TANK OVERFILL VALVE

Abstract: An overfill valve having a saddle-shaped, flapper valve element located within an inlet pipe and a mating valve seat disposed about the inner wall of the pipe. A spring couples a weighted float to the valve element and extends generally outward from the pipe. The float moves the valve element from a normally open position to a closed position as the float is raised. A controlled drain aperture through the valve ele­ ment permits standing fluid within the pipe to drain. The spr­ ing allows the float to be moved to permit the pipe to be slid down a storage tank casing. A triggering mechanism is coupled to the float and valve element so that the float shifts a triggering element into the liquid flow through the valve, and the force of liquid flow against the triggering element forces the valve element toward the closed position.

Description: BACKGROUND OF THE INVENTION The present invention relates to tank overfill valves, and in particular to overfill valves for tanks used in the storage of toxic or flammable liquids such as those common to automotive service stations and the like. Liquid (e.g. gasoline) storage tanks are normally provided with an upright casing. A drop tube is received down the casing and is used as a fill tube for the tank. The drop tube normally extends down to about the bottom of the tank. A common problem with such storage tanks is that the tank is often overfilled, resulting in spillage of the liquid product. Such spills present a severe health and environmental hazard. It is well known to provide an overfill valve to prevent spillage of liquids in the filling of liquid storage tanks, as exemplified by U.S. Patent 3,078,867. Briefly, all overfill valves of the type herein contemplated comprise a valve, disposed in the conduit through which liquid is introduced into the storage tank. A float is then mounted within the storage tank. When the level of liquid in the tank reaches the float, the float is elevated. A mechanical connection between the float and then valve causes the valve to close when the float is so elevated, thereby preventing further filling of the tank. A significant factor in providing overfill protection of storage tanks, as used in automotive service stations is that their design is now standardized. This is to say that the casing (14) through which the drop tube (12) is inserted has a relatively small diameter (cross sectional area). Of necessity the diameter of the drop tube (12) through which liquid (i.e. gasoline) flows is less than that of the casing, particularly in maintaining a space (32) to provide a possible means for venting vapor from the tank. Another significant factor in providing overfill protection for storage tanks, as used in automotive service stations, is in preserving the ability to employ an elongated rod to gauge the amount of fuel in a tank, in order to determine whether filling is required. The most pertinent prior art, applicable to independent claims 1 and 4 is believed to be French Patent 2,355,736 (Gallier), U.S. Patent 3,078,867 (McGillis) and French Patent 2,331,732 (LaFon). Gallier '736 discloses and overfill valve for use in liquid storage tanks comprising what might be an upstanding casing through which a compositely formed inlet pipe is inserted. A float is coupled to the closure member by a support arm in a manner providing a fixed angular relation between the float and the closure member. Pivotally movement of Gallier's float toward a position aligned with his fill pipe is limited by engagement of his closure member with a valve housing. Assuming that Gallier '736 actually shows an upstanding casing, the outer profile of the inlet pipe would have to be substantially smaller than the inner profile of the casing. Gallier '736 thus does not provide a means for providing an adequate inlet flow area, where an inlet pipe (drop tube) is to be inserted into a preestablished casing (14) of relatively small diameter. In other words, an overfill valve, according to Gallier '736, would limit the rate of flow so that an unacceptable length of time would be required to fill the storage tank. McGillis '867 discloses a float controlled shut off valve (closure member), but does not teach "access means" or other structure which permits at least a portion of the float means to be disposed within the vertical profile of the inlet pipe to enable insertion of the overflow valve through an upstanding casing in order to mount the overfill valve in a liquid delivery position. Likewise McGillis '867 does not disclose an overfill valve that can be retrofitted into existing storage tanks and also removed from a tank for inspection and