U.S. patent number RE33,823 [Application Number 07/343,815] was granted by the patent office on 1992-02-18 for rotary sprinkler head.
This patent grant is currently assigned to Nelson Irrigation Corporation. Invention is credited to Larry P. Meyer, Barton R. Nelson, George L. Sesser.
United States Patent |
RE33,823 |
Nelson , et al. |
February 18, 1992 |
Rotary sprinkler head
Abstract
A rotary sprinkler head comprising a sprinkler body devoid of
any operative dynamic seals for communicating a source of water
under pressure with an outlet for directing water under pressure
communicated therewith into an atmospheric condition in a primary
stream having a generally vertically extending axis. A rotary
distributor is provided which has surfaces for engaging the primary
stream (1) to establish a reactionary force component acting on the
distributor in a direction tangential to the rotational axis
thereof so as to effect rotational movement thereof about its axis
of rotation and (2) to direct the primary stream engaged thereby in
the form of a pattern forming stream or streams including at least
one stream moving away from the distributor in a direction having a
substantial component extending outwardly from the generally
vertical axis of the primary stream so as to define the radius of
the circular spray pattern. A speed reducing assembly is
operatively associated with the distributor for reducing the
rotational speed of the distributor resulting from the reactionary
force component from a relatively high whirling speed which would
occur without the speed reducing assembly to a relatively slow
speed.
Inventors: |
Nelson; Barton R. (Walla Walla,
WA), Meyer; Larry P. (Walla Walla, WA), Sesser; George
L. (Walla Walla, WA) |
Assignee: |
Nelson Irrigation Corporation
(Walla Walla, WA)
|
Family
ID: |
26993643 |
Appl.
No.: |
07/343,815 |
Filed: |
April 24, 1989 |
Related U.S. Patent Documents
|
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
Reissue of: |
777411 |
Sep 18, 1985 |
04660766 |
Apr 28, 1987 |
|
|
Current U.S.
Class: |
239/222.17;
239/252; 239/264; 239/381; 239/522 |
Current CPC
Class: |
B05B
3/0486 (20130101); B05B 3/005 (20130101) |
Current International
Class: |
B05B
3/04 (20060101); B05B 3/02 (20060101); B05B
3/00 (20060101); B05B 003/04 () |
Field of
Search: |
;239/222.11,222.17,224,231,232,256,264,380,381,500,501,522,252 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
|
|
|
|
|
|
|
48682 |
|
Jul 1971 |
|
AU |
|
403351 |
|
Jan 1923 |
|
DE2 |
|
1632916 |
|
Aug 1970 |
|
DE |
|
1321580 |
|
Jun 1963 |
|
FR |
|
2019704 |
|
Feb 1979 |
|
GB |
|
Other References
Rain Bird "CPR-RSN: The Low Pressure Spry with the Rotating
Deflector and Slip-Fit EZ Change Nozzles", 1984. .
Agrifim Irrigation Inc. "Agri-Jets", 1981. .
Dan Sprinklers "Reguated Sprinklers and Irrigation Equipment".
.
James Hardie Irrigation Technical Manual, 1984. .
Solcoor Inc. Irrigation Division, 1984. .
RIS Irrigation Systems Micro-Sprinkler. .
NIFCO Inc., Oil Dampers, specification..
|
Primary Examiner: Kashnikow; Andres
Assistant Examiner: Grant; William
Attorney, Agent or Firm: Nixon & Vanderhye
Claims
What is claimed is:
1. A rotary sprinkler head comprising:
a sprinkler body having an outlet and means devoid of any operative
dynamic seals for communicating a source of water under pressure
with said outlet,
said outlet being defined by surface means for directing water
under pressure communicated therewith into an atmospheric condition
in a primary stream having a generally vertically extending
axis,
a rotary distributor mounted for rotational movement about a
rotational axis with respect to said sprinkler body in engaging
relation with respect to the primary stream directed from said
outlet,
said rotary distributor having surface means for engaging the
primary stream (1) to establish a reactionary force component
acting on said distributor in a direction tangential to the
rotational axis thereof so as to effect rotational movement thereof
about said axis of rotation and (2) to direct the primary stream
engaged thereby in the form of pattern forming stream means
including at least one stream moving away from said distributor in
a direction having a substantial component extending radially
outwardly from the generally vertical axis of said primary
stream,
speed reducing means operatively associated with said distributor
for reducing the rotational speed of the distributor resulting from
said reactionary force component from a relatively high whirling
speed which would occur without said speed reducing means to a
relatively slow speed so related to the distributor surface means
forming the pattern forming stream means as to permit (1) said one
stream to leave said distributor surface means with sufficient
stream integrity to flow outwardly a distance substantially as
great as the same said one stream would flow if the distributor
were held stationary and (2) all of the pattern forming stream
means including said one stream to be distributed within a
generally circular pattern with a desired droplet size and with a
desired water distribution within said generally circular pattern,
the radius of said generally circular pattern being defined by the
maximum extent of flow of said one stream.
2. A rotary sprinkler head as defined in claim 1 wherein the
direction said one stream moves away from said distributor includes
an upward component.
3. A rotary sprinkler head as defined in claim 1 wherein said one
stream comprises the entire pattern forming stream means.
4. A rotary sprinkler head as defined in claim 1 wherein said
pattern forming stream means includes a second stream moving away
from said distributor in a direction having a component extending
radially outwardly from the fixed axis of said primary stream.
5. A rotary sprinkler head as defined in claim 4 wherein said
second stream is generally equal in size in comparison with said
one stream and moves away from said distributor in a direction
having a component extending radially outwardly from the fixed axis
of said primary stream which is equal to and diametrically opposed
to the component extending radially outwardly from the axis of the
primary stream in the direction said one stream moves away from
said distributor.
6. A rotary sprinkler head as defined in claim 1 wherein said
pattern forming stream means is distributed substantially
throughout the entire area of said generally circular pattern.
7. A rotary sprinkler head as defined in claim 6 wherein the
distribution of the pattern forming stream means substantially
throughout the entire area of said generally circular pattern is
such that generally more water is distributed within a peripheral
area adjacent the outer periphery of the circular pattern than
within the inner center area thereof.
8. A rotary sprinkler head as defined in claim 6 wherein the
distribution of the pattern forming stream means substantially
throughout the entire area of said generally circular pattern is
generally uniform throughout.
9. A rotary sprinkler head as defined in claim 1 wherein said speed
reducing means comprises housing means fixed with respect to said
sprinkler body having interior surfaces defining a chamber having a
body of viscous fluid therein, said rotary distributor being
fixedly mounted on a mounting shaft, said housing means carrying a
bearing, said mounting shaft extending through said bearing in
journaled relation therewith and into said chamber, a viscous fluid
engaging member fixed on said shaft within said chamber and so
related to the interior surfaces defining said chamber that viscous
shearing of the viscous fluid takes place during rotation of said
rotary distributor sufficient to effect the desired speed
reduction.
10. A rotary sprinkler head as defined in claim 9 wherein said
viscous fluid engaging member is of annular disk-like
configuration.
11. A rotary sprinkler head as defined in claim 9 wherein said
viscous fluid engaging member is of generally cylindrical
configuration.
12. A rotary sprinkler head as defined in claim 9 wherein said
bearing is a sleeve bearing and has an annular seal on the
outwardly extending end thereof engaging the rotary distributor
shaft.
13. A rotary sprinkler head as defined in claim 9 wherein said
viscous fluid fills said chamber.
14. A rotary sprinkler head as defined in claim 9 wherein said
viscous fluid fills only a portion of said chamber within which
said viscous fluid engaging member is situated, the portion of said
shaft initially communicating with said chamber being spaced from
said viscous fluid when said sprinkler head is oriented in an
operative position or in any other stored orientation thereof.
15. A rotary sprinkler head as defined in claim 14 wherein said
rotary sprinkler head is capable of being operated in the aforesaid
operating position and alternatively in a second operating position
inverted with respect to said first mentioned operating position,
said chamber having a second portion which said viscous fluid fills
when said sprinkler head is in said second operating position, said
viscous fluid engaging member having a first portion engaging said
viscous fluid when the latter fills said first mentioned chamber
portion and a spaced second portion which engages said viscous
fluid when the latter fills said second chamber portion.
16. A rotary sprinkler head as defined in claim 15 wherein each of
said chamber portions are defined by inner and outer cylindrical
wall portions closed at one end by an annular wall which is
oriented at the bottom ends of the cylindrical wall portions when
the associated chamber portion is filled with viscous fluid.
17. A rotary sprinkler head as defined in claim 16 wherein means is
provided for varying the relative positions of the interior
surfaces which effect the viscous shearing defining said chamber
and the surfaces of said viscous fluid engaging member which effect
the viscous shearing so as to vary the amount of viscous shearing
of the viscous fluid that takes place during rotation of said
rotary distributor so as to vary the extent of speed reduction.
18. A rotary sprinkler head as defined in claim 17 wherein said
relative positions varying means includes means for manually
effecting the variation.
19. A rotary sprinkler head as defined in claim 17 wherein said
housing means includes a movable housing part threadedly engaged on
a fixed housing part, said relative position varying means
comprising interior viscous fluid shearing surfaces on said movable
housing part.
20. A rotary sprinkler head as defined in claim 17 wherein said
viscous fluid engaging member is splined to said mounting shaft and
said relative position varying means comprises means for moving
said viscous fluid engaging member along its splined connection
with said shaft.
21. A rotary sprinkler head as defined in claim 20 wherein said
interior viscous fluid shearing surfaces are provided on rings made
of metal, said viscous fluid engaging member being made of plastic
so as to vary the spacing between the cooperative fluid shearing
surfaces in accordance with variations in viscosity of the viscous
fluid due to temperature variations so as to maintain a
substantially constant revolutionary speed of said rotary
distributor.
22. A rotary sprinkler head as defined in claim 17 wherein said
relative position varying means includes sensing means for sensing
a change in condition resulting from a change in the pressure of
the water source and means for effecting the variation of said
relative position varying means in accordance with the change in
condition sensed so as to maintain a generally constant reduced
speed of said rotary distributor throughout a range of pressure
changes in the water source.
