the blades move over the surface to be cleaned and into the recesses 29. The blades 28 thus form a seal to prevent ingress of water under the front and rear of the cleaner.

The tips of the blades 28 are particularly flexible and extend beyond the periphery of the tracks 2 where they wrap around the rollers 3. Thus as the rollers 3 and shafts 4 rotate the blades also rotate and seal against the surface at the front and rear of the cleaner. Those in the front act to wipe the surface and draw loose material lying thereon under the cleaner rather than move it out of the path of travel of the cleaner.

To the underside of the base 1 on each side of the openings 16 and 17 are hinged flexible flaps 30. The flaps 30 extend along the greater part of the length of the base and carry narrow transverse strips 31 of abrasion resistent material at spaced intervals along their lengths.

The free edges of the flaps 30 will contact the surface to be cleaned where the strips 31 act to scour the dirt therefrom.

There are many means which can be provided to cause the gate 18 to be moved between its terminal position. In use it is probable that at least two separate means should be provided, one to ensure reversal after the cleaner has travelled a certain distance and the other to prevent the machine from climbing out of the water in which it operates.

It is also preferred that a piston and cylinder assembly be used to operate the gate 18 and a sensitive mechanism used to control the piston and cylinder.

The piston and cylinder assembly 32 can be mounted on the base 1 on the opposite side of the body 5 to the drive assembly for the tracks 2. The cylinder will be connected to the passage 15 on either side of the divider plate 18 through ports controlled by a slide valve indicated at 33 in Figure 7 which is diagrammatic. Thus flow through the passage 15 can be used to move the piston in the cylinder if the appropriate port is opened. The piston is mechanically connected to the gate 18 to move the latter in unison with itto alternately open openings 16 and 17.

The mechanism used to control the slide valve 33 can be a mechanical linkage illustrated again diagrammatically in Figure 8. The drive rod 14 con nects to the input of reduction gearing 34which has its output gear carrying a spigot 35. This spigot will move in an arcuate manner to act on the linkage indicated at 36 to move the slide valve from one terminal position to the other. With each such movement the piston will move the cylinder and this in turn moves the gate to reverse the direction of operation of the cleaner. By the choice of gear ratios in the gear box the cleaner can be made to travel a specific distance before it is caused to reverse its direction of travel.

Also connected to the slide valve 33 in a manner which will cause accellerated action thereof beyond that of the linkage above described is a second linkage which is operated by a pair of floats 37 on the end of an arm extending a short distance beyond the base at one end and mounted adjacent the side of the body 5 a substantial distance above the base 1.

Thus with the cleaner mounted to move in one direction the float 37 on the one end of the arm will project forwardly of the front end of the cleaner.

Should that end of the cleaner tend to leave the water the weight of the float will push the arm rearwardly to operate the slide valve 33 which in turn results in reversal of movement of the machine. The interaction of the two linkages is such as to ensure that a float extends forwardly of the cleaner with respect to its direction of travel.

In use the cleaner is placed in a swimming pool and the outlet 21 from the body 5 connected, preferably through a swivel coupling to the flexible hose of the usual domestic swimming pool filter system.

When the pump is operated water is drawn through the cleaner which causes the swash plate 6 to move in casing 7 thus revolving drive rods 13 and 14. This results in movement of the tracks and the spigot 35. Due to the lost motion coupling 25 the cleaner will first change its direction and then move in a straight line across the submerged surface on which it is placed. The flow of waterthrough the machine causes a reduced pressure under the base 1 which draws the free ends of flaps 30 against the surface and hold the cleaner against the surface while it moves thereacross. This holding force also enables the cleaner to traverse from the substantially horizontal floor onto the vertical walls provided the dimensions of the rollers and the radius of curvature of the junction between wall and floor are suitably designed.

The movement of the spigot 35 or a float 37 as above described will result in the automatic reversal of direction of movement of the machine. On each such reversal the lost motion coupling will ensure that the cleaner moves over a new path and in this manner all the submerged surfaces of the pool will be cleaned.

It has been found that the series of blades 28 at the front of the cleaner ensures that most debris on the surface is drawn with the water through the cleaner into the filtration unit. Also the scouring action of the strips 31 on flaps 30 effectively remove dirt adhering to the surface being cleaned and enable this dirt also to be passed to the filter unit.