maintenance. LaFon '732 discloses a float controlled shut off valve (closure member) and further shows "access means" which permit the float to be inserted through a tank opening of relatively small diameter. The inlet pipe of LaFon '732 is not inserted through an upstanding casing and is not adapted to be mounted on standard storage tanks of the type employed in automotive service stations. This is further evidenced by the fact that LaFon's inlet pipe does not define an essentially straight flow passage between vertically aligned inlet and discharge ends. The prior art does not teach an overfill valve which can be installed in existing, standard, storage tanks comprising an upright casing, provide an annular spacing between the casing and the inlet pipe of the overfill valve, permit the use of a gauging rod to ascertain the need of filling, and at the same time provide a flow passage of sufficient cross section to fill the tank in a rapid fashion. According to the invention there is provided an overfill valve for use in filling standard liquid storage tanks, as used in automotive service stations, having an upstanding casing (14) having an inner circular profile, comprising an inlet pipe (112) having an outer circular profile less than the inner circular profile of the casing (14), said inlet pipe being insertable through the casing (14) to mount it in a liquid delivery position, said inlet pipe defining a flow passage from an upper inlet end to a lower discharge end (134), a closure member (116 or 216) mounted within said inlet pipe, float means (118 or 218) coupled to said closure member through a coupling means which includes an arm like member (120 or 220), said closure member having a having a normally open position in which it is disposed to one side of said flow passage, said float means and arm like member projecting generally laterally of the inlet pipe when the closure member is in its open position, and pivotal in an upward direction in response to the level of liquid reaching the float, said closure member being moved to a closed position in response to upward movement of said float means, access means (160 or 260), disposed between the inlet and discharge ends of the inlet pipe, which receive the float means and enable the positioning of the float means substantially within with profile of the inlet pipe to enable insertion of the inlet pipe through the casing (14), whereby the outer vertical profile of the inlet pipe can closely approach the inner vertical profile of the casing and maximize the liquid flow area of inlet pipe, and characterized in that the upper inlet end and the lower discharge end being vertically aligned, whereby a gauging pole may be inserted through the inlet end, past the closure member to the discharge end (134). BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a fragmentary, front elevational view of the tank overfill valve taken through a section of the liquid storage tank, the overfill valve being shown in a closed condition; Figure 2 is a fragmentary, side elevational view of the tank overfill valve shown in Fig. 1; Figure 3 is a fragmentary, sectional view of the tank overfill valve taken along plane III-III of Fig. 2, but shown with the overfill valve in an open condition and the weighted float also shown in phantom in a position for lowering down a casing; Figure 4 is a top plan view of the tank overfill valve of Fig. 1 shown in an open condition; Figure 5 is a top plan view of the tank overfill valve of Fig. 1 shown in a closed condition; Figure 6 is a front sectional view of another tank overfill valve forming a second preferred embodiment of the device shown with the overfill valve in an open position and the slot closing collar in a closed condition; Figure 7 is a side sectional view of the tank overfill valve taken along plane VII-VII in Figure 6, shown with the slot closing collar in an open condition; Figure 8 is a fragmentary, perspective view of another tank overfill valve forming a third preferred embodiment of the device, shown with the valve in a tank-inserted condition with the valve in an open position; Figure 9 is a fragmentary, perspective view of the tank overfill valve of Fig. 8 showing the inside of the valve; Figure 10 is a fragmentary, front elevational view of the tank overfill valve of Fig. 8; Figure 11 is a fragmentary, side elevational view of the tank overfill valve of Fig. 8; Figure 12 is a schematic view of the tank overfill valve of Fig. 8 shown in a tank-inserting condition; Figure 13 is a sectional view of the tank overfill valve of Fig. 8, shown with the valve in a tank-inserted condition and the valve in an open position; Figure 14 is a sectional view of the tank overfill valve of Fig. 8, shown with the valve float raised in a filled position and the triggering element shifted away from an at-rest position; Figure 15 is a sectional view of the tank overfill valve of Fig. 8, shown with the valve float raised in a filled position and the triggering element shifted to a triggering position; and Figure 16 is a sectional view of the tank overfill valve of Fig. 8, shown with the valve closure element being shifted toward the closed position. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS EMBODIMENT OF FIGURES 1-5 The first preferred embodiment of a tank overfill valve in accordance with the present invention is shown in Fig. 1 and generally designated 10. As shown, a drop tube or pipe 12 extends coaxially down into a liquid storage tank casing 14. A curved plate or flapper valve element 16 is pivotally mounted in the lower end of tube 12. Tube 12, therefore, defines a housing to element 16. A weighted float 18 is connected to plate 16 by a spring 20 that forms a resilient moment arm between float 18 and plate 16. Weighted float 18 holds plate 16 in a normally open condition so that neither curved plate 16 or float 18 substantially obstructs tube 12. As the tank is filled, float 18 is raised by a fluid level 22, which ultimately causes curved plate 16 to close and substantially shut off fluid flow through tube 12. A controlled amount of leakage is permitted through drop tube 12 when overfill valve 10 is in a closed condition, so that as fluid level 22 lowers, curved plate 16 will return to its normally open position. As shown in Figure 1, a liquid storage tank 30 is of a conventional design used in the storage of toxic or flammable liquid materials, such as for example those used as service station underground gasoline tanks or the like. Casing 14 extends upward from the top of tank 30, and includes at its upper end a coupling (not shown) which is adapted to be mated with truck fill lines or valves. Casing 14 is also of conventional design, and in the case of service station underground storage tanks includes an upper end that is housed within a man hole (not shown). Drop tube 12 extends down through casing 14 and has an outside diameter that is less than the inside diameter of casing 14 so that an annular space 32 is formed between casing 14 and tube 12. At the upper end of tube 12 (not shown) a conventional coupling or mounting device supports tube 12 within casing 14. During the filling of tank 30 a nozzle is fitted onto the upper ends of casing 14 and tube 12. The liquid product is introduced through tube 12 and vapor is recovered through annular space 32 or a second vapor outlet (not shown). Tube 12 has a lower discharge end 34 and a discharge aperture or outlet 36 that extends through tube 12 and opens through the bottom of end 34. Extending downward directly beneath outlet 36 is a discharge zone 37 through which the fluid flows from tube 12. As shown in Figs. 2-4, along the inner wall of tube 12 at discharge end 34 is an inwardly extending flange or valve seat 38. Valve seat 38 extends about the entire inner perimeter of drop tube 12. As shown in Fig. 4, valve seat 38 is narrower on the side opposite the connection with curved plate 16 in order to reduce the flow restriction by seat 38. Seat 38 curves so as to conform to curved plate 16 and includes a curved depending portion 40 located on either side of tube 12. Valve seat 38 therefore has a "saddle-shaped" configuration that appears to be circular in plan view, Fig. 4. From a front view shown in Fig. 3, valve seat 38 has an overall U-shape, while from the side valve seat has an inverted U-shape, Fig. 2. Preferably, valve seat 38 is bent inward from a depending mounting flange 41, Fig. 3. Mounting flange 41 is used to secure valve seat 38 on the inner wall of tube 12, such as by riveting, welding or other conventional means. Alternatively, the lower end of tube 12 can be cut so as to be configured generally similar to the configuration of seat 38 and then bent inward to form valve seat 38 integrally with tube 12. Curved plate 16 is formed from a flat sheet of metal that is cut and bent into a saddle-shape having an outer perimeter corresponding to the shape of valve seat 38. Curved flapper plate 16 therefore has an oval configuration that has been bent into an inverted "U" when viewed from the side, Fig. 2. As shown in Fig. 5, the bent oval configuration of plate 16 results in plate 16 having a circular plan view that is somewhat smaller than the inner diameter of tube 12. This curved configuration allows plate 16 to be oriented generally vertically relative to tube 12 when in an