Abstract:
A water hydrant for suppling potable water from a water source has an internal movable riser contained within a housing that extends beneath the ground to a depth below which freezing temperatures cannot reach. A chamber housing located at a distal end of the hydrant, beneath the frost line, contains a valve which may be actuated by the moving riser to provide a flow of water from the water source and through the riser. The chamber housing is configured to receive residual water from the riser when the flow of water has been shut off by the valve and to store the water beneath the frost line under sanitary conditions. A piston is disposed on a distal end of the riser, is slidably disposed within the chamber housing, and moves with the riser to expel water from the chamber housing when a handle of the hydrant is subsequently moved to reopen the valve.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
   This application claims priority to U.S. Provisional Application Ser. No. 60/542,766 filed on Feb. 6, 2004, incorporated herein by reference in its entirety. 

   FIELD OF THE INVENTION 
   This present invention relates to water hydrants and, more particularly, to a sanitary water hydrant for supplying potable water from a water supply. 
   BACKGROUND OF THE INVENTION 
   Outdoor water hydrants are useful for supplying potable water in various locations, such as parks, farms, railroad yards and various other outdoor settings. Because the water dispensed from such hydrants may be consumed by humans or animals, the water must be provided from the water source under sanitary conditions. Thus, care must be taken that the hydrant is sealed from the surrounding environment against leaks into the hydrant or water supply. If these outdoor hydrants are used with hoses, they are often fitted with vacuum breakers to prevent back flow of water from the environment through the hydrant which could contaminate the water supply. Furthermore, because these outdoor hydrants may be exposed to freezing temperatures, there is a potential for water in the hydrant to become frozen, where it may clog or damage the hydrant. To overcome this problem, valves used in outdoor hydrants are commonly buried in the ground below the level to which freezing temperatures may penetrate (i.e. below the frost line). Accordingly, the valve must be opened from above the ground, whereby water is provided to the surface through a riser pipe and an outlet of the hydrant. 
   Conventional outdoor hydrants have several drawbacks. For example, the external riser which connects the valve buried beneath the frost line to the outlet above the surface of the ground may be exposed to freezing temperatures, whereby water in the riser can freeze to either clog or damage the hydrant. To overcome this problem, water remaining in the riser after the valve is closed is often drained from the riser. This solution creates further problems, however. If the residual water from the riser is drained into the soil around the hydrant, a potential is created for “brown water” to enter the hydrant through drain holes, whereby fresh water may become contaminated on next use of the hydrant. If, instead, the residual water is drained to a reservoir below the frost line, this residual water is generally mixed with fresh water from the supply when the value is reopened. Because the fresh water is mixed with the old water as it is dispensed from the hydrant, it may take a long time, as much as a minute or more, to completely expel the old water from the hydrant. 
   Conventional systems which drain residual water to a reservoir typically utilize a venturi system to draw the water from the reservoir when the valve is reopened, whereby the flow of water from the water supply is used to entrain the stored, residual water and dispense it from the outlet. These venturi systems generally require a high velocity, low pressure flow for proper operation. This high velocity, low pressure flow is often in conflict with the requirements of the vacuum breaker system, which requires a minimum pressure threshold to function properly and which may restrict flow to a point where the venturi is ineffective. Still another drawback of conventional outdoor hydrants is that excavation is required to access and service wear parts of the hydrant which are located beneath the surface. The exposed riser is also susceptible to damage from above the surface, or when excavation is performed near the hydrant. 
   There is thus a need for an improved water hydrant which can be used to supply potable water under sanitary conditions while overcoming drawbacks of conventional water hydrants, such as those described above. 
   SUMMARY OF THE INVENTION 
   The present invention provides a water hydrant which provides potable water in outdoor environments and which overcomes drawbacks of prior water hydrants. In an exemplary embodiment, the water hydrant of the present invention includes an internal riser which itself is reciprocated to operate a water valve located beneath the frost line. The riser is enclosed within a housing that extends beneath the ground to a point below the frost line. The riser is coupled to a handle of the hydrant and is moved by the handle to actuate a water valve located at a distal end of the hydrant, below the frost line. A spigot on the hydrant is attached to the riser and moves with the riser when the riser is actuated by the handle. 
   In another aspect of the invention, the hydrant further includes a chamber housing, located at a distal end of the housing beneath the frost line. The chamber housing defines a chamber into which residual water remaining in the riser after flow of water has been shut off may be drawn to empty the riser and thereby prevent freezing of water in the riser. 
