Patent Publication Number: US-7900851-B2

Title: Pop-up spraying devices with a flexible stem

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims benefit of U.S. Ser. No. 60/962,085, filed Jul. 27, 2007, which is incorporated herein by reference in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     Embodiments of the invention generally relate to irrigation devices, and more particularly, to pop-up irrigation sprayers and sprinklers. 
     2. Description of the Related Art 
     Pop-up and pulsating irrigation pop-up sprayers and sprinklers, used primarily for irrigation of turf, have stems which are rigid and inflexible. These rigid stems are susceptible to breaking from outside forces that may be applied in the field, for example, when someone accidentally steps on or drives over the pop-up sprayer or sprinkler. The breaking of an individual pop-up spraying device can cause many problems, such as a large loss of water that escapes the irrigation system through the body of the broken pop-up spraying device. This large loss of water can causes localized flooding around the broken pop-up spraying device and generally wastes valuable water resources. In some irrigation systems containing the pulsating irrigation pop-up sprayers or sprinklers, the breakage of one pop-up spraying device can cause the remainder of the irrigation system to cease operation because of pressure drop in the water supply system. 
     In some pop-up spraying devices, at the beginning of each irrigation cycle, water flows into the body of the pop-up spraying device, causing the rigid stem to move up, and at the same time, water also flows through the spraying device, which is connected to the outlet of the stem. Therefore a high flow of water is often used to force each unit to a popped-up position. For this reason, traditional pop-up spraying devices are produced with a large inlet port having a diameter within a range from about 1.0 cm to 1.5 cm at the inlet to the body of the pop-up sprinkler device. Therefore, in an irrigation system with traditional pop-up spraying device, a large amount of water is wasted when the rigid stem breaks. 
     Therefore, a need exists for an irrigation pop-up sprayer or sprinkler having a flexible stem, which is more robust than traditional, rigid stems. 
     SUMMARY OF THE INVENTION 
     Embodiments of the invention provide an irrigation pop-up with a flexible stem, which may be a conventional or pulsating irrigation sprayer or sprinkler. The flexible stem enables an extended stem to be bent instead of being severed, as experienced by traditional irrigation systems, if impacted by an outside force, such as being stepped on or driven over. 
     The irrigation pop-up with a flexible stem usually includes a rigid housing containing a body having a water inlet and a cap having a pop-up outlet, a flexible stem disposed at least partially within the rigid housing, and a spring coiled around the flexible stem and disposed within the rigid housing. The irrigation pop-up usually has a wiper seal and a spraying nozzle. The flexible stem may be used for pulsating irrigation pop-ups or for conventional (i.e., non-pulsating) irrigation pop-ups. 
     In one embodiment, the flexible stem contains a lower rigid segment having a first passageway extending therethrough from a lower rigid segment inlet to a lower rigid segment outlet, an upper rigid segment having a second passageway extending therethrough from an upper rigid segment inlet to an upper rigid segment outlet, and an elastic hollow member having a channel and coupled to and in fluid communication with the lower rigid segment outlet and the upper rigid segment inlet. A water flow path may extend from the water inlet, through the first passageway within the lower rigid segment, through the channel of the elastic hollow member, through the second passageway within the upper rigid segment, and out through the spraying nozzle. 
     In another embodiment, the flexible stem may be used in pulsating irrigation pop-ups and contains a lower rigid segment having a first passageway extending therethrough from a lower rigid segment inlet to a lower rigid segment outlet, an upper rigid segment having a second passageway extending therethrough from an upper rigid segment inlet to an upper rigid segment outlet, and an elastic hollow member having a channel and coupled to and in fluid communication with the lower rigid segment outlet and the upper rigid segment inlet. The flexible stem further contains an elastic sleeve at least partially surrounding a rigid insert disposed within the upper rigid segment, the rigid insert contains a first inlet on a bottom surface, a first outlet on a side surface, a second inlet on the side surface, and a second outlet on a top surface. 
     In another embodiment, the flexible stem may be used for conventional or pulsating irrigation pop-up contains a lower rigid segment containing a first passageway extending therethrough from a lower rigid segment inlet to a lower rigid segment outlet, an upper rigid segment containing a second passageway extending therethrough from an upper rigid segment inlet to an upper rigid segment outlet, and a rubber tube containing a channel and coupled to and in fluid communication with the lower rigid segment outlet and the upper rigid segment inlet, and a water flow path extending from the water inlet, through the first passageway, through the channel, through the second passageway, and to the upper rigid segment outlet. Throughout the various embodiments, the upper rigid segment outlet may be coupled to and in fluid communication with a sprinkler head, a spray head, or other types of nozzle. In one example, the upper rigid segment may be bent at an angle of about 90° or less relative to the lower rigid segment upon the application of an outside force. Upon removal of the outside force, the upper rigid segment resorts back its original position. 
