Landscape sprinkler system with adjustable riser

A landscape sprinkler system employs a first fixed vertical riser, typically attached to an inverted T-coupling, extending from a buried water supply pipe array. A second vertical riser having a sprinkler head connected to its top end and being of smaller diameter than the inner diameter of the first riser is telescopically movable up and down within the first riser to an infinite number of positions relative to the first riser. An annular nut and seal surround the second riser and the nut is threaded on the top of the first riser to seal and hold the second riser thereto. When adjacent shrubbery or landscaping grows to a height above the sprinkler head so as to interfere with the exiting sprinkler stream pattern, the nut is loosenable to adjust the height of the second riser and its connected sprinkler head above the height of the shrubbery and the nut retightened at that new position.

FIELD OF THE INVENTION 
This invention pertains to a landscape sprinkler system. More particularly 
the invention is directed to a pipe riser adjustable in height to 
compensate for an increasing growth of plants juxtaposed to the sprinkler 
system. 
BACKGROUND OF THE INVENTION 
Over the past few decades professionally or homeowner-installed water 
sprinkler systems have been employed more and more in home, office and 
public gardens, landscaped areas and grass lawns. These systems generally 
employ horizontal runs or arrays of buried galvanized iron pipe of about 
1.17 cm (1/2 inch) in diameter, with fixed pipe risers threaded into and 
extending from inverted T-unions or couplings between linear runs of the 
piping. The locations of the risers are dictated by the desired area to be 
covered by the "throw" of a sprinkler head mounted at the top of the 
riser. More recently sprinkler systems have been constructed and assembled 
using horizontal runs of polyvinyl chloride plastic pipe with vertical 
risers of the same plastic material adhesively bonded into the top end of 
inverted T-unions connecting the piping runs. Like the galvanized iron 
pipe embodiments, the horizontal piping risers and the inverted T-unions 
are normally buried a few inches under the ground surface with the risers 
and sprinkler heads extending vertically above the ground. While these 
systems are useful for many years on lawns which, due to periodic cutting, 
are kept at a level of from about 2- 6 cm in height above the ground 
level, other installations for watering shrubbery or other landscaping 
directly or for watering lawns from risers located in shrubbery areas, are 
oft times blocked from effective, even spraying by the normal growth of 
the shrubbery. This necessitates either periodically cutting back the 
height of the shrubbery, spoiling its natural top contour, or by 
installing a larger riser or a riser addition(s) between the existing 
risers and the sprinkler heads. This may necessitate digging up the ground 
to expose the union and separating the sprinkler head from the riser. An 
additional nipple or pipe length may be added and threaded between the 
inverted T union and the sprinkler head and/or the old and new risers 
joined by an additional straight vertical union. As plant growth continues 
more and more extensions are necessary creating more work, as well as an 
ugly stack of unions and nipples. In the case of plastic pipe a section of 
the plastic riser must be cut out in place, which is difficult in a mass 
of shrubbery, allowing a longer piece of plastic riser pipe or a nipple to 
be added and adhered on a union(s) between the original and a subsequent 
addition(s). Thus it can be seen that various plumbing tools, particularly 
including a pair of pipe wrenches or plastic pipe cutting tool(s) and 
adhesive applicators must be employed to raise the level of the sprinkler 
head so that its throw (of water) is not interfered with by adjacent 
growing plants. 
Coupling pipes including a so-called "slip joint" have been included in 
various elbow-type plumbing connection between pipes having different end 
separations. These are exemplified in U.S. Pat. Nos. 782,552; 2,021,317 
with respect to a water closet elbow connection; 1,295,106 concerning a 
fountain elbow; 1,799,246 for a straight pipe connection with annular 
tapered packing ring; 1,997,845 for a water meter coupling; 4,258,944 for 
a plumbing trap; 3,136,570 for a bath tub nipple sprout; and 1,613,887 for 
a flush tank and bowl. 
SUMMARY OF THE INVENTION 
The present invention solves the above problems in a simple way with the 
use of a manual unthreading and rethreading or by use of a Crescent or 
other parallel edged wrench. A slip joint is provided between a first 
vertical riser connected to the top of the inverted T-coupling and a 
second vertical riser movable up and down telescopically in the first 
vertical riser. The sprinkler head is fixedly connected, normally by 
threading, to a top of the second riser. A loosenable annular nut and 
annular seal surround the second riser and are threadable on the top of 
the first riser. The second riser may thus be positioned at an infinite 
number of positions with respect to the first riser dependent on the 
particular location of the nut and seal with respect to the second riser. 
In making the vertical installation the second riser is normally set so 
that a high majority, about 60% to about 95%, of its length at its lower 
end telescopes into the lower first riser and the nut turned by hand or by 
a Crescent or other parallel faced wrench to effect a seal between the 
first and second riser and to hold the top of the second riser (and its 
sprinkler head) at a fixed level above the first riser and the ground 
level. When there has been shrubbery growth which tends to interfere with 
the water being sprayed from the sprinkler head it is a simple, 
above-the-ground operation to correct the problem. This involves merely 1) 
loosening the connecting nut, 2) pulling the second riser telescopically 
upwardly from the first riser, 3) moving the nut and seal upwardly on the 
second riser a desired amount to a position above the shrubbery top and 
then reassembling the nut and second riser on the first riser. The 
sprinkler head is then automatically at a higher position with respect to 
the first riser, the ground level and, if moved sufficiently, will be 
above any interfering branches of the shrubbery. 
In a preferred plastic embodiment the nut may be of sufficient outside 
diameter so that the homeowner or landscaper can easily loosen or tighten 
the nut by hand so there is no need of any tool to adjust the height of 
the second riser. The sprinkler heads may be of fixed fan-nozzle type or 
be of the water-impulse type such as those sold under the Rainbird.RTM. 
trademark or other configurations. The water-impulse type heads move 
horizontally over fixed or adjustable horizontal fan-shaped or circular 
areas of from about 30.degree. to about 360.degree..

