Abstract:
A crash valve is located in a liquid tight dispenser pan at a gasoline service station to close a conduit conveying gasoline to a gasoline dispensing unit to prevent uncontrolled flow of gasoline in the event a vehicle crashes into the dispensing unit. The dispenser pan collects any leaking gasoline or inflow of water; the presence of gasoline is an obvious safety hazard and the accumulating water may cause electrical or mechanical malfunction of the crash valve. An actuator, responsive to the presence of either water or gasoline in the dispenser pan, includes a weighted ball secured to a trip arm of the crash valve by a lanyard. The actuator will respond to the presence of gasoline or water by dislodging the ball and cause the ball to drop. The weight of the falling ball, translated through the lanyard, will cause the trip arm to close the crash valve and prevent further flow of gasoline therethrough and preclude the dispensing unit from pumping gasoline until the trip arm is reset.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to actuators and, more particularly, to an actuator for a crash valve located beneath a gasoline dispensing unit at a service station. 
     2. Description of Related Art 
     As is well known, the gasoline pumped through a dispensing unit at a gasoline service station is highly flammable and presents a very serious potential hazard. From time to time a driver may cause his vehicle to hit the dispensing unit with sufficient force to tilt or dislodge the dispensing unit from its mounting. The conduit conveying gasoline from an underground tank to the dispensing unit will be compromised or severed with a resulting outflow of gasoline. Unless such outflow is immediately checked, the outflow of gasoline will create an inferno if ignited. For this reason, a crash valve is located beneath the dispensing unit and through which the gasoline flows to the dispensing unit. The crash valve is designed to shear upon physical repositioning of the gasoline pump, which shearing automatically closes a valve and terminates further flow through the crash valve and into the dispensing unit. Thus, further flow of gasoline is terminated. 
     The shear valve is disposed within a sump or a liquid tight dispenser pan beneath the dispensing unit. This pan will collect any gasoline outflow as a result of leakage of gasoline from the crash valve or from any conduits or fittings within the dispensing unit. Additionally, the dispenser pan will collect any water flowing thereinto due to condensation, rain, or cleaning functions. 
     The presence of gasoline in the dispenser pan is an obvious hazard. The presence of water in the dispensing pan will have a corrosive effect upon both mechanical and electrical components of the crash valve and the apparatus within the dispensing unit due to the resulting humidity and likelihood of periodic condensation. Such corrosion, over a period of time, may compromise the integrity of the gasoline flow path with the obvious resulting safety hazard. Furthermore, the electrical and mechanical control elements attendant gasoline flow may be compromised over a period of time. 
     Presently, there are no known mechanical actuators responsive to either gasoline or a predetermined quantity of water within the dispenser pan for terminating flow of gasoline through the crash valve. 
     SUMMARY OF THE INVENTION 
     The present invention is a mechanical actuator operatively responsive to the presence of either gasoline or water within a dispenser pan located about a crash valve beneath a dispensing unit at a gasoline service station. The presence of gasoline, or any liquid hydrocarbon, will cause elongation of a porous cartridge. The elongation will reposition a plunger that dislodges a weight attached to a pivotable trip arm of the crash valve to terminate flow of gasoline therethrough upon pivotal movement. A float with attached pivoting arm will rise as the water level within the dispenser pan exceeds an acceptable level. The resulting movement of the pivoting arm will dislodge the weight and also result in pivotal movement of the trip arm to terminate flow of gasoline through the crash valve. 
     It is therefore a primary object of the present invention to provide an actuator for terminating flow through a crash valve in the presence of a liquid hydrocarbon or water. 
     Another object of the present invention is to provide a completely mechanical actuator responsive to either gasoline or water within a dispenser pan to cause termination of gasoline flow through a crash valve. 
     Yet another object of the present invention is to provide a simple translatable plunger actuated by an elongating cartridge responsive to the presence of gasoline for dislodging a weight to actuate a trip arm of a crash valve. 
     A further object of the present invention is to provide a simple float vertically responsive to the presence of water in a dispenser pan for dislodging a weight to actuate a trip arm of a crash valve. 
     A yet further object of the present invention is to provide an inexpensive mechanical actuator for terminating flow of gasoline through a crash valve upon the presence of gasoline or a predetermined amount of water in a dispenser pan within which the crash valve is located. 
     A yet further object of the present invention is to provide a method for terminating flow of gasoline through a crash valve upon the presence of gasoline or a predetermined amount of water proximate the crash valve. 