     The elastic hollow member may be a tube, a hose, a pipe, a conduit, a duct, or derivatives thereof. The elastic hollow member may contain rubber or rubber derivatives (e.g., natural or synthetic), as well as elastic polymers, elastic oligomers, elastic plastics, which may have carbon or silicon backbones. In one example, the elastic hollow member is a rubber tube, and in another example, a flexible plastic tube surrounded by a spring. In one example, the elastic hollow member is cemented or glued to the lower rigid segment outlet and to the upper rigid segment inlet. In another example, the elastic hollow member is coupled to the lower rigid segment outlet by a first fitting and coupled to the upper rigid segment inlet by a second fitting. In other examples, a flow control may be coupled to and in fluid communication with the first passageway within the lower rigid segment. 
     In some embodiments for a pulsating irrigation pop-up, the flexible stem may contain an elastic sleeve at least partially surrounding a rigid insert. The rigid insert may contain at least a first inlet on a bottom surface, a first outlet on a side surface, a second inlet on the side surface, and a second outlet on a top surface. For example, the rigid insert may contain a water inlet on the bottom surface, one or more outlets on the circumference of the insert, one or more inlets on the circumference of the insert, and a water outlet on the top surface. In one example, a passageway extends between the first inlet and the first outlet of the rigid insert, extends along and between the side surface of the rigid insert and the elastic sleeve, and further extends between the second inlet and the second outlet of the rigid insert. The rigid insert usually contains at least one barb on the side surface, between the first outlet and the second inlet, and under the elastic sleeve. 
     In other embodiments, the pop-up operates at a relatively low flow as a pulsating irrigation pop-up sprayer or sprinkler. The body of the rigid housing of the pop-up contains a water inlet port disposed between the water inlet and the flexible stem and in fluid communication with the first passageway. The water inlet port is used to restrict water flow rate passing through the body of the pop-up. The water inlet port may have a diameter, for example, within a range from about 2 mm to about 3 mm. In some examples, the body of the irrigation pop-up provides a maximum water flow rate of about 230 liters per hour. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       So that the manner in which the above recited features of the invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments. 
         FIGS. 1A-1D  depict a pulsating irrigation pop-up according to an embodiment described herein; 
         FIGS. 2A-2B  depict a flexible stem according to an embodiment described herein; 
         FIG. 2C  depicts another pulsating irrigation pop-up according to an embodiment described herein; 
         FIGS. 3A-3B  depict a conventional flexible stem according to an embodiment described herein; 
         FIG. 3C  depicts a non-pulsating irrigation pop-up according to an embodiment described herein; 
         FIGS. 4A-4B  depict another flexible stem according to an embodiment described herein; 
         FIGS. 4C-4E  depict another pulsating irrigation pop-up according to an embodiment described herein; 
         FIG. 4F  depicts an irrigation system according to an embodiment described herein; 
         FIGS. 5A-5B  depict another conventional flexible stem according to an embodiment described herein; and 
         FIGS. 5C-5E  depict another non-pulsating irrigation pop-up according to an embodiment described herein. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments of the invention provide an irrigation pop-up sprayer or sprinkler with a flexible stem which may be a pulsating irrigation pop-up or a conventional or non-pulsating irrigation pop-up.  FIGS. 1A-1D  depict pulsating irrigation pop-up  101 , as described in an embodiment herein.  FIG. 1A  illustrates a front view and  FIG. 1B  illustrates a cross-sectional view of pulsating irrigation pop-up  101 . Pulsating irrigation pop-up  101  contains stem  100  at least partially within body  1  and cap  4 . Pulsating irrigation pop-up  101  also contains water inlet  2 , outlet port  3 , wiper seal  6 , spring  7 , and spraying nozzle  8 . Water inlet  2  is disposed on the bottom of body  1 , outlet port  3  is within stem  100  and in fluid communication with spraying nozzle  8 , which is disposed at the top of stem  100 . Wiper seal  6  is positioned between cap  4  and body  1 , while spring  7  coils around stem  100 . Spraying nozzle  8  may be a spraying nozzle, a rotating sprinkler, or another type of nozzle. In one example, spraying nozzle  8  may be a floating, rotating sprinkler as further described in commonly assigned U.S. Pat. No. 5,803,365, which is incorporated herein by reference. 
