Abstract:
A lawn irrigation sprinkler head that internally incorporates an alert and retrieval device which indicates the position of the head if damaged, and facilitates in-situ repair of the damaged head. The sprinkler head has a hollow body containing a pop-up riser connected to a nozzle. The alert and retrieval device is positioned between the base of the riser and the nozzle. Should the nozzle become damaged or dislodged, the alert device telescopically extends from the riser and signals the location of the damaged sprinkler head. The device facilitates the repair of the head by lifting the riser from within the sprinkler head so that a replacement nozzle can be attached. In an alternative embodiment the alert device has an integral shut-off valve which prevents the discharge of water in the event that a subsequent irrigation cycle occurs before the damaged head is repaired. The alert and retrieval device is suitable for retrofit application in existing pop-up style in-ground sprinkler heads, or may be incorporated in the process of the head&#39;s original manufacture.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates to irrigation sprinkler heads and, more particularly, to a pop-up style sprinkler head having an integral device for indicating the position and facilitating the repair of the sprinkler head if it is damaged.  
           [0003]    2. Description of the Background  
           [0004]    Underground lawn irrigation systems commonly comprise a network of buried pipes connected at regular intervals to sprinkler heads. The RAINBIRD™ SP40 series pop-up spray head manufactured by Rain Bird Mfg. Corp., 145 N. Grand Ave., Glenboro, Calif., 91741 is an exemplary pop-up style sprinkler head representative of the prior art.  
           [0005]    [0005]FIG. 1 illustrates a pop-up style sprinkler head connected to an underground irrigation system. The sprinkler head  102  extends upwardly from an elbow or “T” joint  104 , and only the uppermost portion of head  102  is exposed beyond the surface of the ground. Sprinkler head  102  typically comprises a cylindrical housing  107  containing an internal pop-up riser  112  capped by a nozzle  108 . Nozzle  108  emits a spray when actuated by water pressure, and the spray pattern is fixed as determined by the type of nozzle  108  attached to riser  112 .  
           [0006]    At the end of an irrigation cycle, the water pressure shuts off, and an internal spring mechanism retracts the riser  112  back into housing  107  of the sprinkler head. The retracted nozzle lies flush at ground level and is protected from damage by lawn mowers, power trimmers, foot traffic or other ground level hazards which could dislodge the nozzle  108  from riser  112 . It is not uncommon for grass or foliage to overgrow the sprinkler head thereby obscuring it from view in the retracted position.  
           [0007]    During the course of normal use it is also not uncommon for grit or debris to fall into the sprinkler head  102 . An accumulation of this foreign matter prevents the riser from fully retracting, leaving riser  112  extended from housing  107 , and exposing nozzle  108  above the surface of the ground. A pass with a lawn mower can easily dislodge the exposed nozzle  108  from riser  112 , thereby damaging the sprinkler head  102 . The damaged riser thereafter will not be affected by the application or removal of water pressure.  
           [0008]    Alternatively, nozzle  108  may simply become dislodged due to pedestrian traffic or unscrewed from riser  112  rendering sprinkler head  102  defective. Damaged or defective sprinkler heads are difficult to locate, either because they become entirely submerged in large pools of water, or because grass obscures the location of sprinkler head  102  when the riser is in the complete or partially retracted position.  
           [0009]    If nozzle  108  is dislodged from sprinkler head  102 , an uncontrolled geyser gushes from the sprinkler head during subsequent irrigation cycles. This has several adverse consequences. First, it results in flooding of one area of the lawn, which damages turf and promotes disease. Second, under-watering of adjacent areas of the lawn usually occurs as a result of decreased water pressure to the downstream sprinkler heads. Also, the geyser unnecessarily wastes water during the irrigation cycle, and depending on the location and time of day, geysers may go undetected for extended periods of time.  