     These and other objects of the present invention will become apparent to those skilled in the art as the description of invention proceeds. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be described with reference to the following drawings, in which: 
     FIG. 1 is an elevational view of the present invention and its environment; 
     FIG. 2 is an isometric view of a crash valve and an actuator for terminating flow through the crash valve; 
     FIG. 3 illustrates a cross-sectional view of the actuator alongside the crash valve; 
     FIG. 4 is a detailed cross-sectional view of the actuator; 
     FIG. 5 is a side view of the actuator; 
     FIG. 6 is a cross-sectional view of the actuator showing its reaction to the presence of a hydrocarbon vapor; 
     FIG. 7 is a cross-sectional view of the actuator illustrating its response to the presence of a liquid hydrocarbon; 
     FIG. 8 is a cross-sectional view of the actuator illustrating its response to the presence of a high water level; 
     FIG. 9 illustrates the actuator and crash valve after the actuator has been actuated; 
     FIG. 10 illustrates the actuator and crash valve after a fusible link of the crash valve has been severed; and 
     FIG. 11 illustrates shearing of the crash valve upon repositioning of an associated gasoline dispensing unit. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, there is shown a conventional crash valve  10  connected to an inflow conduit  12  through which gasoline flows from an underground tank or other source of gasoline. An outflow conduit  14  extends from the crash valve into apparatus within gasoline dispensing unit  16 , which is of the type found at conventional gasoline service stations. Crash valve  10  is located within a fluid tight dispenser pan located beneath dispensing unit  16  and generally at least partly below grade  20  of the surrounding ground  22 . The dispenser pan is located beneath and generally in vertical alignment with the various apparatus attendant dispensing unit  16  for receiving and retaining any gasoline leakage. Necessarily, it will also collect any water that may be present due to condensation, rain, or washing activities attendant the dispensing unit and the adjacent ground. Because upper end  24  of the dispenser pan is above grade  20 , water on the ground will generally not flow into the dispenser pan. 
     An actuator  30  is mounted at bottom  32  of dispensing pan  18  to ensure that it will be responsive to fluid, whether water or gasoline, that may collect in the dispenser pan. The actuator may be freestanding with respect to crash valve  10 , as illustrated. A trip arm  34  has been added to the crash valve, which trip arm, upon downward pivotal movement, will cause the crash valve to close and prevent any outflow of gasoline through outflow conduit  14 . Actuator  30  is interconnected with the crash valve through a lanyard  36  attached to trip arm  34  and to a weight, which weight may be ball  38 , as illustrated. Further details attendant crash valve  10 , actuator  30  and their relationship are illustrated in the isometric view shown in FIG.  2 . 
     As shown in FIG. 3, upon dislodging ball  38  from the top of actuator  30 , it will drop to a location vertically beneath trip arm  34 , as depicted by dashed line  38 ′. The momentum of the dropping ball, as well as its sheer weight acting through the lanyard ( 36 ′), is sufficient to cause pivotal movement of the trip arm in a downward direction. Such downward movement will cause the crash valve to shut off 
     Referring jointly to FIGS. 4 and 5, further details of actuator  30  will be described. Base  40  supports the actuator upon bottom  32  of dispenser  10  (see FIG.  1 ). Preferably, the base is of brass or other non-magnetically responsive material and includes one or more cavities, of which cavities  42 ,  44  are shown, for supporting magnets  46 ,  48 . Alternatively, the magnet(s) may be located in a hole(s) extending through the base. The magnets cooperate with the magnetically responsive material (such as steel) of bottom  32  of the dispenser pan to retain actuator  30  in position relative to crash valve  10 . Thereby, the actuator is readily replaceable or readily mountable in existing dispenser pans. For a more permanent installation, bolts, screws, epoxy, mastic or other attachment means may be used to secure the base to the dispenser pan. A sleeve  50  may be threadedly engaged with a hollow boss  52  extending upwardly from the base. The sleeve includes a vertical slot  54  to provide a passageway into interior cylinder  56  of the sleeve. An extension slot  55  may be formed in base  40 . Furthermore, a hole  57  in fluid communication with cylinder  56  may be formed in the base. Upper end  58  of sleeve  50  includes interiorly formed threads  60  for threadedly engaging a hollow plug  62 . It is to be noted that upper end  58  may be a separate part attached to sleeve  50  by any means well-known to those skilled in the art; alternatively, the upper end may be formed as part of the sleeve if manufacturing economics so permit. Plug  62  includes a hollow cylindrical channel  64 . Necked down section  66  of the plug may be threaded, as illustrated. A porous hydrophobic cartridge  70  is mounted in cylinder  66  of sleeve  50 . This cartridge supports a disk shaped base  72  of a plunger  74  slidably mounted within channel  64 . 