     In another embodiment, stem  100  contains upper casing  12 , lower casing  18 , and elastic sleeve  11  at least partially surrounding rigid insert  10 . Upper casing  12  is coupled to lower casing  18  and contains rigid insert  10  and elastic sleeve  11 . In another example, upper casing  12  may contain vents along the side (not shown). Further disclosure of casings that may be used in embodiments herein is described in commonly assigned U.S. Pat. Nos. 5,507,436 and 5,727,733, which are incorporated herein by reference. 
     Rigid insert  10  is at least partially surrounded by elastic sleeve  11  and contains inlet port  15 , outlet port  22 , inlet port  17 , and outlet port  24 . Rigid insert  10  also has at least one barb  16  that is tightly surrounded by elastic sleeve  11  when closing water inlet port  17  to outlet port  24  and outlet port  3 . Flow control or dripper  14  containing passageway  21  is coupled to and in fluid communication with inlet port  15  and is used for controlling the flow of water into the upper section segment of stem  100 . In some examples, flow control or dripper  14  may be a nozzle or a dripper. Lower segment  13  of stem  100  serves as a guide for controlling the direction in which stem  100  moves up and down inside of body  1 . Slots  19  on lower segment  13  control the movement of stem  100  inside body  1  of pulsating irrigation pop-up  101 . 
       FIGS. 1C-1D  illustrate pulsating irrigation pop-up  101  at a position in which stem  100  is extended from body  1  through pop-up outlet  23  to provide increased height for spraying nozzle  8 . In one example, stem  100  is extended to provide the highest position for spraying nozzle  8 . Water that flows into body  1  through water inlet  2  and water inlet port  9  fills space  20  of body  1 . Initially, the water pressure in space  20  is low and elastic sleeve  11  tightly surrounds barb  16  of insert  10  closing water inlet port  17  to outlet port  3 . The water which flows through water inlet  2  forces stem  100  to rise. Once the water pressure in space  20  has increased, water flows from space  20  through flow control or dripper  14  into inlet port  15  forcing elastic sleeve  11  to expand and accumulate a small volume of water. As the water pressure increases, elastic sleeve  11  expands enough to open inlet port  17  and force the water to flow through outlet port  24 , then through outlet port  3 , and out spraying nozzle  8 . Since water continues to flow through inlet port  15  at a relatively low controlled flow, elastic sleeve  11  contracts, closing inlet port  17  to outlet port  3  and terminating one pulsating cycle. The preset water pressure of pulsating irrigation pop-up  101  is correlated to the diameter of barb  16  and to the dimension and the physical properties of the elastic sleeve  11 . 
     The pulsating irrigation pop up converts a low continues flow entering its inlet to a high intermittent pulsating flow ejected through its outlet. For example, when dripper  14  controls the flow into flexible stem. 
     In another embodiment, body  1  of pulsating irrigation pop-up  101  contains water inlet port  9  in fluid communication between water inlet  2  and stem  100 . Water inlet port  9  limits the flow of water into body  1  to a maximum flow of, for example, 230 liters per hour. Water inlet port  9  may have a diameter within a range from about 0.5 mm to about 5 mm, preferably, about 2 mm to 3 mm. 
     Examples provide that pulsating irrigation pop-up  101  receives a continuous flow of water entering water inlet  2  and converts the continuous water flow to an intermittent and pulsating high flow ejected through spraying nozzle  8  at a high intermittent pulsating flow. The flow of water through pulsating irrigation pop-up  101  is controlled and limited to a relatively low flow, for example, at about 12 liters per hour (L/hr). In one example, the total flow for operating a lateral irrigation system containing about 25 such pulsating irrigation pop-ups is only 300 L/hr. 
     In such a case, if the port at the inlet to the body of the pulsating irrigation pop-ups will have the same diameter of traditional pop-up spraying devices, which is about 1 centimeter to 1.5 centimeter, and if the stem of one of the traditional pulsating irrigation pop-up breaks, water at a relatively high flow rate will be dispersed through the pulsating irrigation pop-up with the broken stem. The pressure in the irrigation lateral will drop and all the other traditional pop-ups in the irrigation system will stop working. Small Inlet port  9  limits the water flow through the pop-up. If a stem of one or more of the current pulsating irrigation pop-ups breaks, the rest of the pulsating irrigation pop-ups will continue to operate. 
     Each pulsating irrigation pop-up  101  may utilize stem  100  as a preset pressure responding valve. At any pressure lower than a preset pressure, outlet port  3  within pulsating irrigation pop-up  101  remains closed and no water flows from water inlet  2  to outlet port  3 . Therefore, a relatively low flow of water causes stem  100  to move to an extended position. 
