Closure lip seal relief

A closure comprises a hub with a central opening and a head pivotally connected to the hub, the head sealing the central opening when in a closed position. A lip seal relief is defined by a stepped surface between the head and the hub so that when the head is closed, the relief or clearance is provided between the head and hub inhibiting damage to a seal.

CROSS-REFERENCE TO RELATED DOCUMENTS

BACKGROUND OF THE INVENTION

1. Field of the Invention

Present embodiments relate generally to a closure for a pressure vessel or pipe. More specifically, but not by way of limitation, present embodiments relate to a relief structure for a lip seal utilized with a closure mechanism for a pressure vessel or pipe.

2. Description of the Related Art

Closures for pressure vessels and pipes typically utilize a round door or head adapted to fit in the aperture of a body or hub. The hub is connected to a vessel or pipe system or other structure which is typically pressurized. The door or head is lockingly engaged to the hub when in the closed position so that the system or vessel may be pressurized without unknowingly allowing for opening of the head from the hub.

A bore or aperture of the hub has an inner circumferential groove for supporting a portion of a locking member. The door has a locking ring proximate a circumferential portion of an outer surface of the door wherein the locking ring is engaged to cooperate with the groove about the aperture after the door is closed and seated in the aperture. The locking ring is typically biased by a band, ring or segment which is caused to expand or contract, causing the same expansion or contraction of the locking ring to lock or unlock the head from the hub. The locking ring may be formed of one or more segments or may be a unitary structure.

Some closure mechanisms for pressure vessels utilize a seal between the head and the hub in order to inhibit leakage of pressurized fluid from the inside of the closure to the outside. Additional to this point, some seals are designed to be oversized so as to provide and improve the seal between the head and the hub. In certain embodiments, the closure is oriented for use on a vertical pipe such that the head is in a horizontal plane and the weight of the head aids to retain the head against or within the hub. In these embodiments, where a seal is used, it is common for seals to incur damage due to the continuous weight of the head pressing the seal against the hub. In alternate embodiments where the head is in a vertical plane, the head may be so tightly locked in the hub so as to damage the seal. When the seal is oversized, it is possible that the seal may carry much of the load of the head. Over time, this causes damage to the seal and therefore, may result in leakage at the closure.

It would be desirable to overcome these and other deficiencies and provide structure which compensates for the problems associated with overloading of a lip seal.

SUMMARY OF THE INVENTION

According to some embodiments, a closure lip seal relief comprises a hub having a peripheral body and a central opening of circular shape, a head is moveable into and out of said hub to close or open the closure, respectively, the head has an outer peripheral edge and an inwardly facing surface and an outwardly facing surface, a seal groove is located along the inwardly facing surface of the head and adjacent to the outer peripheral edge, a seal is disposed within the seal groove and engages an inwardly facing surface of the hub, a step is located along one of the head and the hub, adjacent to the seal groove creating a clearance between the inwardly facing surface of the head and an engaging surface of the hub, the clearance allows the seal to expand toward the inner surface of the hub, the step carries the weight of the hub or alternatively receives force created between the head and the hub when the head is in a closed position within the hub. The closure lip seal relief wherein the step is disposed radially inwardly of the seal groove. The closure lip seal relief wherein the clearance is disposed radially outwardly of the seal groove. The closure lip seal relief wherein the step is disposed radially outwardly of the seal groove. The closure lip seal relief wherein the clearance is disposed radially inwardly of the seal groove. The closure lip seal relief wherein the seal groove is substantially square in section.

A closure lip seal relief, comprises a hub having a peripheral body and a central opening of circular shape, a head movable into and out of the hub to close or open the closure, respectively, the head having an outer peripheral edge and an inwardly facing surface and an outwardly facing surface, a seal groove located along the inwardly facing surface of the head and adjacent to the outer peripheral edge, a seal disposed within the seal groove and engaging an inwardly facing surface of the hub, the inwardly facing surface of the head having a seal groove disposed near the peripheral edge, a step disposed on the hub and extending toward the head one of radially inward or outward of the seal groove, the step creating a clearance near the other of radially inward or outward of the seal groove. The closure lip seal relief wherein the step has at least one tapered surface. The closure lip seal relief wherein the step has at least one engagement surface which is rounded. The closure lip seal relief wherein the step has an engagement surface which is flat.

A closure lip seal relief, comprises a hub having a peripheral body and a central opening of circular shape, a head movable into and out of the hub to close or open said closure, respectively, the head having an outer peripheral edge and an inwardly facing surface and an outwardly facing surface, a seal groove located along the inwardly facing surface of the head and adjacent the outer peripheral edge, a seal disposed within the seal groove and engaging an inwardly facing surface of the hub, the inwardly facing surface of the head having a seal groove disposed near the peripheral edge, a step disposed on the head and extending toward the hub one of radially inward or outward of the seal groove, the step creating a clearance near the other of radially inward or outward of the seal groove.

All of the above outlined features are to be understood as exemplary only and many more features and objectives of the invention may be gleaned from the disclosure herein. Therefore, no limiting interpretation of this summary is to be understood without further reading of the entire specification, claims, and drawings included herewith.

DETAILED DESCRIPTION

It is to be understood that the exemplary embodiments are not limited in their application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The exemplary embodiments are capable of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” “in communication with” and “mounted,” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms “connected” and “coupled” and variations thereof are not restricted to physical or mechanical connections or couplings.

Furthermore, and as described in subsequent paragraphs, the specific mechanical configurations illustrated in the drawings are intended to exemplify various embodiments and that other alternative mechanical configurations are possible.

As referred to herein, the term axially means in the direction of the axis of the hub12. Also, the term radially refers to the direction of a radius, for example from the axis of the hub toward the outer circumference thereof, or vice-versa.