23. A rotary sprinkler head as defined in claim 22 wherein said
condition sensed is the axial reactionary force component on said
rotary distributor as a result of the engagement of the primary
stream with the surface means thereof.
24. A rotary sprinkler head as defined in claim 23 wherein said
sensing means comprises a spring connected to said mounting shaft
so as to resiliently urge the same toward a limiting position in a
direction opposed to the direction of the primary stream while
yielding to allow axial movement of the mounting shaft in the
opposite direction.
25. A rotary sprinkler head as defined in claim 9 wherein means is
provided for varying the relative positions of the interior
surfaces which effect the viscous shearing defining said chamber
and the surfaces of said viscous fluid engaging member which effect
the viscous shearing so as to vary the amount of viscous shearing
of the viscous fluid that takes place during rotation of said
rotary distributor so as to vary the extent of speed reduction.
26. A rotary sprinkler head as defined in claim 25 wherein said
relative positions varying means includes means for manually
effecting the variation.
27. A rotary sprinkler head as defined in claim 25 wherein said
housing means includes a movable housing part threadedly engaged on
a fixed housing part, said relative position varying means
comprising interior viscous fluid shearing surfaces on said movable
housing part.
28. A rotary sprinkler head as defined in claim 25 wherein said
viscous fluid engaging member is splined to said mounting shaft and
said relative position varying means comprises means for moving
said viscous fluid engaging member along its splined connection
with said shaft.
29. A rotary sprinkler head as defined in claim 9 wherein said
interior viscous fluid shearing surfaces are provided on rings made
of a first material, said viscous fluid engaging member being made
of a second material, said first and second materials having
differing coefficients of thermal expansion so as to vary the
spacing between the cooperative fluid shearing surfaces in
accordance with variations in viscosity of the viscous fluid due to
temperature variations so as to maintain a substantially constant
revolutionary speed of said rotary distributor.
30. A rotary sprinkler head as defined in claim 25 wherein said
relative position varying means includes sensing means for sensing
a change in condition in the primary stream and means for effecting
the variation of said relative position varying means in accordance
with the change in condition sensed so as to maintain a generally
constant reduced speed of said rotary distributor.
31. A rotary sprinkler head as defined in claim 30 wherein said
condition sensed is the axial reactionary force component on said
rotary distributor as a result of the engagement of the primary
stream with the surface means thereof.
32. A rotary sprinkler head as defined in claim 31 wherein said
sensing means comprises a spring connected to said mounting shaft
so as to resiliently urge the same toward a limiting position in a
direction opposed to the direction of the primary stream while
yielding to allow axial movement of the mounting shaft in the
opposite direction.
33. A rotary sprinkler head as defined in claim 1 wherein said
sprinkler body is formed with a tubular inlet portion coaxially
adjacent said outlet, said outlet being tubular and having arm
portions extending outwardly therefrom at diametrically opposed
positions, strut portions extending generally vertically from the
outer ends of said arm portions, a pair of connecting portions
extending inwardly from the ends of said strut portions and a
tubular mounting portion fixed to said connecting portions, said
speed reducing means including housing means having a sleeve
portion fixedly engagable with the tubular mounting portion of said
sprinkler body.
34. A rotary sprinkler head as defined in claim 33 wherein said
sleeve portion is slit to form an integral resilient locking
element having an enlarged head formed with a cam surface for
engaging said tubular mounting portion and a locking surface for
engaging within a recess in said tubular mounting portion.
35. A rotary sprinkler head as defined in claim 1 wherein said
sprinkler body is formed with a tubular inlet portion coaxially
adjacent said outlet, said outlet being tubular, an annular member
journaled in surrounding relation with said tubular outlet, and
means extending axially outwardly with respect to said annular
member for fixedly connecting said rotary distributor thereto.
36. A rotary sprinkler head as defined in claim 1 wherein means is
provided for sensing a change in condition resulting from a change
in the pressure of the water source, and means for varying the
speed reducing means in accordance with the change in condition
sensed so as to maintain a generally constant reduced speed
throughout a range of pressure changes in the water source.
37. A rotary sprinkler head as defined in claim 1 wherein said
whirling speed is of the order of 1800 r.p.m. and said reduced
speed is within the range of from 1/4 r.p.m. to 12 r.p.m.
38. A rotary sprinkler head as defined in claim 1 wherein said one
stream is formed by stepped surfaces establishing portions of said
one stream which have different directional components so as to
cause said different portions to fall out differently.
39. A rotary sprinkler head as defined in claim 1 wherein means is
provided for sensing a change in condition in the primary stream
and means for varying the speed reducing means in accordance with
the change in condition sensed so as to maintain a generally
constant speed of said rotary distributor. .Iadd.
40. A rotary sprinkler comprising:
a body portion having an inlet for receiving water under pressure
and an outlet for discharging a stream of water to atmosphere;
a distributor rotatable relative to said body portion and supported
at one end of a shaft mounted for rotation within a bearing, said
distributor having at least one surface for engaging the stream
discharged from said outlet such that upon engagement with said
stream, said distributor is caused to rotate; and
a brake assembly for reducing rotational speed of said distributor,
said brake assembly including a brake element mounted for rotation
on said shaft remote from said one end, such that said bearing is
located intermediate said distributor and said brake element.
.Iaddend. .Iadd.41. A rotary sprinkler according to claim 40
wherein said bearing is mounted in said brake assembly and wherein
said brake assembly includes a tubular support carried by said body
portion, said brake assembly further including a chamber receiving
said brake element for rotation therein.
.Iaddend. .Iadd.42. A rotary sprinkler according to claim 41
wherein said chamber is substantially filled with a viscous fluid.
.Iaddend. .Iadd.43. A rotary sprinkler according to claim 42
wherein said chamber is at least partially defined by a peripheral
wall, and wherein said brake element includes a fluid engaging
member in close proximity to said peripheral wall to effect
shearing of said viscous fluid upon rotation of said brake element.
.Iaddend. .Iadd.44. A rotary sprinkler assembly according to claim
40 wherein said distributor comprises an annular member, and
wherein said at least one surface comprises at least one groove
having an inlet end substantially coaxially aligned with and
vertically spaced from said sprinkler body portion outlet and
extending along a vertically and horizontally curved path to an
exit end located outwardly of said inlet end, thereby causing said
distributor to rotate upon passage of fluid therethrough. .Iaddend.
.Iadd.45. A rotary sprinkler assembly according to claim 44 wherein
said groove has a relatively narrow surface configuration extending
along at least a part of the groove, said narrow surface
configuration having a curvature different from the curvature of
the
groove. .Iaddend. .Iadd.46. A rotary sprinkler comprising:
a sprinkler body having an inlet and an outlet, said outlet
mounting a removable outlet nozzle;
a distributor supported at one end of a rotatable shaft and axially
spaced from said outlet nozzle, said distributor having at least
one surface for engaging a liquid stream discharged from said
outlet nozzle, and for causing the distributor to rotate, said
shaft mounted for rotation in a bearing supported in a brake
assembly housing, said housing including a chamber substantially
filled with a viscous fluid; and
a brake element secured to the other end of said shaft and located
within said chamber to dampen rotation of said shaft and said
distributor.
.Iaddend. .Iadd.47. A rotary sprinkler as defined in claim 46
wherein said brake assembly housing is mounted within a support
member carried by said sprinkler body. .Iaddend. .Iadd.48. A rotary
sprinkler as defined in claim 47 and further including a dynamic
seal associated with said bearing and engaging said shaft.
.Iaddend. .Iadd.49. A rotary sprinkler as defined in claim 46
wherein said brake assembly and said brake element are effective to
reduce rotational speed of the distributor from an unbraked turning
speed of about 1800 r.p.m. to a braked turning speed of about 1/4
to about 12 r.p.m. .Iadd.50. A rotary sprinkler as defined in claim
46 wherein said brake assembly and said brake element are effective
to maintain sprinkling pattern area radius at about 89% of
sprinkling pattern
area radius of said distributor held stationary. .Iaddend.
.Iadd.51. A rotary sprinkler head comprising:
a non-rotational sprinkler body including an inlet and an outlet,
said outlet including a nozzle for discharging a fluid stream under
pressure to atmosphere;
a rotatable distributor supported by said sprinkler body and
axially spaced downstream from said nozzle, said distributor
aligned with said outlet and including surface means for receiving
and deflecting said stream, said surface means configured to cause
rotation of said distributor upon receiving said stream; and
braking means for reducing rotational speed of said distributor by
a factor of between about 150 and about 7000, wherein said
distributor is mounted on one end of a shaft, the other end of the
shaft received within said braking means. .Iaddend. .Iadd.52. A
rotary sprinkler head as defined in claim 51 wherein said braking
means comprises a brake assembly housing, said shaft being
journalled in a bearing located within said brake assembly housing;
a brake element mounted on said other end of said shaft and
disposed within a chamber provided in said housing, said chamber
being
substantially filled with viscous fluid. .Iaddend. .Iadd.53. A
rotary sprinkler head as defined in claim 52 wherein said chamber
is at least partially defined by a peripheral wall, and wherein
said brake element includes a fluid engaging member in close
proximity to said peripheral wall to effect shearing of said
viscous fluid upon rotation of said brake element. .Iaddend.
.Iadd.54. A rotary sprinkler head as defined in claim 52 wherein
said braking means is operative when said sprinkler head is in
either of at least two positions, one of which is inverted with
respect to
the other. .Iaddend. .Iadd.55. A rotary sprinkler head
comprising:
a non-rotational sprinkler body including an inlet and an outlet,
said outlet including a nozzle for discharging a stream under
pressure to atmosphere;
a rotatable distributor supported by said sprinkler body and
axially spaced downstream from said nozzle, said distributor
including at least one surface at one end thereof for receiving and
deflecting said stream, said surface configured to cause rotation
of said distributor upon receiving said stream; and
braking means for reducing rotational speed of said distributor
from about 1800 r.p.m. to between about 1/4 and about 12
r.p.m.;
wherein said distributor is mounted on one end of a shaft, the
other end of
said shaft received within said braking means. .Iaddend. .Iadd.56.
