WO1998024553A1 - Multi-tube sprinkler hose - Google Patents

Abstract

This invention is directed toward the field of hoses, more particularly hoses for the even delivery and distribution of pressurized water, and most particularly a flexible plastic sprinkler hose (5) having three contiguous tubes with two perforated outer tubes (12 and 14) for spraying water outwardly to the surrounding areas to be watered, and a closed-end imperforate central tube (15) for maximizing water volume and flow in the two perforated tubes (12 and 14). The closed-end imperforate central tube (15) also equalizes water pressure along the length of the hose to cause the hose (5) to lie flat and extended when in use.

Description

MULTI-TUBE SPRINKLER HOSE

FIELD OF THE INVENTION

This invention is directed toward the field of hoses, more

particularly hoses for sprinkling pressurized water, and most particularly

to a sprinkler hose having three contiguous tubes with two perforated

outer tubes and a closed-end imperforate central tube for maximizing

water volume and flow in the two perforated tubes. The closed-end

imperforate central tube also equalizes water pressure along the length

of the hose to cause the hose to lie flat and extended when in use.

BACKGROUND OF THE INVENTION

With the increase in population, water is increasingly used

and shortages occur more frequently. Accordingly, water has become

a more important and scarcer resource that is necessary to conserve.

Cultivation of crops, gardens, lawns, foliage, cultivation benches,

planters and all other outdoor places of cultivated growth are all

important areas of water use. Soil sprinkling devices have been

developed for applying water to these areas in need of supplemental watering. Sprinkling devices must be able to conserve water and

provide adequate saturation without flooding to allow for sufficient

growth while minimizing water loss.

Previous patents disclose water sprinkling hoses. For

instance, U. S. Patent No. 2,730,404 issued to Meisinger, et al.,

discloses a flexible lawn sprinkler hose having two side passages, a

central upper passage and a central lower booster passage. The two

side passages and the central upper passage have perforations to

sprinkle water. The central lower booster passage is open ended to

boost the pressure at the hose ends and give more uniform water jets

throughout the length of the hose. U. S. Patent No. 2,739,842 issued

to Andrews also discloses a coupler and multi-tube sprinkler hose.

In view of the state of the art, more efficient and

inexpensive systems for the uniform delivery of water are still needed.

There is particular need for an advanced low cost multi-tube sprinkler

hose that effectively irrigates crops, cultivation benches, lawns, foliage,

planters and the like, without flooding the vicinity or region immediate

to the hose. This sprinkler hose must be suitable for use with common

pressures and provide a slow, thorough even distribution of water.

SUMMARY OF THE INVENTION

This invention is directed to a flexible sprinkler hose for the

even delivery and distribution of pressurized water. More particularly,

the invention comprises an extruded flexible plastic sprinkler hose having a water inlet end for coupling to a pressurized water source and

three contiguous tubes aligned lengthwise with two perforated outer

tubes for spraying water outwardly to the surrounding areas to be

watered along the length of the hose. A closed-end imperforate central

tube lies between and has a common wall with the two outer tubes.

The closed-end tube equalizes water pressure along the length of the

hose from the water source. The three-tube hose maximizes water

volume and flow in the outer perforated tubes of the hose. In a

preferred form, the hose has a flat bottom and a generally arcuate top

spanning from one edge of the bottom along its length. A reinforcing

rib is formed between the outer ribs, and this rib facilitates perforating

the outer tubes.

In the most preferred form, the central tube has a cross-

sectional V-shaped or generally triangular-shaped configuration. Each

of two sides of the triangle form a common integral wall with each

outer tube. In one form, each side wall begins at opposing upper inner

points of the two outer perforated tubes and converges to a V-shaped

point approximately at the center of the bottom of the hose. In another

form, the triangular side walls form a V-shaped point approximately at

the top of the hose. In either form the cross-sectional triangular-shaped

central tube configuration provides increased volume and flow of water

in the outer perforated tubes. In a most preferred form of the invention, the plastic hose

comprises a water inlet end for coupling to a water source for delivery

of water at pressures ranging from about 25 to about 1 20 psi. The

extruded hose has a flat bottom wall and a ribbed arcuate top wall

spanning from one edge of the bottom wall to the other forming

therebetween three contiguous tubes aligned lengthwise. The hose

walls preferably have a thickness of approximately 0.20 to

about 0.1 20 inches.

The present invention is also directed to a method of

making a flexible plastic sprinkler hose. The method, in its most

preferred form, comprises extruding a thermoplastic polymer

composition for forming a hose divided into the three contiguous tubes

as described above. Spray holes are formed in the two outer tubes

along the length of the hose. The spray holes in the outer tubes may

be formed by manual puncture, by automatic injected needles, laser, or

any other nonmechanical means. The hose configuration of flat bottom

and arcuate-ribbed top facilitates the perforation of the outer tubes.