           [0010]    Replacing the defective sprinkler head with an entirely new sprinkler head remedies the geyser problem. However, even after the geyser is observed locating the damaged sprinkler head once the sprinkler shuts-off is difficult because of the flooding or natural overgrowth problems discussed above. Moreover, once the defective sprinkler head is found, making the a repair entails digging-up the damaged sprinkler head. This requires undue expense and effort and damages the lawn in the area of the repair.  
           [0011]    Alternatively, the defective sprinkler head can be repaired by replacing the missing nozzle. However, this simple remedy is complicated by the fact that, in its retracted position, the riser  112  is not easily accessible inside the narrow body of sprinkler head  102 . The force from a retracting spring (not shown) must be overcome to lift riser  112  from housing  107 , and the narrow cylinder of sprinkler head  102  does not easily permit one to grasp riser  112 . Without a device to withdraw the retracted riser  112 , the threads on the riser remain inaccessible, and a new nozzle cannot be attached without disassembling the complete sprinkler head which in turn usually requires excavating around the unit.  
           [0012]    Few devices in the prior art have addressed the problem of signaling the position of a damaged sprinkler head. U.S. Pat. No. 5,524,824 to Frimmer teaches a shut-off valve for use in a sprinkler head. The shut-off valve is positioned in the riser of the sprinkler head. A short perforated tube extends from the valve, and is spring biased against the underside of the sprinkler head nozzle. If the nozzle is dislodged, the shut-off valve is immediately forced upwardly where it engages a valve seat and prevents the flow of water from the head. The tube extending through the top of the sprinkler head also immediately signals that the sprinkler head is damaged.  
           [0013]    Unfortunately, the Frimmer &#39;824 signaling device is a short fixed tube which becomes susceptible to damage from the same causal sources (rotary mowers, foot traffic or other ground hazards) because it deploys an instant after the nozzle is dislodged. It is highly likely in the case of the lawn mower inflicted damage that the mower would immediately truncate the signaling device negating its intended purpose. Therefore, it would be advantageous to have a sprinkler head with an integral apparatus for indicating the location of the damaged or defective sprinkler head (and facilitating its repair) that would deploy only when the nozzle is dislodged and water pressure is applied.  
         SUMMARY OF THE INVENTION  
         [0014]    It is, therefore, an object of the present invention to provide a lawn irrigation sprinkler head incorporating a signaling device to indicate the position of the lawn sprinkler head if/when damaged.  
           [0015]    It is another object of the present invention to enable the signaling device to facilitate the repair of the damaged head by providing a means to extract the riser from the inside of the damaged sprinkler head in order to replace a missing nozzle.  
           [0016]    It is still further an object of the present invention to provide an integral shut-off valve on the alert and retrieval device to prevent the uncontrolled flow of water from a damaged sprinkler head during an irrigation cycle.  
           [0017]    According to the present invention, the above-described and other objects are accomplished by providing a pop-up style lawn sprinkler head comprising an internal signaling and riser retrieval apparatus. The sprinkler head comprises a hollow, generally cylindrical housing threaded on the end for attachment to an elbow or “T” fitting on an irrigation pipe. The housing comprises an internal central channel occupied by a riser. A nozzle seals the top of the sprinkler head assembly when the riser is fully retracted in the housing.  
           [0018]    The signaling and retrieval mechanism is a brightly colored, multi-stage telescoping element which resides in the central cavity of the riser. Under normal operating conditions, the device accompanies the riser as it is forced upwardly from the sprinkler head body by water pressure during a normal irrigation cycle. Water flows through the riser around the device and out the nozzle. In an undamaged sprinkler head, the upward telescoping movement of the device is limited by the nozzle. However, if the nozzle is dislodged, the water pressure causes the telescoping elements of the device to extend upwardly. When the irrigation cycle is complete, the self-latching device remains visible projecting from the top of the damaged sprinkler head.  
