Graded actuation of hydraulically actuated pool cleaning heads

A hydraulically actuated device is employed as part of a pool cleaning system. An improved structure assembly of a hydraulically actuated core within a housing provides ease of manufacture and assembly. Graded control of the application of pressure and the flow of fluid through the system is provided so that the hydraulic device is actuated in a relatively gradual and graded manner to overcome the deleterious effects of abrupt actuation of such devices and the resultant water hammer, pressure surges which are generated in such abruptly operated systems. Improved jet orifices enclosed within the hydraulically actuated cylinder of the device provide for more efficient disturbance of sediments on the interior surfaces of the pool in the immediate vicinities of the hydraulically actuated devices. Graded control of fluid flow and the sequential actuating of selected hydraulically controlled devices is provided in a manner which ensures that a constant rate of fluid flow through the system is maintained at all times.

BACKGROUND 
1. Field of the Invention 
The invention relates to the field of pool cleaning systems. 
The invention particularly relates to pool cleaning systems wherein pop-up 
water actuated jet cleaning devices are mounted flush with the interior 
surface of the swimming pool. 
The invention specifically relates to the field of pool cleaning apparatus 
wherein the actuation of pop-up jets is a graded, non-abrupt actuation and 
the fluid flow rate through the pool cleaning system is maintained 
constant to prevent water hammer pressure surges which can be deleterious 
to the system. 
2. Prior Art 
In-pool cleaning systems are well known in the prior art. Miller, in U.S. 
Pat. No. 3,247,969, and Werner, in U.S. Pat. No. 3,449,772, provide water 
jet heads which are permanently emplaced a slight distance above the 
interior surface of a pool. Werner also introduces a flush mounted pop-up 
jet head which offers no obstruction to a pool user when the cleaning 
system is in operation. 
Others also have disclosed pop-up rotating jet heads which are embedded 
nominally flush with the interior surface of the pool. Such disclosures 
will be found in Ghiz, U.S. Pat. No. 3,521,304; in Mathews U.S. Pat. Nos. 
4,202,499 and 4,271,541, as well as 4,347,979, and 4,371,994. Another 
rotary pop-up jet is disclosed by Gould in U.S. Pat. No. 4,322,860. All of 
these latter noted pop-up rotary jet heads are characterized by the 
complexity of the mechanism required for establishing the rotation of the 
jet heads. 
Two recent and surprisingly similar U.S. patents disclose pop-up jet heads 
of significantly reduced complexity when compared with the prior art. 
These are the patents to Carter, U.S. Pat. No. 4,188,673 and that to 
Goettl et al, U.S. Pat. No. 4,212,088. Yet as uncomplex a device as these 
latter pop-up heads present, they still present an assemblage of items 
which are subject to failure under the constant, abrupt, battering by the 
pop-up head with the interfering stop elements of the housings. 
It is therefore an objective of the invention to provide a hydraulically 
actuated pop-up cylinder of less complex design than that of the prior 
art. 
It is a further objective of the invention to provide a system in which 
hydraulically actuated cores are reciprocated outward from a housing by a 
graded, non-abrupt application of fluid pressure to the device. 
It is another objective of the invention to provide an in-floor pool 
cleaning system having gradedly, non-abruptly actuated pop-up heads with 
improved jet stream means, the effect of the improved jet stream means 
being more efficient movement into suspension of matter in close proximity 
to the jet head as well as reducing the leakage of pressurized water from 
potential voids which may exist between the housing and the pop-up head 
when the jet is in operation. 
A further objective of the invention is the provision of means for 
maintaining a constant rate of flow of fluid through the system so that, 
unlike prior art systems, there are no water hammer, pressure surges in 
the system, which water surges not only frequently lead to failure of the 
pop-up head assemblies but to plumbing and equipment failures at other 
points throughout the pool cleaning, filtering and water circulation 
systems. 
SUMMARY OF THE INVENTION 
In a first presently preferred embodiment, the invention comprises a 
hydraulically actuated core which is captively ejectable from its housing 
upon application of a hydraulic force. This embodiment comprises a 
cylindrical housing means having open ends. Rather than being an assembly 
of parts, the housing is a single element component. The housing is 
provided with a first diameter-reducing shoulder adjacent to a first open 
end of the housing and a second, similar diameter-reducing shoulder is 
located at a selected position between the open ends of the housing. The 
first diameter-reducing shoulder is interrupted by diametrically opposed 
egress means. 
