U.S. patent number 3,794,245 [Application Number 05/257,741] was granted by the patent office on 1974-02-26 for intermittent sprinkler and system.
This patent grant is currently assigned to Williamson-Built, Inc.. Invention is credited to John D. Wilson.
United States Patent |
3,794,245 |
Wilson |
February 26, 1974 |
INTERMITTENT SPRINKLER AND SYSTEM
Abstract
A system of pressure actuated intermittent discharge sprinkler
units, in which each unit is adapted to be installed below grade
level and includes an accumulator for connection to a source of
water for accumulating water under increasing pressure, a pressure
actuated sprinkler head connected to the accumulator and having a
normally closed valve means carried by a nozzle assembly, such that
the valve means responds to increasing water pressure in the
accumulator and intermittently opens raising the nozzle assembly
above grade level to discharge water therefrom, and a
self-adjusting flow control valve connecting the accumulator to a
source of water such that the periodic build-up and release of
pressure in each unit accumulator does not adversely influence the
operation of the remaining sprinkler units connected to the same
water source. The nozzle assembly which is formed with a radially
directional nozzle includes a ratchet indexing means for cyclically
and incrementally rotating the nozzle assembly each time it is
raised and subsequently lowered by the periodically changing water
pressure in the accumulator. The nozzle assembly desirably includes
a secondary or auxiliary nozzle, spaced below the principal nozzle,
and adapted to deliver water to a substantially smaller radius than
the effective radius of the principal nozzle. The auxiliary nozzle
also serves to discharge the upper portion of water collecting in a
bowl or skirt which houses the valve means and nozzle assembly,
thereby preventing such water from overflowing the bowl and
creating a muddy ring immediately adjacent to the bowl.
Inventors: |
Wilson; John D. (Balboa,
CA) |
Assignee: |
Williamson-Built, Inc. (Santa
Fe Springs, CA)
|
Family
ID: |
22977555 |
Appl.
No.: |
05/257,741 |
Filed: |
May 26, 1972 |
Current U.S.
Class: |
239/206 |
Current CPC
Class: |
B05B
15/74 (20180201); B05B 3/0413 (20130101); B05B
3/16 (20130101) |
Current International
Class: |
B05B
3/16 (20060101); B05B 3/02 (20060101); B05B
15/10 (20060101); B05B 15/00 (20060101); B05B
3/00 (20060101); B05B 3/04 (20060101); B05b
003/00 (); B05b 015/10 () |
Field of
Search: |
;239/204,205,206,238 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: King; Lloyd L.
Attorney, Agent or Firm: Miketta, Glenny, Poms &
Smith
Claims
I claim:
1. A pressure actuated intermittent discharge sprinkler
comprising:
an elongated pipe member having a throat opening at one end and
adapted at its other end for connection to a source of water under
pressure,
a nozzle assembly slidably and rotatably mounted on said pipe
member for reciprocation between retracted and extended positions
and having a nozzle for communication with said pipe member throat
opening,
valve means carried by said nozzle assembly and movable therewith
between the retracted position closing said throat opening of said
pipe member and the extended position communicating said nozzle and
throat opening for water discharge,
bias means urging said nozzle assembly and valve means to said
retracted position such that water under pressure in said pipe
member may overcome said bias means forcing said valve and assembly
to said extended position until pressure is relieved by discharge
through said nozzle, and
a rotation indexer including ratchet means carried by said nozzle
assembly and pipe member translating each cycle of assembly
reciprocation into an increment of rotation thereof.
2. The sprinkler of claim 1, wherein said nozzle assembly is
comprised of a sleeve member having an open end slidably and
rotatably mounted on said upstanding pipe member and a closed
opposite end, said nozzle having a discharge passage adjacent said
closed end extending through said sleeve member and radially
outwardly therefrom to provide water discharge when said nozzle
assembly is in its extended position.
3. The sprinkler of claim 3, wherein said valve means is carried
within said nozzle assembly sleeve member underlying the closed end
thereof for cooperation with the throat opening of said pipe
member, and said bias means is provided by an elongate coil spring
coaxially disposed within said pipe member with an upper end of
said spring abutting a downwardly facing circumferential flange of
said pipe member underlying said throat opening with a lower end
connected to said valve means by a linkage means upwardly extending
therefrom through the throat opening to said valve means, whereby
said spring is placed in compression so as to urge said valve means
and nozzle assembly into said retracted position.
4. The sprinkler of claim 3, wherein said valve means has an
annular poppet valve member and said pipe member throat opening is
annular and provides a valve seat matingly receiving said valve
member, said valve member fixedly carrying a plurality of
downwardly depending circumferentially spaced guide pins defining
vertical guide surfaces for limiting eccentric movement of the
valve member relative to the inside annular surface of said throat
opening.
5. The sprinkler of claim 1, wherein said indexer comprises a pawl
rotatably mounted on said nozzle assembly and said pipe member has
affixed thereto a ring of pawl receiving teeth circumferentially
extending about said pipe member in cooperative relation with said
pawl when said nozzle assembly is in the retracted position, means
for rotation of said pawl in response to upward extension of said
assembly to advance a tooth engaging toe of said pawl relative to
said ring of teeth such that subsequent movement of said assembly
toward said retracted position moves said pawl toe into engagement
with said ring of teeth at the advanced position effecting an
increment of rotation of said nozzle assembly upon completion of
the retraction thereof.
6. The sprinkler of claim 5, wherein said indexer is further
defined by said axis of pawl rotation being normal to the axis of
said nozzle assembly and said pawl having a pair of teeth engaging
toes symmetrically oriented at spaced positions relative to the
axis of rotation thereof, spring bias means connected between said
pawl and nozzle assembly biasing said pawl in one or the other of
two selectable stable orientations and providing said means for
pawl rotation, each pawl orientation providing a different
direction of incremental rotation in response to vertical
reciprocation of said nozzle assembly, and direction control means
fixedly disposed relative to said pipe member for automatically
tripping said pawl from one stable orientation to the other at
preselected circumferential locations about said pipe member,
whereby said nozzle discharge is automatically incrementally
rotated in selected arcuate paths.