           [0019]    Projecting from the sprinkler head, the brightly colored device signals the location of the damaged head, and is used to facilitate the replacement of the missing nozzle. Pulling upwardly on the device lifts the riser from the sprinkler head housing. This exposes the threads on the top of the riser, and enables a repair to be made by simply (1) holding the riser with one hand and pushing the telescoping device down within the riser and (2) screwing a replacement nozzle onto the riser. The riser retrieval feature of the signaling apparatus simplifies the repair process, and eliminates the labor intensive and aesthetically unpleasing task of digging up the entire sprinkler head.  
           [0020]    In an alternative embodiment, the signaling and retrieval mechanism is a multi-stage telescoping element whose base, near the bottom of the riser also acts as a shut off valve. The base, which is spoked to allow the free flow of water when in the “down” position, is spring biased to the “up” position. The shut off valve is prevented from closing during normal irrigation cycles by the top of the telescoping device which is held down by the nozzle (and filter basket). Again, during normal operation, the device rides up and down with the riser and due to its flow-through characteristics does not affect normal sprinkling.  
           [0021]    In a scenario that is all too familiar, the riser, following an irrigation cycle, fails to retract into the sprinkler (due to grit or debris). Subsequent to this a lawn mower (logically being used when the irrigation system is not operating) passes over the riser and in so doing dislodges the nozzle. Due to being hit, the riser may or may not retract within the sprinkler head.  
           [0022]    Immediately, the spring loaded shut off valve moves up within the riser to a valve seat located within the riser. The telescoping device does not extend because water pressure is not present. By not extending at this time the telescoping device does not expose itself to the same causal factors that precipitated the removal of the nozzle. During the next irrigation cycle, water pressure is applied and due to the position of the shut off valve no geyser appears and no water is wasted. However, the water pressure acts on the telescoping device extending it to its self latching position. At the end of the cycle the brightly colored telescoping device remains in the “up” position facilitating observation by concerned individuals. The retrieval/repair function of the telescoping device may then be used as described in the first embodiment.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]    Other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments and certain modifications thereof when taken together with the accompanying drawings in which:  
         [0024]    [0024]FIG. 1 is an environmental view of a prior art sprinkler head installed on an underground irrigation pipe.  
         [0025]    [0025]FIG. 2 is a schematic side view of the sprinkler head of the present invention in an undamaged resting state.  
         [0026]    [0026]FIG. 3 is a schematic side view of the sprinkler head of the present invention in an undamaged condition during a normal irrigation cycle.  
         [0027]    [0027]FIG. 4 is a schematic side view of the sprinkler head of the present invention during a normal irrigation cycle in which the nozzle is missing.  
         [0028]    [0028]FIG. 5 is an exploded sectional view of the signaling and retrieval device of the present invention.  
         [0029]    [0029]FIG. 6 is a schematic side view of an alternative embodiment of the sprinkler head of the present invention in which the signaling and retrieval device comprises an integral shut-off valve.  
         [0030]    [0030]FIG. 7 is a schematic side view of the alternative embodiment of the sprinkler head of the present invention in an undamaged condition during a normal irrigation cycle.  
         [0031]    [0031]FIG. 8 is a schematic side view of the alternative embodiment of the sprinkler head of the present invention in which the nozzle is missing, and the shut-off valve is actuated.  
         [0032]    [0032]FIG. 9 is a schematic side view of the alternative embodiment of the sprinkler head of the present invention during a normal irrigation cycle in which the nozzle is missing.  
         [0033]    [0033]FIG. 10 is a schematic side view of the sprinkler head of the alternative embodiment of the present invention in which the nozzle is missing, showing the fully extended signaling and retrieval device after an irrigation cycle.  
         [0034]    [0034]FIG. 11 is an exploded sectional view of the signaling and retrieval device of the alternative embodiment of the present invention. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0035]    [0035]FIG. 2 shows a preferred embodiment of the improved lawn irrigation sprinkler head  2  of the present invention. The sprinkler head comprises an outer cylindrical housing  7  having distal base  4  and opposing cap  6 . Base  4  preferably comprises inner threads  5  which engage the corresponding threads of an elbow or “T” fitting ( 104 , FIG. 1) extending from an underground irrigation pipe ( 106 , FIG. 1). Cap  6  is screwed to the top of sprinkler housing  7  and defines a constricted top closure. Cap  6  has a central aperture through which a nozzle  8  extends. Nozzle  8  is a short cylindrical element with opposing top and bottom ends. The top end is defined by a series of open slots or perforations  9  which allow water to flow from the sprinkler head. The number and arrangement of slots varies according to the spray pattern and coverage desired.  