A rotary sprinkler head as defined in claim 55 wherein said braking
means is operative when said sprinkler head is in either of at
least two positions, one of which is inverted with respect to the
other. .Iaddend. .Iadd.57. A rotary sprinkler head as defined in
claim 55 wherein said other end of said shaft is journalled within
a bearing within said braking means. .Iaddend. .Iadd.58. A rotary
sprinkler head as defined in claim 57 wherein said braking means
includes a housing supported by said sprinkler body such that said
distributor, said shaft and said bearing are in axially spaced
alignment with said nozzle. .Iaddend. .Iadd.59. A rotary sprinkler
comprising:
a sprinkler body having an inlet and an outlet for discharging a
stream to atmosphere;
a distributor supported at one end of a rotatable shaft and spaced
from said outlet, said shaft mounted for rotation within a bearing,
said distributor having at least one surface for engaging a stream
discharged from said outlet;
a brake element for reducing rotational speed of said distributor,
said brake element mounted for rotation on said shaft remote from
said one end, such that said bearing is located intermediate said
distributor and said brake element;
said at least one surface and said brake element cooperative to
produce a
substantially donut-shaped sprinkling pattern. .Iaddend. .Iadd.60.
A rotary sprinkler head comprising:
a sprinkler body provided with an inlet for receiving a pressurized
fluid, and an outlet for discharging said fluid as a primary
stream, said sprinkler body having no dynamic seals therein;
a distributor rotatable relative to said body and supported at one
end of a shaft mounted for rotation within a bearing, said
distributor having at least one surface for engaging said primary
stream discharged from said outlet;
a viscous brake assembly including a brake element for reducing
rotational speed of said distributor, said brake element mounted
for rotation on said shaft remote from said one end, such that said
bearing is located intermediate said distributor and said brake
element. .Iaddend.
Description
This invention relates to sprinklers and more specifically to
sprinkler heads of the type adapted to distribute a source of water
under pressure to a predetermined ground pattern area.
It has been conventional wisdom for many years that the best and
most efficient sprinkler head is one which is capable of delivering
a given source of water to the largest possible sprinkler pattern
area. It is also generally accepted that the best and most
efficient sprinkler head for accomplishing this result is the
so-called step-by-step impact sprinkler or the step-by-step impulse
sprinkler in larger sizes. The step-by-step rotary sprinkler heads
achieve maximum throw by directing the source of water under
pressure upwardly and outwardly which enables the water to be
extended to a maximum extent. By then slowly rotating the extended
water source in step-by-step fashion a maximum area can be
covered.
In recent years the combined effect of decreasing water supplies
and increasing energy costs has brought this conventional widsom
into question. Maximum throw requires that the source of water be
at relatively high pressure. Moreover, such high pressure is
desirable if not necessary in order to insure that the projected
stream will break up into water particles of a desired size. The
necessity to deliver a predetermined gallonage of water per unit
time at a relatively high source pressure provides a significant
increase in energy costs. The same gallonage per unit time can be
delivered at substantially lesser cost where the source pressure
can be relatively low. One can imagine reducing the source pressure
to a step-by-step impact sprinkler to the point that the stream
remains intact and falls almost as an entity on the ground.
Moreover, it will be understood that in addition to the need for
pressure to break up the stream into desired droplet sizes, this
energy is also needed to accomplish the cycling of the impact arm.
Consequently, in order to reduce the source pressure to a point
where significant energy savings could be obtained, the
conventional wisdom of considering the sprinkler head which is
capable of distributing the water to the largest possible pattern
area has been dropped in favor of providing fixed spray heads
having instantaneous circular patterns which can be overlapped one
with respect to another to provide coverage over the same pattern
area as a single impact sprinkler. Arrangements of this type
requires the provision of more pipe but this added cost was
considered to be offset by the energy savings that could be
effected. For example, a typical spray head may have an
instantaneous spray pattern which has a radius substantially less
than the distance that the same amount of water under the same
pressure could be projected radially outwardly as a stream.
Consequently, even where additional piping is provided to densify
the number of sprinkler heads provided there still exist the
desirability that each sprinkler head should be capable of
projecting the source water delivered thereto to the greatest
possible pattern area.
In summary, it can be stated that conventional impact sprinkler
heads serve to best achieve the end result of distributing a given
source of water and pressure to the largest possible pattern area,
they nevertheless have the following disadvantages (1) they require
a relatively high pressure to operate properly (2) they are subject
to possible self-inflicted damage due to the repeated impacts to
which they are routinely subjected and (3) they are subject to seal
failure due to the fact that they must include a dynamic seal
assembly capable of remaining effective to seal against relatively
high pressures over a period of repeated impact operation.
In order to understand the requirement for high pressure in the
operation of a typical conventional impact sprinkler head, it is
important to consider first that the source of water to be
distributed by an impact sprinkler head is initially projected into
the atmospheric condition prevailing at the ground site to be
sprinkled as a continuously flowing jet stream directed upwardly
and radially outwardly. During each impact cycle there is a period
of time when the jet stream is allowed to flow outwardly
unobstructed and a period of time when the jet stream is obstructed
and deflected by the various surfaces of the impact arm drive
spoon. The water which remains unobstructed in the jet stream falls
on the ground pattern at the outer portions thereof whereas the
obstructed water falls on the inner portions. It is the existence
and utilization of the unobstructed radially outwardly extending
jet stream which enables the impact sprinkler head to cover a
maximum pattern area. However, it is also this characteristic which
dictates the need to operate the sprinkler head at relatively high
pressures. Several factors relating to this characteristic enter
into the pressure limitation. One factor relates to the break up of
the jet stream before it falls onto the ground. For a given outlet
orifice size, adequate break up of the stream is a direct function
of output pressure. As the jet stream leaves the nozzle, the output
pressure energy is converted into velocity energy and the velocity
of the jet stream as it leaves the nozzle outlet largely determines
whether or not the stream will subsequently break up into desired
droplet sizes before ground engagement. As the velocity decreases
droplet size is likely to increase until a point is reached under
the particular atmospheric conditions presented where droplet size
is big enough to have an adverse effect on the plants and/or soil
in or near the sprinkler pattern area. A similar situation is
presented with respect to the distribution of the drive spoon
obstructed water, although the threshold pressure where adverse
effects become manifest is probably below that with respect to the
unobstructed water. A third factor relates to the energy level of
the continuous jet stream necessary to accomplish the operative
cycling of the impact arm. Here again, since the cycling is
accomplished by the jet stream after it leaves the nozzle its total
energy at this point is almost totally represented by its velocity
energy (i.e. pressure energy and potential energy are both
negligible). Thus, the energy level required to accomplish cycling
of the impact arm is likewise a function of stream velocity. Again,
the threshold pressure where adverse effects become manifest may be
below that of both of the other two factors.
With the above in mind, it will be appreciated that efforts have
been made in the past to lower the threshold pressure required
become of the first two factors, by either (1) modifying the nozzle
so as to modify the nature of the jet stream projected to improve
break up at lower pressure (see, for example, commonly assigned
U.S. Pat. No. 4,492,339.) or (2) modifying the jet stream by
structural surface engagement after it has passed the point of
stream engagement by the drive spoon to improve break up at lower
pressures (see, for example, commonly assigned U.S. Pat. No.
4,566,632).
Since these efforts result in diminishing the energy level of the
jet stream before it reaches the ground, they necessarily result in
a decrease in the pattern area covered. This decrease may be
significant when it is considered that a 30% decrease in radius of
throw reduces the area of coverage by more than half. Moreover,
where the jet stream energy reduction takes place at the nozzle,
there is less energy available in the jet stream when it reaches
the drive spoon to accomplish impact arm cycling and hence the
energy required to effect impact arm cycling becomes a pressure
threshold establishing factor. This energy level is determined by
the energy required to move the sprinkler head body one step which,
in turn, is a factor of the mass of the rotating sprinkler body
(and contained water) and the drag of the spring pressed brake and
dynamic seal assembly.
In view of the above, as a practical matter, where the source of
water under pressure is at a low level fixed spray heads have been
recently utilized instead of rotary impact sprinkler heads. A
characteristic of a spray head is that the instantaneous spray
pattern and the full cycle spray pattern of the sprinkler head
itself are for all intents and purposes one and the same. Thus, the
coverage pattern area is materially reduced in comparison with a
sprinkler head, such as the impact head, where the full cycle spray
pattern is greater than the instantaneous pattern by a factor
significantly greater than one.
There quite clearly exists a need for a sprinkler head which can
operate at pressures below conventional impacts with a full circle
pattern to instantaneous pattern ratio significantly above one and
at the same time eliminate the other two disadvantages of impact
sprinkler heads enumerated above, namely (1) self-inflicted damage
and wear due to repeated impacts and (2) operational dynamic seal
failure due to wear and pressurized contamination by sand
particles, etc.
It is an object of the present invention to fulfill the above
identified need. In accordance with the principles of the present
invention, this objective is obtained by providing a rotary
sprinkler head comprising a sprinkler body having an outlet and a
structure devoid of any operative dynamic seals for communicating a
source of water under pressure with the outlet so that the latter
will serve to direct the water under pressure into an atmospheric
condition in a primary stream having a generally vertically
extending axis. A rotary distributor is rotatably mounted in
engaged relation with respect to the primary stream. The rotary
distributor has stream engaging surfaces which serve (1) to
establish a reactionary force component acting on the distributor
in a direction tangential to the rotational axis thereof so as to
effect rotational movement thereof about the axis of rotation and
(2) to direct the primary stream engaged thereby in the form of
pattern forming stream means including at least one stream moving
away from the distributor in a direction having a substantial
component extending radially outwardly from the generally vertical
axis of the primary stream. A speed reducing assembly is
operatively associated with the distributor for reducing the
rotational speed of the distributor resulting from the reactionary
force component from a relatively high whirling speed which would
occur without the speed reducing assembly to a relatively slow
speed so related to the distributor stream engaging surfaces
forming the pattern forming stream means as to permit (1) the one
stream to leave the distributor stream engaging surfaces with
sufficient stream integrity to flow outwardly a distance
substantially as great as the same said one stream would flow if
the distributor were held stationary and (2) all of the pattern
forming stream means including said one stream to be distributed
within a generally circular pattern with a desired droplet size and
with a desired water distribution within the generally circular
pattern, the radius of the generally circular pattern being defined
by the maximum extent of flow of said one stream.