An annular weight is insertable within the cylindrical housing via these 
egress means. It is thereafter positionable within the housing such that 
the transverse axis of the annular weight is orthogonal to the 
longitudinal axis of the housing. When so positioned, the annular weight 
is reciprocal within the housing within the limits defined by the first 
and second diameter-reducing shoulders. 
A cylindrical core is insertable within the housing and is reciprocal 
within the space defined by the first diameter-reducing shoulder. The 
cylindrical core is coupled to the annular weight after emplacement of 
both within the housing and both the core and the weight are then 
reciprocal within the housing within the limits established by the 
interfering relationships of the first and second diameter-reducing 
shoulders with the annular weight. 
Fluid transmission means are employed for communicating fluid under 
pressure to the remaining open end of the housing. To non-abruptly 
exercise the cylindrical core within the housing and within the limits 
established by the first and second shoulders therein, means for gradedly 
governing the fluid pressure provided by a source of pressurized fluid to 
the fluid transmission means is provided. 
When a plurality of these devices is employed, the means for gradedly 
governing the application of fluid pressure to the housings and their 
reciprocating cores further comprises means for sequentially, gradedly 
governing fluid pressure to each of a plurality of transmission means so 
as to sequentially, non-abruptly exercise selected ones of the cylindrical 
cores. 
Each of the cylindrical cores is provided with a jet means for ejecting the 
pressurized fluid employed in actuating the core. Water is ejected from 
the jet means into the surrounding area when selected ones of the cores 
are exercised to protrude beyond the first open end of their respective 
cylindrical housings. With the jet off-set from the longitudinal axis of 
rotation of the cores, a coupling moment is created to rotate each 
cylindrical core about its axis of rotation as the core is exercised 
between the limits established by the first and second diameter-reducing 
shoulders. 
When the devices are emplaced in the interior surface of a water bearing 
container, such as a swimming pool, the pressurized water ejected from the 
jet agitates the water sufficiently to place matter which has settled to 
the interior surface of the container into suspension within the body of 
water contained. By directing the jet downward toward the interior surface 
of the container, improved agitation of the water within the vicinity of 
the device is improved and enhancement in the interfering force exerted 
between the first diameter-reducing shoulder and the annular weight is 
achieved to reduce leakage of pressurized water in this area. 
The means for sequentially, gradedly governing the fluid flow to 
non-abruptly exercise selected ones of these cylindrical cores comprises a 
plurality of sequentially actuated fluid valve means each of which 
communicates with one of the plurality of transmission means. In turn, 
each of said valve means further comprises means for gradedly controlling 
the flow of pressurized fluid sequentially through each of said valves so 
as to gradedly exercise sequentially selected ones of the cylindrical 
cores. Also provided is means for maintaining a constant flow rate of the 
fluid into and out of the means for sequentially, gradedly governing the 
fluid pressure for non-abruptly exercising the selected core. This means 
for maintaining a constant flow rate of fluid comprises means for 
maintaining a fluid flow through at least a selected two of the plurality 
of fluid valves as these valves are sequentially actuated. By maintaining 
at least two of these valves at all times in a state in which fluid is 
flowing, a constant fluid flow rate is maintained even though each of the 
plurality of valves is sequentially actuated to its full fluid flow 
condition as well as being sequentially actuated to its fluid cut-off 
position. The maintenance of this constant fluid flow obviates water 
hammer pressure surges in the system and increases the useful lifetime of 
the system as well as of the component parts thereof. 
Such a constant fluid flow is achieved by use of a plurality of cam valve 
actuating means coupled to a cam shaft wherein the cams are emplaced on 
the cam shaft for selectable sequential, graded actuation of the fluid 
valves such that at least two such valves will always be selectedly, 
gradedly actuated to communicate fluid to selected ones of the 
hydraulically actuated cores. 