         [0036]    The bottom end of nozzle  8  is open, and comprises internal threads  10  which engage the corresponding threads on the top end of a riser  12 . Riser  12  is a hollow tube positioned inside housing  7 . An annular ridge  14  is formed at the lower end of riser  12 . A conventional compression spring  16  is positioned inside of housing  7  and is inserted onto riser  12  such that the top end of the spring lies against the underside of cap  6 , and the bottom end of the spring lies against top face of ridge  14 . The downward bias from spring  16  maintains the riser  12  in a retracted position within the sprinkler head housing  7 . Within the central hollow of riser  12  is a telescoping alert retriever (hereinafter TAR)  18 .  
         [0037]    TAR  18 , shown in FIG. 5, comprises a multi-stage telescoping device having opposing tip  34  and base  36 . A grit filter  24  is optionally attached or rests at tip  34  to collect debris and foreign matter which otherwise would enter the nozzle through the water system or the aperture in cap  6 . Grit filter  24  comprises a tapered, round side-wall  26  coupled to a circular base  28  which bear a plurality of holes  30 . Holes  30  permit the irrigation water to flow upwardly, but prevent debris and foreign material from passing.  
         [0038]    The telescoping sleeves of TAR  18  comprise first stage  40 , second stage  42 , and third stage  44 . First stage  40  is a generally cylindrical hollow tube having opposing top and bottom ends, each end comprising an orifice which permits water to flow through. The bottom end comprises base  36  as described below. The top end slidingly engages second stage  42 . The inner wall of first stage  40  is indented in the area immediately below its top end, and thereby forms a plurality of internal tabs  45 . Tabs  45  hold the bottom end of second stage  42  at piston  48  when it is fully extended. The openings at the top of first stage  40  and second stage  42  are smaller than the respective inside diameters of the stages to prevent over-extension of stages  42  and  44  respectively. A plurality of alignment tabs  17  extend outwardly from approximately the midpoint of first stage  40 , and maintain the alignment of TAR  18  in the central channel of riser  12 .  
         [0039]    Second stage  42  is likewise a generally cylindrical hollow tube having opposing top and bottom ends, the bottom end comprising an orifice which permits water to flow through. The outer wall of second stage  42  bears a circumferential groove  46  at its bottom end. Groove  46  functions as a piston retaining groove for second stage piston  48 . Second stage piston  48  is an annular element which circumferentially engages second stage  42  and lodges against tabs  45  when second stage  42  is fully extended. The inner wall of second stage  42  is indented in the area immediately below its top end, forming a plurality of second stage tabs  50 . Second stage tabs  50  hold the bottom end of third stage  44  when it is fully extended. An external circular ridge at the top of second stage  42  prevents the second stage from dropping out of the first stage  40 .  
         [0040]    Third stage  44  is a solid rod-like element having opposing top and bottom ends. The top end of third stage  44  comprises tip  34 , which is adjacent to optional grit filter  24 . The outer wall of third stage  44  bears a circumferential groove  52  at its bottom end. Third stage groove  52  functions as a piston retaining groove for third stage piston  54 . Third stage piston  54  is an annular element which engages third stage  44  and lodges against second stage tabs  50  when third stage  44  is fully extended. Tip  34  or alternatively the base of grit filter  24  prevents third stage  44  from dropping out of the second stage  42 .  