7. The sprinkler of claim 6, said indexer being further defined by
said pawl toes being positioned on opposite sides of the axis of
rotation thereof and said spring bias continuously urging rotation
of one or the other of said toes toward engagement with said ring
of teeth,
stop means fixedly carried by said nozzle assembly limiting
rotation of said pawl during upward extension of said assembly to
dispose one of the other of said toes in said advanced position
relative to said ring of teeth.
8. The sprinkler of claim 7, said control means for tripping said
pawl comprising:
a pair of pawl engaging control arms fixedly mounted relative to
said pipe member at spaced circumferential locations, and each arm
having catch portions disposed in the arcuate path of said pawl,
said pawl being formed with a shoulder adjacent each toe
individually cooperating with each arm at the ends of said arcuate
path to be engaged by said catch portion such that vertical
reciprocation of said nozzle assembly trips said pawl from one
stable orientation to the other.
9. A system of pressure actuated intermittent discharge sprinkler
units connected to a common water source, each sprinkler unit
comprising:
an accumulator adapted for connection to said water source for
accumulating water under increasing pressure,
a pressure actuated water delivery head including a normally closed
valve means, said head connected to said accumulator and said valve
means being responsive to an increasing water pressure therein to
intermittently discharge water to relieve the pressure in said
accumulator and resume its normally closed condition, and
a self-adjusting flow control valve connecting said accumulator to
said source of water such that periodic build-up and relief of
pressure therein is not communicated to said source and thus does
not adversely influence operation of the remaining sprinkler units
connected thereto.
10. In the system of claim 9, the provision in each sprinkler unit
of:
an upstanding pipe member having a throat opening at an upper end
and connected at an lower end to said accumulator,
a nozzle assembly slidably and rotatably mounted on said pipe
member for vertical reciprocation between retracted and extended
positions and having a directional nozzle for communicating with
said throat opening, said valve means carried by said nozzle
assembly and movable therewith downwardly to the retracted position
to close said throat opening of said pipe member and movable
upwardly to the extended position communicating said nozzle and
said throat opening, spring bias means urging said nozzle assembly
and valve means to said retracted position such that the
intermittent opening is accompanied by upward movement of said
nozzle assembly to said extended position until the pressure of
water in said accumulator is relieved by discharge through said
nozzle.
11. In the system of claim 10, each sprinkler unit head further
comprising a rotation indexer including ratchet means carried by
said nozzle assembly and said pipe member, said indexer translating
each vertical cycle of assembly reciprocation into an increment of
rotation thereof.
12. A pressure actuated periodic discharge sprinkler for subgrade
installation comprising:
a pipe member for vertical disposition below a grade level and
having a throat opening at an upper end thereof,
an annular guard skirt fixedly mounted with and coaxially
surrounding said pipe member adjacent said throat opening and
having an upper rim for disposition substantially at grade
level,
a nozzle assembly slidably and rotatably mounted on said pipe
member for vertical reciprocation between retracted and extended
positions and having a nozzle for communication with said pipe
throat opening, said nozzle assembly including a horizontally
mounted generally circular guard plate overlying said nozzle and
disposed to assume a substantially flush relation with said guard
skirt upper rim when said assembly is in its retracted
position,
valve means carried by said nozzle assembly and movable therewith
downwardly to a retracted position closing said throat opening of
said pipe member and movable upwardly to the extended position
communicating said nozzle and throat opening, and
spring bias means urging said nozzle assembly and valve means to
said retracted position such that water under pressure in said pipe
member overcomes the force of the bias means, forcing said valve
means and assembly to said extended position with said guard plate
and nozzle rising above the rim of said skirt for nozzle clearance
and water discharge until pressure is relieved.
13. The sprinkler of claim 12, wherein said nozzle of said assembly
is a primary nozzle having a relative large discharge passage and
further comprising a secondary nozzle underlying said primary
nozzle and having a relatively smaller discharge passage extending
generally parallel to said primary nozzle passage, said secondary
nozzle passage being disposed on said nozzle assembly such that a
jet of water discharge therefrom during downward movement of said
assembly toward its retracted position is intercepted by an upper
edge of said guard skirt rim causing radially outward spray
deflection of the secondary nozzle discharge jet and partially
evacuating accumulated water in an upper cavity region of said
guard member by a venturi action.
14. The sprinkler of claim 12, wherein said guard skirt member is
in the shape of an inverted truncated cone with the truncated end
circumferentially secured to said pipe member at a location spaced
below said throat opening and upwardly extending therefrom to
define said rim.
15. The invention as defined in claim 12 wherein said pipe member
is connected to a source of pressurized liquid, and including an
accumulator and a conduit communicating the accumulator with said
pipe member.
16. The invention as defined in claim 15 including flow control
means between said source and the conduit.
17. The invention as defined in claim 16 wherein said flow control
means comprises a self-adjusting valve having an opening
therethrough, the effective size of the opening varying in general
inverse relation to the difference of liquid pressure across the
opening.
18. The invention as defined in claim 15 wherein said accumulator
includes upper and lower variable volume chambers separated by
fluid impermeable means movable to change the volumes of the
chambers, the upper chamber being charged with a pressurized gas
and the lower chamber being connected to said conduit.
Description
BACKGROUND AND SUMMARY OF THE INVENTION
In general the present invention relates to sprinkler systems and
more particularly to a system in which each sprinkler head is
pressure-actuated for intermittent water discharge.
Conventional sprinklers apply water at a relatively high and
continuous rate. This characteristic leads to problems in designing
an efficient and effective irrigational sprinkler system. Because
of the high rate or intensity of the water delivered by
conventional sprinkler heads, run-off and leaching of the ground
are likely to result, since the soil is only capable of absorbing
water at a substantially slower rate. The time available for an
optimum irrigating cycle is typically several hours, yet
conventional sprinkler heads and systems deliver the total amount
of water required during such cycles in a matter of minutes.