open position, Fig. 3. In an open position plate 16 will conform to and extend about a portion of the inner perimeter of tube 12 (Fig. 4) and leave aperture 36 through tube 12 generally unobstructed. Located through the center of plate 16 is a controlled drain aperture 42 (Figs. 3-5). Alternatively, drain aperture 42 can be located through the side of tube 12 above seat 38, or may be located at the sides of plate 16 or the like such as an annular opening at a portion of the perimeter of plate 16. Aperture 42 permits liquid trapped above plate 16 to drain from tube 12 when valve 10 is in a closed condition. A hinge 44 pivotally secures one side of plate 16 to the inner wall of tube 12, Fig. 5. As shown in Fig. 3, when plate 16 is in an open position hinge 44 spaces the bottom edge of plate 16 from tube 12 slightly, while upper edge 46 abuts the inner wall to 12. The spacing of plate 16 by hinge 44 causes fluid flowing through tube 12 to force plate upper edge 46 outward against tube 12. Fluid flow through tube 12 therefore maintains valve 10 in a normally open position. The gap behind plate 16 when plate 16 is in an open position may be filled by building up tube 12 with a filling material. This built-up area prevents fluid from backflowing off of seat 38 and up behind plate 16. The built-up portion of tube 12 would therefor prevent any backflow from forcing plate 16 away from tube 12 and prematurely closing plate 16, whether such premature closing would be due to backflow water pressure, vortex shedding or other phenomenon. As shown in Fig. 3, spring 20 is welded or otherwise joined to plate 16 adjacent hinge 44. Spring 20 extends generally radially outward from the side of tube 12 and passes through a slot 50 (Fig. 2) in tube lower end 34. Spring 20 is preferably a coil spring, but alternatively other resilient members such as leaf springs or the like may be used. Float 18 is a conventional ball float mounted at the outermost end of spring 20. Located within float 18 is a spherical weight 52, Figs. 1-3. When outwardly spaced by spring 20 the combined weight of ball 18 and weight 52 is sufficient to overcome the weight of plate 16 so as to pivot plate 16 about hinge 44. Plate 16 is therefore biased into a normally open position shown in Fig. 3. Spring 20 is sufficiently stiff to hold float 18 to the side of tube 12 and up out of discharge zone 37. Discharge zone 37 is therefor generally unobstructed by valve 10. However, spring 20 is sufficiently resilient to permit float 18 to be manually bent down beneath tube 12, as shown in phantom 18a and 20a in Fig. 3. With float 18a bent beneath tube 12, annular space 32 provides enough clearance to permit tube 12 to be slid axially down through casing 14 without interference from float 18a. EMBODIMENT OF FIGURES 6-7 A second preferred embodiment is shown in Figs. 6 and 7 and designated generally by the reference numeral 110. Tank overfill valve 110 is generally similar to tank overfill valve 10 with the exception of the modifications hereinafter noted. Overfill valve 110 includes a drop tube extension 112 having a crimped upper end 113 that allows extension 112 to be joined to the bottom of a conventional drop tube by welding or other conventional techniques. Extension 112 has sufficient length to reach the bottom of the liquid storage tank in which overfill valve 110 is to be installed. Tube extension 112 therefor reduces the production of vapors associated with splash loading of a liquid storage tank. Pivotally mounted within tube extension 112 is a curved valve plate 116 to which is mounted a weighted float 118 by a spring 120. Extension 112 also includes a discharge end 134 through which opens a discharge aperture 136. Secured within extension 112 is a valve seat 138 which is configured in a saddle-shaped configuration similar to that of valve seat 38. Curved plate 116 has the same saddle-shaped configuration as that of curved plate 16 and includes a drain aperture 142 therethrough. Plate 116 is pivotally mounted on valve seat 138 by a hinge 144, Fig. 6. Hinge 144 includes an upstanding flange 145 on seat 138. The upper end of flange 145 is bent outward to form a hook that passes through a rectangular slot 147 in the lower end of curved plate 116. A spacer flange 149 adjacent slot 147 extends upward at a right angle from the upper face of curved plate 116 when curved plate 116 is in the closed condition. As shown in Fig. 6, when plate 116 is in an open condition spacer flange 149 spaces the lower end of curve plate 116 outward from the inner wall of tube extension 112 in the same manner as hinge 44. Spring 120 is connected to curved plate 116 by a connecting arm 151 