Fluted swimming pool cleaner discs

Discs for devices such as automatic swimming pool cleaners are disclosed. The discs incorporate one or more flutes, or raised areas (arched protrusions), extending generally radially from adjacent their central portions to their peripheries. The peripheries themselves, moreover, may include upturned areas (lips) between flutes, and both the discs and footpad may include ramped segments facilitating movement over obstacles extending from swimming pool surfaces.

FIELD OF THE INVENTION 
This invention relates to discs for cleaners of liquid-containing vessels 
and more particularly to automatic pool cleaners having fluted discs for 
improved performance in swimming pools. 
BACKGROUND OF THE INVENTION 
U.S. Pat. No. 4,351,077 to Hofmann and U.S. Pat. No. 4,642,833 to Stoltz, 
et al., incorporated herein in their entireties by this reference, 
disclose automatic, water-interruption-type suction swimming pool cleaners 
having flexible annular discs. These discs are typically mounted near the 
inlets of the suction cleaners and designed to contact pool surfaces when 
in use. By doing so, the discs decrease the tendency of the cleaners to 
disengage from pool surfaces, particularly when the cleaners are 
negotiating transition regions between walls and floors. 
U.S. Pat. No. 4,193,156 to Chauvier, also incorporated herein in its 
entirety by this reference, describes (at column 4, lines 5-55) an annular 
disc having numerous "concertina-like," "circumferentially spaced folds." 
These folds extend when their associated swimming pool cleaner encounters 
a transition region, purportedly "keeping the inflow of water into the 
mouth opening to a minimum." Other existing discs similarly are designed 
for improved adhesion to surfaces to be cleaned, thereby reducing fluid 
flow into the mouth of the cleaners. 
SUMMARY OF THE INVENTION 
The present invention provides alternative flexible discs for devices such 
as automatic swimming pool cleaners. Unlike the discs described above, the 
present invention incorporates one or more flutes, or curved raised areas 
(arched protrusions), therein. Each such flute extends generally radially 
from adjacent the central portion of the disc to its periphery, creating a 
direct fluid flow path from the periphery of the disc to the mouth of the 
associated cleaner. Doing so expands the cleaning area of the disc without 
concurrently enlarging its physical area, enhancing performance over 
conventional discs. 
In particular, fluid flow rates into the cleaner mouth increase 
significantly in the fluted areas. This accelerated flow reduces the 
pressure (according to Bernoulli's equation) not only in the fluted areas 
themselves, but also beyond the periphery of the disc in the regions 
surrounding the openings provided by the flutes. This larger area of low 
pressure results in a greater area of the vessel being subject to cleaning 
for a given-sized disc, since the low pressure region draws debris toward 
the disc (the source of low pressure). 
Certain embodiments of the present invention include dual flutes symmetric 
about a radius of the disc. Fewer or greater flutes may be included, 
however, consistent with the scope of the invention. Moreover, such flutes 
need not be of uniform width or depth, but rather may taper toward the 
central portion of the disc (thereby effectively funneling fluid from the 
periphery) and simultaneously decrease in depth. The boundaries of the 
flutes additionally may be either straight or curved as suitable or 
desired. 
Additional features of the present invention include a curved, or upturned, 
lip between flutes. The lip, forming the leading edge of the disc, 
supplies an inclined surface for and sufficient rigidity to the disc to 
enable it to ride over various objects, including many drains, lights, 
valves, and nozzles, projecting from internal surfaces of pools. The disc 
underside also contains an integrally-formed ramped segment surrounding 
its (nominally circular) central aperture. This ramp likewise assists the 
pool cleaner in negotiating obstacles, supplying a smooth progression from 
the disc bottom to the bottom of the cleaner footpad (which the disc 
surrounds in use), which too may include a ramp. 
Multiple openings through the disc enable fluid to pass from one surface of 
the disc to the other, maintaining a boundary fluid layer between the 
lower surface of the disc and the adjacent surface of the pool. These 
openings facilitate movement of the disc relative to the pool cleaner and 
allow dirt and debris to be entrained in the flow of fluid through the 
openings and in the boundary layer. Another embodiment of the present 
invention includes a multi-featured periphery and a non-circular central 
aperture. 
It is therefore an object of the present invention to provide a disc 
incorporating one or more generally radial flutes extending to its 
periphery. 
It is a further object of the present invention to provide a disc enhancing 
the performance of an automatic swimming pool cleaner through increasing 
its cleaning area by providing a larger low pressure region. 
It is an additional object of the present invention to provide a disc 
having one or more upturned lips to facilitate negotiating obstacles. 
It is yet another object of the present invention to provide a disc having 
an underside containing a ramped segment surrounding its central aperture. 
It is, moreover, an object of the present invention to provide a disc 
including multiple openings therethrough, enabling fluid to pass from one 
surface of the disc to the other.

