Abstract:
A sprinkler that restricts foreign particulate matter from interfering with and/or damaging the operating components of a sprinkler is disclosed. The sprinkler may be a pop-up sprinkler such that the outlet or nozzle is not in a fixed position and is moved from a position above the ground to a position generally below or flush with the ground. To prevent particulate matter from entering, such as through the nozzle or outlet, when the flow of water is shut off, the sprinkler may include a protective member located within the sprinkler head to prevent the particulate matter from have an undesirable effect. The protective member forms a one-way obstruction that permits flow to the nozzle and obstructs flow back into the sprinkler such that particulate matter in the water beyond the protective member is restricted from coming in contact with the internal operating components of the sprinkler. The protective member may be a resiliently deformable flap or a hinged flap.

Description:
FIELD OF THE INVENTION 
     The invention relates to a sprinkler and, in particular, to an internal particulate protective obstruction to restrict the entry of foreign matter into a sprinkler. 
     BACKGROUND OF THE INVENTION 
     Sprinklers are widely used in both commercial and residential settings, for instance, to control the irrigation of crops or to maintain the healthy appearance of lawns. Most often, sprinklers are used in outdoor settings, such as in agricultural or other fields, on golf courses, and on residential lawns. As a result of being in an uncontrolled, outdoor environment, sprinklers are exposed to airborne particles, such as pollen, seeds, and bugs, as well as other loose debris, such as dirt and tree bark. 
     By design, sprinklers have openings to allow water from a pressurized source to be distributed to their surrounding areas. Therefore, it is possible for foreign contaminants to enter the sprinkler housing through the spray head nozzle outlet, especially when water is not flowing. Pop-up sprinklers, in particular, are prone to the entry of foreign contaminants into the sprinkler mechanism. 
     Pop-up sprinklers are especially susceptible to the entry of foreign contaminants due to the nature of their operation. In a pop-up sprinkler, the spray head nozzle outlet is mounted in a movable casing that travels between a position below the surface of the ground and a position above the ground. When the sprinkler is turned off, the spray head may be retracted below the surface of the ground so that the ground is generally flush with or close to the top of the spray head. When the sprinkler is in operation, the spray head moves to a position above the ground to distribute water to the surrounding areas. As a result of this motion, dirt and other particles around the sprinkler housing may become disturbed, making it more likely that these particles will gain entry into the sprinkler. 
     Once the foreign contaminants are inside the sprinkler, they may disrupt its operation. For example, many sprinklers have a rotary drive mechanism. Particles of dirt may prevent the rotary drive mechanism of a sprinkler from properly rotating the spray head, or may even damage the drive mechanism. Such a malfunction or damage caused by the entry of foreign contaminants would mostly likely require the sprinkler to be completely removed from the ground and either replaced or repaired, costing time and energy and potentially disrupting the entire irrigation scheme of the area being watered. 
     Accordingly, there is a need for a sprinkler with improved resistance to the entry of foreign contaminants or particulate matter. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a rotary drive pop-up sprinkler in an extended use position; 
         FIG. 2  is a fragmentary cross-sectional view of the sprinkler of  FIG. 1  in a retracted position showing a protective member in a substantially closed position; 
         FIG. 3  is a partial cross-sectional view of the sprinkler of  FIG. 2 ; 
         FIG. 4  is a fragmentary cross-sectional view of the sprinkler of  FIG. 2  showing a protective member in a substantially open position; 
         FIG. 5  is a perspective view of a drive housing and the protective member of  FIG. 3  in a substantially closed position; 
         FIG. 6  is a cross-sectional view of the sprinkler taken through line  6 - 6  of  FIG. 3  with the protective member in a substantially closed position; and 
         FIG. 7  is a cross-sectional view of the sprinkler taken through line  7 - 7  of  FIG. 3  with the protective member in a substantially closed position. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a representative pop-up sprinkler  10  in an operative position for distributing water. The pop-up sprinkler  10  includes a tubular, fixed housing, or sprinkler case  20 , that is telescopically connected to a tubular, movable housing  30  such that the housing  30  may move from an operative position to an inoperative position. In the operative position, the housing  30  extends from the case  20  to position a spray head  32  is above the ground surface to distribute water to the surrounding area. In the inoperative position, the housing  30  retracts into the sprinkler case  20  such that the spray head  32  is generally flush with or beneath the surface of the ground. 
