(Not Applicable)
(Not Applicable)
The invention relates to sprinkler heads and, more particularly, to sprinkler heads that nutate, or wobble, while they rotate, to thereby minimize the “donut effect” prevalent with conventional rotating sprinkler heads.
Various nutating or wobbling sprinkler head designs have been proposed, examples of which are described in prior U.S. Pat. Nos. 5,381,960; 5,950,927; 6,530,532 and 6,932,279. Commonly owned U.S. Pat. Nos. 5,439,174; 5,588,595; 5,671,885; 6,267,299; 6,341,733; 6,439,477; 7,287,710; 7,562,833; 7,942,345; 8,028,932 and 8,991,724 provide further examples of nutating or wobbling sprinkler heads. There are potential shortcomings, however, that can nullify the very nutating affect that makes such sprinklers attractive in the first instance.
One problem often encountered with sprinklers of this type relates to stalling at start-up or even during normal operation. Stalling occurs when the water distribution plate of the sprinkler head fails to tilt at start-up, or ceases tilting during operation, thereby simply rotating and distributing a stream particularly susceptible to the “donut effect” where the wetted pattern area is shaped like a solid ring around a dry center. When nutating or wobbling sprinklers operate as designed, the nutating action tends to fill in the pattern in a substantially uniform manner. Thus, it is important that the water distribution plate reliably and consistently remain in a tilted orientation on start-up and while rotating to achieve the desired wobbling or nutating action.
The stalling problem discussed above has been solved in different ways (see, for example, U.S. Pat. Nos. 5,381,960 and 6,341,733).
Another problem relates to the relatively high speed of rotation of the wobbling sprinkler head. High rotational speeds create the well-known but undesirable “horse-tail” effect that shortens the radius of throw of the sprinkler. While it has been shown that slowing the rotation of the sprinkler using a brake mechanism is effective to obtain maximum throw, completely satisfying solutions to the problem of slowing the rotation speed of a wobbling sprinkler head have yet to be developed. One attempt to slow a wobbling head is described in U.S. Pat. No. 7,395,977.
There remains a need for a wobbler-type sprinkler that effectively and reliably achieves maximum throw radius while maintaining the pattern-uniformity benefits of the wobbler-type sprinkler.
The embodiments shown in the noted U.S. Pat. No. 8,991,724 utilize a framework that surrounds the moving plate/cage. The framework is bulky and expensive. Additionally, such framework requires a larger diameter canister if the sprinkler head is to be mounted in a pop-up canister. Moreover, the fixed strut portions of the framework create dry shadows in the water pattern. Still further, stringy material such as moss or food processing waste in the water can hairpin and build up on the struts and cause stalling issues.
It would be desirable to overcome the drawbacks with existing designs.
The wobbling sprinkler head according to the described embodiments provides for the desired orbital action and braking without large fixed strut framework. Eliminating the framework enables the use of a smaller diameter canister if mounting in a pop-up canister is desired. Additionally, eliminating the framework avoids the dry shadows as well as the potential for stringy material in the water to hairpin and build up on the struts.
The described sprinkler head also lends itself to many different shapes of water patterns without extra cost or complexity. The sprinkler head can provide for full circle watering or, by removing teeth in selected locations of a fixed gear, the wobbler cage can orbit very quickly to some areas (in areas of unbraked orbital movement) leaving very little water in these areas. Still further, the action of the water deflector plate moving in and out of the nozzle stream creates emerging/receding streams that fill in the water pattern for good distribution uniformity without an external diffuser.
Accordingly, in an exemplary embodiment, a sprinkler head includes a sprinkler body, a nozzle positioned within the sprinkler body, a fixed gear coupled with the sprinkler body, a wobbler cage supported on the sprinkler body, and a water deflector plate coupled with the wobbler cage and disposed downstream of the nozzle. A brake assembly is coupled with the water deflector plate for slowing a rotating and wobbling motion of the wobbler cage and the water deflector plate. The brake assembly includes a shaft extending through the water deflector plate and a brake gear disposed at an end of the shaft, where the brake gear is engageable with the fixed gear.