DETAILED DESCRIPTION 
FIGS. 1-5 illustrate disc 10 of the present invention. Disc 10 defines a 
central aperture 14, nominally circular, in which a footpad of an 
automatic swimming pool cleaner may be received, for example. Disc 10 also 
defines a generally planar upper surface 18, a periphery 20 and, as shown 
in FIG. 3, a lower surface 22. Extending upward from upper surface 18 are 
curved raised areas (arched protrusions), or flutes 26, which effectively 
expand the cleaning area of disc 10 without concurrently enlarging its 
physical area. Each flute 26 extends generally radially from adjacent the 
reinforced area 28 of disc 10 surrounding central aperture 14 to periphery 
20, creating a direct path from the periphery 20 to the mouth of the 
associated cleaner for debris-laden fluid. 
FIGS. 1-3 also detail the raised lip 30 of periphery 20. Located 
intermediate adjacent flutes 26, lip 30 provides a ramped portion of disc 
10 (which may be of increased rigidity) to facilitate the disc 10 
negotiating obstacles often projecting from interior pool surfaces. Pins 
or stops 32, which may be integrally formed with and project upward from 
the reinforced area 28 of disc 10, cooperate with portions of a footpad or 
other component to inhibit misorientation of disc 10. In use, lip 30 forms 
the leading edge of disc 10 as it and associated equipment move throughout 
a pool or other vessel, enabling the disc 10 to ride over objects 
encountered therein. Openings 34 through disc 10 enable fluid to pass 
between upper and lower surfaces 18 and 22 of disc 10 when in use, 
maintaining a boundary fluid layer between the lower surface 22 of disc 10 
and the adjacent surface of the pool or other structure to be cleaned. 
Shown in FIGS. 3-4 is ramp 38, projecting from lower surface 22 of disc 10 
and positioned concentrically about central aperture 14. Ramp 38 promotes 
a smooth transition between lower surface 22 and the bottom of a footpad 
(or other component) received by central aperture 14, facilitating 
unobstructed movement of a swimming pool cleaner associated with the 
footpad. FIG. 3 similarly discloses radius 42 existing between lip 30 and 
lower surface 22 of disc 10, providing a smooth transition therebetween 
and, as noted above, an inclined surface, or ramp, for negotiating 
obstacles. 
In an embodiment of the invention consistent with FIGS. 1-5, flutes 26 are 
positioned symmetrically about a radial axis 46 extending through disc 10 
from central aperture 14 to periphery 20. As shown in these figures, 
flutes 26 need not be of uniform width (W) or height (H), but rather may 
be widest and highest (i.e. protrude further) at periphery 20 and taper in 
width while decreasing in height toward reinforced area 28. As noted 
earlier, fluid flow rates into the cleaner mouth increase substantially in 
the fluted areas of disc 10. This accelerated flow creates a region of low 
pressure extending beyond periphery 20, increasing the effective cleaning 
area of the cleaner. 
Although two flutes 26 are illustrated in FIG. 1, the number of flutes 26 
is not necessarily critical to the invention. Consequently, disc 10 may 
include more or less than two flutes 26 as necessary or desired. Those 
skilled in the art will recognize, however, that including vast numbers of 
flutes 26 on disc 10 may ultimately diminish the effectiveness of the 
associated cleaner by reducing the quantity of the increased fluid flow 
through each to a negligible amount. 
FIG. 5 details selected characteristics of a portion of flute 26 near 
periphery 20. Whereas upper surface 18 and lower surface 22 generally 
define parallel planes, at flute 26 each extends upward above the plane 
formed by upper surface 18. These upwardly-extending surfaces 18A and 22A, 
while remaining approximately parallel at any particular location, no 
longer are planar but rather are curved. The result is an approximately 
semi-conical structure for flute 26 that, as shown in FIGS. 1-2, may be 
truncated adjacent reinforced area 28. 
FIG. 6 illustrates an alternate disc 50 of the present invention. Although 
including flutes 54 similar to disc 10, disc has a multi-featured 
periphery 58 differing in shape from periphery 20. Central aperture 62 of 
disc 50 additionally is configured differently than central aperture 14 of 
disc 10, with reinforced area 66 being more triangular than circular in 
nature. Defining central aperture 62 in this manner permits suitable 
attachment to the style of footpad 70 shown in FIG. 6. Doing so also 
alleviates any need for including stops 32 or other external orientation 
means to be present on disc 50. 
The foregoing is provided for purposes of illustrating, explaining, and 
describing embodiments of the present invention. Modifications and 
adaptations to these embodiments will be apparent to those of ordinary 
skill in the art and may be made without departing from the scope or 
spirit of the invention.