As shown in
The housing 12 provides a protective covering for the riser assembly 14 and serves as a conduit for incoming water under pressure. The housing 12 preferably has the general shape of a cylindrical tube and is preferably made of a sturdy lightweight injection molded plastic or similar material. The housing 12 has a lower end 16 with an inlet 18 that is threaded to connect to a correspondingly threaded outlet of a water supply pipe (not shown). The sprinkler 10 may be one of a plurality of coordinated sprinklers 10 in an irrigation network.
The riser assembly 14 includes a non-rotatable stem 20 with a lower end 26 and an upper end 27. A rotatable turret 22 is mounted on the upper end 27 of the stem 20. The turret 22 rotates to water a predetermined arcuate pattern manually adjustable from 0 degrees to 360 degrees. The sprinkler 10 includes a reversing gear drive mechanism 130 that switches the direction of rotation of the turret 22 to create the desired arcuate sweep. The arc adjustment member 100 allows one to manually adjust the arcuate sweep settings, as described further below.
The stem 20 is generally an elongated hollow tube, which is preferably made of a lightweight molded plastic or similar material. The lower end 26 includes a radially projecting annular flange 24. The flange 24 preferably includes a plurality of circumferentially spaced grooves 42 that cooperate with internal ribs 44 of the housing 12 to prevent the stem 20 from rotating relative to the housing 12. A coil spring 30 for retracting the riser assembly 14 is disposed in the housing 12 about the outside surface 34 of the riser assembly 14. The spring 30 has a bottom coil 28 that engages the flange 24 and an upper coil 36 seated against the inside of a housing cover 40.
The housing cover 40 serves to minimize the introduction of dirt and other debris into the housing 12. The housing cover 40 preferably has internal threads and is mounted to an upper end 46 of the housing 12 which has corresponding threads. The housing cover 40 also preferably includes a grippable external surface that preferably includes a plurality of vertically extending ribs 48 for enhanced gripping and easy mounting of the sprinkler 10 to a water supply pipe outlet.
The housing cover 40 is fitted with a seal 50, preferably a ring-shaped wiper seal, mounted on the inside of the cover 40. More specifically, the support ring 52 seats the wiper seal 50 against the inside of the housing cover 40. The wiper seal 50 preferably has an annular lip 51 that slideably engages the outside of the riser assembly 14, as it reciprocates in and out of the housing 12 to wipe the outside of the riser assembly 14. This wiping action minimizes the amount of debris entering the housing 12 through the space between the housing 12 and the riser assembly 14 and on the surface of the riser assembly 14.
As shown in
A turret cover 54, preferably made of rubber or some other elastomer material, is mounted atop the turret 22 to close the top of the upper recess 21 and provide protection against damage. The turret cover 54 includes protective access ports formed by slits 56 disposed in the top of the turret 22 (
As shown in
As shown in
When the riser assembly 14 is in the elevated spray position, water flows into the stem 20 and causes the turret 22 to rotate. More specifically, water enters the housing 12 through the inlet 18 and passes through the housing 12 to the riser assembly 14. The water passes through a filter 72 mounted within the lower end 26 of the stem 20. The filter 72 prevents grit and other debris from flowing through the riser assembly 14 to enter the riser assembly 14 and possibly causing damage to sensitive sprinkler components downstream of the riser inlet.
Water flows past the filter 72 and through a spacer 74 and a stator 76 to rotatably drive the turbine 66, which rotates at a high rate of speed, such as on the order of nearly 1900 revolutions per minute (“RPM”). In turn, the turbine 66 is connected to an axle 78, which, in turn, is coupled to a series of reduction gears of the gear reduction assembly 68. The gear reduction assembly 68 operatively couples the turbine 66 to the turret 22 and reduces the rotation so that the turret 22 rotates at a relatively much lower rate of speed, such as on the order of 1 RPM. In general, the gear reduction assembly 68 reduces the relatively high speed rotation of the water-driven turbine 66 to a relatively low rotational speed suitable for rotational driving of the turret 22 to provide proper irrigation.
