Note: Descriptions are shown in the official language in which they were submitted.
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21~8737
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SPEED CONTROLLED ROTATING SPRINKLER
BACKGROUND OF THE INVENTION
This invention relates to irrigation sprinklers, and
more particularly, to a new and improved sprinkler
construction for sprinklers of the type generally referred to
as ~spinners~.
There are many different types of rotary sprinkler
constructions used for irrigation purposes, including impact
or impulse drive sprinklers, motor driven sprinklers, and
rotating reaction drive sprinklers. Included in the category
of rotating reaction drive sprinklers are a species of
sprinklers known as a ~spinner~ and which has found particular
application in the irrigation of agricultural crops and
orchards.
Typically, such spinner type sprinklers comprise a
stationary support structure or ~bridge~ which is adapted to
be coupled with a supply of pressurized water, and a rotating
sprinner drive supported by the bridge for rotation about a
generally vertical axis. Most spinner type sprinklers employ
either a rotating reaction drive nozzle to form the spinner
device, or employ a fixed nozzle which ejects a stream of
water vertically onto a rotating deflector which redirects the
stream into a generally horizontal spray, the deflector being
rotated by a reaction force created by the impinging stream
from the fixed nozzle. Exemplary of such prior art spinner
type sprinklers are those disclosed in United States Patent
Nos. 4,356,972; 4,440,345; 4,498,628; 4,660,766; 4,796,811;
and 5,007,586.
One problem that has been encountered with spinner
type sprinklers is that due to a very high rate of rotation of
the spinner devices, the distance water is thrown from the
sprinkler may be substantially reduced. To correct this
problem, the prior art has recognized that brake mechanisms,
typically employing the principle of viscous fluid shear, can
2~ 2873 7
,,
--2--
be added to the sprinkler to very substantially reduce the
rate of spinner rotation, thereby increasing the area covered
by the sprinkler. Such brake mech~ni ~m~ are disclosed, for
example, in the spinner type sprinklers of the aforementioned
U.S. Patent No. 4,440,345 relating to a rotary nozzle type
spinner, and U.S. Patent No. 4,660,766 relating to a fixed
nozzle with rotating deflector type spinner.
The present invention is directed to a new and
improved construction for a spinner type sprinkler,
particularly of the type employing a rotating reaction drive
nozzle, which significantly increases the operational range
and capabilities of such sprinklers, and provides a
substantial increase in performance over prior art spinners,
particularly over such spinners employing fixed nozzle ~ith
rotating deflector type constructions.
SUMMARY OF THE INVENTION
In accordance with the present invention, a new and
improved spinner type irrigation sprinkler construction is
provided which permits the user to select and control the
angle of trajectory of the water stream ejected by the
sprinkler nozzle, and which permits the user to quickly and
easily change nozzle sizes to meet a wide variety of
operational conditions and der~n~. Further, the present
invention provides a brake mech~n;~m to control and optimize
the rate of spinner rotation while still permitting the user
to select from a very wide range of nozzle sizes and
capacities without loss of speed control.
More particularly, the spinner type sprinkler of the
present invention includes a sprinkler assembly mounted for
rotation about a generally vertical axis to a support bridge
adopted to be coupled to a pressurized source of water. The
spinner assembly includes a spinner body to which is coupled a
reaction drive nozzle assembly sPlectively movable between
preset trajectory angle positions whereby the water stream
from the nozzle assembly can be horizontally away from the
~ 21~8737
sprinkler a preselected angle relative to the vertical axis of
rotation. In this respect, the nozzle assembly includes a
generally L-shaped tubular elbow having a first end rotatably
coupled to the spinner body to project laterally therefrom)
and a second end to which a nozzle member is attached so as to
project a water stream in a direction generally tangent to the
axis of rotation. Detent means are provided between the
spinner body and the first end of the elbow, and which secure
to hold the elbow in preselected rotary positions for
trajectory angel controL. A lock collar is releasably secured
over the detent means to lock the elbow in a selected rotary
portion, and which is movable to an unlock position to permit
the detent means to be released and the elbow rotated relative
to the spinner body. Further, the nozzle member is releasably
coupled to the elbow by a bayonet-type connection which
permits the user to quickly and easily change the nozzle size,
thereby to increase the capacity and range of the sprinkler.