that extends along the lower face of curved plate 116 and is riveted thereto. As shown in Fig. 7, drop tube extension 112 includes a float receiving slot 160. Slot 160 extends downward adjacent hinge 144 and is configured slightly larger than the profile of float 118 and spring 120. Slot 160 is used as an assembly slot and permits spring 120 to be resiliently flexed downward so that spring 120 and float 118 pass through slot 160 in order to be positioned internally to tube extension 112. With float 160 positioned within tube extension 112 tank overfill valve 110 may be lowered down a storage tank casing and be positioned within the storage tank. When tube extension 112 has been lowered into the storage tank spring 120 will resiliently return to its relaxed position shown in Fig. 6 and dispose float 118 out of the fluid flow path through extension 112. Slidably received within tube extension 112 beneath valve seat 138 is a slot closing collar 170. Collar 170 is a cylindrical tube or sleeve that abuts the inner perimeter of tube extension 112. Collar 170 is frictionally maintained in position along the length of extension 112. Collar 170 is used to block off slot 160 after tube extension 112 has been positioned within the storage tank. One side of collar 170 is raised into an arcuate, upstanding lip 172 and aligned with slot 160. A flexible line 174 is secured to the top of collar 170 opposite lip 172. After overfill valve 110 has been positioned within the tank, flexible line 174 is used to pull collar 170 upward until slot 160 is substantially covered. Upstanding lip 172 protrudes upward in an arch corresponding to the curve of valve seat 138 such that slot 160 is substantially closed. However, when closed slot 160 remains sufficiently open that spring connecting arm 151 may pass freely through the remaining opening as curved plate 116 opens and closes. After collar 170 has been shifted upward to the closed position, flexible line 174 is dropped down the center of tube extension 112. Alternatively, flexible line 174 is attached to the upper edge of collar 170 by a suitable conventional release mechanism that permits line 174 to be released and pulled up through tube extension 112. Preferably, all the elements of overfill valves 10 and 110 are made from stainless steel, aluminum or other corrosion resistant material in order to prevent rusting. Overfill valves 10 and 110 may alternatively be coated to provide similar corrosion protection. EMBODIMENTS OF FIGURES 8-15 A third preferred embodiment is shown in Figs. 8 through 15 and designated generally by the reference numeral 210. Tank overfill valve 210 is generally similar to tank overfill valves 10 and 110, with the exception of the modifications hereinafter noted. Overfill valve 210 includes an extended drop tube or pipe 212 that is received within the tank and extends to the lower area of the tank. Pivotally mounted within tube 212 is a curved valve plate 216 on which a float 218 is mounted. Float 218 is mounted on plate 216 by a connector arm 220. Tube 212 includes a discharge end 234 (Figs. 8-11), and secured within tube 212 is a valve seat 238. Valve seat 238 is also configured in a curved, saddle-shape configuration similar to that of valve seats 38 and 138. Valve plate 216 has a saddle-shape configuration that mates with valve seat 238, and also includes a drain aperture 242. An access slot 260 opens through the side of drop tube 212 in order to permit float 218 and arm 220 to pass therethrough and align with drop tube 212. As will be seen in Fig. 10, arm 220 is a rigid arm that extends along a tangential line to spherical float 218, so that float 218 extends generally to the lower side of arm 220. This off-set positioning of float 218 permits float 218 to pass through access slot 260 with a reduced degree of pivoting by arm 220 (Fig. 12). A closing collar 270 (Figs. 10-11) is slidably mounted within drop tube 212 and is frictionally held in position along tube 212. Collar 270 is pulled up to a closed position covering the majority of access slot 260 by a flexible line (not shown) after float 218 has shifted outside of drop tube 212. Float arm 220 is resiliently, pivotally mounted on plate 216. Arm 220 is mounted on drop tube 212 by a triggering assembly that includes a trigger element 280. Trigger element 280 has a generally rectangular body that extends normally upwardly from a lower pivotal hinge 281 when in the open or at-rest position shown in Fig. 13. Lower hinge 281 pivotally couples trigger element 280 to a pair of short extensions or tabs that depend from the lower end of flapper plate 216. Lower hinge 281 also pivotally couples trigger element 280 