The fixed gear may include external gear teeth, and the brake gear may be engaged with the external gear teeth of the fixed gear. The external gear teeth may be arranged according to a desired water pattern. In some embodiments, the brake gear remains in engagement with the external gear teeth of the fixed gear regardless of whether water may be flowing through the nozzle. The brake gear may be always positioned out of a water stream flowing through the nozzle.
The sprinkler head may include a gear plate secured to the sprinkler body and positioned between the nozzle and the wobbler cage. The wobbler cage may include a wobbler ring having ridges that may be engageable with the gear plate.
The brake assembly may be a viscous brake assembly that may include a reservoir of viscous material disposed in the water deflector plate. The viscous brake assembly may additionally include a rotor secured to the shaft and rotatable with the shaft, where the rotor is disposed in the reservoir of viscous material.
The fixed gear may include a snout at a downstream end that is positioned adjacent a shoulder of the water deflector plate. In this context, the snout acts as a stop to prevent damage to teeth of the fixed gear or the brake gear upon an application of a side load.
The fixed gear may include a ring gear having internal gear teeth, where in an active position of the wobbler cage, the brake gear may be engaged with the internal gear teeth of the fixed gear. A distal end of the brake gear may be angled, and in an inactive position of the wobbler cage, the brake gear may be coaxial with the ring gear.
In some embodiments, the sprinkler head also includes a canister in which the nozzle, the fixed gear and the wobbler cage may be selectively disposed. The wobbler cage may be displaceable in the canister between a retracted position and an extended position. In the retracted position, the brake gear may be coaxial with the fixed gear. In the extended position, at least a portion of the wobbler cage may be disposed outside of the canister and the wobbler cage may be pivotable into a use position. In the use position, the brake gear may be engaged with the fixed gear. The wobbler cage may be biased toward the retracted position by a spring.
The brake gear may include brake gear teeth engageable with corresponding fixed gear teeth of the fixed gear, where the brake gear teeth extend radially into a water stream flowing through the nozzle when the brake gear is engaged with the fixed gear. The wobbler cage and the water deflector plate may be displaceable between an inactive position in which the brake gear is not engaged with the fixed gear and an active position in which the brake gear may be aligned with the fixed gear, where the brake gear may include an internal water passage that is aligned with the nozzle in the inactive position. In some embodiments, the internal water passage may include a 90-degree bend. The brake gear may be configured to rest on the nozzle to cover the nozzle in the inactive position. In this context, the brake gear may include an angled notch in a surface facing the nozzle.
In another exemplary embodiment, a sprinkler head includes a sprinkler body, a nozzle positioned within the sprinkler body, a fixed gear coupled with the sprinkler body, a wobbler cage supported on the sprinkler body, and a water deflector plate coupled with the wobbler cage and disposed downstream of the nozzle. The water deflector plate may include a cavity for housing a viscous material. A viscous brake assembly is coupled with the water deflector plate for slowing a rotating and wobbling motion of the wobbler cage and the water deflector plate. The viscous brake assembly includes a shaft extending through the water deflector plate, a brake gear disposed at an end of the shaft, and a reservoir of viscous material in the cavity of the water deflector plate, where the brake gear is engageable with the fixed gear.
These and other aspects and advantages will be described in detail with reference to the accompanying drawings, in which:
A fixed gear 16 is coupled with the sprinkler body 12, and a wobbler cage 18 is supported on the sprinkler body 12. A water deflector plate 20 is coupled with the wobbler cage 18 and disposed downstream of the nozzle 14. The water deflector plate 20 is positioned to intercept, i.e., deflect, the water flow output from the nozzle 14. The water deflector plate 20 includes a plurality of deflecting grooves 21 that deflect the water according to a predefined water pattern and also serve to impart a rotating moment on the deflector plate 20.
The wobbler cage 18 supports the water deflector plate 20 as shown. The wobbler cage 18 includes a wobbler ring 22 and a plurality of struts 24 connected to the wobbler ring 22. The water deflector plate 20 is connected to the wobbler cage 18 by the struts 24. The deflection grooves 21 of the water deflector plate 20 may be arranged relative to the struts 24 to minimize interference by the struts 24 during use. Regardless, since the wobbler cage 18 is turning during use, any interference by the struts 24 with the projected water flow is minimal and would not result in the shadow areas that are a problem with the existing strut framework of prior designs.