It can be seen that the operative dynamic seal failures sometimes
heretofore experienced in conventional impact sprinkler heads are
eliminated by eliminating the need to use any such seals. Instead,
the source of water under pressure is confined by static structure
until directed into an atmospheric condition as a primary stream
having generally vertically extending axis. This feature of
statically confining the water under pressure and discharging it
into an atmospheric condition as a primary stream having a
generally vertically extending axis further eliminates the need to
effect a rotational movement of a relatively large pressure
confining structural mass having an operative dynamic pressure seal
and spring pressed brake assembly, such as in the case with
conventional impact heads, a requirement, as aforesaid, which
materially increases the input energy level of the stream required
to sequence the impact arm. Instead, a relatively small rotary
distributor used in conjunction with a speed reducing assembly
performs the function of distributing the water radially outwardly
from the primary stream. A highly advantageous feature of utilizing
a small rotary distributor is that it can be a simple plastic
molding capable of simple replacement to achieve whatever pattern
size, droplet size and distribution characteristics are desired.
The stream engaging surfaces which handle the water at atmospheric
conditions are formed to establish a reactionary force component
which in the absence of a speed reducing assembly would impart a
relatively high whirling speed to the rotary distributor. The speed
reduction assembly reduces this relatively high whirling speed to a
relatively slow speed enabling the ratio of the full cycle pattern
to the instantaneous pattern to be significantly greater than one.
The slow speed of the rotary distributor enables the water engaging
surfaces thereof to direct the water flowing in the primary stream
in an outward direction with respect to the vertical axis of the
latter by changing its direction of movement and acting upon it in
a manner to condition it for subsequent break up without reducing
its energy level to a value less than that required to accomplish
movement through a full cycle. Moreover, by utilizing a smooth
continuous movement rather than repeated impacts to accomplish a
full cycle of movement, the disadvantage of damage and wear
resulting from repeated impacts is eliminated.
Another object of the present invention is the provision of a
rotary sprinkler head of the type described which is simple in
construction, effective in operation and economical to
manufacture.
These and other objects of the present invention will become more
apparent during the course of the following detailed description
and appended claims.
The invention may best be understood with reference to the
accompanying drawings wherein illustrative embodiments are
shown.
In the drawings:
FIG. 1 is a side-elevational view of one form of a rotary sprinkler
head embodying the principles of the present invention;
FIG. 2 is a sectional view taken along the line 2--2 of FIG. 1;
FIG. 3 is a sectional view taken along the line 3--3 of FIG. 1;
FIG. 4 is a sectional view taken along the line 4--4 of FIG. 1;
FIG. 5 is a top-plan view of a rotary distributor of a different
form specifically for controlling the primary stream in such a way
that it is divided into two streams which are directed outwardly in
opposite directions;
FIG. 6 is a vertical sectional view of the rotary distributor shown
in FIG. 5 mounted in conjunction with a speed reducing assembly of
modified form;
FIG. 7 is a view similar to FIG. 1 showing another form of rotary
sprinkler head embodying the principles of the present
invention;
FIG. 8 is a sectional view taken along the line 8--8 of FIG. 7;
FIG. 9 is a side-elevational view of still another form of rotary
distributor;
FIG. 10 is a bottom view of the rotary distributor shown in FIG.
9;
FIG. 11 is a vertical sectional view of a modified form of speed
reducing assembly utilized in the sprinkler head shown in FIGS. 7
and 8 in lieu of the speed-reducing assembly shown therein;
FIG. 12 is a fragmentary side elevational view partly in vertical
section illustrating still another sprinkler head embodying the
principles of the present invention, which sprinkler head is
particularly adapted to be used in either one of two operative
positions which are inverted in relation to one another;
FIG. 13 is a sectional view taken along the line 13--13 of FIG.
12;
FIG. 14 is an enlarged fragmentary sectional view taken along the
line 14--14 of FIG. 12;
FIG. 15 is a view similar to FIG. 12 illustrating the sprinkler
head in an inverted position with respect to that shown in FIG.
12;
FIG. 16 is a composite sectional view in two halves of a speed
reducing assembly of modified form capable of being manually
adjusted, the two halves of the composite sectional view showing
different positions of adjustment;
FIG. 17 is a view similar to FIG. 16 showing still another
embodiment of a manually adjustable speed reducing assembly that
can be utilized in the sprinkler head of the present invention;
FIG. 18 is a view similar to FIGS. 16 and 17 showing an adjustable
speed reducing assembly connected with the rotary distributor in
such a way that changes in the conditions of the primary stream
impinging on the rotary distributor due to changes in the pressure
of the water source are automatically reflected as changes in the
speed reducing assembly;
FIG. 19 is a vertical sectional view of a rotary sprinkler head of
modified form which embodies the principles of the present
invention;
FIG. 20 is a sectional view taken along the line 20--20 of FIG.
19;
FIG. 21 is a sectional view taken along the line 21--21 of FIG.
19.
Referring now more particularly to the drawings, there is shown in
FIGS. 1-4 one embodiment of a sprinkler head, generally indicated
at 10, which embodies the principles of the present invention. In
general, the sprinkler head includes a sprinkler body, generally
indicated at 12, which as shown, is a static structure adapted to
be connected to a source of water under pressure. An outlet nozzle
14 is positioned on the sprinkler body 12 so as to direct the
source of water under pressure into an atmospheric condition at the
site to be sprinkled in a primary stream having a generally
vertically extending axis. The sprinkler head 10 also includes a
rotary distributor, generally indicated at 16, which is mounted for
rotational movement about a rotational axis which preferably is
concentric with the vertical axis of the primary stream. The rotary
distributor 16 includes surface means, generally indicated at 18,
for engaging the primary stream (1) to establish a reactionary
force component acting on the distributor 16 in a direction
tangential to the rotational axis thereof so as to effect
rotational movement thereof about its rotational axis and (2) to
direct the primary stream engaged thereby in the form of pattern
forming stream means which includes at least one stream moving away
from the distributor 16 in a direction having a substantial
component extending radially outwardly from the generally vertical
axis of the primary stream. Finally, the rotary sprinkler head 10
also includes a speed reducing assembly 20 which is operatively
associated with the rotary distributor 16 for reducing the
rotational speed of the distributor 16 resulting from the
reactionary force component from a relatively high whirling speed
which would occur without the speed reducing assembly 20 to a
relatively slow speed so related to the distributor surface means
18 forming the pattern forming stream means as to permit (1) the
one stream to leave the distributor surface means 18 with
sufficient stream integrity to flow outwardly a distance
substantially as great as the same one stream would flow if the
distributor 16 were held stationary and (2) all of the pattern
forming stream means including the one stream to be distributed
within a generally circular pattern with a desired droplet size and
with a desired water distribution within the generally circular
pattern. The radius of the circular pattern is defined by the
maximum extent of flow of the one stream.
In the embodiment shown in FIG. 1, the sprinkler body 12 takes the
form of a known sprinkler body which is utilized in a spray head
currently offered for sale on the market by the owner of the
present application. The design of the sprinkler body of the spray
head is substantially illustrated in commonly assigned U.S. Pat.
No. DES 259,438. The sprinkler body 12 constitutes a molding of
plastic material as, for example, nylon. It will be understood that
other suitable plastic materials may be utilized if desired. The
sprinkler body 12 is molded to include a tubular inlet portion 22
which has exterior threads 24 for engaging within a conduit or the
like (not shown) which contains a source of water under pressure.
As shown, the interior of the tubular inlet portion 22 is provided
with a series of annularly spaced longitudinally extending guide
fins 26 which serve to smoothly direct the water to an adjacent
tubular outlet portion 28 formed on the sprinkler body. The tubular
outlet portion 28 is interiorly threaded, as indicated at 30, to
receive the outlet nozzle 14. As shown, the outlet nozzle 14 is of
conventional metal construction and is configured to direct the
water under pressure entering the tubular inlet portion 22 into the
atmospheric conditions at the site containing the pattern area to
be sprinkled as a downwardly directed primary stream having a
substantially vertical axis which is coincident with the axis of
both the tubular inlet portion 22 and the tubular outlet portion
28.
The particular sprinkler body 12 shown in FIGS. 1-4 provides a
supporting depending structure for the rotary distributor 16. This
supporting structure is in the form of a pair of integral mounting
arm portions 32 which extend outwardly and downwardly from opposite
sides of the tubular outlet portion 28. Extending downwardly from
the arm portions 32 is a pair of parallel vertically extending
strut portions 34, the lower ends of which are fixedly integrally
interconnected a pair of horizontally inwardly extending portions
36 interconnected by a tubular central mounting portion 38. The
strut portions of the sprinkler body are disposed in a position to
be engaged by the stream of the sprinkler head and to minimize the
effect of this engagement on the resulting distribution of water in
the pattern area, the strut portions 34 have a stepped triangularly
shaped tapered cross-sectional configuration, as can be seen from
FIG. 4.
The central tubular mounting portion 38 in the spray head depicted
in the aforesaid design patent has mounted therein a stationary
spray deflector plate. In accordance with the principles of the
present invention, the combined rotary distributor 16 and
associated speed reducing assembly 20 is arranged to be supported
within the tubular mounting portion 38 in lieu of the fixed spray
plate.