To control the speed of rotation of the spinner
assembly, a brake module is releasably coupled to the support
bridge and spinner body. The brake module operates on the
principle of viscous fluid shear, and different modules having
different braking capabilities can be easily mounted to the
sprinkler so that the effective operational range of nozzle
sizes and supply pressures are increased without loss of speed
control. The brake module includes a brake housing releasably
coupled to the support bridge above the spinner body, and
defines a cylindrical chamber within which a brake rotor and
viscous fluid are disposed. The brake rotor is releasably
coupled to the spinner body for rotation therewith. To change
the braking characteristics of the spinner, all that is
required is that the one brake module be released from the
bridge and spinner body, and another having different braking
characteristics be reattached in its place.
A still further feature of the present invention
relates to the support bridge construction which includes a
pair of upst~n~ing support posts extending between a lower
base portion and an upper bridge plate to which the brake
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~ 2t287~7
module is attached. The spinner assembly is rotatably mounted
between the brake module and the lower base portion of the
support bridge and rotates between the posts which are
impinged by the water stream from the nozzle member as the
nozzle assembly rotates. To minimize water stream disruption
and splashing, the support posts which have a generally
triangular horizontal cross section, are rotated so that the
radially inwardly converging sides terminate at an axis which
is formed along a plane tangent to the axis of rotation of the
spinner body. With this construction, water from the nozzle
member will be evenly split around the support posts with a
m; n; ~17m of splash and disruption.
These and many other features and advantages of the ,
present invention will become more apparent from the following
detailed description taken in conjunction with the
accompanying drawings which disclose, by way of example, the
principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGURE l is a fragmentary perspective view of a
spinner type irrigation sprinkler embodying the principles of
the present invention, and shown mounted for operation to a
water supply pipe;
FIGURE 2 is an enlarged side cross-sectional view
taken substantially along the line 2-2 of FIG. l;
FIGURE 3 is a further enlarged cross-sectional view
taken substantially along line 3-3 of FIG. 2;
FIGURE 4 is an enlarged cross-sectional view taken
substantially along line 4-4 of FIG. 3;
FIGURE 5 is a top plan view, partly in cut-away
cross-section of the spinner type irrigation sprinkler of FIG.
2, as viewed in the direction of line 5-5 of FIG. 2;
21287~7
--5--
FIGURE 6 is a fragmentary exploded perspective view
of the nozzle assembly of the spinner type irrigation
sprinkler of FIG. 2, and illustrating the connection between
the nozzle elbow and nozzle member;
FIGURE 7 is an enlarged fragmentary exploded
cross-sectional view of the brake module as seen in the circle
depicted by line 7-7 of FIG. 2;
FIGURE 7a is a cross-sectional view taken
substantially along line 7a-7a of FIG. 7; and
FIGURE 7b is a cross-sectional view taken
substantially along line 7b-7b of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
As shown in the exemplary drawings, the present
invention is embodied in a new and improved rotary sprinkler
10 of the ~spinner~ type primarily intended for use in
applying water to agricultural crops and orchards. In this
instance, the sprinkler 10 is shown coupled to the end of an
upst~n~;ng water supply riser 12 through which water from a
suitable pressurized source is provided, and comprises, in
general, a stationary support bridge 14 coupling the sprinkler
to the riser, a spinner assembly 16 including a reaction drive
rotary nozzle assembly 18 for projecting water outwardly from
the sprinkler as a water spray 20, and a brake assembly 22
(best seen in Figs. 2, 3, and 7) for limiting the rate of
rotation of the nozzle assembly. It should be noted that
although the sprinkler 10 is illustrated in Fig. 1 as being
disposed in an upright position on the riser 12, the sprinkler
can also be mounted in an inverted position, such as may be
required for use on a wheel-line or center-pivot type
irrigation system.