     In one example, an irrigation system contains multiple pulsating irrigation pop-up assemblies  101 , for example, about 25 assemblies. If one or more stems  100  break, the water pressure in the lateral will drop only slightly, and all the rest of pulsating irrigation pop-up assemblies  101  in the irrigation system will continue to operate. The flow into body  1  of pulsating irrigation pop-up  101  is controlled and limited by water inlet port  9 . The water flows into body  1  of pulsating irrigation pop-up  101  may also be controlled by flow control or dripper  14  or an orifice at or near inlet  2 . 
     In another embodiment,  FIGS. 2A-2B  depict flexible stem  200 , which may be used in pulsating irrigation pop-up  102 , as illustrated in  FIG. 2C . Flexible stem  200  contains lower rigid segment  31  and upper rigid segment  32 , both connected by elastic hollow member  33  (e.g., rubber tube). Lower rigid segment  31  contains water inlet  34  which is in fluid communication with water outlet  45  of upper rigid segment  32 . In one embodiment, flexible stem  200  contains lower rigid segment  31  having passageway  47  extending from water inlet  34  to outlet port  40  and upper rigid segment  32  having passageway  48  extending from inlet port  38  to water outlet port  49 . Elastic hollow member  33  has a channel therethrough and is coupled to and in fluid communication with outlet port  40  of lower rigid segment  31  and inlet port  38  of upper rigid segment  32 . Flexible stem  200  further has elastic sleeve  36  at least partially surrounding rigid insert  35  and disposed within upper rigid segment  32 . Rigid insert  35  contains inlet port  38  on a bottom surface, outlet  43  on a side surface, inlet  44  also on the side surface, and water outlet port  49  on a top surface. 
     Elastic hollow member  33  has a channel and has elastic properties, such as being capable of returning to an original length or shape after being stretched, deformed, compressed, or expanded by an outside force. Elastic hollow member  33  may be a tube, a flexible tube, a hose, a pipe, a conduit, a duct, or derivatives thereof. Elastic hollow member  33  may contain a material such as rubber or a rubber derivative (e.g., natural or synthetic rubber), an elastic polymer, an elastic oligomer, an elastic plastic, derivatives thereof, or combinations thereof. The rubber, polymer, or other material contained within elastic hollow member  33  may have a carbon backbone or a silicon backbone. In some embodiments, elastic hollow member  33  may be reinforced by a spring disposed inside, outside, or embedded within elastic hollow member  33 . In one example, elastic hollow member  33  is a tube or hose containing rubber or a rubber derivative. In some examples, elastic hollow member  33  is a flexible tube, such as a flexible plastic tube. In some examples, elastic hollow member is cemented, glued, or welded to a lower rigid segment outlet, such as outlet port  40  and to an upper rigid segment inlet, such as inlet port  38 . In another example, elastic hollow member  33  is coupled to a lower rigid segment outlet, such as outlet port  40  by a first fitting (not shown) and coupled to an upper rigid segment inlet, such as inlet port  38  by a second fitting (not shown). Further disclosure of pulsating irrigation devices for converting a low continues flow to high intermittent pulsating flow that may be used in embodiments herein are further described commonly assigned U.S. Pat. Nos. 5,507,436 and 5,727,733, which are incorporated herein by reference. 
     In some examples, flow control  41 , having passageway  39 , may be coupled to lower casing  55  and in fluid communication with passageway  47  within lower rigid segment  31 . Flow control  41  directs or controls the flow of water into upper rigid segment  32  of flexible stem  200 . Slots  42  on lower rigid segment  31  control the movement of flexible stem  200  inside body  51  of pulsating irrigation pop-up  102 . 
       FIG. 2C  illustrates pulsating irrigation pop-up  102  at a position in which a portion of flexible stem  200  is extended from body  51  and cap  53  through pop-up outlet  54  of cap  53  to provide increased height for sprinkler head  50 . In one example, stem  200  is extended to provide the highest position for sprinkler head  50 . The portion of flexible stem  200  extended or protruding through pop-up outlet  54  includes upper rigid segment  32  and elastic hollow member  33 . Upper rigid segment  32  of flexible stem  200  is coupled to lower rigid segment  31  of flexible stem  200  by elastic hollow member  33 . In the extended position, upper rigid segment  32  of flexible stem  200  may be bent, as much as 90°, by an external force. Upon removal of the external force, flexible stem  200  returns to its original position as illustrated in  FIG. 2C . Therefore, upper rigid segment  32  may be bent at an angle of about 90° or less relative to lower rigid segment  31  upon the applied outside force. In one example, sprinkler head  50  is a floating rotating sprinkler head. 
