This invention relates to pop-up irrigation sprinklers, and more particularly, to pop-up sprinklers having new and improved valve seals.
It is well known in the art to employ with pop-up type irrigation sprinklers a pressure regulator in the pop-up riser of the sprinkler to control and keep constant the pressure at which water from the sprinkler nozzle is ejected into the atmosphere. The use of such pressure regulators is particularly useful with pop-up sprinklers, which will be used where the source pressure supplied to the sprinkler may vary over wide ranges, such as typically found in residential applications or where the sprinklers are to be used in hilly terrain. By using a pressure regulator, the sprinkler nozzle will produce a spray pattern which will be substantially constant over a wide range of supply pressures, thereby assuring that optimum sprinkler performance is achieved even though the source pressure to the sprinkler may vary over wide ranges.
One such pressure regulator, which has been suggested for use within the pop-up riser of pop-up sprinklers, includes a flow seat secured within a lower portion of the stem or riser, and a flow tube that is mounted within the riser for limited reciprocation above the flow seat. The flow tube is typically spring-biased and centered within the riser by O-ring type seals that are disposed about the upper and lower end portions of the tube and which engage the inside side wall of the riser to seal the space between the outside of the tube and the inside of the riser between the seals. The flow tube raises and lowers relative to the flow seat to regulate the water from the source passing through the flow tube to the sprinkler nozzle in response to the inlet water pressure. By controlling the pressure to the nozzle through movement of the flow tube relative to the seat, a substantially constant water pressure at the nozzle can be maintained. A pop-up sprinkler of this pressure regulating stem (PRS) design and one having a grit-protected pressure regulator are respectively disclosed and claimed in U.S. Pat. Nos. 4,479,611 and 4,913,352, assigned to Rain Bird Corporation, which disclosure is incorporated by reference herein.
PRS pop-up sprinklers usually require either under-the-head check valves or built-in check values installed within the sprinklers below the flow tube to trap water in lateral irrigation pipes. Examples of the latter type are Seal-A-Matic™ check valves sold by Rain Bird Corporation. The Seal-A-Matic™ check valves eliminate the need for under-the-head check valves and are installed on commercially available PRS pop-up sprinklers. These check valves not only effectively trap water in lateral pipes, but they reduce wear on the irrigation sprinkler components by minimizing water hammer during initial operation.
There is a need for a pop-up sprinkler, having the advantages of the commercially available PRS pop-up sprinklers discussed in the above paragraph, with fewer parts, fewer manufacturing steps, a reduction in length, and lower cost.
Further features and advantages will become apparent from the following and more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which:
Elements:
In the present embodiment, sprinkler 10 includes a generally upright, cylindrical housing 12 having upper end 14 and lower end 16. Housing 12 is molded from a lightweight molded plastic, suitable for underground installation with the upper end 14 disposed substantially flush with the surface of the soil. Threaded inlet port 20 is formed with lower end 16 of housing 12 for coupling with a pressurized water source (not shown).
Pop-up riser 30, preferably spring-biased as discussed below, moves within housing 12 between an extended, operative position and the retracted position. Pop-up riser 30 has threaded upper end 32 for receiving spray nozzle 34, riser lower end 36, and sidewall 38 connecting upper end 32 and lower end 36. Spray nozzle 34 ejects water outwardly from sprinkler 10 when pop-up riser 30 is in the elevated spray position.
Valve seal 40 shown in
Valve plug 44 of relatively small cross sectional area is dimensioned to be received in relatively small circular inlet port 20 at lower end 16 of housing 12. Valve plug 44 has sufficient length to accommodate circumferential groove 50 for receiving seal means 52, which effectively seals inlet port 20 from inflow and outflow of water from housing 12 when riser 30 is in the retracted position as shown in
Pressure reducing valve 60 is mounted within riser 30 to control and keep constant the pressure at which water from spray nozzle 34 is ejected into the atmosphere. Pressure reducing valve 60 has flow tube 62 mounted for limited longitudinal movement within riser 30. Flow tube 62 has a circular horizontal cross-section outlet port 64, and lower port 68 disposed adjacent upper port 56 of valve body 42. Open lower port 68 of flow tube 62 is urged against upper surface 48 of valve plug 44, without completely closing port 68, by a surge of pressurized water when riser 30 is in the extended, operative position. The diameter of outlet port 64 is substantially greater than the outer diameter of flow tube 62 to avoid any restriction while flow tube 62 moves within riser 30 to maintain a constant pressure during operation.
Pop-up riser 30 has vent port 70 located in sidewall 38 of riser 30 between upper end 32 and lower end 36, preferably adjacent to lower end 36 so that it is between upper port 64 and lower port 68 of flow tube 62. Vent port 70 provides an atmospheric reference vent for pressure reducing valve 60 as described below.