'
2128737
-6
With reference to Figs. 1 through 3, the bridge 14
herein comprises a lower tubular body portion 24 defining an
internal cylindrical water passageway 26 through which water
from the riser 12 is admitted to the sprinkler 10, and which
is provided with external threads 28 for threadably securing
the sprinkler to the riser. Herein, a hex-nut shaped flange
30 extends outwardly around the lower body portion 24 above
the threads 28, and is provided to facilitate tightening and
loosening of the threaded connection with the riser 12.
Disposed above the flange 30 is an inwardly stepped
cylindrical portion 32 defining an internal central
cylindrical cavity 34 and thereabove, a bearing and support
sleeve opening 36 which functions as a bearing and support for
the lower end of the spinner assembly 16. Projecting radially
outwardly from diametrically opposed sides of the lower body
portion 24 are a pair of horizontal support struts 38 which
terminate outwardly in upst~n~;ng vertical posts 40, the upper
ends of which are connected to a horizontally disposed
elongated support plate 42 to which the brake assembly 22 is
centrally attached. Preferably, the lower body portion 24,
struts 38, posts 40 and support plate 42 forming the bridge 14
are integrally formed as a single unit, such as by molding the
bridge from a suitable plastic material.
The spinner assembly 16 is rotatably mounted at its
lower end to the bridge 14, and at its upper end, the spinner
assembly is coupled to the brake assembly 22 so that the
spinner assembly is rotatable about a vertical axis extending
along the center line of the cylindrical water passageway 26
defined by the lower body portion 24 of the bridge 14. As
best seen in Fig. 3, the spinner assembly 16 includes a
spinner body 44, preferably formed of molded plastic,
comprising a tubular lower end portion 46 having an outside
diameter dimensioned to be rotatably received through the
bearing sleeve opening 36 in the lower body portion 24 of the
bridge 14, and which defines an internal water passage 48 for
receiving water from the riser 12. Extending above the lower
end portion 46 is an upwardly projecting main body portion 50
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2128737
--7
terminating at its upper end in an upstanding cylindrical
support pin 52 adapted to be coupled to the brake assembly
22. The internal water passage 48 is formed to extend
upwardly into the main body portion 50 to a point
approximately mid way between the upper and lower ends of the
posts 40 of the bridge 14, and then makes a substantially
right angle turn to project laterally of the spinner body 44.
Projecting outwardly in a lateral direction from the spinner
body 44 is a tubular mounting extension, generally designated
54, internally forming an extension of the water passage 48,
and which functions as a mounting for the reaction drive
rotary nozzle assembly 18.
To rotatably secure the spinner assembly 16 to the
lower body portion 24 of the bridge 14, the tubular lower end
portion 46 is dimensioned to project through the bearing
sleeve opening 36 into the interior of the lower body portion
24 of the bridge. Disposed in the central cavity 34 between
the lower body portion 24 of the bridge 14 and the lower end
portion 46 of the spinner body 44 is a cylindrical dynamic
seal member 56 which functions to seal the spinner assembly
against water leakage during operation. To retain the dynamic
seal 56 in the central cavity 34, a cup-shaped cylindrical
retainer 58 is press-fit within the passageway 26 of the lower
body portion 24 below the seal, and is provided with a central
opening 60 through which the bottom of the lower end portion
46 of the spinner body 44 projects. The central opening 60 is
enlarged relative to the outside dimension of the lower end
portion 46 to permit water from the riser 12 to flow
therebetween into the central cavity 34.