For distributing and gradedly controlling the fluid flow to the system, 
fluid distribution apparatus is employed. This apparatus comprises a fluid 
reservoir having an input connected to the source of pressurized fluid and 
a plurality of outputs for the egress of pressurized fluid from the 
reservoir. A selected one of each of a plurality of fluid valves is 
coupled to a selected one of the reservoir outputs to gradedly control the 
egress flow of fluid to such output. Individual valve actuating means 
selectedly coupled to each of the fluid valves sequentially and gradedly 
actuates each said valve and maintains a constant fluid flow rate through 
the reservoir. 
As earlier noted, a cam shaft and individual cam valve actuators coupled to 
the shaft are employed to actuate selected ones of the plurality of fluid 
valves in a graded, non-abrupt manner such that at least a selected two of 
the fluid valves is being so gradedly actuated at all times to maintain a 
constant fluid flow rate through the reservior. Ball valves have proven 
efficient and the cams may be staggered along the cam shaft to provide a 
sequential graded actuation of each said ball valve between full-open and 
full-closed conditions of the ball valves in a manner to maintain a 
sum-total egress fluid flow rate through at least a sequentially selected 
graded actuated two of these ball valves which egress fluid flow rate is 
eqivalent to the ingress fluid flow rate into the reservoir. 
The invention may be described in a specific embodiment of a swimming pool 
cleaning system for maintaining matter introduced into the water of the 
pool in suspension whereby the removal of such suspended matter from the 
pool water is facilitated as the water is circulated through the filtering 
system associated with the pool. Such filtering systems have means for 
circulating water under pressure to and from the pool through the 
filtering system. The swimming pool cleaning system comprises an assembly 
of elements which in turn comprise a cylindrical housing embedded in the 
interior of the swimming pool. The housing has first and second open ends 
with the first open end communicating with the interior of the swimming 
pool and the second open end beneath the interior surface of the swimming 
pool and communicating with a source of pressurized circulating pool 
water. As before, the housing is also provided with a first 
diameter-reducing shoulder adjacent to the first open end and a second 
diameter-reducing shoulder at a selected position between the first and 
second open ends. Weighting means are provided which are insertable within 
the cylindrical housing and positionable thereafter for reciprocal motion 
within the housing between limits defined by an interfering relationship 
between the weight and the first and second shoulders. Again, a 
cylindrical core is insertable within the first open end of the housing 
and is coupled to the weight for reciprocation with the weight within the 
housing. 
Means are provided for gradedly governing the flow of water to the second 
open end of the housing from a source of pressurized circulating pool 
water so as to non-abruptly reciprocate the cylindrical core within the 
housing. 
Jet means are coupled to the cylindrical core to eject a jet of water 
downwardly toward the interior surface of the swimming pool when the 
cylindrical core is reciprocated outwardly from the housing in response to 
a graded increase of water flow from the source of the pressurized 
circulating pool water being communicated to said housing. 
By supporting the jet means off-set from the longitudinal axis of rotation 
of the core, a coupling moment is again created to rotate the core within 
the housing as the core is reciprocatingly exercised within the housing by 
the graded governing of the flow of water to the housing. A plurality of 
such assembly of elements may be located in spaced apart relationship in 
the interior of the swimming pool, the graded governing of the flow of 
water provided by means which sequentially and gradedly govern water flow 
to sequentially selected ones of the housings. For this purpose, a water 
distribution assembly is emplaced between the source of pressurized 
circulating pool water and said housings. 
A plurality of gradedly actuatable fluid flow valves comprises part of the 
water distribution assembly. 
To prevent water hammer pressure surges, the water distribution assembly 
also comprises means to maintain a constant water flow rate through the 
distribution assembly. The distribution assembly itself further comprises 
a water reservoir having an input connected to the source of pressurized 
circulating pool water and a plurality of outputs for the egress of 
pressurized water from the reservoir to selected ones of said housings. 
Means are provided so that a selected one of the plurality of gradedly 
actuatable fluid flow valves is coupled to a selected one of the plurality 
of outputs of the reservoir. Means are, of course, provided for 
sequentially and gradedly actuating selected ones of the plurality of 
fluid flow valves. This latter means comprises a cam shaft with a 
plurality of cam valve actuators coupled thereto to cammingly sequentially 
actuate selected ones of the plurality of valves in a graded, non-abrupt 
manner such that at least a selected two of the valves are so gradedly 
actuated at all times to maintain a constant water flow rate through the 
water reservoir.