The machine above described is effective in operation and can be made compact and simple to maintain.

It will be appreciated that the design can be varied substantially from that described without departing from the scope of the invention. In particular the tracks may be driven directly from the output shaft driven by drive rod 13 by mounting a sprocket thereon and engaging this with suitable formations formed on the inside of the tracks. Also the tread on the outer surface of the tracks can be varied to be the most suitable for the type of surface that is to be cleaned.

Other mechanisms can also be used to reverse the direction of movement and in particular it is envisaged that the quantity offlow ofwaterthroughthe machine can be used to operate the slide valve of the piston and cylinder assembly on the gate directly at predetermined intervals.

Preferably the components of the pool cleaner of this invention will be moulded from suitable plastics material and it will be appreciated that it will be made to have a slightly negative bouyancy but with a centre of gravity close to the centre of the base to ensure that it will orientate correctly on a horizontal surface under water.

Claims

1. A swimming pool cleaner comprising a body supported on a base carried by a pair of tracks, the body housing a drive mechanism for the tracks in the form of a swash plate assembly having a casing with a divider plate extending radially from a central spherical mounting for a swash plate located in a slot in the swash plate, part spherical seats for the mounting and an inlet and an outlet communicating with the interior of the casing on either side of the divider plate, a passage in the body around the casing connecting the outlet from the casing to a coupling connectable to a flexible hose, an opening through the base communicating with the inlet to the casing and the spherical mounting having a radially projecting drive rod extending out of the casing to form a member of the drive mechanism for the tracks.

2. A pool cleaner as claimed in claim 1 in which the divider plate is hollow and forms a guide for a slide projecting radially from the spherical mounting at substantially right angles to the drive rod.

3. A pool cleaner as claimed in claim 2 in which the slide has an antifriction bearing mounted on the free end thereof engage in an enlarged outer part to the divider plate.

4. A pool cleaner as claimed in claim 1, claim 2 or claim 3 in which the inlet and outlet to the casing are interchangeable through a slide gate controlling a pair of openings through the base and the inlet to the passage around the casing.

5. A pool cleaner as claimed in claim 4 in which the tracks are carried by rollers mounted adjacent the ends of the base and at least one of which is driven by the drive mechanism.

6. A pool cleaner as claimed in claim 5 in which the drive mechanism includes a belt extending between pulleys secured to at least one roller and an output shaft driven by the drive rod.

7. A pool cleaner as claimed in claim 6 in which the rollers on opposite sides of the base are connected together in pairs by shafts coupled together lost motion couplings.

8. A pool cleaner as claimed in claim 7 in which the shafts for the rollers each carry a series of radially extending blades at least the tips of which are flexible and extend beyond the outer periphery of the tracks around the rollers.

9. A pool cleaner as claimed in any preceding claim in which the swash plate consists of an annular flexible disc secured to a hard abrasive spherical mounting by engagement of the inner periphery of the disc in a peripheral radially extending slot in the spherical mounting.

10. A pool cleaner as claimed in any of claims 4 to 9 in which the sliding gate is connected through a mechanical linkage to a pair of floats one located on each end of an arm supported adjacent the body to reciprocate under the influence of gravity on the floats to move the gate between its terminal positions.

11. A pool cleaner as claimed in claim 10 in which the arm carrying the floatrs is connected to a slide valve controlling operation of a piston and cylinder assembly with the piston connected to reciprocate the gate.

12. A pool cleaner as claimed in claim 11 in which the slide valve is connected through a linkage to the rotatable output gear of a reduction gearing arrangement driven by a drive rod extending from the spherical mounting of the swash plate assembly.

13. A pool cleaner as claimed in any of claims 5 to 12 in which resilient flaps are provided hingedly connected to the bottom of the base on each longitudinal side of the openings through the base and extending to the outer part of the base and substantially the length thereof.

14. A pool cleaner as claimed in claim 13 in which the flaps each carry a series of transversely extending strips of abrasion resistent material in spaced relationship along the length of the flaps.

15. A pool cleaner substantially as herein described with reference to and as shown in the accompanying drawings.