     Water flows into body  51  through water inlet  52  to increase the water pressure within body  51 . Initially, the water pressure is low therefore the water flowing through water inlet  52  forces flexible stem  200  to extend through pop-up outlet  54 . Once the water pressure in body  51  has increased, water flows from within body  51  through water inlet  34 , through passageway  47 , through passageway  39  of flow control  41  out of lower rigid segment  31  through outlet port  40 . Subsequently, the water passes though elastic hollow member  33  and enters into upper rigid segment  32  by inlet port  38 . 
     Initially, flexible stem  200  is extended because the water pressure is low and elastic sleeve  36  tightly surrounds barb  46  of rigid insert  35  closing inlet port  44  to outlet port  49 . The water travels from inlet port  38 , through passageway  48 , and through outlet port  43  forcing elastic sleeve  36  to expand and accumulate water. As the water pressure increases, elastic sleeve  36  expands enough to open inlet port  44  and force the water to flow through outlet port  49 , then through water outlet  45 , and out sprinkler head  50 . Since water continues to flow through passageway  48  at a relatively low controlled flow, elastic sleeve  36  contracts, closing inlet port  44  to outlet port  49  and terminating one pulsating cycle. The preset water pressure of pulsating irrigation pop-up  102  is correlated to the diameter of barb  46  and to the dimension and the physical properties of the elastic sleeve  36 . 
     In another embodiment,  FIGS. 3A-3B  depict flexible stem  300 , which is a conventional, i.e., non-pulsating, flexible pop-up stem. Flexible stem  300  may be used in non-pulsating irrigation pop-up  103 , as illustrated in  FIG. 3C . Flexible stem  300  contains lower rigid segment  61  and upper rigid segment  62 , both connected to elastic hollow member  63  (e.g., rubber tube). Elastic hollow member  63  has a channel therethrough and is coupled to and in fluid communication with outlet port  73  of lower rigid segment  61  and inlet port  68  of upper rigid segment  62 . 
     Lower rigid segment  61  contains lower casing  80  having passageway  74  extending from water inlet  64 , through port  69 , and to outlet port  73 . Slots  72  on lower rigid segment  61  control the movement of flexible stem  300  inside body  71  of non-pulsating irrigation pop-up  103 . Upper rigid segment  62  contains insert  66  coupled to and in fluid communication with upper casing  79 . Insert  66  contains inlet port  68  on a bottom surface, channel  75  extending therethrough, and outlet  81  on a top surface. Upper casing  79  has passageway  76  extending therethrough and in fluid communication with outlet  81  of insert  66  and water outlet  65  disposed on the top of upper casing  79 . 
     Elastic hollow member  63  has a channel and has elastic properties, such as being capable of returning to an original length or shape after being stretched, deformed, compressed, or expanded by an outside force. Elastic hollow member  63  may be a tube, a flexible tube, a hose, a pipe, a conduit, a duct, or derivatives thereof. Elastic hollow member  63  may contain a material such as rubber or a rubber derivative (e.g., natural or synthetic rubber), an elastic polymer, an elastic oligomer, an elastic plastic, derivatives thereof, or combinations thereof. The rubber, polymer, or other material contained within elastic hollow member  63  may have a carbon backbone or a silicon backbone. In some embodiments, elastic hollow member  63  may be reinforced by a spring disposed inside, outside, or embedded within elastic hollow member  63 . In one example, elastic hollow member  63  is a tube or hose containing rubber or a rubber derivative. In some examples, elastic hollow member  63  is a flexible tube, such as a flexible plastic tube. In some examples, elastic hollow member is cemented, glued, or welded to a lower rigid segment outlet, such as outlet port  73  and to an upper rigid segment inlet, such as inlet port  68 . In another example, elastic hollow member  63  is coupled to a lower rigid segment outlet, such as outlet port  73  by a first fitting (not shown) and coupled to an upper rigid segment inlet, such as inlet port  68  by a second fitting (not shown). 