In accordance with the novel features and embodiments

of this invention which will become further apparent hereinafter, the

present invention will be described with reference to the detailed

description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a partially broken-away perspective view of an

embodiment of a hose of the present invention with the coupling end

shown in partial cross-section.

Fig. 2 is a cross-sectional view taken along line 2-2 of the

hose of Fig. 1 illustrating the three contiguous tubes and one form of

the triangular cross-section of the central tube.

Fig. 3 is a cross-sectional view of another embodiment of

the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now more particularly to the Figures in which like

reference to characters indicate like elements throughout, Fig. 1 shows

a partially broken-away perspective view of a preferred embodiment of

a flexible sprinkler hose 5 of the present invention with the inlet

coupling end 6 shown in partial cross-section. The inlet end 6 of the

hose 5 has a female coupling 7 for attachment to a pressurized

household water source or to another section of hose. The opposite

end of the hose 5 is closed by a metal end cap 13 that is crimped onto

hose 5. Sized to fit inside the female coupling 7 is a coupling

washer (not shown) for additional securement and seal against leakage

when the female coupling 7 is secured onto the pressurized water

source for the delivery of water. Tubes 12 and 14 are perforated with

holes 20 which provide for uniform sprinkling therethrough to the surrounding areas along the length of hose 5. The closed-end

imperforate central tube 15 with its cross-sectional triangular-shaped

wall configuration, and common integral walls 18 and 19, maximizes

water flow and volume in the outer perforated tubes 12 and 14 to

sprinkle water outwardly. An end cap 13 to equalize water pressure

along the length of the hose to stabilize the hose and cause it to lie flat

and extended.

Fig. 1 further illustrates the hose inlet 6 with an external

ferrule 16 and an internal corrugated connector 17 to form a standard

female coupling connector 7 for crimping to the end of hose 5.

Crimping is the procedure that is used to securely fasten connecting

couplings. Briefly explained, a hardened steel collet (not shown) is

inserted into connector coupling 7 with connector 17 that has been

placed into hose 5 end. Hose end 5 is first prepared by slitting or

cutting the common internal walls 18, 19 at the end of hose 5 to allow

the connector 17 to be inserted for crimping. A tapered shaft (not

shown) is then driven forward deforming some portion of the

connector 17 inside the hose 5 in a corrugated pattern and creating a

leak-proof seal by wedging the wall of hose 5 between the deformed

connector 17 and an opposingly corrugated ferrule 16. The crimping

is done in a corrugated fashion, i.e., there are areas of greater and

lesser compression, thus allowing for a better seal of the wall of hose 5

with coupling connector 7. A male connector coupling (not shown) could be attached the same way as a female connector coupling in

place of end cap 13 which may then be sealed by a screw cap (not

shown). This arrangement would allow the user to connect multiple

hoses in series to allow for watering a much greater area than one hose

would cover. Thus, in a preferred embodiment of the present invention,

a flexible plastic sprinkler hose is adapted to be coupled at the inlet end

with standard metal or plastic annular couplings can be used. Plastic

couplings can be molded onto the hose, if desired. An opposite or

closed end of the hose can be sealed by closed end plastic or metal

fittings in a fashion well understood in the art, or may have a further

connection for attachment to another section of hose.

Also shown in Fig. 1 , the outer tubes 12 and 14 have a

plurality of holes 20 for projecting streams of water outwardly by water

delivery through the tubes 12, 14 under pressure. Central tube 15 does

not contain perforations, rather it is imperforate to equalize the pressure

from the inlet end 6 to the closed-end.

Fig. 2 is a cross-sectional view of Fig. 1 taken along

line 2-2 of Fig. 1 through holes 20. In this preferred embodiment of the

invention, a flexible plastic garden sprinkler hose 5 is provided for

coupling to a water source at pressures ranging from about 25 to

about 1 20 psi. The extruded hose 5 has a flat bottom wall 8 and a

ribbed arcuate top wall shown generally at 9 spanning from one edge

of bottom wall 8 to the other edge forming therebetween the tops of three contiguous tubes 12, 14 and 1 5 aligned lengthwise along the

same plane. The walls of hose 5 preferably have a thickness of

approximately 0.20 to about 0.1 20 inch. The closed-end imperforate

central tube 15 forms common walls 18, 19 between two perforated

outer tubes 12 and 14. The central tube 15 with its two internal

walls 18 and 19 form a cross-sectional triangular configuration with

wall 21 for maintaining and equalizing pressure along the hose length

while maximizing water volume and flow in outer perforated tubes 12

and 14. In this preferred form, the outer wall 21 of the central tube 15

forms a rib between opposed upper inner points of outer perforated

tubes 12 and 14. The walls 18, 19 converge to a point approximately

at the center of the bottom of the hose as shown in Fig. 2.