Accordingly, in these conventional systems provision must be made
for actuating each sprinkler in the systems for a short interval
during the irrigating cycle. This is accomplished with manually
operated quick-coupler valves or with an automated control system
including electrical timers, switches, relays, control wiring and
remote control valves. Both approaches are expensive, the former in
terms of labor time and the latter by reason of the cost of
equipment. Furthermore, systems which employ automatic controllers
have been found generally unreliable, probably an inherent
characteristic resulting from their complexity. The cost of
maintaining one of these automatic systems is quite high, since
they are subject to failure not only in the controllers, valve and
sprinkler heads but also in the control wiring buried in the
ground. For example it has been found that these systems are
susceptible to damage by lightning
Still another disadvantage of these presently used systems is in
their requirements of a substantial supply or delivery rate to each
of the sprinkler heads in order to support the relatively high
water discharge rate thereat. This high delivery rate is required
even though each sprinkler head may be operated only for a short
interval, as dictated by the irrigation cycle. Nevertheless, since
the discharge during this interval is continuous, the high flow
rate must be sustained, and this in turn necessitates more
expensive pumping and piping capacity. The high flow rate demands
on the water supply also result in complicating the watering
schedules in that overlap conflicts can occur between two or more
automatic controllers, which if turned on at the same time result
in an excessive demand on the water supply system. This in turn
results in a reduced flow to the affected sprinklers thereby
leaving large ground portions unirrigated.
In general it is an object of the present invention to avoid the
foregoing disadvantages associated with conventional sprinkler or
irrigation systems by providing a sprinkler head and system in
which the water delivery to the ground is intermittent rather than
continuous, and the flow of water from the source is continuous
during operation. Prior efforts along these lines have been
attempted as exemplified by U. S. Pat. No. 3,321,138 to Curry, U.
S. Pat. No. 1,998,592 to Schenk and German Pat. No. 1,044,496 to
Moser. One reason why such previous attempts have not been
successful concerns their lack of any means to accurately control
the delivery rate to the individual pressure actuated sprinkler
heads in a system comprising a plurality of such heads. These prior
approaches have employed a throttling device, such as a fixed
restricted orifice to control the frequency of the water discharge.
Thus by using a throttling device, the rate of water flow or
admittance into an accumulator associated with one of these earlier
devices is variable, the rate increasing or decreasing as the
amount of water in the accumulator changes, thus decreasing or
increasing the water pressure therein. This results in a constantly
changing demand on the water supply system causing a fluctuating
pressure in the supply line which interferes with the operation of
the remaining sprinkler heads in the system. If one sprinkler in
such a system is found to be delivering too little water,
increasing the delivery rate to its accumulator will result in a
reduced delivery rate to the other sprinkler unit. This problem of
balancing the system and being unable to provide head-to-head
control over the various sprinklers has rendered such prior
intermittent discharge sprinklers unsuccessful for large scale
applications, for example on a golf course. Of course, where only
one sprinkler is required, for example the home use sprinkler as
illustrated in the Curry U.S. Pat. No. 3,321,138, this system
balancing problem does not exist.
Furthermore, most of these prior intermittent discharge sprinklers
are not adapted for permanent installation in an environment, such
as a golf course, where the sprinkler must be disposed so as not to
be an obstacle to the players or to lawn manicuring equipment.
Additionally this installation requirement must be met in
conjunction with a sprinkler head capable of delivering water at
substantial distances, such as a 100 foot radius per head.
Accordingly it is one object of the present invention to provide an
intermittent sprinkler head and system capable of covering a large
area per head and yet requiring a relatively low and constant rate
of water flow to each head. An advantage of this sprinkler system
is its ability to deliver water to the soil at a rate commensurate
with the soil's ability to absorb water. This in turn provides a
further advantage in that the total water usage rate for the entire
system is reduced to a minimum, and allows for concurrent operation
of all the sprinklers associated with one system. The need for
manual or automatic control of the individual sprinklers is
eliminated. A further object of the present invention is to provide
such a sprinkler head and system capable of being permanently
installed in environments where the sprinkler heads must not offer
obstructions to ground maintenance equipment.
It is an advantage of the present invention that each discharge
sprinkler requires only a relatively low volume flow rate for
operation such that the size of piping and the capacity of the
pumping equipment is minimized thus reducing the installation cost
of the system. Further advantages of the intermittent sprinkler of
the present invention are that, once installed, it is automatically
actuated merely by a straightforward manual or automatic control of
the main water line; that it is a relatively simple device and
inherently reliable; and that it is designed such that no water
hammer occurs and no pressure fluctuations are communicated to the
main water line.
These and further objects and advantages of the sprinkler and
system of the present invention will become apparent to those
skilled in the art from a consideration of the following detailed
description of an exemplary embodiment thereof. Reference will be
made to the appended drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a composite schematic and vertical sectional view of a
system in accordance with the present invention, including a
sprinkler unit with the parts in retracted position; and an
accumulator, partially in section to show the diaphagm in solid
lines in its lowermost position, and in dotted outline in its
uppermost position; other similar units are schematically shown,
together with a pump, a controlling timer and piping
interconnecting the several units making up a system;
FIGS. 2A and 2B are fragmentary vertical sectional views, on an
enlarged scale, of a preferred form of a flow control valve used in
the invention, respectively showing the valve in its maximum and
minimum flow rate positions, in response to pressure differential
across the valve.
FIG. 3 is an enlarged fragmentary sectional view of the valve
mechanism of the sprinkler head, taken along lines III--III of FIG.