to the inboard end of float arm 220 (Fig. 13). A torsion spring 282 is located about hinge 281 and biases trigger element 280 and float arm 220 toward each other. Torsion spring 282 therefore biases arm 220 and float 218 out through access slot 260, and biases trigger element 280 toward an upright at-rest position shown in Fig. 13. The upper end of trigger element 280 widens out into a square plate 283 that provides an increased surface area that obstructs fluid flow when trigger element 280 is pivoted out into the fluid flowing through drop tube 212 as disclosed herein. Flapper valve 216 is pivotally mounted on valve seat 238 by an upper hinge 284 that is located above lower hinge 281. Effectively, float arm 220 and trigger element 280 pivot relative to valve plate 216 about lower hinge 281, while flapper valve plate 216 pivots relative to drop tube 212 about upper hinge 284. A wedge shaped land 285 (Fig. 9) on the face of valve plate 216 above trigger element 280 assists in producing a smooth flow of liquid over the upper edge of trigger element 280 and increases pressure to hold open plate 216 under high flow conditions. As shown in Fig. 13, the upper end of float arm 218 forms a float stop 286 that abuts the inside face of trigger element 280 when float 218 is raised. The lower end of trigger element 280 provides a triggering stop 287 that abuts the upper end of float arm 220 when trigger element 280 has been shifted into a triggering position, shown in Fig. 15. The lower edge of flapper valve plate 216 provides a plate stop 288 that abuts the upper face of float arm 220 when float arm 220 has been raised as shown in Fig. 15. Float stop 286 therefore permits arm 220 to pivot relative trigger element 280 from an inserting position (Fig. 12) until a predetermined filled position is reached, and thereafter trigger element 280 is shifted by arm 220 as float 218 is raised. Triggering stop 287 permits trigger element 280 to pivot relative to arm 220 until trigger element 280 reaches a triggering position (Fig. 15), and thereafter trigger element 280 shifts arm 220. Plate stop 288 permits both trigger element 280 and arm 220 to pivot relative to flapper valve plate 216 until arm 220 contacts plate stop 288, so that flapper valve plate 216 is shifted toward the closed position (Fig. 16) as trigger element 280 is shifted through the triggering position. Located above flapper valve 216 within drop tube 212 is a flow baffle 290 (Figs. 10-11) that also forms an air cushion above seat 236. Flow baffle 290 is an annular ring that reduces the diameter of the orifice through drop tube 212 just above the upper edge 291 of flapper valve plate 216 when in the open position (Figs. 10-11). Flow baffle 290 deflects the flow of liquid away from plate upper edge 291 and thus prevents liquid flow through drop tube 212 from causing an accidental closing of plate 216. Flow baffle 290 also reduces the force necessary for trigger element 280 to initially move flapper plate 216 toward a closed position, since the dynamic force of the liquid flow against flapper valve plate 216 is reduced. The presence of air in the annular space 292 behind baffle 290 creates an air cushion that is compressible to reduce the water hammer effect produced upon the closing of plate 216. When plate 216 is quickly closed, any resulting hydraulic shock that would travel back up drop tube 212 contacts the air behind baffle 290. Since air is a compressible medium, the air operates as a damper on the shock effect. Located on the upper surface of seat 238 opposite hinge 281 is a raised tab or land 296 (Fig. 10) that mates with a recess or slot 298 in plate 216 adjacent upper edge 291. When plate 216 is shifted to a closed position, land 296 is received in slot 298 in order to position plate 216 on seat 238. This reduces the stresses exerted on hinge 281 in holding plate 216 in position, and prevents plate 216 from slipping sideways along seat 238. OPERATION In order to mount drop tube 12 with overfill valve 10 within tank 30, spring 20 is manually bent downward until float 18a is located beneath discharge aperture 36 as shown in Fig. 3. Drop tube 12 is then slid down casing 14 without interference from float 18. When drop tube 12 is secured to the top of casing 14 in a conventional fashion, spring 20 returns float 18 and weight 52 to a normally open position. In the open position plate 16 is generally vertically oriented with upper edge 46 resting against the inner wall of tube 12. Spring 20 depends to the side of tube 12 at a generally downward angle that holds float 18 out of the discharge zone beneath tube 12. As fluid flows through tube 12, the pressure exerted