The plastic sprinkler hose 5 may be formed of vinyl plastic,

such as polyvinyl chloride (PVC). Other polymers such as natural or

synthetic rubber or rubber-thermoplastic blends may be used for the

sprinkler hose. This sprinkler hose is made by standard extrusion

techniques through a die configured to provide the hose shown in

Figs. 1 and 2 under conditions well known in the art. For example, a

blended hose composition comprises (by weight) a polyvinyl chloride

(PVC) resin 40-50%, plasticizer 1 5-20%, lubricant 1 .5-2.5%, stabilizer

1 -5%, and filler, such as calcium carbonate, 1 0-25%. The extruded

sprinkler hose of PVC has a wall thickness of about 0.1 -0.2 inch and

perforations to deliver 1 -2 gallons per minute along approximately a 50-foot length. Although the hose inside diameter (ID) may vary, the

ID is approximately 0.5 to 3 inches given an inside configuration with

the internal walls 18,19 removed at hose 5 end.

In another embodiment, the hose 5 may serve as a

combined soaker and sprinkler hose. In this form, the hose is made to

have a microporosity to weep along its length and also sprinkle water

through holes 20. The closed-end central tube 15 is essentially or

substantially imperforate to perform its stabilizing functions of equalized

water pressure and water flow in outer sprinkler tubes 12,14 as

detailed above. The microporosity of the hose 5 can be controlled to

provide these dual functions. The composition of the flexible sprinkler/

soaker hose essentially contains from about 30-50% by weight of

thermoplastic binder resin, about 60-70% by weight, preferably

63-67% by weight, of discrete elastomer or rubber particles. Further,

the composition may contain optional ingredients such as small

amounts of lubricants or slip agents to aid in mixing and extruding the

hose. The moisture content of the rubber particles is maintained below

1 .0% by weight, usually below 0.5% by weight, and preferably as low

as possible, such as no more than 0.1 % by weight. Moisture can be

removed from the rubber particles by passing them through a drier

before feeding to the extruder. The thermoplastic binder resin has a

melting temperature suitable for extrusion of the microporous hose,

generally from 250° F to 450° F, usually from 275° F to 350° F. The resins can be polyolefins or polyvinyl resins. Polyethylene resins are

preferred due to their flexibility, inertness and extrudability. The

polyethylene can be of the high density or low density types. Low

density resins having a density below 0.95, usually 0.92-0.94, provide

products with better flexibility and elongation, especially linear low

density (LLD) polyethylene which has less chain branching and a

narrower molecular weight distribution. The elastomer particles are

prevulcanized. They remain discrete and do not dissolve in the binder

resin. The particles are preferably reclaimed rubber recycled from the

tread portion of used tires or other sources. They also can be virgin

rubber such as flashings from tire manufacture. The rubber is ground

to a particle size excluding large particles above about 40 mesh.

Excessive fines should b e avoided. A preferred product is a 30 mesh

granular reclaimed rubber having a moisture contend as delivered of no

more than 0.5% by weight.

In the sprinkler/soaker hose, a mixture of binder resin and

rubber particles is formed into the hose 5 of the present invention by

continuous extrusion. Venting is not necessary to produce high quality

hose. The extruder barrel is heated to a temperature above the melting

point of the binder resin. In the case of low density polyethylene, the

extruder barrel is heated to a temperature from 250° F to 450° F. The

die is generally separately heated to a temperature from 300° F to

400° F. The extruder may contain compression and mixing sections or can contain a single screw with continuous spiral thread. The resin and

rubber particles can be premixed in a mixer such as a ribbon blender.

As the hot, compressed extruded product leaves the die, the rubber

particle expand to their normal volume. The hose passes through a

long cooling trough containing cooling water generally at or near

ambient temperature, usually from 50° F to 80° F. Further details of

making porous hoses from rubber particles may be had by reference to

U. S. Patent 4,958,770, directed to Process for Making Uniform

Porosity Flexible Irrigation Pipe, which issued on September 25, 1 990,

and which is incorporated in its entirety by reference herein; and to

U. S. Patent Applications Serial Nos. 08/722,505, directed to Gas

Injection Process for Producing Porous Plastic Pipe; 08/722,506,

directed to Method of Blending Components for Porous Plastic Pipe

Processing; and 08/720,078, directed to Aeration Pipe and Method of

Making Same, all three of which were filed on September 1 7, 1 996,

and all three of which are incorporated herein in their entireties by

reference.