It will be understood that an arrangement of the type described
above wherein the spray head type sprinkler body is utilized and
the primary stream established therein is directed downwardly finds
particular use in moving irrigation systems, such as pivot move
systems. An example of such a use is disclosed in commonly assigned
U.S. Pat. No. 4,405,085 wherein the spray heads 22 shown therein
could readily be replaced by rotary sprinkler heads 10 of the
present invention, such as illustrated in FIGS. 1-4.
It will be understood however that the sprinkler head 10 of the
present invention may be readily adapted for use in any sprinkler
set-up where either rotary impact sprinkler heads have been
previously used or where spray heads have been recently used in
place of impacts. As previously indicated, the rotary sprinkler
head 10 of the present invention achieves satisfactory operation at
lower pressures than conventional rotary impact sprinkler heads and
achieves a more desirable and extensive spray pattern that can be
achieved with a comparably sized spray head. U.S. Pat. No.
4,405,085 discloses the mounting of spray heads on booms supported
by drop tubes from the elevated conduit of a pivot move or lateral
move irrigation system. The rotary sprinkler heads 10 of the
present invention would be particularly useful with drop tubes
and/or booms in the configuration as depicted in FIGS. 1-4.
The rotary sprinkler head 10 which is depicted in FIGS. 1-4
exemplifies a desirable configuration of the surface means 18 of
the rotary distributor 16 when it is desired to project all of the
water in the primary steam as a single stream. In the embodiment
shown, the rotary distributor 16 is in the form of a molded body of
suitable plastic material. An exemplary embodiment is nylon
although it will be understood that other suitable plastic
materials may be employed if desired. The rotary distributor 16, as
shown, also includes a metal insert 40 which is integrally molded
in the plastic body for accurately receiving one end of a mounting
shaft 42 which extends axially from the rotary distributor
body.
The surface means 18 which serves to engage the primary stream and
to establish the reactionary force component and to direct all of
the primary stream outwardly as a single stream is of course molded
in the distributor body. The shape of the surface means can best be
understood by considering the same to be formed by a spherical burr
tool which is moved in cutting relation through the distributor
body first downwardly and then outwardly and slightly upwardly
toward the periphery at the same time moving arcuately rather than
straight out radially. The characteristic of the surface means 18
thus formed is that the issuing stream which is defined by the
surface has a major component in the radial direction with respect
to the axis of the primary stream. Moreover, there is a slight
upwardly component to the issuing stream which serves to achieve
the greatest possible outward extent of movement of the stream and
hence to define a maximum radius dimension for the resulting
circular pattern area of the rotary sprinkler head 10. This
direction of issuing stream movement is indicated in FIG. 2 and it
will be noted that therefrom and from the plan view shown in FIG. 4
that the direction of the stream issuing from the surface means 18
is such that its axis is parallel with a radial line extending from
the vertical axis of the primary stream. The extent of offset is
slight so that the force component which acts in a tangential
direction with respect to the axis of the rotary distributor to
rotate the same is relatively small compared with the radially
outward directional component of the stream. Nevertheless, this
reactionary force component is considerably greater than would be
required to rotate the distributor without a speed reducing
assembly associated therewith at the slow speeds herein
contemplated.
The speed reducing assembly 20 which is embodied in the rotary
sprinkler head 10 is preferably a speed reducing assembly which
operates on the principle of damping the rotational movement
through viscous fluid shear between two relatively moving surfaces.
The embodiment shown in FIGS. 1-4 is particularly constructed to
cooperate with the tubular mounting portion 38 of the sprinkler
body 12 constructed in accordance with the known manner previously
described.
To this end, the speed reducing assembly 20 includes a first outer
housing part 44 which includes a disk-shaped central portion 46
having a sleeve portion 48 extending outwardly therefrom which is
adapted to engage within the tubular mounting portion 38 of the
sprinkler body 12. In order to retain the upstanding sleeve portion
48 of the assembly housing part 44 within the mounting portion of
the sprinkler body, the sleeve portion 48 has a pair of downwardly
extending slits formed therein which define an integral resilient
locking element 50 therebetween. As shown, the locking element 50
includes an enlarged head having an upwardly and outwardly facing
cam surface 52 and a downwardly facing locking surface 54. With
this arrangement, the outer housing part 44 can be simply pushed
upwardly through the mounting portion 38 of the sprinkler body 12
which action cams the resilient locking element 50 radially
inwardly by virtue of the engagement of the upper cam surface 52
thereof. When the housing part 44 has been moved fully into the
mounting portion 38 of the sprinkler body 12 the enlarged head of
the resilient locking element 50 moves radially outwardly into a
slot or opening 56 formed in the tubular mounting portion 38 so as
to provide an upwardly facing surface to lockingly engage the
downwardly facing locking surface 54 of the resilient locking
element 50.
The first housing part 44 also includes a downwardly extending
peripheral flange 58 which is exteriorly threaded, as indicated at
60, to receive an interiorly threaded skirt portion 62 formed on a
second housing part 64. The first housing part 44 also includes a
inner upwardly extending hollow sleeve portion 66 which serves to
receive a sleeve bearing 68. The mounting shaft 42 of the rotary
distributor 16 extends into and is journalled within the sleeve
bearing 68 and has its lower extremity disposed within a cavity or
chamber 70 formed within the two housing parts 44 and 64.
Filled within the chamber 70 is a body of viscous fluid 72. The
viscous fluid 72 may be of any known type, an exemplary embodiment
being silicone. As shown, the lower extremity of the mounting shaft
42 of the rotary distributor 16 extends downwardly from the sleeve
bearing 68 into the center of the chamber 70 and has fixed thereto
the hub of a viscous fluid engaging member 74. As shown, the member
74 has a disk configuration which extends outwardly from the upper
end of the hub. It will be noted that both the upper surface of the
fluid engaging member 74 as well as the lower surface thereof is
disposed in closely spaced proximity to the adjacent walls of the
chamber 70 thus providing surfaces which are relatively movable and
have viscous fluid 72 therebetween, which viscous fluid is sheared
when the relative movement takes place. This viscous shearing
dampens the rotatonal movement of the rotary distributor 16 and
reduces its speed from a relatively high whirling speed which the
rotary distributor would achieve if the speed reducing assembly 20
were eliminated to a relatively slow speed.
Examples of the speeds which are herein contemplated are a
relatively high whirling speed of approximately 1800 revolutions
per minute to a reduced operating speed of approximately 2.1
revolutions per minute. It will be understood that it is within the
contemplation of the present invention to reduce the speed within
an operative range of approximately 1/4 r.p.m. to approximately 12
r.p.m. and somewhat thereabove. The advantage of utilizing a
relatively slow speed, such as 2.1 r.p.m., is that the
horse-tailing effect of the stream that issues from the surfaces 18
of the rotary distributor 16 is minimized and the stream projects
outwardly for a distance substantially the same as the stream would
project if the rotary distributor 16 were held stationary. By
maximizing the outward extent of the stream, the circular pattern
area of the sprinkler head is likewise maximized which is highly
desirable. For example, the rotary distributor 16 which achieves a
relatively slow operating speed of 2.1 r.p.m. serves to project the
issuing stream operating a distance of approximately 161/2 feet
which compares favorably with an 181/2 foot projection when the
rotary distributor 16 is held stationary and the reduction in the
pattern radius is only down to 89% of maximum. On the other hand,
where the rotary distributor 16 is allowed to turn freely at 1800
r.p.m., the horse-tailing effect of the stream is so significant
that the stream is almost immediately broken up into droplets which
fall instantaneously throughout a circular pattern. This reduced
circular pattern of coverage is effectively the same as the
instantaneous pattern of the stream. The pattern area radius is
reduced down to 70% of maximum resulting in a pattern area which is
less than 50% of the maximum pattern area.
In the embodiment of the speed reducing assembly 20 shown in FIGS.
1-4, the viscous fluid 72 substantially fills the chamber 70 and
can escape therefrom only after finally passing through a dynamic
seal 76 which is provided exteriorly between the mounting shaft 42
and the sleeve bearing 68. Moreover, the shape of the chamber 70 is
such that so long as the sprinkler head 10 is oriented in its
operating position, the viscous fluid 72 will be retained within
the chamber 70 by gravity without any tendency to leak. The seal 76
is provided primarily to prevent the ingress of deleterious
material between the mounting shaft 42 and the sleeve bearing 68.
However, as previously indicated, it also would have the effect of
sealing in the viscous fluid 72 in the event that the same were to
seep through the mating surfaces of the mounting shaft 42 and the
sleeve bearing 68 while the sprinkler head 10 is inverted.
The filling of the chamber 70 with viscous fluid 72 has the
advantage of physically excluding the entrance of moisture into the
chamber 70 which could mix with the viscous fluid 72 and change its
viscosity so as to allow the rotary distributor to run faster than
desired. In conjunction with the filling of the chamber 70 with
viscous fluid 72 it is desirable to provide a means for
accommodating thermal expansion and contraction of the viscous
fluid without an attendant increase or decrease in the pressure
condition of the viscous material. Such a means is exemplarily
shown in FIG. 2 as a diaphragm insert assembly 77 suitably fixedly
mounted in a wall defining the chamber 70. As shown, the diaphragm
insert assembly 77 is mounted in the annular radially extending
wall of the second housing part 64 leading to the skirt portion 62
thereof.
It can be seen that the speed reducing assembly 20 is thus quite
stable in operation and is capable of mounting the rotary
distributor 16 for rotational movement and effectively reducing
that speed to a constant value for any given primary stream. The
relatively slow constant speed of rotation has its effect on the
fallout of the stream which issues from the rotary distributor 16.
Thus, the combination of the surface means 18 of the rotary
distributor 16 and the speed reducing assembly 20 itself serves to
condition the stream which issues from the rotary distributor 16
not only in the sense of its initial projecting direction but also
its conditioning with respect to its fallout characteristics. The
fallout characteristics have a determination effect on the water
distribution within the circular pattern of the rotary sprinkler
head 10. For example, where a major part of the water is projected
out and falls adjacent the periphery of the circular pattern so
that at the central portion of the pattern relatively little water
is distributed, the water distribution is non-uniform. Where the
water distribution is heavied up at the periphery of the circular
pattern, this non-uniform distribution is conventionally referred
to as a donut pattern distribution and a donut pattern is desirable
in moving irrigation systems because a concentration is presented
to the newly sprinkled earth which is capable of receiving the
greatest amount of water without runoff.