       FIG. 3C  illustrates non-pulsating irrigation pop-up  103  at a position in which a portion of flexible stem  300  is extended from body  71  and cap  67  through pop-up outlet  78  of cap  67  to provide increased height for spray head  70 . In one example, stem  300  is extended to provide the highest position for sprayer head  70 . The portion of flexible stem  300  extended or protruding through pop-up outlet  78  includes upper rigid segment  62  and elastic hollow member  63 . Upper rigid segment  62  of flexible stem  300  is coupled to lower rigid segment  61  of flexible stem  300  by elastic hollow member  63 . In the extended position, upper rigid segment  62  of flexible stem  300  may be bent, as much as 90°, by an external force. Upon removal of the external force, flexible stem  300  returns to its original position as illustrated in  FIG. 3C . Therefore, upper rigid segment  62  may be bent at an angle of about 90° or less relative to lower rigid segment  61  upon the applied outside force. 
     Water flows into body  71  through water inlet  77  to increase the water pressure within body  71 . Initially, the water pressure is low therefore the water flowing through water inlet  77  forces flexible stem  300  to extend through pop-up outlet  78 . Once the water pressure in body  71  has increased, water flows from within body  71  through water inlet  64 , through passageway  74 , through port  69 , and out of lower rigid segment  61  through outlet port  73 . Subsequently, the water passes though elastic hollow member  63  and enters into upper rigid segment  62  by inlet port  68 . Thereafter, the water travels from inlet port  68 , through channel  75 , through outlet  81 , through passageway  76 , and out spray head  70 . 
     In another embodiment,  FIGS. 4A-4B  depict flexible stem  400 , which is a pulsating flexible pop-up stem. Flexible stem  400  may be used in pulsating irrigation pop-up  1102 , as illustrated in  FIGS. 4C-4E . Flexible stem  400  contains lower rigid segment  131  and upper rigid segment  132 , both connected by elastic hollow member  133  (e.g., rubber tube). Lower rigid segment  131  contains water inlet  134  which is in fluid communication with water outlet  145  of upper rigid segment  132 . In one embodiment, flexible stem  400  contains lower rigid segment  131  having passageway  147  extending from water inlet  134  to outlet port  140  and upper rigid segment  132  having passageway  148  extending from inlet port  138  to water outlet port  149 . Elastic hollow member  133  has a channel therethrough and is coupled to and in fluid communication with outlet port  140  of lower rigid segment  131  and inlet port  138  of upper rigid segment  132 . Flexible stem  400  further has elastic sleeve  136  at least partially surrounding rigid insert  135  and disposed within upper rigid segment  132 . Rigid insert  135  contains inlet port  138  on a bottom surface, outlet  143  on a side surface, inlet  144  also on the side surface, and water outlet port  149  on a top surface. 
     Elastic hollow member  133  has a channel and has elastic properties, such as being capable of returning to an original length or shape after being stretched, deformed, compressed, or expanded by an outside force. Elastic hollow member  133  may be a tube, a flexible tube, a hose, a pipe, a conduit, a duct, or derivatives thereof. Elastic hollow member  133  may contain a material such as rubber or a rubber derivative (e.g., natural or synthetic rubber), an elastic polymer, an elastic oligomer, an elastic plastic, derivatives thereof, or combinations thereof. The rubber, polymer, or other material contained within elastic hollow member  133  may have a carbon backbone or a silicon backbone. In some embodiments, elastic hollow member  133  may be reinforced by a spring disposed inside, outside, or embedded within elastic hollow member  133 . In one example, elastic hollow member  133  is a tube or hose containing rubber or a rubber derivative. In some examples, elastic hollow member  133  is a flexible tube, such as a flexible plastic tube. In some examples, elastic hollow member is cemented, glued, or welded to a lower rigid segment outlet, such as outlet port  140  and to an upper rigid segment inlet, such as inlet port  138 . In another example, elastic hollow member  133  is coupled to a lower rigid segment outlet, such as outlet port  140  by a first fitting (not shown) and coupled to an upper rigid segment inlet, such as inlet port  138  by a second fitting (not shown). Further disclosure of pulsating irrigation devices for converting a low continues flow to high intermittent pulsating flow that may be used in embodiments herein are further described commonly assigned U.S. Pat. Nos. 5,507,436 and 5,727,733, which are incorporated herein by reference. 
     In some examples, flow control or dripper  141 , having passageway  139 , may be coupled to lower casing  155  and in fluid communication with passageway  147  within lower rigid segment  131 . Flow control or dripper  141  directs or controls the flow of water into upper rigid segment  132  of flexible stem  400 . Slots  142  on lower rigid segment  131  control the movement of flexible stem  400  inside body  151  of pulsating irrigation pop-up  1102 . 