The dynamic seal member 56 herein is provided with a
pressure activated lip seal portion 62 disposed to engage the
outside of the lower end portion 46 of the spinner body 44,
and is defined by a downwardly and radially inwardly
projecting annular lip which, when water pressure is admitted
into the lower body portion 24 through the riser 12, is forced
by hydraulic pressure into sealing engagement with the lower
end portion of the spinner body, thereby to seal against the
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21~8737
--8--
leakage of water therebetween. In this connection, it should
be noted that due to the pressure actuation feature of the lip
seal portion 62 of the seal member 56, which preferably is
made of an elastomeric material, when pressurized water is
initially admitted to the sprinkler 10 and before full line
pressure is experienced, a small flow of water will pass
between the lip 58 and the lower end portion 46 of the spinner
body 44 so that any dirt or particulate material that may have
entered the annular space between the lower end portion and
the bearing sleeve opening 36 will be flushed upwardly out of
the annulus, thereby to prevent such dirt from jamming or
otherwise preventing the sprinkler from operating. To inhibit
dirt from entering the annulus between the bearing sleeve
opening 36 and the lower end portion 46, an enlarged radial
flange 64 having a downturned rim 66 is formed at the base of
the main body portion 50 of the spinner body 44, and is
dimensioned to overlie and shield the upper end of the stepped
cylindrical portion 32 of the bridge 14, as best can be seen
in Fig. 3.
In accordance with one important aspect of the
present invention, the reaction drive nozzle assembly 18 is
mounted to the spinner body 44 in such a manner that the
trajectory angle of the water spray 20 from the sprinkler 10
can be simply and easily selectively adjusted to meet a
variety of user needs. Further, the nozzle assembly 18
permits a user to quickly and easily change the size and
capacity of the sprinkler 10, even while the sprinkler is in
operation.
Toward the foregoing ends, the nozzle assembly 18
includes a nozzle elbow 68 which is coupled to the spinner
body 44 through the mounting extension 54 for quick and
reliable rotary adjustment, and which can be locked in pre-set
rotary positions corresponding to predetermined nozzle
trajectory angles, in this instance, angles of 24O, 16, 80
and -8 relative to a horizontal plane perpendicular to the
axis of rotation of the spinner assembly 16. The nozzle elbow
68 is tubular in form having an inlet end portion 70 and an
2128737
g
outlet end portion 72, and defines an internal water conduit
74 extending laterally from, and in axial alignment with the
portion of the water passage 48 defined internally of the
mounting extension 54, and which then bends to form a right
angle turn in a direction generally tangent to the axis of
rotation of the spinner assembly 16. Releasably coupled to
the outlet end portion 72 of the elbow 68 is a nozzle member
76. As a result of water flow through the conduit 74 of the
elbow 68 and the nozzle member 76, a reaction force tangent to
the axis of rotation of the spinner assembly 16 is created,
thereby to cause the spinner assembly and attached nozzle
assembly 18 to rotate and spin relative to the support bridge
14.
As best seen in Figs. 2 through 4, the inlet end
portion 70 of the elbow 68 is telescoped within the mounting
extension 54 which herein is formed as four cantilever
finger-like arcuate segments 78, 80, 82, and 84 projecting
laterally outwardly from the main body portion 50 of the
spinner body 44. Each of the finger segments 78, 80, 82, and
84 is formed at its outer end with an inwardly projecting lip
86 defining a rearwardly facing shoulder 88, and which is
adapted to abut a forwardly facing shoulder so formed by a
radially outwardly ext~n~;ng flange 92 formed
circumferentially around the inlet end portion 70 of the elbow
68, the position of the flange 92 on the elbow being selected
such that when the inlet end portion 70 of the elbow is
inserted into the mounting extension 54, the rearwardly facing
shoulder 88 will snap-fit against the forwardly facing
shoulder 9o and hold the inlet end of the elbow firmly against
the inside wall of the water passage 48 adjacent its juncture
with the main spinner body 44, thereby to provide a fluid seal
to restrict water from escaping between the elbow and mounting
extension. With this construction, the elbow 68 can be
rotated within the mounting extension 54 to control the
trajectory angle of the spray ejected from the nozzle member
76.