The smoothness of the surface means 18 and the extent to which the
primary stream is bent or redirected also has a significant effect
on the fallout which occurs after the stream issues from the rotary
distributor. In the embodiment shown in FIGS. 1-4, the surface
means 18 is constructed to minimize the redirection of the primary
stream and to always engage the stream with as smooth a surface as
possible. Thus, the distribution pattern is a donut
distribution.
It will be noted that when the issuing stream is directed toward
the strut portions 34, the stream will be broken up and there will
be relatively small segments behind the triangular shaped strut
portions 34 which do not receive water distribution within the
circular pattern. These non-wetted areas are considered
insignificant particularly where the rotary sprinkler head 10 is
being utilized in a moving irrigation system. Usually, full wetting
within the circular pattern is desirable and in some embodiments as
will be noted hereinafter a full wetting of the full circular
pattern is accomplished. Nevertheless, the present invention
contemplates a coverage within less than the full circular pattern
and contemplates in this regard a part-circle operation as
well.
FIGS. 5 and 6 disclose modifications in the rotary distributor and
in the speed reducing assembly that can be embodied in the
sprinkler head 10 of the present invention. As shown in these
Figures, there is provided a rotary distributor, generally
indicated at 78, which includes surface means, generally indicated
at 80, for engaging the primary stream and dividing the primary
stream into two separate and generally equal streams and directing
the same outwardly in generally opposite directions. It will be
noted that the shape of the surface means 80 is such as to include
two intersecting surfaces 82 similar in shape to the surface means
18 previously described except that they are displaced 180.degree.
with respect to one another and intersect one another along a
perpendicular stream dividing line passing through the center.
As before, the rotary distributor 78 includes an insert 84 that
serves to accurately receive the upper end of a mounting shaft
86.
FIG. 6 illustrates a modified speed reducing assembly, which is
generally designated by the reference numeral 88. The assembly 88
includes a first housing part 90 which is substantially the same as
the housing part 44 previously described. As such, there is
included a sleeve portion 92, a resilient locking element 94 having
an enlarged head with a cam surface 96 and a locking surface 98, an
inner sleeve 100 which receives a sleeve bearing 102 having a
dynamic seal 104 on the upper end thereof which engages the
mounting shaft 86.
The first housing part 90 differs from the housing part 44
previously described in that it includes a depending peripheral
skirt 106 which is internally threaded so as to cooperatively
engage exterior threads on a upstanding peripheral portion 108 of a
second housing part 110. The portion of the housing part 110
extending inwardly from the peripheral portion 108 is formed so as
to provide an annular chamber 112 which is defined by an outer
cylindrical wall portion 114, an inner cylindrical wall portion 116
and a annular bottom connecting wall portion 118. As shown, the
upper end of the outer cylindrical wall portion 114 is integrally
connected with the threaded peripheral wall portion 108 and a
center wall portion 120 interconnects the upper end of the inner
cylindrical wall portion 116.
As before, the annular chamber 112 is filled with viscous fluid
122. However, the filled chamber also communicates with a larger
annular chamber 124 within which the lower end of the mounting
shaft 86 extends. As before, a viscous fluid engaging member 126 is
fixed to the lower end of the shaft 86 and is disposed within the
chamber 112. As before, the member 126 is in the form of a hub
having a disk projecting radially outwardly from its central
portion. The member further includes a depending cylindrical skirt
portion 128 extending downwardly from the outer end of the
disk-like portion. It is the lower end of this annular skirt
portion 128 which engages within the viscous fluid 122 filled
within the annular chamber 112. The cylindrical exterior and
interior surfaces of the skirt portion 128 cooperate, respectively,
with the interior surface of the outer wall portion 114 and the
interior surface of the inner wall portion 116 to provide the
desired viscous shearing of the viscous fluid 122 suitable to
accomplish the damping of the rotational speed of the rotary
distributor 78 to a desired slow speed, such as previously
indicated.
The advantage of the arrangement depicted in FIGS. 5 and 6 is that
since the chamber 112 which contains the viscous fluid is in
communication with an adjacent air chamber 124 of greater volume
the expansion and contraction of the viscous fluid 122 due to the
change in the temperature or weather conditions will have very
little effect, if any, on the damping characteristics. Where the
viscous fluid is completely filled within the chamber as in the
embodiment described above with respect to FIGS. 1-4, there exist
the possibility that the pressure of the viscous fluid could
increase to a value above atmospheric pressure so as to tend to
pass outwardly beyond the seal 74. Conversely, a negative pressure
could be created in which case the negative pressure would serve to
induce passage of deleterious material inwardly past the seal 74.
For that reason, the use of what is effectively a partially filled
chamber in the manner described above with reference to FIGS. 5 and
6 is sometimes preferable. The combined rotary distributor 78 and
speed reducing assembly 88 depicted in FIGS. 5 and 6 would provide
satisfactory use in pivot move systems where relatively large spray
heads or impact heads have been previously used. The configuration
of the surfaces 82 serve to divide the primary stream much in the
same way that impact heads of larger capacities are provided with
dual nozzles. It will be understood that the two streams may be
made unequal by simply widening the surface resulting from one of
the cuts while the other is narrowed. Moreover, one of the cuts
could be made to extend perfectly radial so that all of the
reactionary force component would be derived from the other cut. It
will also be understood that more than two cuts may be provided but
here again when such cuts are of equal size there is a substantial
tendency to reduce cycle pattern size which is contrary to the most
desired characteristic of the sprinkler head. Namely, to achieve as
great a cycle pattern area as is practically possible commensurate
with the securement of proper droplet size and water distribution
with such a pattern.
In the embodiments of the invention thus far described, the
sprinkler body 12 of the rotary sprinkler head 10 is oriented
during operation so that the primary stream flows vertically
downwardly. This orientation is representative of drop tube or boom
mountings in pivot or lateral move systems. FIGS. 7 and 8 are
representative of sprinkler head mountings directly on top of the
main pipe in pivot move or lateral move systems.
In FIGS. 7 and 8, there is illustrated a modified sprinkler head
210 embodying the principles of the present invention. The
sprinkler head 210 includes a sprinkler body, generally designated
by the numeral 212, which is constructed exactly in accordance with
sprinkler body 12 previously described. Consequently, a detailed
description is not deemed necessary. Instead it is believed
sufficient to note that in FIGS. 7 and 8 of the drawings comparable
parts of the sprinkler body 212 are designated with comparable
reference numerals except for the addition of the prefix number 2.
Similarly, the rotary sprinkler head 210 includes an outlet nozzle
214, a rotary distributor 216 having primary stream engaging
surface means 218, and a speed reducing assembly 220. With the
above in mind, the sprinkler head 210 will be described with
reference to the corresponding parts which differ from those
previously described. The surface means 218 of the rotary
distributor 216 is formed with surfaces 282 which are similar to
the surfaces 82 except that they are inverted. Moreover, since the
primary stream is moving upwardly rather than downwardly it is not
necessary to turn it outwardly and then upwardly but rather simply
outwardly to reduce the upward component until it equals the upward
component desired. This difference in shape is clearly reflected in
FIG. 8 when compared with FIG. 6.
The speed reducing assembly 220 is mounted above the sprinkler body
mounting portion 238 and is formed of two housing parts 244 and
264. Housing part 244 includes means for securing the assembly 220
to the sprinkler body such as a depending outer sleeve portion 248
within which is formed a resilient locking element 250. The housing
part 244 also includes an inner sleeve portion 266 which provides
for the rotational mounting of the rotary distributor 214 as by an
inner sleeve bearing 268. The housing part 244 also includes an
upstanding exteriorly threaded peripheral portion 258. The second
housing part 264 is in the form of a cap including a peripheral
interiorly threaded wall portion 262. A chamber 270 is formed
within the housing parts which has the shape of the two
communicating chambers 112 and 124 previously described. A viscous
fluid 272 fills the lower annular portion of the chamber 270. As
before, a viscous fluid engaging member 274 is provided which has a
shape similar to the member 126 previously described. It will be
noted that the interior configuration and size of the chamber 270
and the amount of viscous fluid provided is such that no seal is
required to keep the viscous fluid from leaking out of the chamber
270 around the shaft 242. This is clearly the case in the operating
position shown and it is true even though the assembly might be
stored in any position other than the operating position. It can be
seen that the sprinkler head 210 will function in the same manner
as the sprinkler head 10 previously described particularly in so
far as the characteristics of the spray issuing from the surfaces
282 of the rotary distributor 212. Here again, the water
distribution is essentially a donut distribution pattern.
FIGS. 9 and 10 illustrate a rotary distributor 290 that can be
utilized in the sprinkler head 210 in lieu of the rotary
distributor 216 previously described. The rotary distributor 290
illustrates an embodiment of primary stream engaging surface means
292 formed in the rotary distributor which would facilitate the
securement of a substantially uniform distribution within the
circular pattern area thus rendering the sprinkler head 210 more
suitable for use in solid set systems or as a single applicator,
such as for lawn use. As shown, the surface means 292 includes a
narrow surface 294 superimposed upon a larger surface 296 formed
essentially like the surface means 18 previously described except
for the difference previously noted with respect to the inverted
position thereof. The narrow surface 294 communicates throughout
its extent with the larger surface 296. However their curvatures
are different as can be seen from FIG. 10. The effect is to
maintain the stream as it issues from the rotary distributor 290 as
a single stream but with a relatively smaller portion having a
directional component which causes that portion to drop out more
quickly than the remainder as the stream flows outwardly from the
rotary distributor. Consequently, more water than before is
distributed within the central area of the circular pattern and
less is delivered to the periphery resulting in a more uniform
distribution throughout the pattern area. The communicating
relationship between surfaces 294 and 296 is preferred since it
leaves the total energy in a single stream as it leaves the
distributor. Of course, they may be separated, if desired, and
varied in size with respect to one another as well as
curvature.