Fig. 3 shows another embodiment of a cross-sectional

configuration for hose 5. In this embodiment perforated outer

tubes 30,31 are shown with central imperforate tube 32 having a

triangular cross-sectional configuration formed by walls 33,34 with

outer rib 35. This alternative embodiment functions like the hose

shown in Fig. 2 by providing the reinforcing rib 35 between tubes 30,31 which also facilitates their perforation with holes 40. The

bottom 36 is also flat to serve the same functions as the flat bottom 8

of Fig. 2. The composition of the Fig. 3 hose can be varied as stated

for the Fig. 2 hose to provide a sprinkler or a sprinkler/soaker hose as

described above.

While specific embodiments of the invention have been

shown and described, it should be apparent than many modifications

can be made thereto without departing from the sprit and scope of the

invention. Accordingly, the invention is not limited by the foregoing

description, but is limited by the scope of the claims appended thereto.

WHAT IS CLAIMED IS:

Claims

1 . A flexible plastic sprinkler hose for the delivery of

pressurized water therethrough comprising:

an extruded plastic hose having a water inlet end for

coupling to a pressurized water source and a closed opposite end,

the extruded hose having a plurality of contiguous

tubes aligned lengthwise with at least two perforated outer tubes each

having holes spaced therealong for spraying water outwardly along the

length of said hose and a closed-end substantially imperforate central

tube integrally formed between said outer perforated tubes for

equalizing water pressure along the length of said hose and maximizing

water volume and flow in said outer perforated tubes.

2. The sprinkler hose of claim 1 wherein said central

tube is completely imperforate.

3. The sprinkler hose of claim 1 wherein said two outer

perforated tubes are also microporous along their length to provide the

dual function of spraying water through said spray holes and for

weeping water along the hose length.

4. The sprinkler hose of claim 1 wherein said central

tube has a cross-sectional generally triangular-shaped configuration,

each of two sides of which form a common integral wall with each of

the two outer perforated tubes and the remaining side of which forms

a reinforcing rib along a top of the hose length between said two outer

perforated tubes.

5. The hose of claim 4 wherein said sides form cross-

sectional V-shaped configuration near the bottom of the hose along its

length.

6. The hose of claim 4 wherein said sides form a

cross-sectional V-shaped configuration near the top of the hose along

its length.

7. The hose of claim 1 wherein said extruded hose has

a flat bottom and an arcuate top along its length, said arcuate top

spanning from one edge of said bottom to the other edge forming

therebetween said contiguous tubes aligned lengthwise.

8. The hose of claim 1 for use as a garden hose.

9. The hose of claim 1 for use with water at pressures

ranging from about 25 to about 1 20 psi.

10. The hose of claim 1 made from a polymer selected

from the group consisting of vinyl plastic, natural or synthetic rubber,

rubber- thermoplastic blends and any combinations thereof.

1 1 . The hose of claim 1 wherein said hose has a wall

thickness of approximately 0.20 to about 0.1 20 inch.

1 2. A flexible plastic sprinkler hose for the delivery of

pressurized water therethrough comprising:

an extruded plastic hose having a water inlet end for

coupling to a pressurized water source ranging from about 25 to about

1 20 psi and a closed opposite end,

said extruded hose having a flat bottom and an

arcuate top spanning from one edge of said bottom to the other edge

forming therebetween three contiguous tubes aligned lengthwise, said

tubes each having a thickness of approximately 0.20 to about 0.1 20

inches, said hose having a closed-end imperforate central tube integrally

formed between two perforated outer tubes, each having spray holes

spaced therealong said central tube having a cross-sectional generally

triangular-shaped configuration for maintaining and equalizing water

pressure along the length of said hose and maximizing water volume

and flow in said outer perforated tubes.

1 3. The hose of claim 1 2 wherein said arcuate top has

an integral reinforcing rib formed along the hose length.

14. The hose of claim 1 2 wherein said central tube has

a cross-sectional generally triangular-shaped configuration, each of two

sides of which form a common integral wall with each of the two outer

perforated tubes and the remaining side of which forms a reinforcing rib

along a top of the hose length between said two outer perforated

tubes.

1 5. The hose of claim 1 2 wherein said sides form cross-

sectional V-shaped configuration near the bottom of the hose along its

length.

1 6. The hose of claim 1 2 wherein said sides form a

cross-sectional V-shaped configuration near the top of the hose along

its length.