1 thereof;
FIG. 4 is a fragmentary sectional view illustrating the sprinkler
head during active water discharge;
FIG. 5 is a fragmentary vertical sectional view of the sprinkler
head similar to FIG. 4 except illustrating the head as it
approaches retracted position;
FIG. 6 is a fragmentary top plan view taken from arrows VI--VI of
FIG. 5, the cover plate being partially cut away for clarity;
FIG. 7 is a sectional view taken along the arrows VII--VII of FIG.
4;
FIG. 8 is a sectional view taken along the plane VIII--VIII of FIG.
5;
FIG. 9 is a diagrammatic showing of the indexing mechanism of the
head;
FIG. 10 is a sectional view taken along the plane X--X of FIG. 5,
with the rotatable parts rotated substantially 90.degree.
counter-clockwise as seen in FIG. 10;
FIGS. 11, 12, 13 and 14 are fragmentary side elevational views,
with the lower portion of the bowl shown in section, illustrating
the rotation or indexing mechanism carried by sprinkler head 11
during various operating conditions as viewed from XI--XI of FIG.
10.
DETAILED DESCRIPTION
With reference to FIG. 1, the present invention provides a system
of pressure actuated intermittent discharge sprinkler units, such
as units 16, 17 and 18, connected to a common water source in this
instance provided by a water line 13. In detail, unit 16 includes a
sprinkler head indicated generally at 11, a gas biased water
accumulator 12 having an upper chamber 22 adapted to be precharged
with gas to a desired pressure and separated by a diaphram 20 from
an expandable volume lower chamber 23 communicating via conduit 24
with flow control valve 14 to receive water from line 13 such that
lower chamber 23 expands with an increasing volume of water thereby
decreasing the volume of chamber 22 and increasing the gas pressure
therein. A pressure actuated sprinkler head 11 including a normally
closed spring biased valve means, here in the form of poppet valve
26, is connected to chamber 23 of accumulator 21 through a conduit
27 and conduit 24. The spring biased valve means including poppet
valve 26 of each sprinkler head 11 is disposed to respond to
increasing water pressure in accumulator 12, caused by the increase
in gas pressure in upper chamber 22, to open against the spring
bias and discharge water through a nozzle as best illustrated in
FIG. 4 relieving the pressure in accumulator 12 and thus
subsequently returning to its normally biased closed condition.
While sprinkler system including an accumulator and pressure
actuated discharge head operating generally in this manner are
known, the present invention provides an improved cooperation
between these components and between the remaining pressure
actuated units, such as unit 17 and 18 by the provision of flow
control valve 14. Valve 14 regulates the flow, volume per unit
time, of water into accumulator 12 such that a constant flow is
achieved notwithstanding the periodic variation in the water
pressures within chamber 23 of accumulator 12 and within conduits
24 and 27 because of the intermittent actuation of head 11. Whereas
in previous systems the source of water, such as water line 13,
would fluctuate in pressure in accordance with the periodic
increase and decrease of water pressure within chamber 23 of
accumulator 12, the present invention substantially eliminates the
influence of each discharge unit, such as unit 16 on the available
water supply. In this manner the remaining discharge sprinkler
units, such as units 17 and 18 connected to source 13, operate from
a constant water supply pressure and thus each may be individually
adjusted for maximum efficiency and proper ground coverage.
Although flow control valve 14 may be provided by any of several
known devices, one commercially available unit utilizing a
resilient annulus 28 defining as best shown in FIGS. 2A and 2B a
variable cross section orifice 29 in response to the differential
pressure across the device has been found particularly suited for
this application. This device, available from the Dole Division of
Eaton Yale and Towne, Inc. Morton Grove, Ill., may be purchased in
several sizes and provides a self adjustment between a relatively
large orifice 29 when an inlet pressure P1 approaches an outlet
pressure P2 as shown in FIG. 2A, to a more constricted orifice 29
as shown in FIG. 2B where the outlet pressure P2 is substantially
less than the inlet pressure P1. Accordingly, in the combination in
the present invention annulus 28 of flow control valve 14 assumes
its restricted condition when the inlet pressure P1 is
substantially greater than the pressure within chamber 23 of
accumulator 12. As the pressure within chamber 23 increases with
the flow of water into accumulator 12, the outlet pressure P2 of
the flow control valve increases until it approaches the inlet
pressure such that the orifice 29 expands allowing the same flow
rate of water under the conditions of a lower differential inlet to
outlet pressure. This type of flow control valve is more fully
disclosed in U.S. Pat. Nos. 2,389,134 and 2,454,929.
Although in the illustration of FIG. 1, flow control valve 14 is
shown jointly connected to conduits 24 and 27 communicating with
accumulator 12 and head 11 respectively, it will be appreciated
that head 11 may alternatively be connected directly to chamber 23
of accumulator 12 through another opening therein so long as head
11 freely communicates with the water chamber 23 of the
accumulator. Similarly, flow control valve 14 could be connected
individually and directly to chamber 23 of accumulator 12 from
supply line 13 so long as valve 14 is not disposed serially within
the discharge path between the accumulator and the head.
Further in accordance with the present invention each pressure
actuated intermittent discharge sprinkler head 11 is comprised of
an upstanding pipe member 31, best shown in FIG. 4, having a throat
opening 32 at an upper end of member 31 and adapted at a lower end
for connection to a source of water under pressure. Such connection
is in this instance by means of a lower pipe extension 33 also
vertically disposed and connected to communicate with conduit 27 as
illustrated in FIG. 1. Thus pipe extension 33 and pipe member 31
define a vertically disposed passage upwardly from conduit 27 to
throat opening 32. A nozzle assembly 34 is provided having a sleeve
member 36 slidably and rotatably mounted on pipe member 31 adjacent
throat opening 32 for vertical reciprocation of nozzle assembly 34
between a retracted position as shown in FIG. 1 and an extended
position as shown by FIG. 4. A directional nozzle means including a
primary nozzle 37 and a secondary nozzle 38 are formed by assembly
34 adjacent an upper and closed end 39 of sleeve member 36 for
communication with throat opening 32 of pipe member 31 and
discharge of water outwardly in radially directional streams as
shown by FIG. 4. In order to provide selective opening and closing
of throat opening 32, a valve means in the form of poppet valve 26
is carried by assembly 34 for vertical reciprocation therewith
between a retracted position as it is shown in FIG. 1 with valve 26
closing the opening 32 and an extended position vertically spaced
from the retracted position so as to communicate throat opening 32
with nozzles 37 and 38 for water discharge as shown in FIG. 4. To
achieve this joint movement, poppet valve 26 is fastened to upper
end 39 of sleeve 36 by means of a rod 41 coaxially threaded to
valve 26 and extending upwardly therefrom through an opening in
closed end 39 and secured there by a nut 42 threaded on rod 41 for
tightening a lower shoulder 43 of nut 42 against an upper abutment
44 of enclosed end 39 with an annular washer seal 46 interposed
therebetween.