2128737
--10--
Circumferentially surrounding the mounting extension
54 is a locking collar 94 provided for releasably locking the
elbow 68 in a selected rotary position. The locking collar 94
is slidably mounted around the mounting extension 54 for
movement between a forward lock position, shown by the solid
line position of Fig. 3, and a rearward unlock position,
represented by the broken line position of Fig. 3. In the
solid line lock position, the collar 94 prevents the finger
segments 78, 80, 82, and 84 from radially expanding, while in
the unlock, broken line position, the collar will allow the
finger segments to undergo limited radial expansion.
As shown in Fig. 4, formed around the outer periphery
of the flange 92 around the elbow 68, are two sets of multiple
recesses 96, herein having a generally V-shaped cross section
formed on diametrically opposed sides of the flange, and which
are adapted to be engaged by a pair of radially inwardly
projecting teeth-like tabs 100 formed along the inside of the
elbow, one tab being herein formed on the finger segment
designated 80 and the other on finger segment 84. Engagement
of the tabs 100 in the recesses 96 serves as a detent means to
locate and hold the elbow 68 in a selected rotary position
relative to the mounting extension 54. To adjust the angle of
the elbow 68, the locking collar 94 is moved rearwardly to the
broken line position shown in Fig. 3, and the elbow is
rotated, thereby causing the finger segments 80 and 84
carrying the tabs 100 to radially deflect and ~p~n~ as the
tabs snap from one recess to another. Once the desired angle
of the elbow 68 has been reached, the lock collar 94 can be
moved to the solid line position of Fig. 3 overlying the
flange 92, thereby to prevent the tabs 100 from moving out of
engagement within the selected recesses 96 by preventing the
finger segments 80 and 84 from expanding in a radial
direction.
As earlier noted, in this instance the elbow 68 is
formed to be selectively adjustable for angles of inclination
of 24, 16, 8 and -8 relative to the horizontal. This is
achieved by selecting the location and number of recesses 96
21287~7
--11--
of each set such that when the tabs 100 are received therein,
the elbow will be inclined at the appropriate angle. It has
been found that an angle of approximately 24 is generally
suitable when the sprinkler lo is to be used for spraying
water over the tops of the trees in an orchard, such as for
cooling the trees, while an angle of approximately 8 is
particularly suitable for use in applying irrigating water
below the tree canopy or in high wind conditions. The
provision of a 16 angle is generally considered a good
all-around angle of inclination for general purpose
irrigation. Provision of a -8 angle (the condition
illustrated in Fig. 2~ is useful for situations when the
sprinkler 10 is to be mounted in an inverted position, such as
on a wheel-line or center-pivot type irrigation system. Thus,
by allowing the nozzle elbow 68 to be adjusted for different
spray angles, the useful applications for the sprinkler 10 of
the present invention are significantly increased and
~nh~n~, In this regard, it should be apparent that a wide
variety of other spray angle adjustments can be provided
simply by adding or changing the number and location of the
sets of recesses 96.
Moreover, the nozzle member 76 is releasably coupled
to the elbow 68 in such a manner that it can be quickly and
easily changed to permit a user to readily alter the
irrigation characteristics of the sprinkler 10 to meet varying
demands. Toward this end, the nozzle member 76 herein
comprises a generally tubular body 77 having a converging
nozzle outlet passage 79, and is secured to the outlet end 72
of the elbow 68 through a bayonet-type coupling 102, herein
comprising a pair of radial ears 104 formed around the elbow
which are friction fit into corresponding key-way type
recesses 106 formed on the nozzle body, as best seen in Fig.
6. The ears 104 herein are wedge shaped and include a small
detent 108 in their rearwardly facing wall. The key-way
recesses 106 of the nozzle member 76 include a pair of
diametrically opposed and enlarged arcuate openings 110 which
are adapted to receive the ears 104 on the elbow 68, and
2128737
-12-
intermediate wall portions 112 against which the wedge shaped
ears engage when the nozzle member is rotated relative to the
elbow. A pair of forwardly projecting nipples 114 are formed
on the intermediate wall portions 112 which are adapted to
snap-fit into the detents 108 on the ears 104 of the elbow 68,
thereby to frictionally lock the nozzle member 76 in place on
the elbow. To facilitate attachment to and removal of the
nozzle member 76 from the elbow 68, the nozzle member is
provided with enlarged radially projecting wings 116 which can
be easily grasped to rotate the nozzle member relative to the
elbow. Thus, provision of the bayonet-type coupling 102
permits a user to ~uic~ly and easily change the flow rate and
capacity of the sprinkler 10 simply by removing one nozzle
member 76 and replacing it with another, thereby further
increasing and enhancing the usefulness and versatility of the
sprinkler.
