Fluid sprinkling – spraying – and diffusing – Processes
Reexamination Certificate
2000-03-05
2002-03-19
Scherbel, David A. (Department: 3752)
Fluid sprinkling, spraying, and diffusing
Processes
C239S201000, C239S204000, C239S206000, C239S281000, C239SDIG001, C239S203000
Reexamination Certificate
active
06357668
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to the field of lawn and garden sprinklers and particularly to pop-up, spraying inserts for such sprinklers.
Lawn and garden sprinklers have been available for many decades. Sprinklers are usually attached to a buried pipe system which is attached to a pressurized water supply via a valve. Pipe systems are usually constructed of galvanized steel pipe and fittings in a manner well known by plumbers. The valves may be manually or timer operated. When it is desired to water the grass, or plants or both, the valve is turned on. Many homeowners in the United States and other countries rely on such sprinklers to deliver water to their lawns and gardens during dry weather.
A typical sprinkler head is one manufactured by Champion, Los Angeles. The early, standard metal heads comprise a hollow, cylindrical, aluminum or galvanized steel body threaded at its lower entrance in order to screw onto the threaded riser. At the upper end, a brass spray insert is screwed into a specially threaded cavity. The insert has an angled hole or slot that is designed to spray water upwards in an angle in an arc or a full circle. Inserts are available which will spray anywhere from approximately 30° to 360°. Inserts are also available with threaded restrictor screws so that the radius of the arc or circle may be adjusted.
It is current practice to assemble sprinkler systems completely from plastic or with plastic horizontal segments and fittings, and plastic risers. However, decades ago, plastic pipe was not available so galvanized steel risers were used. In the intervening years, the galvanized piping system tends to corrode and the sprinkler head bodies corrode onto the risers. Moreover, with time the grade of the grass increases. Consequently, over time, spray from the sprinklers does not reach up over the adjacent grass and it is impossible to remove and replace risers or sprinkler heads or both without destroying the piping system. To rebuild a sprinkler system, by digging up and replacing the originally installed system, is very labor intensive and very expensive. To lower the grade of the grass is also very labor intensive and expensive.
Development of a modification which will allow sprinklers to operate properly again without the need to replace the sprinkler system or lower the grade of the grass represents a great improvement in the field of lawn and garden sprinklers and satisfies a long felt need of homeowners who have older, metal sprinkler heads installed.
There is another problem with currently available pop-up sprinkler heads. Pop-up sprinklers carry the spray head at the top of a weighted shaft which slides inside a hexagonal opening in the center of the sprinkler head body. When the water is off, the gravity is supposed to keep the pop-up down. Water pressure overcomes the weight and lifts the spray head for operation. However, the tolerances of the opening and shaft are very loose and garden debris accumulates in the bowl created by the sprinkler head body. As a result the pop-up frequently sticks in the up position where it may cause persons to trip or be cut off by a lawn mower. Once the pop-up is cut, the weight falls into the riser, from which it is difficult to retrieve, and a geyser is caused when next the sprinkler system is operated.
Development of a sprinkler modification which eliminates the bowl, thus eliminating accumulation of debris and eliminating sticking pop-ups also represents a great improvement in the field of lawn and garden sprinklers and satisfies a long felt need of homeowners.
SUMMARY OF THE INVENTION
The primary objective of the present invention is to modify sprinklers so that they will again operate properly without the need to replace the sprinkler system or lower the grade of the grass. This invention comprises a riser tube, a collar, a pop-up shaft with a threaded head, an o-ring, a weight, and a spray insert. The riser pipe is threaded at both ends. The lower threads are designed to mate with the specially threaded cavity in the sprinkler head body. Threaded onto the upper threads is the collar, which has a opening, having a hexagonal (or other shaped) cross-section, in its upper web. Sliding inside this opening is the cylindrical pop-up shaft which has a mating, outer, hexagonal (or other matching shaped) cross-section. The O-ring is slipped over the lower end of the shaft and a cylindrical (or other shaped) weight is screwed onto the lower end of the shaft. Both the O-ring and the weight are of larger diameters than the shaft so as to preclude leakage. The upper end of the shaft terminates in a cylindrical pop-up head which is also larger in diameter than the shaft. The upper end of the head is threaded to receive the spray insert, which must be identical to a standard spray insert. In typical fashion the insert has a small, upwards slanting exit hole or slot. This invention is intended to replace the brass spray inserts which are easy to remove in existing older sprinkler heads with the capability to continue usage of the sprinkler head at any grass level required.
The second objective of the present invention is to eliminate the sprinkler head housing entirely. This is accomplished by utilizing the collar, the pop-up shaft with threaded head, the o-ring, the weight, and the spray insert defined above. In this alternate embodiment, the threads of the collar are standard pipe threads. Thus the collar can be screwed directly onto the in-ground riser. The pop-up is assembled through the hole in the collar and the spray insert screwed into the pop-up head before the collar is screwed onto the in-ground riser. This embodiment eliminates the sprinkler head body. Thus accumulation of debris and sticking pop-ups are eliminated.
An appreciation of the other aims and objectives of the present invention and an understanding of it may be achieved by referring to the accompanying drawings and description of a preferred embodiment.
REFERENCES:
patent: 1938511 (1933-12-01), Brady
patent: 3776463 (1973-12-01), Dyck
patent: 5996905 (1999-12-01), Bedford
Kim Christopher S.
Scherbel David A.
Townsley Norton R.
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