DETAILS OF THE INVENTION 
For the purposes of promoting an understanding of the principles of the 
invention, reference will now be made to the embodiments illustrated in 
the drawings and specific language will be used to describe the same. It 
will, nevertheless, be understood that no limitation of the scope of the 
invention is thereby intended, such alterations and further modifications 
in the illustrated device, and such further applications of the principles 
of the invention as illustrated therein being contemplated as would 
normally occur to one skilled in the art to which the invention relates. 
In FIG. 1 is illustrated a system wherein hydraulically actuated devices 10 
are coupled to the outputs of the fluid distribution device 24 by means of 
fluid transmission means 23, for example, plastic piping. The fluid 
distribution assembly 24 accepts fluid from a source of pressurized fluid, 
for example, water, and outputs it to the fluid transmission lines 23 for 
communication of fluid from the distribution device 24 to individual ones 
of the hydraulically actuated pop-up cores of hydraulic devices 10. The 
fluid distribution device 24 provides for a graded application of fluid 
pressure in a sequentially selectable manner to each of the fluid 
transmission lines 23 and thus to each of devices 10 in a sequential 
manner. As will be more fully disclosed and as indicated by the two arrows 
indicative of fluid flow from distribution device 24, fluid will always 
flow from distribution device 24 into at least two of fluid transmission 
lines 23 such that the sum total of fluid flowing from all outputs of 
device 24 at all times equal the flow rate of fluid into device 24. 
As suggested in FIG. 1, the hydraulically actuated device 10 may be 
embedded with its top surface essentially flush with the interior surface 
25 of a swimming pool or other fluid container. 
The hydraulically actuated devices 10 are disclosed in greater detail in 
the cross-sectional views of FIGS. 2 and 2A. Device 10 is seen to comprise 
a housing 11 of circular cross-section. Housing 11 is a one-piece 
structure. Housing 11 is provided with a first open end 12 and a second 
open end 13. 
A first diameter-reducing shoulder 14 is provided at the open end 12 of 
housing 11. A second diameter-reducing shoulder 15 is emplaced at a 
selected position between the first open end 12 and the second open end 13 
of housing 11. 
Diametrically opposed notches 16, hereinafter referred to as egress means 
16, are emplaced in shoulder 14. Egress means 16 are best seen in the 
illustration of housing 11 in FIG. 3. A weighting means 17, here depicted 
as an annulus, is emplaced within the open end 12 of housing 11 and 
positioned to rest with its central axis of rotation parallel to the 
central axis of rotation of cylinder 11. 
A hydraulically actuated cylindrical core 18 is emplaced through open end 
12 into the housing 11 and is coupled to weight 17 by means of, for 
example, screw fasteners 21 as referenced in FIG. 3. 
Fluid transmission means, or piping, 23 is coupled to the open end 13 of 
housing 11. An adhesive may be employed, in conventional manner, to affix 
fluid transmission means 23 to housing 11. 
In the assembled cross-section of hydraulically actuated device 10 in FIG. 
2, the cylinder 18 is illustrated with its top essentially flush with the 
first open end 12 of housing 11. This condition occurs when cylinder 18, 
coupled to weight 17, is in its retracted position, with weight 17 resting 
on shoulder 15 in the absence of fluid pressure in fluid transmission 
means 23. When a flow of water or other fluid, as indicated by the arrows 
in FIG. 2A, is introduced into the transmission means 23, the hydraulic 
pressure applied to cylinder 18 as a result causes cylinder 18 to rise and 
be partially ejected from housing 11. Total ejection is prevented by the 
interfering relationship between weight 17 and shoulder 14 of housing 11. 
The assembly of hydraulic device 10 is illustrated in the exploded 
perspective assembly drawing of FIG. 3. The annular weight 17 is inserted 
so as to pass through egress means 16 into housing 11. Weight 17 may 
thereafter be rotated within housing 11 to lie on shoulder 15 as 
illustrated in the cross-section of FIG. 2. Cylinder 18 is then inserted 
into the open end 12 of housing 11 and screw fasteners 21 are passed 
through counter-bored openings 27 for engagement with threaded openings 22 
in weight 17. The resultant assembly is that depicted in FIG. 2. 