Nozzle assembly 34 and poppet valve 26 are jointly biased in the
retracted position with throat opening 32 closed by means here in
the form of an elongate coiled spring 47 coaxially mounted within
pipe member 31 and being connected between valve 26 and member 31
to provide a spring bias continuously urging nozzle assembly 34 to
the retracted position. An upper end 48 of spring 47 is disposed so
as to circumferentially abut a downwardly facing circumferential
flange 49 fixed relative to pipe member 31 underlying throat
opening 32 while a lower end 51 of the spring is connected to valve
26 by a linkage means here in the form of a lower integral
extension of rod 14 and a bracket 52 threaded to rod 41 with the
rod upwardly extending therefrom to its threaded engagement with
valve 26 as best illustrated in FIG. 4. Bracket 52 is formed with
an annular flange portion 53 providing an upwardly facing abutment
for the lower end 51 of spring 47 and being connected to a portion
54 threaded to rod 41 by means of a plurality of circumferentially
spaced struts 56 providing in cooperation with an annular opening
57 in flange 53 for the free flow of water upwardly toward throat
opening 32 as illustrated by arrow 58 in FIG. 4. Spring 47 is
placed in compression between flange 53 and flange 49 with bracket
52 being longitudinally adjustable on threaded rod 41 for varying
the amount of spring bias supplied on valve 26 and nozzle assembly
34 and with lock nut 55 securing the assembly.
In particular, spring 47 under compression provides a threshold
force holding valve 26 in a closed position against a force on the
lower exposed face of valve 26 by reason of the water pressure
within pipe member 31. With reference to FIG. 3, this water
pressure in member 31 is applied to the area of valve 26
circumscribed by opening 32 and when this force exceeds the bias
force of spring 47 by reason of the increasing water pressure
within accumulator 12, poppet valve 26 is forced upwardly off a
valve seat 61 at throat opening 32. Once poppet valve 26 unseats,
an additional pressure receptive area is exposed to the accumulated
water pressure within member 31 causing the valve to rise very
rapidly and carry nozzle assembly 34 with it upwardly to the
extended position as shown in FIG. 4. The additional surface area
of valve 26 is provided by the lower radially outermost
circumferential surfaces 62 of the valve as best illustrated by
FIGS. 3 and 4. As indicated above this operation communicates
opening 32 with nozzles 37 and 38 effecting a water discharge
therefrom with such discharge continuing at varying intensity until
the pressure is relieved within member 31 at which time the bias of
spring 47 predominates, forcing assembly 34 and valve 26 to return
to the retracted position as shown by FIG. 1.
It is observed that the upper limit of vertical movement of
assembly 34 is determined solely by the balancing of the spring
force against the water pressure at the throat of member 31. Thus
there is no wear or potential breakage due to impact against
mechanical limits.
In the retracted position, an O-ring seal assembly, consisting of a
valve seat member 60, an O-ring 63 and an O-ring retainer 65, is
provided at opening 32 for sealing engagement between a
circumferential shoulder 64 formed on the lower surface of poppet
valve 26 and O-ring 63 as best illustrated in FIGS. 3 and 4.
Additionally, to effect a rapid opening of valve 26 when the water
pressure within pipe 21 reaches the threshold level, member 31 is
provided with a circumferential flange adjacent throat opening 32
having a vertically extending annular wall 66 rising above and
circumferentially surrounding valve seat 61 for inhibiting water
leakage between surface 62 and the seat 61 engageable therewith by
reason of the 90.degree. corner which water leakage must follow in
order to escape. Such leakage which might otherwise occur as the
water pressure approaches the threshold level, meets the obstacle
provided by the circumferential vertical wall 66 and is redirected
to apply additional pressure against the lower surface 62 of the
valve so as to force it rapidly upwardly to its open position. It
is also observed that in accordance with the operation in the
present invention, the continual inflow of water through control
valve 14 as the pressure within accumulator 12 and pipe member 31
approaches the threshold discharge pressure facilitates the rapid
opening of the valve mechanism.
In order to guide poppet valve 26 between its retracted and
extended positions, a plurality, in this instance four downwardly
depending guide pins 71 secured at the upper ends thereof to
circumferentially spaced locations of poppet valve 26 so as to
define vertical guide surfaces slidably engaging an inside annular
surface of O-ring retainer 65 at throat opening 32 as illustrated
by FIGS. 3 and 4. Pins 71 are of sufficient length so that their
lower ends extend below opening 32 when assembly 34 and valve 26
are in their most upwardly extended position, such that upon
retraction the pins effectively guide the lower surfaces including
shoulder 64 of valve 26 into sealing engagement with the O-ring
assembly.