After flowing past the turbine 66, water continues to flow through flow passage 70 and into the turret 22 through the flow tube 82. As shown in
As shown in
The arc adjustment member 100 defines an elongated second flow passage 112 extending centrally therethrough. During flushing operation, as discussed further below, water flows through the second flow passage 112 from the second end 106 to the first end 102 to flush debris from the slot 104 (
With reference to
The second flow path is within the housing 12 but outside the stem 20. Water first flows through a first gap 114 defined by grooves 42 of the flange 24 of the riser assembly 14 (
This flushing action causes a relatively high pressure pulsing action, on the order of 5-6 pounds per square inch (“psi”), which serves to clean other sensitive parts of the sprinkler 10 that are prone to clogging. For example, the flushing water is forced out through the slit 56 overlaying the slotted first end 102 of the arc adjustment member 100, thereby cleaning the slit 56. Also, the flushing action has been found to clean debris from the interior of the turret 22 near the second gap 118, including cleaning debris from the gear teeth of both the arc adjustment member 100 and the corresponding mating second gear 110, as water flows cyclically into and out of the lower recess 23 of the turret 22. Further, flushing water is forced out of the second flow passage 112 in the turret 22 for cleaning debris from desired areas of the interior of the turret 22.
The flushing action occurs when the riser assembly 14 is traveling between a retracted position and an elevated position. The slot 104 is preferably flushed once as the riser assembly 14 starts moving upward and once as the riser assembly 14 is returning to a retracted position. Thus, the slot 104 is flushed twice during an ordinary irrigation cycle, as described below.
The second flow path receives water while the second gap 118 is below the lip 51 of the wiper seal 50. As the riser assembly 14 continues to move upward, however, the second flow path eventually leaves communication with the water supply when the second gap 118 rises above the lip 51 of the wiper seal 50, e.g., when the bottom of the turret 22 is spaced above the top of the housing cover 40. Thus, when a cycle begins and water initially flows into the housing 12 and riser assembly 14, a pulse of water is transmitted through the second flow passage 112 to flush slot 104 and through the overlaying slit 56 in the turret cover 54.
The same flushing action is repeated when the riser assembly 14 returns from an elevated spray position to a retracted position. When the riser assembly 14 is in the elevated position, the second flow passage 112 is not in communication with the water supply because the second gap 118 is spaced outside the housing 12. However, as the riser assembly 14 continues to return to its retracted position, the second gap 118 eventually passes below the lip 51 of the wiper seal 50, thereby placing the second flow passage in communication with the water supply. Thus, as the irrigation cycle ends and the spring 30 returns the riser assembly 14 to its retracted position, a second pulse of water is transmitted through the second flow passage 112 to flush slot 104 and slit 56.
The periodic flushing of the arc adjustment member 100 and interior of the turret 22 prevents accumulation of sand particles and other debris and is effective to maintain the operation of various components of the arc adjustment mechanism. In contrast, the accumulation of sand particles and other debris in arc adjustment members can prevent a screwdriver or other hand tool from freely engaging member 100, thereby making routine adjustments difficult, and cause deterioration of the engaging components.
Experience has shown that the size of the cross-section diameter of the second flow passage 112 impacts the effectiveness of the flushing. For example, a flow passage 112 having a cross-sectional diameter of 0.062 inches at the first end 102 was effective in flushing all of the units having that cross-sectional diameter, whereas a flow passage 112 having a cross-sectional diameter of 0.040 inches at the first end 102 was effective in flushing only about 80% of the units having that diameter. The larger diameter passage 112 at the first end 102 was more effective in maintaining the slot 104 free of sand and grit and allowed a screwdriver to freely engage the slot 104. It should be evident that the desired diameter of the flow passage 112 will depend on the size and configuration of the arc adjustment member 100.
Although one form of an arc adjustment member 100 is shown in
In addition, other forms of the sprinkler 10 may include an adjustment member 100 with a flow passage 112 therethrough and/or one or more other flushing orifices 39. More specifically, as described above, the sprinkler 10 may include adjustment member 100, which defines a flushing orifice through the turret 22, and need not include other flushing orifices 39. Alternatively, other embodiments may include one or more flushing orifices 39 to flush debris from the interior of the turret 22 and need not include an adjustment member 100 with a flow passage 112 therethrough. Moreover, other forms of the sprinkler 10 may not flush a member 100 at all but may instead flush a predetermined portion of the interior of the turret 22. More specifically, other forms of the sprinkler 10 may flush water out through a flushing orifice 39 in the outer wall 41 that defines the lower recess 23 of the turret 22 and/or through the partitioning wall 25 for cleaning debris from desired areas of the interior of the turret 22. In such forms, water exits the flushing orifice 39 as the riser assembly 14 cycles between the spring-retracted position and the elevated spraying position.
The foregoing relates to preferred exemplary embodiments of the invention. It is understood that other embodiments and variants are possible which lie within the spirit and scope of the invention as set forth in the following claims.