   Advantageously, the chamber housing is sealed off from the surrounding environment, whereby water may only enter and exit the chamber housing through the valve and riser. The hydrant thus ensures that sanitary conditions of the water supply and water stored in the chamber housing are properly maintained. 
   In yet another aspect of the invention, the exemplary hydrant includes a piston located at a distal end of the riser and slidably disposed within the chamber housing. The piston moves with the riser and expels residual water which has been stored in the chamber housing prior to actuation of the valve with the riser to open the valve. The residual water is quickly expelled from the spigot at the initiation of flow from the water supply. 
   In yet another aspect of the present invention, the exemplary hydrant includes an opening in the upper end of the housing which may be covered by a removable cap. The opening permits servicing of hydrant components from above grade, without the need to excavate around the hydrant. 
   The features and objectives of the present invention will become more readily apparent from the following Detailed Description taken in conjunction with the accompanying drawings. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a general description of the invention given above, and the detailed description given below, serve to explain the invention. 
       FIG. 1  is a perspective view of an exemplary hydrant of the present invention; 
       FIG. 1A  is a perspective view of a second exemplary hydrant, having a rotatable handle for operating the hydrant; 
       FIG. 2  is a cross-sectional view of the hydrant of  FIG. 1  taken along line  2 - 2  of  FIG. 1 ; and 
       FIGS. 3A-3E  show detail views of the lower valve and chamber of the invention of  FIG. 2  and depict operation of the hydrant. 
   

   DETAILED DESCRIPTION 
   Referring to  FIG. 1 , there is shown an exemplary water hydrant  10  of the present invention. The hydrant  10  includes a housing  12  which has an upper casing  14  that is generally exposed above the ground, and an elongate pipe  16  which extends from the upper casing  12  beneath the ground. The hydrant  10  further includes a handle  18  for operating the hydrant  10  and a spigot  20 , having an outlet  22 , for dispensing water from a water supply. In an exemplary embodiment, the handle  18  of the hydrant  10  is a lever type handle, but may be of other types such as a rotary knob  18 ′, as depicted in  FIG. 1A , or any other suitable device for manipulating the hydrant elements described herein. 
   Referring further to  FIG. 2 , the handle  18  is pivotally mounted to a shaft  19  and is coupled to a riser  24  contained within the housing  12 . The riser  24  extends from the upper casing  14  through the pipe  16  and is movable to engage a valve assembly  30  located beneath the surface and coupled to the water supply. In the exemplary embodiment shown, handle  18  is coupled to riser  24  by a linkage assembly  26  and a manifold  28 . The linkage assembly  26  includes a disk-shaped cam  21  fixed to the end of handle  18  for pivotal movement about shaft  19 . A link member  23  has a first end  25  pinned to the cam  21  and a second end  27  pinned to the manifold  28 . Movement of the handle  18  about shaft  19  rotates cam  21  to move link member  23  and thereby cause the manifold  28  and riser  24  to reciprocate within the housing  12  such that a valve  32  of valve assembly  30  may be selectively opened or closed, as will be described more fully below. 
   When valve  32  is opened by movement of the handle  18 , water from the water supply may flow through the valve  32  and riser  24  and out of the spigot  20 . The spigot  20  is coupled to the riser  24  through manifold  28  and moves with the riser  24  on a slidable plate  34 , which is joined to the spigot  20  and slidably retained on an outer portion of the casing  14 . In an exemplary embodiment, the spigot  20  extends through a slot  36  in the casing  14  and moves in the slot, with the riser  24 . In another embodiment, the valve assembly  30  is located at least to a depth D 1  beneath the surface  29  which is deeper than the depth to which freezing temperatures may reach, in other words, below the frost line  31 . 
   In yet another embodiment, hydrant  10  is configured to provide a mechanical safety to the internal components of the hydrant  10  so that damage to the internal components can be avoided in the event that excessive force is applied to handle  18 . In the embodiment shown in  FIG. 2 , link member  23  of linkage assembly  26  has reduced dimensions in a target area  29 , whereby target area  29  will deform or break under application of excessive force to handle  18 . While this embodiment depicts a link member  23  with reduced dimensions to protect the internal components, it will be recognized that various other mechanical safeties may be employed to protect the internal components of the hydrant  10 . 