In the embodiment shown in
A brake assembly 32 is coupled with the water deflector plate 20 for slowing a rotating and wobbling motion of the wobbler cage 18 and the water deflector plate 20. The brake assembly 32 may include a shaft 34 that extends through the water deflector plate 20 and a brake gear 36 disposed at an end of the shaft. The brake gear 36 is engageable with the fixed gear 16. In some embodiments, the brake assembly 32 is a viscous brake assembly including a rotor 38 that is press fit to the shaft 34 and is rotatable with the shaft 34. A bearing 42 supports the opposite end of the shaft 34. A high-viscosity damping fluid fills the cavity 40 and acts between the rotor 38 and the deflector plate 20. Braking action is imparted when the fluid is sheared as the rotor 38 rotates relative to the deflector plate 20.
In the embodiment shown in
In use, water flowing through the nozzle 14 impacts the grooves 21 on the water deflector plate 20, which disperses the water according to a predefined water pattern. The water flow impacting the grooves 21 on the water deflector plate 20 causes the water deflector plate and the wobbler cage 18 to rotate. The brake gear 36 engaged with the teeth 44 of the fixed gear 16 serves to control a rotating speed of the water deflector plate 20. In some embodiments, an exemplary normal speed of rotation may be in the range of 0.5-5 RPM. By removing gear teeth 44 in selected locations of the fixed gear 16, the deflector plate 20 can orbit very quickly through some areas. In areas of unbraked orbital movement, the deflector plate 20 may quickly accelerate to a speed of several hundred RPMs or more, leaving very little water in these areas. Exemplary gear teeth configurations for the fixed gear 16 and the resulting water pattern wetted areas are shown in
In the embodiment shown in
In some applications, the water deflector plate 20 may be subjected to side impact loads, e.g., being dragged through crops or the like. In order to prevent damage to the gear teeth 44 of the fixed gear 16 and/or the brake gear 36, the fixed gear 16 is provided with a snout 46 that extends below the gear 16, and the water deflector plate 20 is provided with a shoulder 48 that together take the load if the plate 20 gets struck from the side. See, e.g.,
The sprinkler head 110 in
In this embodiment, the gear plate 126 may be without spokes, and corresponding ridges 150 are provided on a deflector plate side of the wobbler ring 122 and an upstream surface of the ring gear 116. See
As shown in
Gear teeth from the ring gear 116 may similarly be removed so that the deflector plate 120 can orbit very quickly through some areas to control the water pattern. Exemplary gear teeth configurations for the gear 116 and the resulting water pattern wetted areas are shown in
In use, a water stream from the nozzle 214 impacts an angled surface 252 of the yoke arm 236 to force the wobbler cage 218 to an offset position toward the active position. Subsequently, the water flow impacting the water deflector plate 220 maintains the wobbler cage 218 and the deflector plate 220 in the active position. The yoke arm 236 is fixed to the shaft 234 of the brake assembly 232.
In the active position, with reference to
In the retracted position, the brake gear 336 is aligned with the nozzle 314 and is coaxial with the fixed gear 316. Once the nozzle 314, wobbler cage 318 and water deflector plate 320 are displaced to the extended position by water flow through the nozzle 314, the wobbler cage 318 is pivotable into a use position as shown in
In this embodiment, teeth 437 of the brake gear 436 are engageable with corresponding fixed gear teeth 444 of the fixed gear 416. As shown in
The brake gear 436 also may be provided with an internal water passage 452. See
The described embodiments provide for braking of the orbital action of a wobbler cage without using large fixed strut framework. The resulting structure reduces costs and sprinkler head size while also eliminating the dry shadows in the water pattern created by the fixed strut portions of prior designs. Eliminating the struts also prevents stringy material such as moss or food processing waste in the water to hairpin and build up on the struts. Still further, water patterns can be readily selected by positioning and/or removing teeth from the fixed gear or otherwise switching out the fixed gear to one suited for the desired water pattern. The action of the plate grooves moving in and out of the nozzle stream creates emerging/receding streams that fill in the water pattern for good distribution uniformity without an external diffuser.
While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.