In addition to the vertical reciprocation of nozzle assembly 34
relative to upstanding pipe member 31, the assembly is also
rotatable relative to pipe 31 and a rotation indexing means is
provided in the form of ratchet means 76 as best shown in FIGS. 8
through 14, carried by nozzle assembly 34 and pipe member 31 for
translating each vertical cycle of reciprocation of the assembly
into an increment of rotation thereof. In this manner, directional
nozzles 37 and 38 discharge jets of water in a laterally or
radially outward and upward trajectory, and are indexed circuitely
to a new radial direction during each cycle of operation. In
particular the indexing ratchet means 76 includes a pawl 77
rotatably mounted to nozzle assembly 34 adjacent a lower edge 78 of
sleeve member 36 so as to dispose the pawl in a position for
cooperating with a crown ratchet 79 providing a plurality of pawl
receiving notches or teeth 81 circumferentially extending about
pipe member 31 and fixed relatively thereto by a plurality of bolts
82 mounted in a base flange 83 of pipe member 31. Flange 83 also
provides a junction for joining the lower end of pipe member 31 to
pipe extension 33 as shown. An axis of rotation 84 for pawl 77
extends in a direction normal to the longitudinal axis of sleeve 36
of nozzle assembly 34 and the pawl is formed with a pair of toes 86
and 87 symmetrically spaced about axis 84 for movement into
engagement with teeth 81 of crown ratchet 79. In particular pawl 77
is biased by spring 88 connected between the pawl and nozzle
assembly 34 as illustrated to dispose pawl 77 in one or the other
of two stable orientations relative to nozzle assembly 34 and teeth
81, each orientation providing incremental rotation of the nozzle
assembly in one angular direction or the other.
In the position shown by FIG. 5, pawl 77 is in an orientation in
which spring 89 urges toe 86 toward teeth 81. With this orientation
in mind and with reference to FIG. 9, as nozzle assembly 34
responds to a threshold discharge pressure, it is driven upwardly
to an extended position whereby toe 86 disengages from teeth 81
allowing spring 89 to rotate pawl 77 about axis 87 until an
abutment 91 adjacent toe 86 engages a limit stop provided by stub
92 as illustrated in FIGS. 5 and 9. This permits toe 86 to advance
its position relative to teeth 81, in this instance moving a notch
from left to right as viewed in FIG. 5. Subsequent return of
assembly 34 toward its retracted position causes toe 86 of pawl 77
to engage teeth 81 at the advanced position as best illustrated in
FIG. 9 by the phantom representation of pawl 77. Upon completion of
the retraction cycle, toe 86 abuts a face 93 of one of teeth 81 at
the advanced tooth position causing a camming action forcing axis
84 of pawl 77 and sleeve 36 of the nozzle assembly to rotate from
left to right or in a counter clockwise direction when viewed from
the top of the assembly. Thus as illustrated by FIG. 9, a vertical
upward extension and subsequent retraction of axis 84 of pawl 77
over a distance a is translated into an increment of rotation of an
amount b with pawl 77 assuming the position shown by the solid
lines in FIG. 9 when nozzle assembly 34 is in its fully retracted
position. As described herein, means are provided for moving nozzle
assembly 34 back and forth through arcuate segments less than a
full 360.degree. of rotation and for this purpose pawl 77 includes
the additional toe 87 symmetrically spaced from toe 86 on an
opposite side of axis 84 and an additional stop in the form of stud
98. Spring 88 is joined to pawl 77 at connection 93 overlying axis
84 and continuously urges connection 94 of pawl 77 away from a
connection 96 to sleeve 36 such that pawl 77 may be shifted from
its present position in which toe 86 is urged toward teeth 81 to
another stable orientation in which connection 94 on the pawl is to
the right of connection 96 so as to urge toe 87 toward teeth 81.
This other orientation of pawl 77 is illustrated by FIG. 14 and
provides for rotating nozzle assembly 34 in a right to left
direction as viewed in FIG. 5 or a clockwise rotation as viewed
from the top of the assembly.
One of the features of the present invention is best illustrated in
FIG. 9 in which toe 86 with pawl 77 and nozzle assembly 34 in the
retracted position is angulated relative to abutment face 93 of
teeth 81 so as to provide a slippage angle therebetween for
semi-free rotation in the event of accidental rotation of the
nozzle assembly. Such rotation, which may for example be
inadvertently caused by an eccentric engagement of the wheel of a
vehicle with a top guard plate 97 of assembly 34 can occur in
either a clockwise or a counter clockwise direction and with either
of toes 86 or 87 engaged with teeth 81. In this manner, damage to
the indexing mechanism of sprinkler head 11 is avoided thus
providing a distinct advantage over many conventional sprinkler
heads and systems in which rotation is achieved by gear mechanisms.
Notwithstanding the slip action of pawl 77, the incrementation
provided thereby is positive and trouble free. In the present
embodiment, which provides a primary jet discharge of up to 100
feet, each increment of rotation provides a 3.degree. positive
rotational step such that a uniform distribution of water is
achieved over the preselected area to be covered. The 3.degree.
step is provided by dividing crown ratchet 79 into 120 equally
dimensioned teeth.
Mounted at preselected circumferential locations about said pipe
member 31 are a pair of upstanding trip control arms 111 and 112 as
best shown in FIGS. 5 and 10 for automatically shifting pawl 77
from one stable orientation to the other. This causes change in the
direction of incremental rotation of nozzle assembly 34 at each of
the control arms and thereby provide sprinkler head 11 with arcuate
discharge patterns less than 360.degree.. For example, by disposing
the control arms at positions generally 180.degree. from each other
as shown for control arms 111 and 112 in FIG. 10, a semicircular
discharge pattern for nozzle assembly 34 is achieved. Arms 111 and
112 are in this instance secured by bolts 82 at the 180.degree.
opposed locations and with four such bolts 82 as shown, any desired
arcuate pattern of one quarter circle (90.degree.), half circle
rotation (180.degree.) or three quarters circle rotation
(270.degree.) may be obtained merely by selective positioning of
arms 111 and 112.
Each of arms 111 and 112 is formed with a catch portion 113 and 114
respectively defined by the junction of a relatively slender leg
116 and 117 with an upper flange 118 and 119 bent at right angles
relative to the legs 116 and 117 of arms 111 and 112 respectively.
Catch portions 113 and 114 defined generally downwardly facing
abutments turned inwardly toward the arcuate path followed by pawl
77.