Weight 17 provides the necessary mass to return cylinder 18 from its 
ejected position, FIG. 2A, to its retracted position, FIG. 2, as a result 
of gravity acting on the mass of weight 17. 
A jet outlet 26 may be provided in cylinder 18 to communicate with the 
pressurized water communicated to housing 11 for actuation of cylinder 18. 
By supporting jet orifice 26 such that its axis A, FIG. 4, is displaced 
from the axis of rotation C of cylinder 18, a coupling moment is created 
when a jet of water is emitted from jet orifice 26 causing the rotation of 
cylinder 18 about its axis C. 
When hydraulic devices 10 are embedded in the interior surfaces 25 of 
swimming pool, as suggested in FIG. 1, the communication of a pressurized 
fluid via fluid transmission means 23 to housing 11 causes cylinder 18 to 
be partially ejected from housing 11, as depicted in FIG. 2A, and a jet of 
water to be emitted from jet orifices 26 to agitate the water in the 
immediate vicinity of hydraulically actuated device 10 so as to raise 
matter, which has settled into the pool, from the interior surface of the 
pool and to place such matter in suspension so that it may be more easily 
and readily drawn by the water circulation system of the pool to the 
filter associated with such pool. In prior art devices of a similar 
nature, the pressurized stream of water emitted by the jet orifice 26 is 
directed in an adjacent parallel relationship to the inner surface of the 
pool. It has been found that a significant improvement in the scrubbing 
action of the emitted jet stream with respect to the interior surface of 
the swimming pool results by departing from the prior art's prescription 
of emitting the jet stream of water in a parallel relationship to the 
inner surface of the pool. By directing jet orifice 26 in a downward 
direction, as depicted in FIG. 12, the accelerated stream of water 
interacts with settled matter lying closer on the interior surface of the 
pool to hydraulically actuated device 10. Thus, settled matter in close 
proximity to device 10 is stirred up and put into suspension in the water 
of the pool. Further, the action of the downward accelerated stream of 
water emitted by jet 26 tends to further raise cylinder 18 to bring weight 
17 into more intimate bearing relationship with shoulder 14 so as to 
prevent the leakage of water around the intersection of weight 17 and 
shoulder 14. 
A significant problem is associated with prior art devices using pop-up 
water distributors similar to hydraulically actuated device 10. This 
problem arises from the fact that water pressure has been applied to the 
pop-up head in essentially step-functional change of pressure from zero 
pressure to maximum pressure. Such a step functional pressure shock causes 
the pop-up head of prior art devices to be abruptly actuated to slam 
outwardly from its housing and to be brought to an abrupt and shocking 
stop at the limit of its travel. Thus, the pop-up head assemblies of prior 
art devices have experienced limited useful lives and, in many instances, 
have required expensive repairs to be made with respect to the cleaning 
system of the swimming pools in which they are used. 
An additional problem occuring with the step functional application and 
withdrawal of water pressure is the water hammer, pressure surge 
experienced by the entire pool cleaning system which can lead to failures 
of the plumbing lines, water pump, and filter mechanisms. 
In the system disclosed herein, pressure is applied in a graded manner to 
the hydraulically actuated device 10 such that cylinder 18 moves 
reciprocally within housing 11 in a graded, non-abrupt manner. The word 
"graded" is here used to indicate a gradual increase or decrease of fluid 
pressure or fluid flow or a gradual increase or decrease of movement of 
elements with respect to the step-functional increase of pressure or 
movement normally associated with prior art systems. 
To further insure that water hammer, pressure surges are obviated from the 
system being here disclosed, means are provided for maintaining the 
circulating flow of pressurized fluid at a constant flow rate regardless 
of which of the hydraulically actuated devices 10 are being actuated. 
The fluid distribution device 24 provides for the graded control of 
pressure and fluid flow to the system. The graded fluid distributor 24 is 
comprised of a water vessel, or reservoir, 27 having an inlet 28 which is 
connected to a source of pressurized water or other fluid, not shown. A 
plurality of ball valves 29 are housed within reservoir 27. A plurality of 
fluid outputs 30, one of each associated with one of each of ball valves 
29, provide for the output of fluid from reservoir 27. Outputs 30 also act 
at the valve seat for ball valves 29. A guide rod 31 is coupled to each 
ball valve 29 to be exercised within guideways 32. 