     The sprinkler case  20  has an inlet connection  22  for connecting to a pressurized water supply line  5  that delivers water to the sprinkler  10 . The sprinkler  10  may include a filter or screen  12  ( FIG. 2 ) located near the inlet connection  22  and in the path of the entering water to screen out foreign particulate matter from the water source. The water passes through the sprinkler  10  and is emitted from the spray head  32 . 
     The housing  30  includes a base portion  34 , and the spray head  32  is disposed at the distal end of the base portion  34 . The spray head  32  includes a nozzle outlet  36  from which water is projected out of the sprinkler  10 . When the sprinkler  10  is shut off so that substantially no water is emitted, the movable housing  30  retracts to the inoperative position. In the inoperative position, the nozzle outlet  36  is retracted into the sprinkler case  20  to close off the sprinkler  10 . However, in some instances, loose debris, bugs, or proximal plants may enter the nozzle outlet  36 , such as when it moves between the inoperative and operative positions, and, as a result, the nozzle outlet  36  does not retract completely to close the interior of the sprinkler  10 , which may allow a seepage of groundwater and contaminants. 
     Prior to the sprinkler  10  being activated to distribute water to the surrounding area, the sprinkler  10  is in the retracted inoperative position, as is shown in  FIG. 2 , wherein the housing  30  and its internal components are located within the sprinkler case  20 . Once the water is turned on and the sprinkler  10  is activated for distributing water, the water pressure from the inlet  22  forces the movable housing  30  upwards so that it extends from the sprinkler case  20 , and water can emit from the nozzle outlet  36 . The movable housing  30  has an exterior surface  40  generally directed towards an interior surface  42  of the sprinkler case  20 . The surfaces  40 ,  42  generally include cooperating structure that permits the movable housing  30  to move generally along the central longitudinal axis X of the sprinkler case  20 , while generally preventing relative rotation between the sprinkler case  20  and the movable housing  30 . Preferably, the cooperating structure includes a plurality of ribs  44  radially located on the interior surface  42  of the sprinkler case  20 , and recesses (not shown) equal or greater than the number of ribs  44  and located on the exterior surface  40  of the movable housing  30 . The cooperating structures, such as the ribs  44  and recesses, guide the relative longitudinal movement between the housing  30  and the sprinkler case  20 . The recesses may be formed on a lower portion, such as a ratchet (not shown), of the movable housing  30 . 
     As the water passes through the movable housing  30 , it drives a rotary drive mechanism  50  disposed within the movable housing  30 . The drive mechanism  50  utilizes the force of the water to rotate the spray head  32  relative to the movable housing  30  and the sprinkler case  20  so that water projected from the spray head  32  is distributed over a predetermined arcuate range, such as a full or partial circular area. 
     Water entering the rotary drive mechanism  50  located at a lowermost portion of the movable housing  30  generally strikes a turbine  52 , including turbine blades  54 , as illustrated in  FIG. 3 . The turbine  52  has a generally disc-like configuration with openings (not shown) to permit water to pass through the turbine  52 . The blades  54  are located radially about a central axis T of the turbine  52  and adjacent the openings in the turbine  52  so that a portion of the kinetic energy of the water is imparted to the blades  54  when the water strikes there against as the water passes through the turbine  52 . 