FIG. 11 illustrates a modified speed reducing assembly, generally
indicated at 300, which can be utilized with the sprinkler head 210
in lieu of the speed reducing assembly 220. The assembly 300
includes a first housing part 302 which is similar to the housing
part 244 previously described, except as to the interior surfaces
which define an open cylindrical chamber 304 closed by a threadedly
secured second housing cap part 306. Viscous fluid 307 partially
fills the chamber 306 and a disk-shaped viscous fluid engaging
member 308. It is the viscous fluid 307 between the bottom surface
of the chamber 304 and the lower surface of the disk-like member
308 which is sheared to provide the damping effect. The amount of
fluid above the disk-like member 308 does not have significant
viscous shearing and hence does not have a significant effect on
the damping provided. The arrangement therefore provides the same
advantage as that embodied in the speed reducing assembly 88 of
FIG. 6 and the speed reducing assembly 220 of FIGS. 7 and 8.
FIGS. 12 through 15 disclose still another embodiment of a rotary
sprinkler head, generally indicated at 310, which embodies the
principles of the present invention. The rotary sprinkler head 310
is particularly adapted to be utilized in pivot move systems or
lateral move systems and specifically is arranged to accommodate
orientation in an operative position similar to the sprinkler head
10 of FIGS. 1-4 or in the inverted position of the sprinkler head
210 illustrated in FIGS. 7 and 8. The rotary sprinkler head 310 is
shown in FIG. 12 in a position corresponding with the position of
the sprinkler head 210. Here again, the sprinkler head 310 includes
a sprinkler body 312 which is similar to the sprinkler body 12
described above in connection with the sprinkler head 10. As with
the sprinkler body 212, the sprinkler body 312 is inverted with
respect to the sprinkler body 12 of FIG. 1. Thus, the portion of
the sprinkler body 312 which includes the output nozzle is not
illustrated although it will be understood that such a nozzle is
provided and that the primary stream which is directed therefrom
extends in an upward direction and engages a rotary distributor
316, shown in FIG. 12, which is provided with surface means 318 for
directing the water in a manner previously described. In addition,
the sprinkler 310 includes a speed reducing assembly 320 which is
suitable for operation in either one of two operating positions,
one of which is inverted with respect to the other.
The sprinkler body 312 is constructed exactly in accordance with
the construction of the sprinkler body 12 previously described.
Consequently, as before, a detailed description is not believed
necessary. Instead it is believed sufficient to note that in FIGS.
12-15 of the drawings, comparable parts of the sprinkler body 312
are designated with comparable reference numerals except for the
addition of the prefix number 3. The rotary distributor 316 is
similar to the rotary distributor 16 previously described in that
it is formed with a surface means 318 which is configured in
relation to the surface means 18 just as the surfaces 282 are
configured with respect to the surfaces 82. The rotary distributor
316 also includes an insert 340, however it differs from the insert
40 previously described in that it includes an axially outwardly
projecting hub portion 341 which is adapted to receive the shaft
342 therein. The exposed hub portion 341 enables the user to
readily replace the rotary distributor and for this purpose there
is provided a set screw 343 which extends through the hub portion
341 in engagement with a suitable recess in the shaft 342, see FIG.
14.
The speed reducing assembly 320 is constructed similarly to the
assemblies previously described in so far as the mounting of the
same within the sprinkler body and the rotatable support which they
provided for the rotary distributor is concerned. As before, the
assembly 320 includes two housing parts 344 and 364. The housing
part 344 is constructed most nearly like the housing part 244,
shown in FIG. 8, except that the outer peripheral wall portion 358
forms a continuation of the outer cylindrical wall portion which
forms the exterior of an annular chamber 370. It is only the lower
section of the outer peripheral wall portion 358 which is
exteriorly threaded to receive the interior threads on the
generally cap shaped second housing part 364. The exterior surface
of the peripheral wall portion 358 of the housing part 344 is
smooth so as to receive an O-ring seal 359 mounted in a suitable
groove within the peripheral wall portion 362 of the second housing
part. The second housing part 364 rather than being a simple cap
shape element has its center wall recessed inwardly so as to define
the upper end of the chamber 370 with an annular shape similar to
the lower end thereof defined by the first housing part 344.
As before, viscous fluid 372 of an amount sufficient to fill the
lower annular portion of the chamber 370 is filled in the chamber.
The viscous fluid engaging member 374 includes a single outer
cyclindrical portion 375 the ends of which are disposed within the
annular portions of the chamber.
It can be seen that when the rotary sprinkler head 310 is in the
position shown in FIG. 12 with the primary stream being directed
upwardly the viscous fluid 372 within the chamber 370 will be
disposed within the annular portion provided by the first housing
part 344. This position is clearly illustrated in FIG. 12 and it
will be noted that the stream issuing from the surface means 318
will be directed outwardly and with a slight upward component.
FIG. 15 illustrates the position which the rotary sprinkler head
310 assumes when it is operating in an inverted position with
respect to that shown in FIG. 12. It will be noted that the viscous
fluid 372 has now drained into the annular portion of the chamber
370 which is defined by the second housing part 364. The
arrangement provides all of the advantages heretofore noted with
respect to FIGS. 6 and 8 in both operating positons. In the
position shown in FIG. 15, the rotary distributor 316 may be
utilized in which case the stream issuing from the distributor has
a downward component. Alternatively, the rotary distributor 316 may
be readily replaced by one which gives the stream a slight upward
component of movement.
FIG. 16 illustrates a speed reducing assembly, generally indicated
at 420, which is similar to the speed reducing assembly 320 shown
in FIGS. 12-15, except that it is provided with two additional
functional capabilities, one, the capability of manually adjusting
the amount of viscous fluid shear which takes place and two, the
function of compensating for viscosity changes in the viscous fluid
due to temperature changes. As shown, the speed reducing assembly
420 includes a pair of housing parts 422 and 424. The one housing
part 422 provides the means for effecting the fixed connection of
the assembly 420 with the sprinkler body in the manner previously
described and in addition provides for the mounting of the rotary
distributor shaft 426. In the embodiment shown in FIG. 16, the
shaft 426 is modified so that the upper end thereof which extends
into an interior chamber 428 provided by the cooperating housing
parts 422 and 424 is exteriorly splined as indicated at 430.
Chamber 428 is partially filled with viscous fluid 432 and has
therein a viscous fluid engaging member 434, which is mounted on
the shaft 426 by an internally splined hub portion 436 so that the
hub portion and hence the entire viscous fluid engaging member 434
can be moved axially with respect to the mounting shaft 426.
As shown, the vicous fluid engaging member 434 is provided with a
cylindrical peripheral portion 438 which is connected with the hub
portion 436 by radial spokes 440. Extending from the exterior of
the cylindrical portion 438 at each end thereof are annular
sections 442 having exterior cylindrical surfaces which cooperate
with metal rings 444 mounted within the associated portions of the
housing parts 422 and 424 respectively. The upper end of the hub
portion 436 has a flanged section 446 above the interior spline for
receiving a pair of spring gripping fingers 448 formed on the end
of a manually adjustable stem 450 suitably threaded in the central
portion of the housing part 424. As shown, an O-ring seal 454 is
mounted within an appropriate groove in the housing part 424 so as
to engage the smooth upper periphery of the stem 450. The outward
extremity of the stem 450 is formed with a slot 452 for receiving a
turning tool, such as a screwdriver, so as to enable the user to
manually rotate the stem.
It can be seen that by manually rotating the stem 450, the spring
fingers 448 will turn within the hub section 446 and the vertical
component of movement of the stem 450 by virtue of its threaded
connection will effect a vertical movement of the hub portion 436
with respect to the mounting shaft spline 430. This movement
changes the dimension of the co-extension area between the exterior
surface of the annular sections 442 and the interior surface of the
rings 444. Since these surfaces constitute the primary area of
viscous shear, the extent of the shear of the viscous fluid 432
within the chamber 428 is adjusted by virtue of the vertical
movement of the member 434 within the chamber. The purpose of the
manual adjustment is to accomodate different primary steam defining
nozzle sizes and different rotary distributors used therewith as
well as differing water source conditions.
With respect to the temperature compensation for viscosity changes,
it will be noted that the viscous fluid engaging member 434 is
formed of a suitable plastic material as, for example, nylon. The
stator rings 444 on the other hand are formed of metal. The
characteristics of the two materials are chosen such that the
plastic part will, for example, shrink four to fourteen times as
much as the metal part in response to decreases in temperature so
that the clearance between the shearing surfaces will increase at
lower temperatures thus decreasing the shearing as the viscosity of
the viscous fluid becomes greater due to the lower temperatures.
Conversely, as temperatures increase and the viscosity of the
viscous fluid decreases, the clearance between the shearing
surfaces will diminish due to the difference in expansion of the
two parts so that there is provided compensation in both directions
for viscosity changes due to temperature changes. The compensation
insuring a constant rotational speed for the rotary
distributor.
FIG. 17 discloses still another speed reducing assembly, generally
indicated at 520, which can be utilized in any of the rotary
sprinkler heads previously described. As shown, the speed reducing
assembly 520 includes the usual two housing parts 522 and 524. As
before, one part 522 serves to fix the assembly 520 on the
sprinkler body and to provide a mounting for the rotary distributor
shaft 526. In the embodiment shown in FIG. 17, the housing parts
522 and 524 define an interior chamber 528 having therein viscous
fluid 532 and a viscous fluid engaging member 534 which is
constructed like the member 434 previously described except that
its hub portion 536 is fixed to the mounting shaft 526. The viscous
fluid engaging member 534 also includes a cylindrical peripheral
portion 538 having exterior annular sections 542 on both ends
thereof which cooperate with annular enlargements or shearing
sections 544 formed on the interior periphery of the housing part
524 so as to extend inwardly from an outer peripheral wall 546
thereof.