   Referring further to  FIGS. 3A through 3E , the hydrant  10  further includes a chamber housing  40  connected at a distal end of the pipe  16 . The chamber housing  40  has two interior chambers  42 ,  44 . The valve assembly  30  is disposed in the first chamber  42  of the chamber housing  40 . A valve body  46  has at least one inlet passage  47  and at least one flow passage  48  in valved fluid communication with a water supply pipe. When the valve is opened, water from the supply may flow through the passages  47 ,  48  and into the riser  24  to the outlet  22  of the spigot  20 . The valve body  46  may be threadably attached to chamber housing  40  and may include O-rings  49  to seal the valve body  46  against the chamber housing  40 . The valve assembly  30  further includes a moveable valve member  32  movably positioned in the valve body  46 , and operable with seal  33  against seat  35  to seal off passage  48  to prevent flow of water from the supply through the valve body passages  47 ,  48 . In an exemplary embodiment, the valve member  32  comprises a poppet valve having a valve seal  33  which is biased by a spring  50  in a direction which seals the flow passage  48 . The valve  32  is also biased in a direction to close the flow passage  48  by the water pressure in the water supply. 
   The second chamber  44  of the chamber housing  40  houses a piston  52  which is slidably disposed within the chamber  44  of the chamber housing  40 . The piston  52  includes O-rings  54  disposed on an outer circumference of the piston  52  to seal against the interior walls of the chamber housing  40 . The piston  52  is reciprocally mounted at a lower end of the riser  24  whereby motion of the riser  24  moves the piston  52  from a first position ( FIG. 3A ) defining a volume V 1 , in the chamber  44  of the chamber housing  40  beneath the piston  52 , toward a second, extended position ( FIG. 3C ) adjacent the valve assembly  30 , where the piston  52  seats against floor  45  of the chamber housing  40  (see  FIG. 3B ). In this position, all water residing in chamber  44  is expelled upwardly through riser  24 . In an exemplary embodiment, the piston  52  is attached to a fitting  58  or plunger connector on the riser  24  by means of a plunger  56  coupled to the distal end of the fitting  58 . The plunger  56  includes fluid passages  60  and a central passage  62  in fluid communication with the riser  24  to permit the flow of water therethrough. 
   The piston  52  is slidably connected to the plunger  56  such that the plunger  56  may continue to move toward the valve assembly  30  once the piston  52  has sealed against the floor  45  of the chamber housing  40 . Once the piston  52  has sealed against the chamber housing  40  ( FIG. 3B ), the riser  24  and plunger  56  then continue to move toward the valve assembly  30 , where the forward end  57  of plunger  56  engages the valve stem  37  such that the valve  32  is moved to an open condition ( FIG. 3C ). Water flows from the water supply, through the passages  47 ,  48  through the plunger  56 , and riser  24 , to exit the outlet  22  of the spigot  20 . A spring  64  disposed at a distal end of the riser  24 , and plunger connector  58  biases the piston  52  in a direction toward the valve assembly  30 , allowing plunger  56  to continue its forward motion against valve stem  37  even when piston  52  is bottomed out. In an exemplary embodiment, the plunger  56  includes O-rings  66  to sealingly engage an interior bore  51  of the valve body  46  prior to opening of the valve  32  ( FIG. 3C ). 
   Because the valve assembly  30  is separate from the riser  24  and plunger  56 , the valve assembly  30  can be optimized to provide a desired valving performance irrespective of the length or movement of the riser  24 . The valve assembly  30  may also be manufactured to conventional tolerances regardless of the length of the riser  24 , and may even be a commercially available component. The separate valve assembly  30  and riser  24  also permits more efficient dispensing of substantially all of the water from the chamber  44  at the onset of flow after handle  18  has been moved to cause water to flow from the hydrant  10 . 
   Referring to  FIGS. 2 and 3A  through  3 E, the operation of the hydrant  10  will now be explained. For clarity, water behind closed valve  32  (from the water supply) has been omitted in  FIGS. 3A ,  3 B,  3 D and  3 E. When the handle  18  of the hydrant  10  is at a no-flow position P 1 , the piston  52  is disposed at a first position at an upper end of the chamber housing  40  and away from the valve assembly  30  as seen in  FIG. 3A . A volume V 1  of residual water, which has been previously drained from the riser  24 , is stored in the chamber  44  of the chamber housing  40 , between the valve assembly  30  and the piston  52 . The residual water in chamber  44  is sealingly stored from the environment and is located beneath the frost line ( FIG. 2 ). As the handle  18  is moved from the no-flow position P 1  toward a flow position P 2 , the piston  52  is urged toward the valve assembly  30  under the influence of the riser  24  and spring  64 . As the piston  52  moves towards the valve assembly  30 , the volume V 1  of residual water stored in the second portion  44  of the chamber housing  40  is forced through the flow passages  60  in the plunger  56  and up through the riser  24 . 