During operation, pawl 77 may be disposed with a toe 86 biased by
spring 88 so as to cooperate with teeth 81 rotating assembly 34 and
pawl 77 in a direction toward control arm 112 as illustrated by
FIGS. 10, 11 and 12. Each of the arms, in this instance arm 112, is
disposed with the catch portion, in this instance catch portion
114, in the arcuate path of pawl 77 as nozzle assembly 34 rotates
pursuant to the incrementation. As pawl 77 approaches arm 112, toe
87 opposite the functioning toe 86 moves into engagement with
flange 119 and on a downward stroke of assembly 34 toe 86 cams
against one of the teeth 81 forcing toe 87 into flange 119
deflecting arm 112 as illustrated in FIG. 12. Control arms 111 and
112 are formed of a spring metal or other material of suitable
strength and resiliency and each of these legs is relatively
slender to provide an elastic deformation when disposed in the
condition of arm 112 as shown in FIG. 12.
Toes 86 and 87 of pawl 77 are in this instance formed by integral
tabs 121 and 122 extending outwardly at right angles on opposite
sides of axis 84 from a rotatably mounted pawl body 123 and thereby
defining generally upwardly facing shoulders 126 and 127 engageable
with catch portions 113 and 114 of the control arms respectively.
In particular, with reference to FIGS. 12 and 13 as assembly 34
completes its downward stroke into the retracted position toe 87
engages flange 119 and deflects arm 112 until toe 87 slides under
flange 119 allowing arm 112 to return to its generally upright
disposition disposing catch portion 114 above shoulder 127 of tab
122. Subsequently on the next upward storke or extension of
assembly 34 as shown by FIG. 14, catch portion 114 engages shoulder
127 of the pawl, restraining toe 87 from further upward movement
and thus tripping the pawl to a position as illustrated by FIG. 14.
Toe 87 is thus biased toward teeth 81 for incrementing assembly 34
in a right to left hand direction or clockwise rotation as viewed
from the top. The same tripping function occurs at the other end of
the arcuate path this time with shoulder 126 cooperating with catch
portion 113 of control arm 111.
With reference to FIGS. 1 and 5 each of the sprinkler units
including a pressure actuated head 11, and accumulator 12 and a
flow control valve 14, is adapted to be installed below a grade
level 131 to recess the various components, so as not to obstruct
or interfere with the use of the grounds. For this purpose, each
sprinkler head 11 is provided with an annular guard skirt 132 here
having the shape of an inverted truncated cone with the truncated
end being disposed circumferentially about and fixed to a lower end
of the pipe member 31 and in this instance being an integral
casting portion of pipe extension 33. Guard skirt 132 thus slopes
upwardly and outwardly from its secured truncated end to define an
upper rim 133 which is adapted for disposition at or slightly above
grade level 131 as shown by FIGS. 1 and 5. During installation the
conduit leading to pipe extension 33, in this instance conduit 134
is positioned relative to grade level 131 such that guard skirt 132
and pipe extension 33 when threadedly secured to conduit 134
disposes rim 133 as shown substantially at grade level. In this
manner guard skirt 132 retains the surrounding soil or grade
material from interfering with nozzle assembly 34 or the indexing
mechanism associated therewith. Pipe member 31 extends upwardly
from section 33 and thus from the lower end of guard skirt 132 to
throat opening 32 which is vertically spaced below rim 133 of the
guard skirt such that nozzle assembly 34 assumes in its retracted
position a disposition substantially as shown by FIG. 1 in which
the upper enclosed end 39 of assembly sleeve member 36 is just
slightly below grade level 131. Nozzle assembly 34 carries at the
upper end thereof a cover or guard plate 97 having a circular
periphery and suitably fastened by means such as screws 136 to a
raised circumferential wall 137 of sleeve member 36 adjacent
enclosed end 39 as illustrated with raised wall 137 cooperating
with a recess 138 in plate 97 to provide clearance for nut 42 and a
lock screw 139. The perimeter of plate 97 is shaped to matingly
seat with rim 133 as shown at 141 providing further protection of
nozzle assembly 34 against debris or the like and forming a
generally flat horizontal platform substantially coplanar with the
surrounding grade level 131 and flush with guard skirt rim 133 when
nozzle assembly 34 is in its retracted position. Plate 97 has in
this instance a notched portion 140 adjacent the perimeter thereof
and overlying nozzle 37 for clearance of the jet discharge
therefrom.
During installation, following the placement of pipe extension 33
and integral guard skirt 132, upstanding pipe member 31 may be
disposed in place and secured together with crown ratchet 79 and
control arms 111 and 112 by means of bolts 82 extending through and
securing base flange 83 of member 31 to a circumferential seat
formed by the connection of skirt 132 to the pipe extension 33. An
annular seal 142 is disposed between flange 83 and the
circumferential seat defined by extension 33 and guard skirt 132.
Thereafter nozzle assembly 34 may be mounted in place and with
guard plate 97 removed, nut 42 and lock screw 139 may be installed
to secure assembly 34 to rod 41 and valve 26 as shown in FIG. 4.
Finally guard plate 97 may be mounted in place.
It is observed that by this construction, pipe extension 33 serves
to house the lower half of spring 47 and bracket 52 and moreover to
guide bracket 52 in its vertical reciprocation by means of splines
143 formed longitudinally on the interior wall of pipe section 33.
The outer peripheral edge of annular flange portion 53 thus
slidably engages splines 143 as best shown by FIG. 8.
Further in accordance with the present invention nozzle assembly 34
is comprised of a primary nozzle 37 having a discharge passage 146
extending through sleeve 36 in a direction radially outwardly
therefrom sloping upwardly from the horizontal to define a
trajectory for a primary discharge stream 147 having a trajectory
angle of about 30.degree. from the horizontal for efficient water
coverage by the discharge. Passage 146 is formed with a plurality
of longitudinal vanes 148 and a tapered nozzle portion 149 for
forming jet stream 147 with the tapered portion 149 being defined
by a removable plastic nose piece 151.