Valve lifters 33 are provided on guide rods 31 to permit the graded 
actuation of ball valves 29 by cams 34 emplaced along cam shaft 35. A 
drive motor 36 drives cam shaft 35 to sequentially bring cams 34 into 
contact with sequentially selected valve lifters 33 of ball valves 29. 
FIG. 5 illustrates ball valves 29 particularly designated by the letters R, 
S, T, W, and X. The arrows flowing to the outlets 30 about ball valve S 
and ball valve T are indicative of the relative fluid flow passing out of 
valves S and T. The broader arrows at valve S, labeled 80%, indicate that 
80% of the fluid flowing through input 28 into reservoir 27 is exiting the 
output 30 of ball valve S. The smaller arrows directed to the output of 
ball valve T and labeled 20% indicate that 20% of the input fluid flow to 
reservoir 27 is exiting via the output 30 of ball valve T. By way of 
example, it is presumed that ball valve S has been raised by its cam 34 to 
its maximum displacement from its valve seat 30 and at this point, for 
illustrative purposes, 80% of the input fluid flow exits through ball 
valve S. Again, by way of example, it is presumed that when ball valve S 
has been drawn up to its maximum excursion point, ball valve T will have 
been drawn upward by its associated cam 34 to the extent that 20% of the 
input fluid flow exits through ball valve T. 
The fact that two of the plurality of ball valves 29 are illustrated as 
being in an opened position such that one hundred per cent of the input 
fluid flow exits reservoir 27 is intentional since by maintaining an 
output flow rate equivalent to the input flow rate, no water hammer, 
pressure surges can result in the system. The operation of cam shaft 35 is 
to sequentially raise ball valves 29 from their valve seats 30. The 
raising of these valves from their valve seats is a graded, non-abrupt 
movement. The sequential operation of the valves is depicted in the series 
of illustrations 7A-7D. Referring momentarily to the position of ball 
valves 29 in FIG. 5, it is seen that valve S is at the top of its 
excursion and that valve T has been partially exercised to permit 20% of 
the input fluid flow to exit thereby. In FIG. 7A, ball valve T has been 
exercised to its topmost excursion such that 80% of the input fluid flow 
passes thereby; valve W has been partially raised to permit 20% of the 
input flow to pass thereby; and valve S has once again been seated in its 
valve seat. This sequence is repeated throughout the illustration. In 7B, 
valve W passes 80% of the input flow while X passes 20% and valve T has 
closed. In FIG. 7C, valve R has been exercised to pass 80% of the fluid 
flow and valve S has been exercised to the point where it passes 20%. In 
FIG. 7D, valve R has been permitted to close and valve S exercised to its 
maximum excursion to pass 80% of the fluid flow and valve T partially 
exercised to permit 20% of the flow. This operational sequence then 
returns to that of FIG. 5 and continues as illustrated again in FIGS. 7A 
through 7D. 
It is thus seen that the operation of water distribution system provides 
graded pressure control to the output of fluid to transmission lines 23 
coupled to the outputs 30 of reservoir 27. Each of transmission lines 23 
is sequentially and gradedly charged by the fluid flowing into and out of 
reservoir 27. The hydraulically actuated devices 10, as illustrated in 
FIG. 1, are thus themselves sequentially and gradedly actuated so that the 
exercise of cylinder 18 within housing 11 is a graded actuation moving the 
cylinder 18 outward and back into housing 11 in a graded, non-abrupt 
manner. 
Such graded actuation of cylinder 18 into and out of housing 11 has the 
added advantage in that jet orifice 16 does not abruptly obtrude above 
opening 12 of housing 11 but rather is raised in a gradual and graded 
manner permitting a jetted stream of water to be ejected into the 
surrounding pool interior while cylinder 18 is still rotating in the 
course of its excursion into and out of housing 11. Thus, the stream of 
water injected into the pool from jet orifice 16 is not done so abruptly 
and in a fixed direction but is done relatively gradually while the jet 
orifice is still rotating with cylinder 18 during the excursion of 
cylinder 18 into and out of housing 11. Such action provides a further 
improvement over the action of prior art, abruptly exercised pop-up heads. 