     In the quiescent state of actuator  30  when neither water nor gasoline (liquid hydrocarbon) is present within dispenser pan  18 , end  76  of plunger  74  is below annular end  78  of necked down section  66 . A weight, such as ball  38 , rests upon the annular end. A bolt  80  is in threaded engagement with a threaded cavity  82  in the ball. Upon threaded engagement, the bolt will extend outwardly from the ball and cause the center of gravity of the ball to be off-center toward the bolt as a function of the degree of imbalance created by the weight of the bolt and its extension from the ball. The bolt includes a hole or passageway  84  in the head of the bolt for attaching lanyard  36  (See FIG.  3 ). 
     A bracket  90  may be in threaded engagement with neck down section  66  and extends laterally therefrom. The bracket pivotally supports an arm  92  at pivot point  94 . By including a plurality of apertures  96  along arm  92 , the pivot point of the arm may be adjusted as necessary. Lower end  98  of the arm supports a float  100 . 
     The operation of actuator  30  in response to the presence of hydrocarbon vapor or liquid hydrocarbon within the dispenser pan  18  will be described with joint reference to FIGS. 6 and 7. Upon permeation of either a hydrocarbon vapor or liquid hydrocarbon into porous hydrophobic cartridge  60 , the cartridge will elongate. A cartridge suitable for this purpose is Part No. 5361 manufactured by Porex Porous Plastics of Fairburn, Ga. The degree of elongation is primarily a function of the amount of liquid hydrocarbon permeating therewithin. Often, and as part of the natural course of operation of a dispensing unit  16 , a degree of hydrocarbon vapor will be present within the dispenser pan and permeate the porous hydrophobic cartridge. Such permeation will cause a slight elongation of the cartridge, as shown in FIG.  6 . Typically, the elongation due to permeation of a hydrocarbon vapor is about one half (½) of the elongation due to permeation of a liquid hydrocarbon. Specifically, in the quiescent state the space between annular end  78  and end  76  of plunger  74  is of a certain dimension, as shown in FIG.  4 . As porous hydrophobic cartridge  70  elongates in the presence of a hydrocarbon vapor, as shown in FIG. 6, such elongation will translate plunger  74  upwardly through channel  64 . By selecting the space between annular end  78  and end  76  of plunger  74  to be a sufficient amount, as shown in FIG. 4, the elongation of the porous hydrophobic cartridge due to permeation of hydrocarbon vapor is insufficient to cause end  76  of the plunger to extend past annular end  78 . Accordingly, no contact between end  76  of the plunger and ball  38  will occur in the presence of a hydrocarbon vapor within the dispenser pan  18 . 
     If a liquid hydrocarbon, such as gasoline, leaks from dispensing unit  16 , crash valve  10  or from another source into dispenser pan  18 , the gasoline will flow through slot  55  and hole  57  in base  40  and through slot  54  in sleeve  50  into contact with porous hydrophobic cartridge  70 . Upon such contact, the gasoline will wick throughout the porous hydrophobic cartridge and cause elongation of the cartridge very rapidly. The elongation of the cartridge will act upon base  72  of plunger  74  and result in upward travel of the plunger as a function of the degree of elongation. By appropriate dimensioning of the components, the upward travel of plunger  74  will be sufficient to cause end  76  of the plunger to extend above annular end  78  of neck down section  66 , as shown in FIG.  7 . As described above, bolt  80  offsets the center of gravity (represented by reference numeral  110 ) of ball  38  in the direction of the bolt. Thus, in the quiescent state (as shown in FIG.  4 ), the center of gravity ( 110 ) of the ball is offset from the center line (represented by reference numeral  112 ) of plunger  74  toward the bolt. As end  76  of the plunger comes into contact with ball  38  due to elongation of the porous hydrophobic cartridge, the center of gravity of the ball, being offset of center line  112  of the plunger, will cause the ball to roll in the direction of the bolt  80 . Such rolling will continue until the ball falls free of actuator  30 . The resulting drop of the ball (see ball  38 ′ in FIG. 3) will result in drawing down lanyard  38  until the lanyard becomes vertical (see lanyard  36 ′ in FIG.  3 ). The downward movement of the ball being arrested by the lanyard results in a downward jerk upon trip arm  34 . This jerk will cause the trip arm to pivot downwardly and result in shut off flow of gasoline through crash valve  10 . 
     Referring to FIG. 8, the operation of actuator  30  will be described when water seeps or flows into dispenser pan  18 . Porous hydrophobic cartridge  70  is non-responsive to the presence of water and therefore will not elongate. Thus, the position of plunger  74  remains steady. As the water level within dispenser pan  18  rises, float  100  will rise due to its buoyancy. The rising float will cause arm  92  to pivot about pivot point  94  of bracket  90 . As the pivot arm pivots, upper end  102 , or a portion thereof, will come into contact with and bear against ball  38 . When the water level rises to a predetermined level, as depicted by numeral  104 , float  100  will have risen sufficiently to cause end  102  to push ball  38  off center line  112 . The resulting repositioning of the center of gravity ( 110 ) of the ball will cause it to roll on its own off annular end  72 . Thereafter, the ball will drop and result in actuation of trip arm  34 , as described above. 