The outer peripheral wall 546 of the housing part 524 is formed
with an exterior central threaded section 548 which is adapted to
engage interior threads 550 formed on a peripheral wall portion 552
of the housing part 522. An O-ring seal 554 is mounted within an
exterior groove formed in the lower exterior surface of the
peripheral wall portion 546 of the housing part 524 for sealably
engaging the cylindrical interior surface of the peripheral wall
portion 552 of the housing part 522 below the interiorly threaded
section thereof.
It can be seen that by turning the housing part 524 with respect to
the housing part 522 by virtue of the interengagement of the
threaded sections 548 and 550, the viscous shearing sections 544 on
the inner periphery of the housing part 524 can be moved into
different axial positions with respect to the annular shearing
sections 542 of the viscous fluid engaging member 534. This
adjustment adjusts the amount of shear of the viscous fluid 532
between the surfaces and hence the damping in the manner previously
described.
FIG. 18 discloses still another speed reducing assembly, generally
indicated at 620, which is similar to the assemblies 420 and 520
previously described in that the assembly 620 is provided with the
capability of adjustment of the viscous fluid shearing and hence
damping provided but, in addition, is provided with the capability
of sensing a change in a condition resulting from a change in the
pressure of the water source of varying the variable damping
capability in accordance with the change in condition sensed so as
to maintain a generally constant reduced speed of the rotary
distributor throughout a range of pressure changes in the water
source. It is within the contemplation of the present invention to
sense a change in any condition resulting from a change in the
pressure of the source water. Thus, the sensor may be a pressure
sensor, a speed change sensor, such as a fly-wheel governor or the
like, or a position sensor for sensing a change in position
resulting from a force application change due to pressure change in
the primary stream.
Where the sensor senses a change in rotational speed or a change in
the axial force acting on the rotary distributor due to a change in
the viscosity and/or flow rate of the primary stream, the system
automatically compensates for changes in the nozzle size utilized.
Rotational speed and axis load are equally affected by changes in
primary stream velocity and flow rate. Velocity is a function of
source pressure. Flow rate is a function of source pressure and
nozzle size. The ability to automatically compensate for the nozzle
size utilized is a desirable feature in that it eliminates the
necessity of the user making a manual adjustment in the speed
reducing assembly after having chosen the desired nozzle size to
utilize.
The embodiment shown in FIG. 18 senses a change in the axial force
component of the primary stream reaction on the surface means 618
of the rotary distributor 616. To this end, the mounting shaft 624
the rotary distributor 616 is not only journaled within a sleeve
bearing 626 mounted within a housing part 628 but is also mounted
for limited longitudinal or axial movement within the bearing 626
as well. As shown, a coil spring 630 is disposed in surrounding
relation to a portion of the mounting shaft 624 which extends
outwardly from the sleeve bearing 626. The upper end of the coil
spring 630 engages the sleeve bearing 626 while the other end
engages the lower end of a bellows seal assembly 632, the opposite
end of which is connected with the inner sleeve portion of the
housing part 628.
It can be seen that when the primary stream impinges upon the
surface means 618 of the rotary distributor 616 there is created by
virtue of the shape of the surfaces an upward reactionary force
component which tends to move the rotary distributor 616 upwardly
together with its mounting shaft 624 against the bias of the spring
630. As the mounting shaft 624 is moved upwardly, a viscous fluid
engaging member 634 fixed thereto, which is similar in construction
to the members 434 and 534 previously described, is moved upwardly
therewith so that the area of the viscous fluid shearing surfaces
642 thereof increases with respect to the cooperating surfaces 644
on the housing part 628 and a cooperating second housing part 646,
so as to increase the amount of viscous shearing of a viscous fluid
648 within chamber 650 provided within the housing parts 628 and
646. In this way, the amount of damping provided is varied.
It can be seen that as the pressure of the source of water
increases, the energy level of the primary stream issuing from the
outlet nozzle will increase thus increasing the axial force
component acting on the rotary distributor 616. The mounting of the
rotary distributor by virtue of the spring 630 and the capability
of its axial movement serves as a sensor for sensing the change in
the axial force component. The arrangement is such that the sensing
of the change automatically causes the viscous fluid engaging
member 634 to be moved into a new position to compensate for the
increased energy level in the primary stream which would tend to
cause the rotary distributor to rotate faster by providing
additional damping so as to maintain the rotational speed of the
rotary distributor at a substantially constant level. Similarly, a
decrease in the source pressure produces a condition of decreased
energy level in the primary stream which, in turn, reduces the
reactionary axial force component acting to depress spring 630.
Spring 630 thus moves shaft 624 outwardly causing a lesser
cooperating surface area between the shearing surfaces 642 and 644
which, in turn, reduces the viscous fluid shearing and hence the
damping provided. The arrangement therefore maintains a generally
constant speed of the rotary distributor for a relatively wide
range of variation, both up and down, in the source pressure.
The rotary sprinkler heads 10, 110, 210 and 310 described above are
all provided with a sprinkler body of a known construction which
renders the related combined rotary distribution and speed reducing
assembly susceptible of being simply attached to a sprinkler body
of the type already in existence. With this feature is an
advantage, a disadvantage of utilizing the existing sprinkler body
is that the strut portions 34 are disposed in a position to engage
the stream issuing from the rotary distributor so as to disrupt the
distribution of the water within segments of the circular pattern
corresponding in position to the position of the strut
portions.
FIGS. 19 through 21 depict a rotary sprinkler head, generally
indicated at 710, constructed in accordance with the principles of
the present invention, which has the capability of eliminating the
strut portions from engaging the stream issuing from the rotary
distributor. As shown in FIG. 19, the rotary sprinkler head 710
includes a sprinkler body, generally indicated at 712, which
includes a tubular inlet portion 714 exteriorly threaded, as
indicated at 716, for engaging internal threads of a water source
pipe (not shown). The sprinkler body 712 adjacent the inlet portion
714 includes a tubular outlet portion 718 which is interiorly
threaded to receive a conventional outlet nozzle 720. Disposed in a
position of substantial axial alignment with the outlet nozzle 720
is a rotary distributor, generally indicated at 722, which is
associated with a speed reducing assembly, generally indicated at
724.
As shown, the sprinkler body 712 includes a radial wall portion
726, extending outwardly from the exterior of the tubular body
portions 714 and 718 at a position adjacent the juncture thereof.
Extending upwardly from the periphery of the radial wall portions
726 is a peripheral wall portion 728. The interior cylindrical
surface of the periphery wall 728, the upper surface of the radial
wall portion 726 and the exterior of the tubular outlet portion 718
define an annular chamber 730 within which a body of viscous fluid
732 is filled.
Mounted within the chamber 730 is a ball bearing assembly 734 the
outer race of which is fixed to the central section of the
cylindrical interior surface of the peripheral wall portion 728 and
the inner race of which is connected with the lower exterior
periphery of a tubular mounting shaft 736 which, as shown is
integral with the rotary distributor 722. As shown, the viscous
fluid 732 is filled within the chamber 730 up to the level of the
upper surface of the ball bearing assembly 734. The primary
surfaces for accomplishing the shearing of the viscous fluid 732
are the interior surfaces of the tubular shaft 736 which extend
into the viscous fluid and the co-extensive area of the exterior
periphery of the tublar outlet portion 718 of the sprinkler body
712. The mounting of the tubular shaft 736 by the ball bearing
assembly 734 within the chamber 730 of the sprinkler body 712
includes a slit ring 738 engaged in a periphery groove within the
tubular shaft 736 for engaging the upper end of the inner bearing
race and a outwardly extending flange 740 on the inner end of the
tubular shaft 736. The outer race of the ball bearing assembly 734
is fixed within the peripheral wall portion 728 of the sprinkler
body 712 by a ring seal unit 742. A split ring 744 in an interior
annular groove in the peripheral wall portion 728 serves to retain
the seal unit 742 in position.
A flexible annular seal 746 is carried by the seal unit 742. The
flexible seal 746 includes a pair of oppositely extending flexible
lips 748 which sealingly engage the adjacent exterior periphery of
the tubular shaft 736. The interior of the tubular shaft 736 is
sealed with respect to the sprinkler body 712 by a flexible annular
seal 750 having a pair of inner lips 752 which seal against an
adjacent cylindrical surface 754 of the tubular outlet portion 718
of the sprinkler body 712.
The rotary distributor 722 as shown is provided with surface means
754 which is constructed in a manner similar to that described
above in connection with the rotary distributor shown in FIGS. 9
and 10. Thus, there is a relatively narrow groove surface 756
formed within a relatively large groove surface 758, the two
surfaces having different curvatures. It will be noted that the
upper end of the tubular shaft 736 which is integrally connected
with the rotary distributor 722 has an opening 760 formed therein
which allows for the passage of the water from the primary stream
outwardly in the manner previously described.
The rotary sprinkler head 710, shown in FIGS. 19-21, is
particularly suitable for operation as a single unit for a lawn
sprinkler in which case the inlet portion is suitably mounted
within an appropriate base. Alternatively, the rotary sprinkler
head could be utilized as the pop up sprinkler head in pop up
sprinkler assemblies used in underground lawn and turf watering
systems. The rotary sprinkler head 710 can also be utilized in
agricultural sprinkler head applications of the type previously
described. The level of the viscous fluid 732 within chamber 730 is
shown with the thought that the rotary sprinkler head 710 will
always be used in the operating position shown. Where dual inverted
operative positions are contemplated, the chamber 730 may be filled
in the manner suggested in the embodiment of FIGS. 1-4 or the
arrangement may be modified to follow the structural arrangement of
FIGS. 12-18.
It thus will be seen that the objects of this invention have been
fully and effectively accomplished. It will be realized, however,
that the foregoing preferred specific embodiment has been shown and
described for the purpose of illustrating the functional and
structural principles of this invention and is subject to change
without departure from such principles. Therefore, this invention
includes all modifications encompassed within the spirit and scope
of the following claims.
* * * * *