At this juncture, it should be noted that the
reaction force causing rotation of the spinner assembly 16 is
a function of the pressure of the water supplied to the
sprinkler 10 and the size and capacity of the nozzle member 76
coupled to the elbow 68, the larger the supply pressure and/or
the larger the nozzle size, the greater the reaction force
created, and hence, the greater the rotational speed of the
spinner assembly. It has been found that for r~ um distance
of water throw from the sprinkler 10, the rate of rotation of
the spinner assembly 16 should ideally be maintained at a
relatively low level, preferably on the order of about 10 rpm
over the entire range of working supply pressures, typically
from 25 to 50 psi, and nozzle sizes, typically from 0.3 to 2.5
gpm. In accordance with another important aspect of the
present invention, the brake assembly 22 of the sprinkler 10
is capable of substantially slowing and controlling the rate
of rotation of the spinner assembly 16 such that substantially
maximum distance of throw is achieved over the entire range of
typical supply pressures and nozzle sizes.
2I2873 7
-13-
Toward the foregoing end, the upper end portion of
the support pin 52 of the spinner body 44 is drivingly coupled
to the brake assembly 22 which employs the principle of
viscous shear to restrict and control the rate of rotation of
the spinner assembly 16. Moreover, the brake assembly 22 is
formed as a self-contained module which is releasably and
removably attached to the support bridge 14 so that different
modules having different braking characteristics can be
selectively used for various nozzle sizes and/or supply
pressures to achieve the desired rotation speed of the spinner
assembly 16.
As best seen in Figs. 1 through 4, the brake assembly
22 herein includes a main housing member 118 defining a
central cylindrical chamber 120 within which is contained a
viscous fluid 122 and a rotatable brake rotor 124. The
support pin 52 of the spinner body 44 projects into the
chamber 120 and is drivingly coupled to the brake rotor 124 so
that as the spinner assembly 16 rotates, the brake rotor is
rotated through the viscous fluid 122 which acts through
viscous frictional shear to retard the rate of rotation of the
spinner assembly.
In this instance, the housing member 118 of the brake
assembly 22 is formed to have an upper or top generally
elongated plate shaped portion 126 adapted to be releasably
attached to the support bridge 14 by two downwardly projecting
cantilever tabs 128 having out turned flanges 130 on their
ends which snap-fit through cooperatively formed openings 132
in the support plate portion 42 of the bridge. Disposed
radially inwardly of the tabs 128 is a first downwardly
directed cylindrical flange 134 which is dimensioned to be
snugly received within a cylindrical hole 136 formed centrally
through the support plate portion 42 of the bridge 14, and
which serves to locate and hold the brake housing 118
centered to the bridge.
The central chamber 120 of the brake assembly 22 is
defined by a second downwardly directed cylindrical flange or
wall 138 concentric with the first flange 134, and has an open
.. . ~128~37
-14-
lower end 140 to which is frictionally coupled an end cap 142
having a central aperture 144 therethrough for receiving the
support pin 52. The end cap 142 herein has a peripheral
lateral flange 146 adapted to overlie and abut the lower end
140 of the cylindrical wall 138, and an upwardly projecting
skirt 148 dimensioned to be frictionally fit against the
inside surface of the cylindrical wall, a small annular bead
150 being herein provided above the lateral flange 146 around
the skirt 148 and which is adapted to be received in a
corresponding annular recess 152 formed around the inside of
the cylindrical wall to secure the cap to the housing 118. A
cylindrical packing seal 154 is disposed radially inwardly of
the skirt 148 to form a fluid tight seal around the support
pin 52 when the brake assembly 22 is in operation, and a
disc-shaped bearing 156 is disposed between the seal and the
lower end of the rotor 124 to promote free rotation.