     A main water channel  66  is located within the movable housing  30  and above the turbine  52 . A lower cavity  60  defined in part by a bottom plate  63  of a drive housing  62  and by a turbine draft surface  61  of the movable housing  30  is located in part below the drive housing  67  and in part below the channel  66 . The channel  66  is generally located between a portion  68  of an interior surface  64  of the movable housing  30  and the drive housing  62 . The drive housing  62  abuts another portion  65  of the interior surface  64  of the movable housing  30  and includes the bottom plate  63 . Once the water passes through the turbine  52 , it flows either directly through the lower cavity and into the channel  66  or into the portion of the lower cavity  60  under the bottom plate  63  of the drive housing  62 . The bottom plate  63  forces the water to a channel side  69  of the lower cavity  60  for passage into the channel  66 . The water generally follows the channel  66  to the nozzle outlet  36  for distribution or emission from the sprinkler  10 . 
     With reference to  FIG. 2 , the turbine  52  is fixed at its central axis T to a drive shaft axle  70  such that rotation of the turbine  52  causes rotation of the drive shaft  70 . The water force on the turbine blades  54  is transmitted through the turbine  52  and to the drive shaft  70 . The drive shaft  70 , in turn, extends through the bottom plate  63  of the drive housing  62  and is in geared cooperation with a drive mechanism  72  which is, in turn, connected to the spray head  32  by an output gear  74 . The drive mechanism  72  includes a series of gears ratioed to reduce the input rotational velocity of the turbine  52  and drive shaft  70  to a desired output rotational velocity for the spray head  32 . A head pipe  76  depends from the spray head  32  into the channel  66 . The channel  66  directs the water through the sprinkler  10  and into the head pipe  76 . The head pipe  76  has external gear teeth  78  that mate with the gear teeth of the output gear  74  such that the drive mechanism  72  transmits rotational drive to the head pipe  76 . Thus, rotation of the drive mechanism  72  rotates the head pipe  76  which, in turn, rotates the spray head  32  to which the head pipe  76  is connected. The turbine  52 , drive shaft  70 , drive mechanism  72 , head pipe  76 , and spray head  32 , among other components, may be lubricated, such as with a grease, to reduce friction. 
     When the sprinkler  10  is emitting water, foreign particulate matter is generally prevented from entering the sprinkler  10 . That is, the force of exiting water prevents matter from entering the nozzle outlet  36 , and the filter or screen  12  prevents matter from entering into the sprinkler  10  through the inlet  22  or water source. However, when the sprinkler  10  is shut off, foreign matter may enter. 
     More specifically, when the sprinkler  10  is shut off, the movable housing  30  is biased by a spring  77  to retract into the sprinkler case  20 . In the event the sprinkler  10  operates as intended, the movable housing  30  retracts so that the nozzle outlet  36  recedes into the sprinkler case  20  at a position close to or flush with the ground, yet the nozzle outlet  36  is not protected from the elements until it is located within the sprinkler case  20 . Further, the movable housing  30  may occasionally not operate as intended, leaving the nozzle outlet  36  exposed to the elements. In either event, it has been found that with prior sprinklers, when they are shut off, water will drift downward through the main water channel and through the turbine, which has been found to enable entry of foreign matter, such as through a vacuum being created. As a result, the foreign matter carried by the water may infiltrate into the internal components, such as the drive shaft turbine and gearing of the drive mechanism, and cause them to malfunction or become damaged. Moreover, the foreign matter will become stuck in any lubricant, such as grease, and cause excessive wear. 
     In order to reduce the potential for foreign matter to enter the sprinkler  10  through the nozzle outlet  36 , a protective member  80  is disposed to operate in the channel  66  of the movable housing  30  between the main water channel  66  and the lower cavity  60 . The protective member  80  may be a screen (not shown) or other structure that permits the passage of fluid, while generally restricting or preventing the passage of particulate contaminants. Preferably, the protective member  80  is in the form of a movable barrier. The barrier  80  has a generally closed or obstructing position ( FIG. 3 ) that generally prevents the backflow of water and foreign matter toward the water source, and has an open position ( FIG. 4 ) in which the barrier  80  is moved generally out of the stream of water as it passes through the sprinkler  10  from the lower cavity  60  to the main water channel  66 . The force of the passing water causes the barrier  80  to move from the closed position to the open position, as depicted in  FIG. 4 . 