   When the piston  52  has seated against the floor  45  of the chamber housing  40  ( FIG. 3B ), substantially all of the residual water has been forced from the chamber  44  into the riser  24 . At this point, the valve  32  remains biased in a closed condition and the plunger  56  is just beginning to enter the bore  51  of valve body  46 . As the handle  18  continues to move toward the flow position P 2 , the riser  24  and plunger  56  continue to move in a direction toward the valve  32  and the plunger  56  sealingly engages in bore  51 . 
   As the riser  24  and plunger  56  move further, the end  57  of plunger  56  engages the valve stem  37  and urges the valve  32  in a direction away from the passages  47 ,  48 , against the action of the valve spring  50  and water supply pressure, to permit water to flow from the water supply, through the passages  47 ,  48 , through the plunger passages  60 , and into the riser  24  ( FIG. 3C ). Water continues to flow up the riser  24  and out of the outlet  22  of the spigot  20 . Advantageously, the entire volume V 1  of residual water is forced out of the outlet  22  of the spigot  20  at the onset of flow and preferably in less than 0.5 second. Thereafter, only fresh water is supplied from the water supply through the hydrant outlet  22 . 
   After a desired amount of water has been dispensed from the hydrant  10 , the handle  18  may be moved from a flow position P 2  to a no-flow position P 1  to close the valve  32  and stop the flow of water. Referring to  FIG. 3D , as the handle  18  moves toward the no-flow position P 1  from the flow position P 2 , the riser  24 , plunger  56  and piston  52  are drawn away from the valve assembly  30 . The plunger  56  first disengages the valve stem  37  allowing the valve  32  to move into a closed condition under the influence of the spring  50  and pressure of the supply. Flow from the water supply is stopped. The plunger  56  is withdrawn from sealing engagement with the bore  51  and plunger flange  59  engages the piston  52  to pull the piston  52  away from the valve assembly  30 . As the piston  52  moves from the second position seated against the floor  45  toward the first position, the increasing volume developed beneath the piston  52  in chamber  44  creates a positive suction which draws residual water remaining in the riser  24  above the frost line, down through the passages  60  of the plunger  56  and into the volume V 1  beneath the piston  52  ( FIG. 3E ). 
   An air bypass valve  70  may be located on the spigot  20  to permit the residual water to drain from the riser  24  without drawing water into the hydrant  10  from the outside environment. In one embodiment, the air bypass valve  70  is a vacuum breaker type valve, as known in the art. In another embodiment, the air bypass valve is a spring-biased check valve that is configured to be closed to atmosphere during normal operation of the hydrant  10  to deliver water through spigot  20 , and opens to atmosphere to permit residual water to drain from the riser  24  when handle  18  is moved toward the no-flow position P 1  to stop the flow of water from the hydrant  10 . The chamber housing  40  is configured such that the volume V 1 , created beneath the piston  52  when the piston  52  is moved to the first position, corresponds to the volume of water remaining in the riser  24  after flow of water has been shut off. Advantageously, the residual water may be stored in the chamber housing  40 , sealed off from the environment and below the frost line, until the handle  18  of the hydrant  10  is once again moved toward the flow position P 2  to dispense water from the water supply, as described above. 
   Referring to  FIGS. 1 and 2 , the upper casing  14  comprises a cap  72  which is removably attached to the casing  14  to cover an opening  74  in an upper portion of the casing  14 . When the cap  72  is removed, the opening  74  provides access to the interior components of the hydrant  10  for servicing, as may be required. Advantageously, the opening  74  permits the replacement of wear items, such as O-rings  49 ,  54 ,  66  or valve seat  33 , or to permit servicing of other components from above grade without the need to excavate. The valve body  46  can be unscrewed by insertion of a long wrench inserted through opening  74  and the entire valve  30  as well as piston  52  can be removed, maintained, and replaced. 
   While the present invention has been illustrated by the description of the various embodiments thereof, and while the embodiments have been described in considerable detail, it is not intended to restrict or in any way limit the scope of the appended claims to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details, representative apparatus and methods and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope or spirit of Applicant&#39;s general inventive concept.