         [0041]    Base  36  comprises a plurality of outwardly directed prongs  32  for engaging sprinkler housing  7 . Referring back to FIG. 2, in an operative configuration within sprinkler housing  7 , prongs  32  are sandwiched between ridge  14  on their top surface and shelf  3  of sprinkler body  2  on their bottom surface. Shelf  3  is an annular element extending from the inner wall of housing  7  near base  4 .  
         [0042]    [0042]FIG. 3 shows the sprinkler head of the present invention during a normal irrigation cycle. Pressurized water  20  enters sprinkler head  2  through base  4 , and flows into the channel of riser  12 . The pressurized water flows past TAR  18  and strikes the underside of nozzle  8 . The water pressure overcomes the downward force of spring  16  on riser  12 , and thrusts nozzle  8  and riser  12  upwardly out of sprinkler head  2  through the aperture in cap  6 . Ridge  14  secures the lower end of riser  12  within sprinkler head  2  and prevents the riser from being ejected in response to the surge of water pressure. Under normal operating conditions, water is thereby emitted from the nozzle and the lawn is irrigated.  
         [0043]    As shown in FIG. 3, the presence of nozzle  8  is critical to the proper operation of the sprinkler head  2 . By contrast, FIG. 4 shows damaged sprinkler head  22  of the present invention where nozzle  8  is dislodged. After pressurized water  20  flows through riser  12  and around TAR  18 , it bursts through the aperture in cap  6 . Unimpeded by a nozzle, the pressurized water creates a geyser  23  from the damaged sprinkler head  22 . Without the nozzle  8  in place the riser  12  remains inside the sprinkler head.  
         [0044]    Water pressure  20  entering damaged sprinkler head  22  also enters the hollow body of TAR  18 , and exerts force on pistons  48  and  54  and the bottom of stage three  44  (not visible in FIG. 4), causing the stages to telescope upwardly out of housing  7 . Water pressure  20  causes full extension of TAR  18 , and first stage tabs  45  and second stage tabs  50  (not visible in FIG. 4) engage pistons  48  and  54  respectively locking TAR  18  in its fully extended position where it remains after water pressure  20  shuts off. TAR  18  is thus visible above the surface of the ground, and above any pool accumulated water, thereby signaling the location of the damaged sprinkler head until it is discovered. Subsequent irrigation cycles do not cause TAR  18  to retract.  
         [0045]    FIGS.  6  to  11  show an alternative embodiment of the present invention in which a modified TAR  218  additionally includes an integral shut-off valve. As shown in FIG. 6, riser  212  is modified to accommodate the modified TAR  218 . Necessary modifications to modified riser  212  are shown in FIG. 6, and include the addition of a valve seat  62 , a shut-off valve spring  68 , and a retention groove  64  (visible in FIG. 11).  
         [0046]    Valve seat  62  comprises an annular ridge on the inside wall of modified riser  212  approximately at its midpoint. The annular ridge forms an aperture of a sufficient diameter to allow passage of water and all three stages of modified TAR  218 .  
         [0047]    Retention groove  64  (visible in the sectional view of FIG. 11) comprises an annular recess having a plurality of notches on the inner wall of modified riser  212  opposite the top margin of ridge  214  on the outer wall. A snap ring  65  comprises radial extensions  67  which engage the notches in retention groove  64 , and provides a seat for shut-off valve spring  68 . Shut off valve spring  68  is a coil spring having a top end which lies against shut-off valve  70  (fully described below) and a bottom end which lies against snap ring  65 . Spring  68  exerts an upward force on modified TAR  218 . In the normal operative state, the lower face of nozzle  8  provides a downward force which compresses spring  68 , and prevents shut-off valve  70  from engaging valve seat  62 .  
         [0048]    With reference to FIG. 11, modified TAR  218  is generally similar to the three stage telescoping device in accordance with the first embodiment, but modified as follows: Prongs  32  are replaced at the base of modified first stage  40   a  by shut-off valve  70 . Shut-off valve  70  comprises an annular which engages the base of modified first stage  40   a . The outside diameter of valve  70  is approximately equal to the inside diameter of modified riser  212 , and the outer edge of valve  70  rides along the inner walls of modified riser  212 . Valve  70  is perforated to allow the passage of water when the valve is open.  