by the flowing fluid forces plate upper edge 46 outward against tube 12. This outward biasing of plate 16 is caused by an overcentering action resulting from the spacing of the lower edge of plate 16 from tube 12 by hinge 44. As the level of liquid within the tank rises to discharge end 34, float 18 is raised as shown in Figs. 1 and 2. The raising of float 18 causes plate 16 to pivot downward onto seat 38 and close discharge aperture 36. Hinge 44 provides some play between plate 16 and tube 12 so that plate 16 is permitted to seat itself correctly upon valve seat 38. While slowly being lifted, float 18 is required to overcome the pressure exerted against plate 16 by the fluid flowing through tube 12. When float 18 is raised sufficiently to force plate upper edge 36 away from the inner wall of tube 12, upper edge 46 of plate 16 is moved past its overcentered position. Thereafter plate 16 is very rapidly pivoted to a closed position by the fluid flowing through tube 12. The closing pressure of the fluid flowing through tube 12 raises float 18 above the upper level 22 of the liquid. When plate 16 shuts, delivery from the truck is halted. Control drain aperture 42 permits the standing head of liquid within tube 12 to drain into tank 30 at a controlled rate. Drain aperture 42 bleeds off the standing head at a preferred rate of less than two to three gallons per minute. When tube 12 has drained sufficiently that the weight of float 18 and weight 52 overcome the remaining fluid head in tube 12, plate 16 will be biased open and permit the remainder of the fluid to drain into tank 30. If tank 30 is filled in such a manner as to raise liquid level 22 enough to hold float 18 in a constantly closed condition (Figs. 1 and 2), the tank fill lines can be drained into tank 30 by loosening the fill line coupling with the top of tube 12 and casing 32. The liquid will then run down annular space 32. Thereafter, as liquid is removed from tank 30 and fluid level 22 lowers, any standing head remaining in tube 12 will drain through aperture 42 and plate 16 will return to its normally open position. Since neither plate 16 or float 18 are positioned within discharge zone 37 beneath discharge end 34, the fluid level within tank 30 may be gauged in a conventional fashion by lowering a pole down through tube 12. The pole will not be obstructed by objects along its path and may be lowered to the bottom of tank 30. Valve 110 in drop tube 112 is positioned in the same manner as valve 10 above. However, collar 170 is first slid downward to an open position and spring 120 with float 118 attached thereto is flexed through slot 160. When tube extension 112 with valve 110 is positioned within the storage tank, spring 120 returns float 118 to its at-rest open position. Flexible line 174 is used to draw collar 170 up to a closed position shown in Fig. 6. Thereafter, valve 110 operates in the same manner as valve 10 described above. For the insertion of valve 210 into a tank, float 218 and arm 220 are shifted into alignment with drop tube 212 so that float 218 is received through access slot 260 as shown in Fig. 12. When valve 210 is in place, torsion spring 282 biases float arm 220 and float 218 out of drop tube 212 (Fig. 13), and trigger element 280 is biased toward an at-rest position. The weight of float 218 causes trigger element 280 to pivot flapper plate 216 into the open position shown in Fig. 13. When the tank is filled, float 218 will raise to a filled position, causing float stop 286 to abut the side of trigger element 280 and shift trigger element 280 out into the flow of liquid through drop tube 212 (Fig. 14). Trigger element 280 is thus shifted by float 218 toward the triggering position shown in Fig. 15. Once trigger element 280 has been shifted sufficiently, the flow of liquid through drop tube 212 causes trigger element 280 to pivot quickly into the triggering position (Fig. 15) with triggering stop 287 abutting float arm 220. The increased surface area of plate 283 increases the force exerted by trigger element 280 against arm 220. Trigger element 280 thereafter continues to be pivoted by the fluid flow and raises float arm 220 until plate stop 288 abuts the upper side of float arm 220. The force generated by the fluid flow against trigger element 280 causes flapper valve plate 216 to be shifted toward the closed position (Fig. 16). Once flapper valve plate 216 is moved sufficiently, the flow of liquid through drop tube 212 quickly forces flapper valve plate 216 into a closed condition. Trigger element 280 is therefore an initiator element that initiates or triggers the movement of flapper valve plate 216 toward the closed position.