Graded water distributor 24 is such that no tight tolerances are employed 
anywhere in the system. This is an important feature since sand or other 
small matter may pass through the filter and into fluid distributor 24. 
Guide rods 31 need not be precisely aligned within guideways 32 to provide 
proper operation of ball valves 29. Neither is it required that there be a 
precision of contact in the relationship between cams 34 and valve lifters 
33. The ball valves 29 are generally self-seating and self-cleaning 
devices. 
Reference is now made to the cross-section of FIG. 6 taken along line 6--6 
of FIG. 5. Ball valve 29 is illustrated in phantom outline seated in valve 
seat 30. As cam shaft 35 rotates, cam 34 is brought into contact with 
valve lifter 33, lifting ball valve 29 from valve seat 30 and moving guide 
rod 31 upwards into guideway 32. Cam 34 has a curved surface so that when 
ball valve 29 is drawn to the topmost point of its excursion, contact 
between valve lifter 33 and cam 34 is withdrawn in a gradual, graded 
manner as cam shaft 35 continues its rotation. Thus, ball valve 29 is 
gradedly raised from valve seat 30 and similarly, gradedly lowered back 
into contact therewith. 
In the illustration of FIG. 6, the effect of gravity upon ball valve 29 is 
utilized to return ball valve 29 to its valve seat 30. This requires, 
then, that guide rods 31 be oriented in an essentially vertical plane with 
the ball valve 29 at the lower end of guide rod 31. Should it be desired 
for any reason that water distributor 24 be operated in any other 
orientation, an optional valve spring 37, illustrated in FIG. 8, may be 
provided to return ball valve 29 to its seat 30 after being exercised by a 
cam 34. 
In the cross-sectional illustration of the graded water distribtor device 
24 of FIG. 5, an electric drive motor was employed to drive cam shaft 35. 
In FIG. 9, a simplified cross-sectional view of graded water distributor 
24, a water turbine wheel 38 and associated gear train 39 is employed for 
driving cam shaft 35. The water turbine wheel 38 is rotated adjacent to 
the input 28 to water reservoir 27. The entering water causes turbine 
wheel 38 to rotate and this rotation is communicated by gear train 39 to 
cam shaft 35. Additional details are shown in FIGS. 10 and 11. The 
conceptual details of such turbine drives are well known to those skilled 
in the art. 
Turning again to FIG. 12, it is noted that the jet orifice 26 is provided 
with rifle lands 41. The action on the jet of water exiting jet orifice 26 
is similar to that experienced by a bullet exiting a rifle. Riffle land 41 
imparts a spin to the water jet which obviates the tendency for formation 
of laminar flow of the jet in the pool water which can occur with a 
non-spinning jet. The spinning water jet has a greater agitation effect on 
the surrounding water and on the settled matter on the interior surface of 
the pool. Thus, the settled matter is moved more readily into suspension 
in the pool water to be carried thereby to the filtering system of the 
pool. 
What has been described is a hydraulically actuated device which may be 
employed as part of a pool cleaning system. An improved structural 
assembly of a hydraulically actuated core within an assembly provides ease 
of manufacture and assembly. Graded control of the application of pressure 
and the flow of fluid through the system is provided so that the hydraulic 
device is actuated in a relatively gradual and graded manner to overcome 
the deleterious effects of abrupt actuation of such devices and the 
resultant water hammer, pressure surges which are generated in such 
abruptly operated systems. Improved jet means enclosed within the 
hydraulically actuated cylinder of the device provides for more efficient 
disturbance of sediments on the interior surfaces of the pool both in the 
immediate vicinities of the hydraulically actuated devices and at 
distances further removed therefrom. Means for gradedly controlling fluid 
flow and sequentially actuating selected hydraulically controlled devices 
are provided in a manner which ensures that a constant rate of fluid flow 
through the system is maintained at all times. 
Those skilled in the art will recognize that other embodiments of the 
invention may be drawn from the illustrations and the teachings herein. To 
the extent that such alternate embodiments are so drawn, it is intended 
that they shall fall within the ambit of protection of the claims appended 
hereto.