         [0049]    A further modification includes the addition of load relief ridge  76  (visible in FIG. 10) to modified third stage  44   a . Load relief ridge  76  comprises an annular extension of the respective third and second stages, and facilitates load transfer from the shut-off valve spring to the nozzle without passing the force through the pistons.  
         [0050]    [0050]FIG. 7 shows the alternative embodiment of the sprinkler head of the present invention during a normal irrigation cycle. Pressurized water  220  enters sprinkler head  202 , and flows into the channel of modified riser  212 . The pressurized water flows through the perforations in shut-off valve  70 , past modified TAR  218 , around valve seat  62 , through optional grit filter  224 , and strikes the underside of nozzle  208 . The water pressure overcomes the downward force of spring  216  on modified riser  212 , and thrusts nozzle  208  and modified riser  212  upwardly out of sprinkler head  202  through the aperture in cap  206 . Ridge  214  secures the lower end of modified riser  212  within sprinkler head  202  and prevents the riser from being ejected in response to the surge of water pressure. Under normal operating conditions, water is thereby emitted from the nozzle and the lawn is irrigated.  
         [0051]    [0051]FIG. 8 illustrates the sprinkler head of the present invention in which nozzle  208  has been dislodged from modified riser  212 , not during an irrigation cycle. Absent the downward force from nozzle  208 , modified TAR  218  is forced upward by valve spring  68 , and shut-off valve  70  lodges valve seat  62 , effectively shutting-off the flow of water during the next irrigation cycle. However, the telescoping stages of modified TAR  218  remain retracted inside the sprinkler head body.  
         [0052]    [0052]FIGS. 9 and 10 show the consequences of the next irrigation cycle. Water pressure  220  entering the damaged sprinkler head forces modified riser  212  upward out of the sprinkler head body. However, shut-off valve  70  contains the water in the sprinkler head. As shown in FIG. 9, water  220  entering the base of modified TAR  218  causes the extension of the telescoping stages of the modified TAR  218 . As shown in FIG. 10, at the end of the irrigation cycle, modified riser  212  retracts back into the sprinkler head body under the force of riser return spring  216 . However, the telescoping stages of the modified TAR  218  remain extended with second and third stages locked in place at their respective retention grooves. The modified TAR  218  is thus visible above the surface of the ground, thereby signaling the location of the damaged sprinkler head until discovered. Subsequent irrigation cycles do not cause the TAR  218  to retract, or shut off valve  70  to open.  
         [0053]    Finally, in each embodiment, the TAR device facilitates the repair of the damaged sprinkler head. Pulling upwardly on the extended TAR overcomes the force exerted by the riser return spring, and lifts the riser from the sprinkler head body exposing the threads at the top of the riser. This enables a new nozzle to be threaded onto the riser without having to dig up the sprinkler head. The repair is executed by retracting the extended telescoping stages of the TAR back into the riser, screwing a replacement nozzle onto the existing riser, and allowing the riser to retract back into the sprinkler head body. The sprinkler head and alerting mechanism are now in working order for the next irrigation cycle.  
         [0054]    Alternatively, if the riser has sustained damage, the cap is first removed from the sprinkler head. In the first embodiment, a new riser with nozzle can be replaced into the sprinkler head to restore it to operative condition, and the TAR  18  can be reinstalled in the sprinkler head. Likewise, the device as taught and practiced in the present invention permits retrofit installation of the signaling device in an existing pop-up style sprinkler head.  
         [0055]    Having now fully set forth the preferred embodiments and certain modifications of the concept underlying the present invention, various other embodiments as well as certain variations and modifications of the embodiments herein shown and described will obviously occur to those skilled in the art upon becoming familiar with said underlying concept. It is to be understood, therefore, that the invention may be practiced otherwise than as specifically set forth in the appended claims: