Patent Application
20060102246
This invention relates generally to liquid dispensing devices, and more particularly to seal assemblies for liquid dispensing devices.
Fluid dispensers include a variety of components for selectively controlling the flow of and dispensing a fluid. Fuel dispensing systems can include, for example, a stem for assisting in actuating a poppet valve between opened and closed positions to control fluid flow between an inlet and outlet port. For instance, a fluid dispensing system is described in U.S. Pat. No. 3,811,486 (the '486 Patent) to Wood, the entire disclosure of which is hereby incorporated herein by reference.
Fluid dispensing assemblies or nozzles can comprise a main body with an inlet port adapted to communicate with a source of pressurized fluid, and an outlet port adapted to dispense fluid from the main body. In such devices, a stem, for actuating a valve, slides relative to a seal or to a packing (typically loose material stuffed around the stem in a chamber). As described in further detail in the referenced '486 patent, the stem, together with a lever, can assist in actuating the valve, such as a poppet valve, to control fluid dispensing.
Typically, the packing, an O-ring or a related flanged lip seal has been provided to prevent leakage of fluid along the stem, and more particularly between the stem and portions of the main body. In some devices, a flanged lip seal with an internal O-ring energizer has been utilized.
However, such seals and sealing systems have exhibited problems with respect to sealing performance and/or durability. For example, such seals may exhibit rapid deterioration and wear from movement within the dispenser. Accordingly, the seal can become quickly compromised, resulting in leakage of the fluid. In addition, such seals typically have an inner surface which seals against the moving stem, or other component, and an outer surface which seals against the stationary dispenser body. Friction from movement of the seal caused by movement of the stem can compromise the sealing surface against the stem as well as the sealing surface against the stationary body.
In addition, inserting a seal into a dispensing device can be time consuming and tedious. The seal is typically small and required to be fitted within a narrow chamber. Often, specialized tools are required to compress the seal and place it into the housing of the dispenser against the components being sealed.
Accordingly, it is desired to obviate problems and shortcomings of conventional seal assemblies. More particularly, in some embodiments, it is desired to provide improvements in durability and/or performance of seals in fluid dispensing apparatus. Moreover, in some embodiments, it is desired to reduce the difficulty and minimize the time needed for assembling a fluid dispensing apparatus.
According to one aspect, a fluid dispenser is provided comprising a fluid dispenser housing having an inner chamber defined by a chamber surface, and a cylindrical stem that includes an outer surface. The stem is configured to control the flow of fluid through said housing. The dispenser also includes an insertable module which is selectively engaged with said inner chamber and includes an opening slidingly receiving said stem. A stem seal member is retained by said module and is in sealing contact with the outer surface of the cylindrical stem when the module is engaged with the inner chamber to provide a first seal. The stem seal member is separated from the housing by a portion of the module and the said stem seal member contacts the stem and a substantially non-porous portion of said module. The assembly also includes a housing seal member retained by the module and in sealing contact with the chamber surface of the housing when the module is engaged with the inner chamber to provide a second seal. The housing seal member is separated from the stem by a portion of the module whereby the second seal provides a static seal against the chamber surface. The module is configured to retain the stem seal member and the housing seal member when the module is disengaged from the chamber.
According to another aspect, a fluid dispensing assembly is provided comprising a main body including an inlet port adapted to communicate with a source of pressurized fluid and an outlet port adapted to dispense fluid from said main body, the main body including an inner chamber defined by a chamber surface. The assembly also includes a stem having an outer surface, wherein the stem is adapted to assist in regulating fluid between said inlet port and said outlet port of said main body. In addition, the assembly includes a stem seal having an opening slidably receiving the stem and comprising an inner sealing surface, wherein the inner sealing surface sealingly contacts the outer surface of the stem to provide a first seal. In addition, the assembly includes a body seal sealingly contacting the chamber surface of the body to provide a second seal, and a module configured to selectively engage the inner chamber and including an opening for receiving the stem. The module is adapted to retain the stem seal and the body seal when the module is disengaged from the chamber. The stem seal provides the first seal against the stem when the module engages the inner chamber and the body seal provides the second seal against the chamber surface when the module engages the inner chamber. The assembly further includes a manual actuator adapted to control movement of the stem and control the flow of fluid through the main body.
According to an additional aspect, a fluid dispenser is provided comprising a main body including an inlet port adapted to communicate with a source of pressurized fuel and an outlet port adapted to dispense fuel from said main body, wherein said main body includes an inner chamber defined by a chamber surface. The dispenser also includes a seal having a sealing surface, wherein the sealing surface sealingly contacts a component of the fuel dispensing assembly to provide a first seal. The dispenser also comprises an insertable retainer configured to selectively engage the inner chamber, wherein the retainer is adapted to retain the seal when the retainer is disengaged from said chamber, and wherein the seal provides the first seal against the assembly component when the retainer engages the inner chamber. The dispenser also includes a manual actuator adapted to control the flow of fuel through the main body, and a shut-off actuator configured to automatically shut off flow of fuel through the main body in response to a fill condition.
According to another aspect, a method for assembling a fuel dispensing apparatus is provided, the method comprising placing a seal on a module such that the seal is held on said module, and providing components for assembling a fuel dispensing apparatus. The method also comprises engaging the module with a housing for a fuel dispensing apparatus, such that the seal contacts at least one of the housing and the components and provides a fluid-tight seal therewith. The method further comprises assembling the components and the housing as a fuel dispensing apparatus.
In accordance with another aspect, a fluid dispenser is provided comprising a fluid dispenser housing having an inner chamber defined by a chamber surface, and a poppet stem assembly residing within the inner chamber. The poppet stem assembly comprises a cylindrical stem including an outer surface, the stem being configured to control the flow of fluid through the housing. The assembly also includes a stem seal member in sealing contact with the outer surface of said cylindrical stem to provide a first seal, wherein the stem seal member does not contact said housing. In addition, the assembly includes a housing seal member in sealing contact with the chamber surface of the housing to provide a second seal, wherein the housing seal member does not contact the stem.
Still other aspects of the present invention will become apparent to those skilled in the art from the following description wherein there are shown and described alternative illustrative embodiments including inventive aspect. These embodiments and descriptions are provided only as illustrative examples, and in no way are intended, nor should they be interpreted, as limiting. As will be realized, the invention is capable of other different embodiments, all without departing from the scope of the invention. These other possible embodiments will be understood by those skilled in the art based upon the description and teachings herein. Accordingly, the drawings and descriptions should be regarded as illustrative and exemplary in nature only, and not as restrictive.
While the specification concludes with claims particularly pointing out and distinctly claiming the inventive aspects, it is believed the same will be better understood from the following description taken in conjunction with the accompanying drawings in which:
a is a cross sectional view of an illustrative embodiment of a poppet stem seal module, made and operating according to principles of the present invention;
b is a perspective view of the module of
a is a cross sectional view of an illustrative embodiment of a seal that can be used in the stem seal module of
b is a top view of the seal of
a is a perspective view of an illustrative embodiment of the cantilever spring of the seal of
b is a perspective view of the seal of
As further illustrated in
In this embodiment, the seal 50 is retained by an insertable and removable module 28, according to principles of the present invention. The module 28 can be selectively engaged with the main body 12, such as via threads or other suitable engagement methods. The module 28 can include multiple components for retaining and holding the seal 50, which provides a seal against the stem 20. The module 28 holds the seal 50 even when the module is disengaged from the main body 12. In this embodiment, module 28 also retains a seal 48 which provides a seal against the main body 12. As will be discussed in more detail below, the module 28 of this embodiment can provide improved sealing performance and durability, as well as increase the ease of assembling the components of the stem seal assembly 18.
The removable seal module 28 of this embodiment is shown in more detail in
The module 28 retains one or more seals for use in the poppet valve stem seal assembly. In particular, in this embodiment, the sleeve 30 includes recesses or voids for placement of two seals which resists leakage of fuel as it flows through the dispenser. In this example, a first recess comprises a groove 36 formed in the exterior of the sleeve 30. Within the groove 36 is held a housing seal member 48 to thereby retain the seal 48 within the module 28 when it is disengaged from the main body/housing 12 (
In addition, the module 28 retains (e.g., houses) a second seal 50 for providing a seal against the stem 20. Accordingly, this seal 50 is likewise retained by the module 28 prior to the module being engaged with the housing 12. In particular, in this embodiment, the sleeve 30 includes a recess 37 at one end, formed by a narrow wall portion 39 and an interior seat 38. Accordingly, the ring-like seal 50 resides within the recess 37 and against the seat 38, with the narrow wall 39 surrounding the seal.
The module 28 can further include a guide or cap 42, for additional support in retaining the seal 50. In particular, in this embodiment, the diameter of the end portion 43 of the guide 42 is approximately the same as the inner diameter of the recess 37 between walls 39. Accordingly, an interference fit or engagement is provided between the end portion 43 of the guide 42 and the recess 37 of the sleeve. Guide 42 can likewise be made of a friction reducing material, such as DELRIN for example. An extension 41 from the guide 42 can be provided as stop to abut the wall 39 when the guide 42 is engaged with the sleeve 30.
Accordingly, with reference to
To assemble the module 28, seal 48 can be slided over the exterior surface of the sleeve 30 until it rests in groove 36. The bushing 34 is placed into the chamber until it reaches the narrow passage 33 such that it abuts and mates with the sleeve 30. Seal 50 can be placed into recess 37, and guide 42 can be pressed into the recess 37 until extension 41 reaches and is stopped by the bottom wall 39. Accordingly, the module 28 is ready to receive the stem 20 and to be engaged with the housing 12. Thus, the seals 48 and 50 are assembled with and retained by the module when it is disengaged from the fluid dispenser housing 12, and can be later placed into the fluid dispenser without the need for special tools and without requiring difficult placements of small parts. Rather, the entire module 28 can be placed into the housing 12 as a complete unit, such as by engaging threaded portion 35 with a corresponding threaded portion 15 within the housing 12 (See
More specifically, as best seen in
The seal 50 can also be arranged such that the outer flange 54 contacts an inner surface of the module sleeve 30 to similarly create a seal therewith. The outer flange 54 thus provides a second or outer ring-like seal adjacent the inner surface of the sleeve. In certain embodiments of the present invention, and as illustrated in
The ring-like contact can be a knife-like contact (e.g., near surface, edge or lip 64, 66) or a limited vertical contact surface. The seal 50 is thus provided in the shape of a torus or general donut shape having an opening in the center (i.e., either in the center or off-center depending upon the application) to receive and sealingly engage the stem 20 in use.
With reference to
It has been found that particularly advantageous performance and durability (with respect to friction characteristics, and durability and size stability when in contact with fuel) can be attained by constructing substantially the entire seal 50 using a TEFLON material. In addition, the inner surface 74 of the sleeve 30 and/or the outer surface 22 of the stem 20 may be made of low friction materials and/or appropriately finished or coated/treated to further prevent undue friction and wear, and to optimize the service life of the assembly. In one example of a fuel dispenser nozzle stem, the outer surface 22 of the stem 20 may be optionally finished with a finish of at least 12 for use with a seal 50 having a TEFLON coating, or comprising or consisting of TEFLON. The material used to construct the seal 50, partially or completely, preferably results in a dynamic and/or static coefficient of friction relative to the stem of less than about 0.1, such as less than about 0.05 for example, which can result in improved performance of the fueling nozzle. In particular, according to one embodiment of the invention, using a seal made from TEFLON and a stem made from stainless steel can provide a coefficient of friction of the seal relative to the stem of about 0.04.
As shown in
In another example, the flared end 51 of this embodiment may be energized by the choice of materials or other geometrical characteristics of the flared end. In one example, the flared end may be formed as a composite of different materials having different properties.
In still further embodiments of the present invention, the energizing of the flared end is achieved with an energizing member 60 as best shown in
Various types of energizing members 60 could be utilized. For example, due to differing material properties, the energizing member could then act to energize the flared end 51 of the seal. In other examples, a wedge could be used as the energizing member to cause the flanges to bias away from one another. In other examples, the energizing member could take the form of a pressurized bladder, an O-ring, or material compressed within the flared end of the seal, or any material or component suitable to cause the flanges 52 and 54 to bias away from one another. With respect to other aspects of the inventions, it will be understood that other shapes of energizing members could be used such as energizing members with square, rectangular, triangular, wedge-shaped, or other cross sectional shapes, or that the energizing member could be removed. Moreover, while a single energizing member is illustrated in the embodiments, it is understood that a plurality of energizing members could be provided, and that the energizing member need not be unitary in nature. For example, a plurality of spaced, or overlapping energizing members might be placed within a recess. For instance, a plurality of O-rings could be stacked, one upon another, or concentrically arranged. In addition, a plurality of energizing members, such as spheres or ball bearings could be radially arranged at least partially within the recess of the seal. Similarly, it will be understood that the seal 50 could be formed with a plurality of recesses that can each receive one or more energizing members. With respect to some embodiments incorporating aspects of the inventions, the energizing member could take other forms, such as a hollow ring. In still other embodiments, the energizing member may take the form of a coil spring, or similar arrangement, connected end-to-end in the shape of a torus.
Returning to
In addition, in this embodiment, the fingers 92 are connected at their ends 93, such as by an integral connection, which allows the spring 60 to form a single continuous unit from its two end points. By positioning and retaining the spring 60 in the recess 62 in this manner, the fingers 92 of the spring provide a substantially uniform or constant force or load on the inner and outer walls 94 and 96 of the seal 50. It has been found that this arrangement can provide improved sealing performance of the lip 64 against the stem 20 and of the lip 66 against the sleeve 30, even under varying loads, pressures, and conditions.
As an alternative to the cantilever spring 60, other finger-type springs, flexible fingers, or flexible linear members might be utilized. Such members can be disposed, bent, or compressed between the inner and outer walls 94 and 96 to provide force on these walls to improve the performance of the seal 50.
Other embodiments are also possible. For example,
In addition, the module 70 includes an insert 74 also having a central passage or opening 71 for receiving the stem 20. The insert 74 also engages the retainer 72 forming a two piece module with an internal chamber. In particular, in this example, the retainer 72 includes a reduced diameter portion 77 having a diameter D2, while the insert 74 includes thin upper walls 79 having a spacing slightly larger than the diameter D2 such that the walls 79 of the insert 74 surround the reduced diameter portion 77 of the retainer 72, until the upper surface of the walls abut the larger portion of the retainer 72. Thus, the retainer 72 is nested within the insert 74. Other structures for engaging the members 72 and 74 can be provided, such as by interference fittings, other piloted configurations, and/or threadable engagements or similar interlocking arrangements, for example. Because the distance between opposite surfaces of the walls 79 is larger than the diameter of the remainder of the central passage 71 of the insert 74, a recess 78 is created, which is enclosed by the retainer 72 once the retainer and insert are engaged with one another. This recess 78 allows the module 70 to be assembled with and house a seal when it is engaged with and disengaged with the housing 12.
In particular, the module 70 further includes a seal 50 that can be retained by the removable module, even before it is engaged with the housing 12. In particular, in this example, the seal 50 is held within the recess 78. The seal 50 provides a sealing interface with the stem 20 as it moves in the dispenser. The seal can comprise a flanged seal with an internal energizing member, such as has been described above with respect to
In this example, the removable module 70 also includes a seal 76 that provides a seal against the housing 12. This seal 76, in this embodiment, is separate from seal 50 which does not seal against the housing but rather seals against the stem 20. Accordingly, the functions of sealing against the stem 20 and against the housing 12 are provided by separate seal structures in this embodiment. The seal 50, which can move slightly due to the stem movement, is isolated from and does not contact the potentially porous material of the housing 12, but rather contacts the insert 74 which can be made of a smooth, low-friction, and/or non-porous material, such as a metal or metal alloy like AMPCO 18 for example. Similarly, seal 76 is does not contact the stem, and is isolated from the stem movement, such that it experiences little movement against the porous housing 12. Accordingly, improved durability and performance are achieved in this embodiment.
To retain the seal 76 on the module, a second recess 80 is provided and is defined by and resides between inner extension 81 and outer extension 83. Accordingly, the seal 76 at least partially resides within the recess 80. However, seal 76 may be sized slightly larger than the recess, such that, when the module 70 is threaded into the housing 12, the seal 76 is compressed or crushed against the lower surface 84 of the inner chamber 17 for the poppet stem assembly, defined within the housing 12. For example, the seal 76 could comprise a crush seal O-ring made of a suitable material, such as an elastomer material. In this example, the extension 81 of the insert 74 engages the poppet stem opening formed in the housing 12 (at the bottom of chamber 17). Accordingly, the poppet stem 20 slidingly engages the insert 74 at this location as well.
To assemble the module 70 of this example, the seal 76 can be placed around the extension 81 of the insert 74 and pushed along the extension until it rests in the recess 80. The seal 50 can be placed within the recess 78, and the retainer 72 can then be engaged with the insert 74. Accordingly, at this point, the seals 50 and 76 are held or retained by the module members. This assembly can occur separate from the fuel dispenser and without the need for separate tools or for careful placement of the seals within the dispenser. The module 70 can then be engaged with the housing 12, such as by threading the retainer 72 into the housing chamber 17. While threading the retainer 72, the seal 76 compresses against the housing surface 84, providing a fluid tight crush seal against the housing. The poppet stem 20 can be slided through the middle of the module 70, and thus resides at the center of and is surrounded by the retainer 72, the seal 50, the insert 74, and the seal 76. All of these components in this embodiment therefore have a passage through their center having a diameter, at least at some portion, that is approximately the same as or slightly larger than the diameter of the stem 20. The seal 50 can include a flange or extension that abuts the stem 20 to provide a fluid tight seal against the stem. As the stem is inserted through the module 70, the seal 50 can compress radially within the recess 78 to provide the sealing force against the stem. The recess 78 restrains the seal 50 from movement as the stem 20 slides up and down against the seal 50 during use. The low friction material of the insert 74 results in reduced wear on the seal 50 as the stem moves. The seal 76 is isolated from the stem 20 and therefore does not move in response to the stem.