Flow tube 62 has upper shoulder 76 and lower shoulder 78 adjacent upper port 64 of flow tube 62 to form second groove 80 there between. O-ring 82 is mounted in groove 80 to provide the upper sealing means between flow tube 62 and inner wall 83 of riser 30. Retainer 90 adjacent to lower port 68 of flow tube 62 and is positioned between upper port 56 of valve body 42 and shoulder 94 formed within lower end 36 of riser 30. Groove 92 is formed between lower surface 95 of retainer 90 and upper port 56 of valve body 42 to receive O-ring 96 to provide a lower seal between flow tube 62 and upper inner vertical surface 100 of valve seal 40.
Control spring 97 is engaged between upper surface 98 of retainer 90 and the lower shoulder 78 of flow tube 62 in chamber 99. Spring 97 controls water pressure at upper port 64 of flow tube 62. When lower port 68 is urged against upper surface 48 of valve seal 40, control spring 97 is compressed to achieve the set pressure range at upper port 64 and to nozzle 34.
The pressure regulator 60 operates to control the pressure of water, typically 30 pounds per square inch (psi), supplied to nozzle 34 by controlling movement by flow tube 62 against the bias of the control spring 97 in response to the backpressure of water acting at upper port 64 on the downstream side of pressure regulator 60 within riser 30. As water under pressure is supplied to nozzle 34 through riser 30, backpressure upstream of nozzle 34 builds due to nozzle constriction. Backpressure upstream of nozzle 34 acts against upper shoulder 76 flow tube 62 and against the bias of control spring 97, lower shoulder 78 being exposed to atmospheric pressure within chamber 99 and providing a reference pressure for flow tube 62. Advantageously, the area of upper shoulder 76 of flow tube 62 is designed to have a larger area than that of the diameter of lower end 68 of flow tube 62. As a consequence of this design, the backpressure on upper shoulder 76 acts over a larger area than the pressure of the water entering lower end 16, thereby creating a force differential tending to urge the flow tube downwardly against the bias of control spring 97.
Sprinkler cover 110 is mounted by means of inter-engaging sets of housing threads 112 on upper end 14 of housing 12 and cover threads 114 on cover 110. Cover 110 has central opening 115 through which elongated, hollow cylindrical pop-up riser 30 is movable between a retracted position and an elevated spraying position. Cover 110 is provided with elongated annular wiper seal 116 formed of flexible material such as rubber or soft plastic, and which may be of the type shown are described in U.S. Pat. No. 4,316,579, and is disposed in opening 115.
Wiper seal 116 is designed to restrict passage of deleterious particulate material between sidewall 38 of riser 30 and cover 110. In addition, wiper seal 116 seals riser 30 when riser 30 is in the extended, operative position. At least one slot 120 is provided to extend from vent port 70 to create a gap between said cover 110 and vent 70 for optimal venting.
Lower end 36 of riser 30 has flange 140 projecting outwardly from riser 30. Ultrasonic welding or other attachment techniques securely fasten lower shoulders 142 of flange 140 to riser 30 in order to achieve a watertight attachment between riser surface 141 of riser 30 and valve seal surface 143 of valve seal 40.
Compression spring 144 is biased between adjusting guide 151 mounted on riser 30 adjacent flange 140 and the underside of cover 110 to provide spring-bias to pop-up riser 30 toward the retracted position as shown in
In the operational position, with riser 30 extended above upper end 14 of housing 14, water flowing through riser 30 to nozzle 34 passes through the pressure regulator 60 which functions to regulate the pressure supplied to nozzle 34 so that a substantially constant pressure of inlet water enters nozzle 34. By controlling the pressure at nozzle 34, any given nozzle will operate to provide the same water distribution pattern regardless of the inlet water pressure, and also will permit a wide range of nozzle sizes to be operated at the same selected pressure level.
Valve seal 40 combines the features of a PRS sprinkler with a built-in check valve in the form of washer 52 that effectively traps water in lateral pipes in elevation changes of up to approximately 14 feet and reduces wear on the sprinkler system components by minimizing water hammer during start-up. The sprinkler of the present embodiment also prevents drainage from spray heads at lower elevations, stops water waste, and ends landscape damage due to flooding and/or erosion.
Tubular funnel 150 is preferably fixedly mounted within riser 30 and projects downwardly into upper port 64 of flow tube 62 for deflecting and directing grit and other particulate material downwardly from riser 30 into flow tube 62 when riser 30 is in its retracted position; see U.S. Pat. No. 4,913,352 for a detailed description of one type of tubular funnel suitable for this application.
To filter particulate material entering sprinkler 10 with the supply water before passing through spray nozzle 34, elongated filter screen 160 is mounted adjacent upper end 32 of riser 30 below nozzle 34 as shown in
Without departing from the spirit and scope of this invention, one of ordinary skill in the art can make various changes and modifications to the embodiment of the sprinkler of the present invention to adapt it to various usages and conditions. As such, these changes and modifications are properly, equitably, and intended to be, within the full range of equivalents of the following claims.
While certain embodiments of the present invention are shown in the drawings and described above in detail, it should be understood that there is no intention to limit the invention to the specific form or forms disclosed. On the contrary, the intention is to cover all modifications, alternative constructions, and equivalents falling within the spirit and scope of the invention. The present invention is limited only by the claims that follow.
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