DETAILED DESCRIPTION 
FIG. 1 illustrates the landscape water sprinkler system 10 of the invention 
in which a linear run or array of pipes 11, 12 and 13 are positioned in a 
trench 14 in a ground surface 15. Each pipe length is connected by 
threading, or adhesive bonding in the case of polyvinyl chloride piping 
and unions, to cross-bar openings 16 in an inverted T-union or coupling 
17. A first tubular riser 21 of a first relatively large internal diameter 
extends vertically from a threaded or bonded position in the top end 19 of 
each of the couplings 17. A second tubular riser 20 having an outer 
diameter slightly smaller than the inner diameter of the first riser 
telescopically extends upwardly from the interior of riser 21 so that a 
sprinkler head 30 is positionable at a desired height above ground level 
15 and extends above a shrub 40 or other obstruction so that the shrub top 
does not interfere with the throw or water spray stream 31 exiting the 
sprinkler head. Nut 22, which surrounds riser 20 and includes an 
elastomeric seal typically in the form of a rubber cone washer 26 (FIG. 
2), is tightened onto the top threads 21a of riser 21 to seal and fixedly 
hold riser 20 vertically with respect to riser 21. When bush 40 grows to 
the size of bush 40' nut 22 may be loosened, the riser 20 (and attached 
sprinkler head) moved upwardly (arrow 26') to a higher position denoted by 
the prime marks so that the head 30' and its water spray stream 31' 
effectively clear the higher shrub 40'. The washer 26 is moved downwardly 
on riser 20 to a position juxtaposed to the top end of the fixed first 
bottom riser 21 and the nut 22 rethreaded by its internal threads 25 onto 
the external threads 21a on riser 21, again sealing the riser assembly at 
an annular position while holding the second riser 20' at a higher 
position with respect to the higher bush 40'. A metal backing washer 23 
may also be employed to protect the rubber cone washer and aid in 
distribution of the sealing forces when the washer is sealingly pressed 
against and between the risers. The up and down telescopic movement of 
riser 20 with respect to fixed riser 21 is illustrated by double-headed 
arrow 26. While this embodiment has been discussed in terms of raising 
riser 20 there may be occasions when one wishes to plant a new smaller 
bush or severely cut back a bush, in which event the riser 20 may be 
lowered and resealed so that the risers do not extend too high above the 
bush creating an unaesthetic appearance and subjecting the spray stream to 
unwanted wind effects. It is to be understood that the interior of the 
risers are only subject to water main pressure when a valve (not shown) is 
opened in a main water supply line connected to pipe 11 or 13. The sealing 
provided by the nut and seal between the two risers merely prevents water 
from squirting out at the juncture between the risers while the water is 
flowing upwardly through the risers to the sprinkler heads. 
It is contemplated that the polyvinyl chloride or other plastic piping and 
unions may be other than the 1.27 cm (1/2 inch) size. They also may be 
about 1.90 cm (3/4 inch). The risers with accompanying nut and seal may be 
sold in kit form typically in three sizes so that the outer bottom fixed 
riser and top movable riser each have an about 10-20 cm length or an about 
20-40 cm length or an about 40-80 cm length. 
As shown in FIG. 3 the risers assembly may also be constructed of 
galvanized iron or copper pipe where the fixed riser 51 is threaded or 
brazed to or otherwise connected to a pipe length (not shown) and movable 
riser 50, also made of iron or copper material, telescopes into the 
interior of riser 51 as indicated by double-headed arrow 52. A metal 
compression seal ring 53 is wrench tightened by the turning of nut 54 on 
outer threads 51a of pipe 51 or on a threaded male/female connection or 
nipple 58 attached to pipe 51 by nut 55. Connector 56 is employed to mount 
the upper end of riser 50 and provides an upper threaded end onto which a 
sprinkler head is threaded. In some cases the seal 53 may actually crimp 
onto the pipe riser 50 in which event it may be necessary to cut off an 
end of the riser 50 and place a new compression seal over the riser after 
the riser 50 has been extended from riser 51. Alternatively, a rubber 
washer similar to that shown in FIG. 2 may be employed to seal and reseal 
risers 50 and 51. 
The above description of embodiments of this invention is intended to be 
illustrative and not limiting. Other embodiments of this invention will be 
obvious to those skilled in the art in view of the above disclosure.