A manual lever or actuator assembly 119/219 can also be provided, which in this example includes a lever, a lower lever, a trigger, a spring to bias the trigger, and a rivet for securing the components. Near the top of the stem is provided a disc holder 108/208 which retains a disc 109/209, both of which are provided on a skirt 110/210. These components serve as an interface between the stem and the main spring 111/211 which biases the stem. O-rings 112/212 or similar seals can be provided for sealing of components, as shown. A filter screen 154/254 can also be provided to filter the pressurized fuel flowing through the nozzle from the inlet end 180/280 to the outlet end 190/290. A guard sub-assembly 123/223 can also be provided to guide and protect the lever 119/219, and can include a guard piece, a rack, and a rivet.
The operation of the lever assembly 119/219 with respect to the stem assembly 102/202 can be similar to that described above with respect to the other embodiments. In particular, movement of the poppet stem 102/202 by the lever 119/219 can move the skirt 110/210 and disc 109/209 off of their seat, permitting fuel to flow through the housing, and in particular, from the inlet end 180/280, around the poppet stem 102/202 and shut off components held within the housing (described below), and out the spout end 190/290.
Another spring 143/243 can be provided between a body cap 113/213 and a vapor valve 141/241, which can comprise, for example, a valve body, a stem 142/242, a lip seal, an insert, retaining rings, and a disc and disc holder. The spring 143/243 can be used for biasing the vapor valve. Another retaining ring 135/235 can be provided for retention of components. The vapor valve can operate as known in the art for flow of vapors.
In addition, a shut-off valve assembly 132/232 can be provided for automatic shut off of the fuel flow upon detection of a full condition in a fuel tank. This assembly can include a diaphragm biased by a spring, a support cup, a support, and other components such as a snubber, a wear washer, and a cap. In addition, a diaphragm sub-assembly 133/233 can be provided, which can include a diaphragm and diaphragm support, a lower diaphragm connector, a flat washer, and an upper pin and spring pin. Additional shut-off components can include a diaphragm spring 114/214, a latch spring 115/215, a latch ball 122/222, a latch ring 134/234, and a latch plunger 116/216, and the shut-off components can connect with the lever 119/219 via a plunger pin 120/220 and push nut 121/221. These components can operate in ways known in the art, or later to be developed, for automatic shut off of the nozzle, such as by using Venturi vacuum principles for example.
The spout end of the fueling nozzle can include a spout sub-assembly 118/218 including a tube, spring, poppet, bleeder seat ring/outer tube, sleeve, and ferrule, as well as various O-rings for sealing, and retaining rings for securing components. A vapor escape guard 148/248, and clamp 149/249 therefor, can also be provided to prevent escape of vapors. An anchor spring 155/255 and ring 156/256 can also be utilized. The spout components can operate as known in the art or in a desired manner.
Other components can also be provided, as needed or desired, to create the appropriate fueling nozzle for the application at issue. For example, rivets 125/225 and screws 130/230 can be provided for securing components together, insulating material 126/226 and 140/240 can be provided to insulate the metal pieces from the user, identification washer 136/236 and screw 137/237 can be provided for identification of the nozzle, and O-rings 138/238, 139/239, 128/228, 129/229, and 124/224 can be provided for appropriate sealing of components.
The modules 28 and 70 of these embodiments therefore operate to seal fluid from leaking along the stem or along the main body. These modules 28 and 70 can exhibit increased durability and performance and reduced assembly requirements.
The foregoing description of the various embodiments of the invention has been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the inventions to the precise form disclosed. Many alternatives, modifications and variations will be apparent to those skilled in the art of the above teaching. For example, although the module is shown as comprising multiple engaged members and two seals in some embodiments, the module could comprise a single integrated component and/or a single seal in other embodiments of the invention. As another example, although multiple inventive aspects have been presented, such aspects need not be utilized in combination, and various combinations of aspects are possible in light of the various embodiments provided above. Accordingly, it is intended to embrace all possible alternatives, modifications, combinations, and variations that have been discussed and suggested herein, and all others that fall within the principles, spirit and broad scope of the inventions as defined by the claims.
This application is related to U.S. patent application Ser. No. ______ (Attorney Docket No. 3356-179) filed on Nov. 18, 2004, entitled Liquid Dispenser with Stem Sealing System, the entire disclosure of which is hereby incorporated herein by reference.