Claims: An overfill valve for use in filling liquid storage tanks, as used in automotive service stations, having an upstanding casing (14) having an inner circular profile, comprising an inlet pipe (112) having an outer circular profile less than the inner circular profile of the casing (14), said inlet pipe being insertable through the casing (14) to mount the overfill valve in a liquid delivery position, said inlet pipe defining a flow passage from an upper inlet end to a lower discharge end (134), a closure member (116 or 216) mounted within said inlet pipe so as to be selectively shiftable between a closed position and an open position, float means (118 or 218) coupled to said closure member through a coupling means which includes an arm like member (120 or 220) such that said closure member moves from said open position to said closed position as said float means is raised, said closure member (116 or 216) in its open position being disposed to one side of said flow passage, said float means and arm like member projecting generally laterally of the inlet pipe when the closure member is in its open position, and pivotal in an upward direction in response to the level of liquid reaching the float, access means (160 or 260), disposed between the inlet and discharge ends of the inlet pipe, which receive the float means and enable the positioning of the float means within the outer profile of the inlet pipe (112 or 212) sufficient to enable insertion of the inlet pipe through the casing (14), whereby the outer vertical profile of the inlet pipe can closely approach the inner vertical profile of the casing and maximize the liquid flow area of inlet pipe, and characterized in that the upper inlet end and the lower discharge end being vertically aligned, whereby a gauging pole may be inserted through the inlet end, past the closure member to the discharge end (134). An overfill valve, according to claim 1, characterized in that said coupling means permits relative movement between the float means (118 or 120) and the closure member (116 or 216) to facilitate positioning of the float means substantially within the profile of the inlet pipe. An overfill valve, according to claim 2, characterized in that said coupling means is resilient and arranged to dispose the float means generally laterally of the inlet pipe in the delivery position of the inlet pipe. An overfill valve, according to claim 1, characterized in that the closure member (216) is pivotally mounted on the inlet pipe (212), at a location (281) interiorly of the storage tank, when the fill pipe is in its delivery position, and the float means arm (220) is rigid and also pivotally mounted on the inlet pipe. An overfill valve, according to claim 4, characterized in that the closure member (216) and the float means arm (220) are mounted on a common axis (281) and spring means (282) interconnect the float means arm (220) and the closure member 216) and permit relative movement between the float means and the closure member to facilitate positioning of the float means substantially within the profile of the inlet pipe and to dispose the float means generally laterally of the inlet pipe in the delivery position of the inlet pipe. An overfill valve according to claim 5 characterized in that a triggering element (280) is pivotally mounted in said inlet pipe to pivot from an at-rest position to a triggering position in the flow of liquid through said inlet pipe, said triggering element being coupled to said float and said closure member such that it pivots from said at-rest position toward said triggering position as said float is raised and said closure member is pivoted from said open position toward said closed position as said triggering element pivots through said triggering position. An overfill valve according to claim 6, characterized in that said triggering element (280) includes a first stop (287) thereon engaged by said float when said float is raised to a preselected filled level; and said closure member includes a second stop (288) thereon engaged by one of said float and said triggering element when said triggering element reaches said triggering position. An overfill valve according to any preceding claim in which the access means are such that the float means (118 or 218) may be disposed substantially within the vertical profile of the inlet pipe (112 or 212). An overfill valve according to any preceding claim, characterized in that the access means is an opening (160 or 260) in the inlet pipe through which the float means (118 or 218) may pass in being brought to a position within the vertical profile of the inlet pipe, and a closure member (170 or 270) is provided for said access opening.

Inventors: DRAFT, ROGER A.
Applicants: DRAFT, ROGER A.
Application year: 1986
Main classification: F16K31
IPC codes: F16K31, F16K21