It is observed in connection with primary nozzle 37 that discharge
head 11 functions in combination with a precharged accumulated 12
for maximum efficiency. In particular accumulator 12 is precharged
in upper chamber 22 with a gas pressure of approximately 60 psi via
access hole 153 and a normally secured valve means 154
communicating with upper chamber 22. Relative to this precharge
pressure of 50 to 70 psi, spring 47 is selected to provide when
adjusted by bracket 52, a threshold valve opening or discharge
pressure of 100 to 120 psi. This relatively high operating pressure
range for head 11, available by virture of the prechargeable
accumulator 12, permits primary nozzle 37 to operate most
efficiently. Nozzles operating under lower pressure limits do not
provide sufficient stream breakup which in turn results in
relatively large drops of water causing turf damage and the like by
reason of the heavy impact. Efficient stream breakup as provided by
the present invention results in a finer spray and more effective
irrigation.
In this instance accumulator 12 is provided with a diaphram 20
which prevents absorbtion of the gas into the water. with the lower
chamber 23 filled with water, immediately prior to discharge,
diaphram 20 assumes a disposition as shown in phantom in FIG. 1,
and the gas in the upper chamber 22 is at or approaching its
highest pressure in the cycle of operation. A suitable accumulator
for this purpose is available from Greer Olaver Product Division of
Greer Hydraulics, Inc., Los Angeles, Calif.
Another aspect of the present invention is the disposition of a
secondary nozzle 38 extending parallel to and underlying nozzle 37
and having a substantially smaller discharge passage 156 relative
to the dimensions of passage 146. With reference to FIGS. 4 and 5,
secondary nozzle 38 provides a secondary stream 157 which is in
this instance moderately broken up by a finger 158 carried by
nozzle 38 at the opening of passage 156, for providing water
delivery to the ground areas close to head 11. Stream 147 which
provides effective coverage at greater distances is not efficient
for those areas immediately surrounding the head. The close-in
coverage of secondary nozzle 38 is aided by an orientation of
nozzle 38 in accordance with the present invention by which stream
157 thereof is intercepted by rim 133 of skirt 132 during downward
retraction of assembly 34 as best shown in FIG. 5 to cause a
dispersion of stream 157 as shown at 159 for effective close-in
water delivery.
An important function of this placement of nozzle 38 is to achieve
a partial evacuation of water which unavoidably and undesirably
accumulates in the bowl region defined by skirt 132 and which but
for the action of nozzle 38 would cause a water puddle surrounding
head 11. In particular, stream 157 during the downward stroke of
assembly 34 causes a venturi-like effect adjacent the upper regions
of skirt 132, thus pulling the water from this upper region and
dispersing it at 159 such that the accumulated water assumes a
level approximately as shown at 161 when the assembly is fully
retracted. The evacuated upper region thus provides sufficient air
space for the retraction of assembly 34 without causing a plunging
action forcing water to spill over rim 133 and flood the
surrounding area.
Although accumulation of water within skirt 132 has been found
generally unavoidable, it is to a certain extent minimized by the
provision of an annular seal 162 fixedly carried by an interior
wall of sleeve member 36 and slidable relative to an exterior
surface of pipe member 31 so as to discourage leakage of water from
the lower end of sleeve member 36 during discharge when nozzle
assembly 34 is in its extended position. Accompanying annular seal
162 are a pair of annular bearings 163 and 164 each in this
instance provided by a cylindrical section of Teflon (Trademark
owned by Du Pont) material mounted within annular recesses of
sleeve member 36 as shown in FIG. 4.
Accordingly, any number of sprinkler units may be provided, as
units 16, 17 and 18 as shown by FIG. 1 and connected to a common
source of water in this instance via supply line 13. Each of the
units may be separately adjusted for individualized water coverage
by changing the precharge pressure on accumulator 12, adjusting the
compression force in spring 47 to change the threshold discharge
pressure of head 11 or by changing the size of flow control valve
14. Typically it will be desirable to provide a pressure on line 13
of approximately 100 to 120 psi so as to meet the threshold
discharge pressure of each of the sprinkler heads. This may be
provided by a pump 166 connected to a water main at a pressure
substantially lower than 100 psi (not shown) and operated by
suitable control means which in this instance is shown by timer
167. With this arrangement pump 166 provides sufficient pressure at
a relatively low flow rate sufficient for example to supply each
sprinkler unit with 3 to 4 gallons per minute, over line 13 to the
accumulators, accumulator 12 for unit 16, 12' for unit 17 and 12"
for unit 18, through individual flow control valves 14 for unit 16,
14' for unit 17 and 14" for unit 18. Each of the pressure actuated
discharge heads, head 11 for unit 16 and heads 11' and 11" for
units 17 and 18, responds to the accumulation of water within each
of the respective accumulators to intermittently discharge the
built-up water pressure in accordance with the more detailed
description set forth above. For a typical precharge pressure in
each of the accumulators of 60 psi, corresponding to the pressure
at which the valve returns to its retracted or closed condition
following a discharge and a threshold discharge pressure of 100
psi, at which the valve opens, the cyclic rate of the present
embodiment of head 11 is three discharges per minute, each
discharge lasting for approximately one half of a second. With this
embodiment of the invention operating with these pressures, a
discharge range of up to 100 feet is achieved for the stream
discharged by primary nozzle 37.
It is observed in connection with the overall operation of the
system that the various discharge heads do not produce undesirable
water hammer effects on the supply line. Each head opens in
response to the rising pressure in the associated accumulator and
commences to close smoothly as the increasing restorative force of
spring 47 overcomes the decreasing water pressure against valve 29
at throat opening 32. Thus the sprinkler system in accordance with
the present invention does not strain the supply line and pumping
equipment with repeated water hammer effects each time the various
heads operate.
* * * * *