     In the preferred embodiment, the movable barrier  80  is positioned to operated between the drive housing  62  and the interior surface  64  of the movable housing  30  adjacent the lower cavity  60 . When the water is shut off, the movable barrier  80  shifts from the generally open position to the generally closed position, in which it extends between the drive housing  62  and the interior surface  64  to obstruct flow from the main water channel  66  to the lower cavity  60 . This movement can be effected in a number of ways, such as with a bias mechanism, resilient material, the weight of the barrier  80 , or a combination thereof. Although there may be a slight delay from when the water is shut off and the movable barrier  80  reaching the closed position, foreign matter entering the nozzle outlet  36  when the water is shut off in the preferred embodiment will not reach the barrier  80  before the barrier  80  is able to move to the closed position because of the distance from the nozzle  346  to the barrier  80 . 
     With reference to  FIG. 5 , the preferred barrier  80  has a flap-like construction  82  with a first edge  83  and a free edge  85 . The first edge  83  is anchored to the drive housing  62 . The flap  82  extends from the channel side  69  to the interior surface  64  of the movable housing  30 . With reference to  FIGS. 3-5 , the preferred flap  82  is a unitary structure formed of a resiliently deformable material. The first edge  83  may be clamped between the bottom plate  63  and the drive housing  62 , as can be seen in  FIG. 3 . The force of water applied to a bottom side  84  of the flap  82  will cause the flap  82  to be folded upward into the channel  66  so that water may pass by the flap  82  and into the channel  66 . When the water is shut off, the natural resilience of the flap  82  will cause the flap  82  to return to the generally closed position. In the generally closed position, the free edge  85  rests against the interior surface  64  of the movable housing  30  such that water backflow, as well as any particulate matter therein, is generally restricted from passing into the lower cavity  60 . The flap may have any other structure, such as a hinge (not shown), or a bias element (not shown), such as a spring, that enables the flap  82  to act as a one-way valve type obstruction for particulate matter in the water flow. 
     The channel  66  preferably includes an internal shoulder  86  on which the free edge  85  of the flap  82  rests when the flap  82  is in the generally closed position. The shoulder  86  ensures that the flap  82  does not deform or move downward, which otherwise may allow foreign particulate matter to pass by. Alternatively or in addition, the flap  82  may be over-sized. The flap  82 , when laid flat, traverses across the channel  66  and may have an area greater than the transverse cross-section of the channel  66 . In this form, the over-sizing of the flap  82  helps prevent foreign particulate matter from passing by the flap  82 . When the flap  82  moves to the generally closed position, it can bunch against the interior surface  64  and/or the shoulder  86  of the movable housing  30 . In any case, the flap  82  may have either a uniform thickness or a varying thickness. For example, the over-sized form of the flap  82  benefits from thinning towards the free end  85  because the described bunching is promoted by a more compliant structure. 
     With the embodiments described above, when the flap  82  is in the substantially closed position, foreign particulate matter that may enter the sprinkler  10  from the exterior is restricted or obstructed from entering the lower cavity  60 , and thus encountering the turbine  52 , the drive shaft  70 , the drive mechanism  72 , and other moving parts of the sprinkler  10 . Any such matter or debris that enters the sprinkler  10  falls onto a top surface  88  of the flap  82 . When the sprinkler  10  is activated and water forces the flap  82  to move to the substantially open position, the foreign contaminants or matter resting on the top surface  88  are generally flushed out of the sprinkler  10  by the water flow through the channel  66  and out of the nozzle  30 . 
     While the invention has been described with respect to specific examples, including presently preferred modes of carrying out the invention, those skilled in the art will appreciate that there are numerous variations and permutations of the above described systems and techniques that fall within the spirit and scope of the invention as set forth in the appended claims.