       FIGS. 4C-4E  illustrates pulsating irrigation pop-up  1102  at a position in which a portion of flexible stem  400  is extended from body  151  and cap  153  through pop-up outlet  154  of cap  153  to provide increased height for sprinkler head  150 . In one example, stem  400  is extended to provide the highest position for sprinkler head  150 . The portion of flexible stem  400  extended or protruding through pop-up outlet  154  includes upper rigid segment  132  and elastic hollow member  133 , as well as a portion of lower casing  155  of lower rigid segment  131 . Upper rigid segment  132  of flexible stem  400  is coupled to lower rigid segment  131  of flexible stem  400  by elastic hollow member  133 . In one example, sprinkler head  150  is a floating rotating sprinkler head. Pulsating irrigation pop-up  1102  also contains spring  157  coiled around flexible stem  400  and a wiper seal within cap  153 . 
     Water flows into body  151  through water inlet  152  and inlet port  159  to increase the water pressure within body  151 . Initially, the water pressure is low therefore the water flowing through water inlet  152  forces flexible stem  400  to extend through pop-up outlet  154 . Once the water pressure in body  151  has increased, water flows from within body  151  through water inlet  134 , through passageway  147 , through passageway  139  of flow control or dripper  141  out of lower rigid segment  131  through outlet port  140 . Subsequently, the water passes though elastic hollow member  133  and enters into upper rigid segment  132  by inlet port  138 . 
     Initially, flexible stem  400  is extended because the water pressure is low and elastic sleeve  136  tightly surrounds barb  146  of rigid insert  135  closing inlet port  144  to outlet port  149 . The water travels from inlet port  138 , through passageway  148 , and through outlet port  143  forcing elastic sleeve  136  to expand and accumulate water. As the water pressure increases, elastic sleeve  136  expands enough to open inlet port  144  and force the water to flow through outlet port  149 , then through water outlet  145 , and out sprinkler head  150 . Since water continues to flow through passageway  148  at a relatively low controlled flow, elastic sleeve  136  contracts, closing inlet port  144  to outlet port  149  and terminating one pulsating cycle. The preset water pressure of pulsating irrigation pop-up  1102  is correlated to the diameter of barb  146  and to the dimension and the physical properties of the elastic sleeve  136 . 
     A relatively low continuous flow of water which enters through the inlet of pulsating irrigation pop-up  1102  ejects at a high intermittent pulsating flow through its outlet. 
       FIG. 4E  illustrates pulsating irrigation pop-up  1102  at a position in which extended flexible stem  400  is bent by an external force, such as being stepped on or driven over. Elastic hollow member  133  slightly elongates and upper rigid segment  132  of flexible stem  400  bends as the external force is applied thereto. In one embodiment, flexible stem  400  and elastic hollow member  133  may be bent as much as about 90°, such that flexible stem  400  is lying on the ground. Therefore, upper rigid segment  132  may be bent at an angle of about 90° or less relative to lower rigid segment  131  upon the applied outside force. When the external force is removed, elastic hollow member  133  contracts and upper rigid segment  132  of flexible stem  400  return to its original position as depicted in  FIG. 4C . Pulsating irrigation pop-up  1102  having flexible stem  400  is much more robust than an irrigation system having a rigid, non-flexible, or non-elastic stem due to the drastically reduction in the possibility of breaking flexible stem  400 . 
       FIG. 4F  depicts an irrigation system according to another embodiment.  FIG. 4F  illustrates, in a top view, irrigation system  420  containing pulsating irrigation pop-ups  1102  coupled to and in fluid communication with flexible tubing  422 , which is coupled to and in fluid communication with irrigation lateral  424 . The small size of flexible tubing  422  may be used to restrict the flow of water from irrigation lateral  424  to pulsating irrigation pop-up  1102 . Also, flexible tubing  422  is useful for better locating pulsating irrigation pop-up  1102  at the desirable locations in the field, as opposed to traditional irrigation systems, in which the pop-up is directly connected to a rigid irrigation lateral. Flexible tubing  422  may have a length of about 1 meter, and generally has a small, restricting diameter. The inner diameter of flexible tubing  422  may be within a range from about 2 mm to about 6 mm, preferably, from about 3 mm to about 5 mm, for example, about 4 mm. 
     In another embodiment,  FIGS. 5A-5B  depict flexible stem  500 , which is a conventional or non-pulsating, flexible pop-up stem. Flexible stem  500  may be used in non-pulsating irrigation pop-up  1103 , as illustrated in  FIG. 5C . Flexible stem  500  contains lower rigid segment  161  and upper rigid segment  162 , both connected to elastic hollow member  163  (e.g., rubber tube). Elastic hollow member  163  has a channel therethrough and is coupled to and in fluid communication with outlet port  173  of lower rigid segment  161  and inlet port  168  of upper rigid segment  162 . 