The brake rotor 124 is rotatably disposed within the
chamber 120 of the brake assembly 22, and herein is formed as
a pair of spaced concentric cylindrical sleeves 158 and 160,
the outer sleeve 158 being integrally attached to the inner
sleeve 160 by a series of arcuately spaced radial webs 162,
herein four equally spaced webs, extending adjacent the
bottoms of the cylindrical sleeves. Spaces formed between the
webs 162 permit the viscous fluid 122 within the chamber 120
to circulate between the inner and outer cylindrical sleeves
158 and 160. Projecting downwardly from the housing 118
radially inwardly of the second wall 138 is a third
cylindrical flange 164 which extends into the annular space
between the inner and outer cylindrical sleeves 158 and 160 of
the brake rotor 124 to provide, in addition to the inside
surface of the second cylindrical wall defining the chamber
120, stationary surfaces adjacent the rotating surfaces of the
rotor for producing a shearing action in the viscous fluid
122. Preferably, the various components of the brake assembly
22 are formed of molded plastic, with the exception of the
packing seal 154 which is preferably formed of an elastomeric
material. Notably, although the brake rotor 124 herein is
shown as formed of plastic, other materials, such as metal,
~ 2l28737
--15--
can be used, and the rotor can take other shapes, such as a
solid cylinder or a series of vertically spaced horizontal
disks.
To drivingly couple the support pin 52 of the spinner
body 44 to the brake rotor 124, the inside surface of the
inner cylindrical sleeve 160 is formed with a central,
generally cylindrical opening 166 having diametrically opposed
longitl~;n~lly extending flats 168 formed along the length,
and which cooperate with corresponding flat surfaces 170
formed along the upper portion of the support pin, the opening
and flats being ~i~e~ioned to frictionally receive the
support pin thereby to couple the pin to the rotor and prevent
the support pin from rotating relative to the brake rotor.
Viscous shearing action created by the brake rotor 124 turning
within the viscous fluid 122 is transmitted through the drive
connection with the support pin 54 to the spinner body 44 to
produce a retarding force slowing the rate of rotation of the
spinner assembly 16.
The viscous fluid 122 disposed within the chamber 120
can be of any suitable type for producing the desired viscous
shear retarding action, and it has been found that a methyl
silicone material marketed by William F. Nye of New Bedford,
Massachusetts having a viscosity rating of 600,000 centi stoke
is particularly well suited for general applications, although
viscosity ranges of between 100,000 and lo million centi stoke
may also be satisfactory, depending upon the effective braking
area of the brake rotor 124, and the supply pressures and
nozzle sizes used, the larger the brake area and/or the lower
the supply pressure and smaller the nozzle size, the lower the
viscosity level required. By way of example, it has been
found that with a supply pressure range between 25 psi and 50
psi, using the foregoing 600,000 centi stoke viscous fluid 122
in the chamber 54 produced a rotational speed of between 3 rpm
and 17 rpm with nozzle sizes in the range of between 0.3 gpm
and 1.5 gpm. By increasing the viscosity of the viscous fluid
122, similar rotational speeds can be achieved for higher
pressures and larger nozzle sizes. Notably, without the brake
2128737
-16-
assembly 22 used in the foregoing example, it was found that
the rotational speed of the spinner assembly 16 would be
between approximately 2000 rpm and 3000 rpm, and the distance
of water throw from the sprinkler would be reduced by
approximately fifty percent over that achieved with the brake
assembly coupled with the spinner body 44.
It should be noted that due to the high viscosity of
the fluid 122 within the chamber 120, the foregoing structure
alone has been found to be sufficiently fluid tight to prevent
significant leakage of viscous fluid from the chamber. It
should be readily apparent, however, that should leakage
occur, such as when the sprinkler 10 has not been in use for
prolonged periods, further seals can be added to prevent
leakage, such as by the addition of a packing seal, for
example an 0-ring seal, positioned between the upper end of
the inner sleeve 160 and the portion of the housing 118
forming the closed end of the chamber 120.
As previously indicated, one advantage of the brake
assembly 22 of the present invention is that it is formed as a
removable module enabling a user to select different braking
capabilities to suit the particular supply pressure range
and/or nozzle size range to be used. Thus, for very large
supply pressures and/or large nozzle sizes, the brake assembly
22 can be altered by increasing the diameter of the second
cylindrical wall 138 forming the chamber 120, thereby to
increase the size of the chamber, and increasing the size and
surface area of the brake rotor 124, for example by adding a
third concentric cylindrical brake sleeve. Since such a size
change does not affect the attachment of the brake assembly
housing 118 to the support plate 42 of the bridge 14, nor the
connection of the support pin 52 of the spinner assembly 16 to
the brake assembly, different brake assemblies can be readily
substituted to meet varying d~n~ simply by releasing the
tabs 128 of one brake assembly from engagement with the
support plate 42, removing the brake assembly upwardly from
the bridge 14 to slide the support pin 52 out of engagement
with the rotor 124, and then inserting the new brake assembly
module in its place.
21~737
-17-
In accordance with a still further feature of the
present invention, the vertical posts 40 of the support bridge
14 are constructed to reduce interference with the water spray
20 from the rotating nozzle 76, thereby to increase sprinkler
effectiveness by reducing the stream brake-up and close-in
water fall out typically found in spinner type sprinklers.
Toward this end, the posts 40 are formed to have a generally
triangular or wedge-shaped horizontal cross section, best seen
in Fig. 5, but unlike conventional spinner posts, the
diverging surfaces are formed to extend from an apex,
designated 172, which is aligned with the direction of the
water spray 20 exiting the nozzle 76.
More particularly, unlike conventional support bridge
posts such as shown, for example, in United States Patent Nos.
Des.259,438 and 4,660,766 which have wedge-shaped cross
sections with the radially inner apex of the posts directed
toward the axis of nozzle rotation, the posts 40 of the
present invention are rotated so that the side walls 174 of
each post converge inwardly to one apex 172 defining a
vertical plane which extends in a direction tangent to the
axis of rotation of the nozzle 76, and which extends through
the nozzle outlet when the outlet is pointing in the direction
of the posts. With this construction, the water spray 20 from
the nozzle 76 will be smoothly split around the posts 40 over
the side walls 174 with a ;n; um of water splash and
disruption, thereby minimizing stream break-up and early water
fall out and r~ ing the distance of water throw from the
sprinkler 10.
From the foregoing, it should be apparent that the
present invention provides a sprinkler 10 which is very
versatile and capable of meeting a wide variety of user
demands. In this respect, the brake assembly 22 insures that
the spinner assembly 16 will rotate at a very low speed to
maximize distance of throw, and is adaptable to a wider range
of nozzle sizes and supply pressures.
It has been found that use of the brake assembly 22
can increase the distance of water throw from the sprinkler 10
2128737
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by as much as fifty percent over similar sprinklers without
such brakes, and that the useful life of the sprinkler is
substantially increased due to a reduction in bearing wear.
Moreover, the nozzle assambly 18 permits the rapid
and easy adjustment of nozzle trajectory as well as nozzle
size changes, thereby to increase the capacity and uses to
which the sprinkler 10 can be put. It has also been found
that the use of a rotating nozzle construction like that of
the present invention will provide as much as a twenty percent
increase in the distance of water throw as compared with prior
art spinner type sprinklers employing a fixed nozzle which
ejects a stream vertically for interception and lateral
deflection by a rotating horizontal deflector.
While a particular form of the present invention has
been illustrated and described, it will be apparent that
changes and modifications therein can be made without
departing from the spirit and scope of the invention as
defined by the following claims.