     The high water level  104  sufficient to raise float  100  to cause ball  33  to roll off annular end  78  must be below the top end of porous hydrophobic cartridge  70  for the following reason. The porous hydrophobic cartridge is impermeable to water. If there is some water in dispenser pan  18  and a liquid hydrocarbon (gasoline) subsequently flows into the dispenser pan, it will float on top of the water as it is less dense than water. Ultimately, the liquid hydrocarbon will migrate into contact with the porous hydrophobic cartridge. Upon such contact, the liquid hydrocarbon will permeate throughout the porous hydrophobic cartridge due to its wicking action and elongation will result. With such elongation, plunger  74  will be translated upwardly and ball  38  will become dislodged, as described above. If the high water level ( 104 ) were above the top of the porous hydrophobic cartridge, any liquid hydrocarbon then present would not cause the actuator to be actuated due to the presence of any liquid hydrocarbon. 
     In some parts of the country, earthquakes occur from time to time. Such earthquakes can and do cause leaks of gasoline from burst or damaged gasoline conveying conduits. Ball  38  of actuator  30  requires a very small disturbing force to cause it to roll off annular end  78 . The shaking of the ground due to an earthquake is enough to cause the ball to topple. Thus, upon occurrence of an earthquake actuator  30  will close crash valve  10  and further flow of gasoline therethrough will cease. 
     As shown in FIG. 9, in the presence of gasoline or a liquid hydrocarbon (gasoline) within the dispenser pan  18 , ball  38  will have been caused to become dislodged off annular end  72  of actuator  30 . The resulting position of the ball will be essentially below the engaged point of trip arm  34 . The momentum and weight of the ball will have caused the trip arm to pivot downwardly, as illustrated. 
     Referring jointly to FIGS. 2 and 9, operation of crash valve  10  upon pivotal movement of trip arm  34  will be described. A fusible link  120  is biased to the counterclockwise position shown in FIG.  9  and in this position mechanisms internal to crash valve  10  will shut off further flow of gasoline through the crash valve. The fusible link is retained in its clockwise position shown in FIG. 3 by a pin  122  extending from the upper body  10 ′ engaging an aperture  124  at the end of the fusible link. The attachment of the fusible link allows it to pivot in a plane extending through its connecting shaft  126  but not about the shaft. Trip arm  34  includes a rod  128  extending therefrom. To cock the trip arm, it is raised to the position shown in FIG. 2 which places rod  128  behind fusible link  120  when it is in engagement with pin  122 . Upon downward pivotal movement of trip arm  34 , rod  128  bears against the back side of the fusible link and pulls it off pin  122  to release it from the pin. Thereafter, the fusible link is free to pivot counterclockwise to the position shown in FIG.  9 . 
     As shown in FIG. 10, fusible link  120  includes two links  130 ,  132  normally in engagement with one another to thereby work in concert. Solder or similar low melt temperature material secures the links to one another. In the presence of fire or other heat source, the solder will melt and the links will separate, as shown. Upon such separation link  132  will pivot counterclockwise and further flow through crash valve  10  will terminate. 
     FIG. 11 primarily illustrates the designed shearing of crash valve  10  as a result of displacement of dispensing unit  16  due to impact from a vehicle or the like. The resulting jostling of actuator  30  will also result in movement of ball  38  off annular end  72  of actuator  30  and result in downward pivotal movement of trip arm  34 . Simultaneously, fusible link  120  will be released from pin  122  to permit movement to its biased position and shut off further flow of gasoline through crash valve  10 . 
     It is to be appreciated that the sensitivity for dislodging ball  38  off annular end  78  is a function of the diameter of the annular end (and the diameter of the circumscribed plunger end  76 ) and the diameter (degree of curvature of ball  38 ). Thus, the larger the ratio of the diameter of the ball to the diameter of the annular end, the more sensitive is the actuator to a force attempting to dislodge the ball from the annular end. 
     It is to be understood that switch means  140  may be associated with the fusible link trip arm  34  (as shown in FIG. 11) to provide an electrical signal for use at a remote location to determine the on or off state of the crash valve and/or the armed or unarmed state of actuator  30 . 
     While the invention has been described with reference to several particular embodiments thereof, those skilled in the art will be able to make the various modifications to the described embodiments of the invention without departing from the true spirit and scope of the invention. It is intended that all combinations of elements and steps which perform substantially the same function in substantially the same way to achieve the same result are within the scope of the invention.