     Lower rigid segment  161  contains lower casing  180  having passageway  167  extending from water inlet  164 , through port  169 , and to outlet port  173 . Slots  172  on lower rigid segment  161  control the movement of flexible stem  500  inside body  175  of non-pulsating irrigation pop-up  1103 . Upper rigid segment  162  contains insert  166  coupled to and in fluid communication with upper casing  179 . Insert  166  contains inlet port  168  on a bottom surface, channel  170  extending therethrough, and outlet  181  on a top surface. Upper casing  179  has passageway  171  extending therethrough and in fluid communication with outlet  181  of insert  166  and water outlet  165  disposed on the top of upper casing  179 . Non-pulsating irrigation pop-up  1103  also contains spring  187  coiled around flexible stem  500  and a wiper seal within cap  177 . 
     Elastic hollow member  163  has a channel and has elastic properties, such as being capable of returning to an original length or shape after being stretched, deformed, compressed, or expanded by an outside force. Elastic hollow member  163  may be a tube, a flexible tube, a hose, a pipe, a conduit, a duct, or derivatives thereof. Elastic hollow member  163  may contain a material such as rubber or a rubber derivative (e.g., natural or synthetic rubber), an elastic polymer, an elastic oligomer, an elastic plastic, derivatives thereof, or combinations thereof. The rubber, polymer, or other material contained within elastic hollow member  163  may have a carbon backbone or a silicon backbone. In some embodiments, elastic hollow member  163  may be reinforced by a spring disposed inside, outside, or embedded within elastic hollow member  163 . In one example, elastic hollow member  163  is a tube or hose containing rubber or a rubber derivative. In some examples, elastic hollow member  163  is a flexible tube, such as a flexible plastic tube. In some examples, elastic hollow member is cemented, glued, or welded to a lower rigid segment outlet, such as outlet port  173  and to an upper rigid segment inlet, such as inlet port  168 . In another example, elastic hollow member  163  is coupled to a lower rigid segment outlet, such as outlet port  173  by a first fitting (not shown) and coupled to an upper rigid segment inlet, such as inlet port  168  by a second fitting (not shown). 
       FIG. 5C  illustrates non-pulsating irrigation pop-up  1103  at a position in which a portion of flexible stem  500  is extended from body  175  and cap  177  through pop-up outlet  178  of cap  177  to provide increased height for spray head  174 . In one example, stem  500  is extended to provide the highest position for spray head  174 . The portion of flexible stem  500  extended or protruding through pop-up outlet  178  includes upper rigid segment  162  and elastic hollow member  163 . Upper rigid segment  162  of flexible stem  500  is coupled to lower rigid segment  161  of flexible stem  500  by elastic hollow member  163 . 
     Water flows into body  175  through water inlet  176  and inlet port  189  to increase the water pressure within body  175 . Initially, the water pressure is low therefore the water flowing through water inlet  176  forces flexible stem  500  to extend through pop-up outlet  178 . Once the water pressure in body  175  has increased, water flows from within body  175  through water inlet  164 , through passageway  167 , through port  169 , and out of lower rigid segment  161  through outlet port  173 . Subsequently, the water passes though elastic hollow member  163  and enters into upper rigid segment  162  by inlet port  168 . Thereafter, the water travels from inlet port  168 , through channel  170 , through outlet  181 , through passageway  171 , and out spray head  174 . 
     A relatively low continuous flow of water which enters through the inlet of non-pulsating irrigation pop-up  1103  ejects at a high flow through its outlet. 
       FIG. 5E  illustrates non-pulsating irrigation pop-up  1103  at a position in which flexible stem  500  is bent by an external force, such as being stepped on or driven over. Elastic hollow member  163  slightly elongates and upper rigid segment  162  of flexible stem  500  bends as the external force is applied thereto. In one embodiment, flexible stem  500  and elastic hollow member  163  may be bent as much as about 90°, such that flexible stem  500  is lying on the ground. Therefore, upper rigid segment  162  may be bent at an angle of about 90° or less relative to lower rigid segment  161  upon the applied outside force. When the external force is removed, elastic hollow member  163  contracts and upper rigid segment  162  of flexible stem  500  return to its original position as depicted in  FIG. 5C . Non-pulsating irrigation pop-up  1103  having flexible stem  500  is much more robust than an irrigation system having a rigid, non-flexible, or non-elastic stem due to the drastically reduction in the possibility of breaking flexible stem  500 . 
     While the foregoing is directed to embodiments of the invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.