Referring now toFIGS. 1-9, closures are provided which include a lip seal relief. The relief or clearance is formed by a step extending from one of the head or the hub toward the other of the head or the hub. The clearance allows a seal is disposed in a seal groove to expand toward the opposed head or hub. This inhibits the seal being damaged by the weight or force of the door closing against the seal.

Referring initially toFIG. 1, a perspective view one embodiment of an alternative closure10is depicted. The closure10includes a hub12having a central bore or opening13. The hub12of the exemplary embodiment is annular in shape however, the hub12may take various shapes other than the circular cross-section shape depicted. The head14is blocked from view inFIG. 1by a cover plate30. This cover plate30encloses an actuator mechanism, according to the exemplary embodiment but according to some embodiments may not be utilized depending on the structure used to open and close the closure10. The hub12is weldable to the pressure vessel11or other system, such as a tank, pipeline, or enclosure subjected to pressure differential. The instant closure is mounted in a vertical configuration meaning the opening of the closure is facing upward or vertically or has a surface in a substantially horizontal plane. In this embodiment, the closure10does not utilize a hinge structure to open the head14from the hub12, however a hinged design is also within the scope of the instant embodiments as will be shown and described further herein.

A post20extends from the cover30and provides a pivot axis for an actuator positioned therebelow. As noted before, rotation of the cover30causes movement of the actuator mechanism to move the locking segments into and out of engagement with the hub12. A handle32is connected to the cover30to provide a means to pivot or rotate the cover30wherein such movement causes axial and rotational movement of an actuator below the cover30.

A plurality of lugs are disposed about the outer perimeter of the hub12. The lugs12a,12band12callow lifting of the hub12or the closure assembly10for positioning on pipe or extension of a vessel. This configuration is typically utilized, although not limited to, a vertically configured pipe or extension wherein the surface of the cover30lies in a generally horizontal plane and the central opening13is also disposed in a horizontal plane.

The embodiment further comprises a davit40. The davit40provides mechanical force through an input handle or crank assembly42to lift or lower the head14. The davit includes a vertically extending post44, a curved shoulder46and an arm48which extends horizontally over the head14of the closure10. The curved shoulder46allows pivoting of arm319about the vertical axis of the post44. An end of the arm48includes a crank assembly42which is rotatable to either lift or lower the head314. An axial strut50is connected to the crank assembly42and may be connected by fastener or permanent connection, for example by welding, or integrally formed with, to the cover30. Thus when the crank or handle assembly42rotates, the strut50raises or lowers the head. Similarly, the davit40may be utilized to lower the head14into the hub12as desired.

Referring now toFIG. 2, a perspective view of an alternate closure110is depicted. The closure110comprises a hub112and a head114which is pivotally connected to the hub112by hinge assembly116. The closure110differs from the embodiment previously discussed in that the closure110is mounted, generally, on a horizontal pipe or vessel portion so that the axis of the hub112is horizontal and the head114is generally disposed in a vertical plane. Accordingly, this embodiment utilizes a hinge assembly116which allows the head114to be controllably removed from the hub112or re-inserted into the hub112.

The closure110allows access to the pressure vessel or other system by way of the openable head114. The head114is shown having a circular shape which fits within the bore113of the hub112. When the head114is in the closed position as shown inFIG. 2, the pipe system or pressure vessel to which the closure110is connected may be pressurized. The hinge assembly116allows the head14to move from the closed position to an open position. In the open position, the head allows access to a pipe or pressure vessel or other pressurized system11(FIG. 1) to which the closure110is attached.

The hinge116may take various forms. According to an exemplary embodiment, the hinge assembly116includes at least one first hinge arm117and a second hinge arm118pivotally connected to the at least one first hinge arm117. The second hinge arm118is connected to a third hinge arm119in pivotal fashion so that a double pivoting structure is provided in order to connect the head114to the hub112. The at least one first hinge arm117is connected to the head114and may be integrally connected, such as by welding, or may be a bolted connection such as shown in the figure. The second hinge arm118has a first end and a second end. The first end is pivotally connected to the first pivot arm117. The second end is pivotally connected to the third pivot arm119. These pivotal connections between arms has a vertical pivot axis about which motion occurs.

Extending through the head114and through a cover plate130is a post120which connects to the third hinge arm119. First the post120defines a structure about which the cover plate130may pivot. The post120allows for structure to connect to the hinge assembly16so that the head114may be moved when an actuator is retracted. This allows interior access to the hub112and the pressure vessel or system.

Referring now toFIG. 9briefly, an alternate closure embodiment510is depicted. The closure510includes a hub512and a head514with a hinge516allowing opening and closing of the head514relative to the hub. The instant embodiment includes a locking assembly517which differs generally from the previous embodiments. The structure utilizes a plurality of locking segments joined by a band. The band may be actuated to move the locking segments into or out of engagement with the hub512. It should be understood from the descriptions that various closures and locking assemblies may be utilized with the instant lip seal relief and that any of the embodiments provided are merely exemplary and should not be considered limiting.

Referring now toFIG. 3, a perspective view of the closure110is depicted with the closure110situated in an open position wherein the door or head114is opened away from the hub112. This allows internal access to the hub112and pressure vessel or pressurized system11(FIG. 1) after the vessel or system is depressurized. The double pivoting function of the hinge is depicted wherein the second hinge arm118is pivoted relative to the at least one first hinge arm17. Additionally, the third hinge arm119is pivoted relative to the second hinge arm18. Hence the two pivoting functions of the hinge assembly116. However, it should be understood that a single pivot hinge assembly may be utilized or other hinge assembly three or more pivots.

Additionally shown inFIG. 3is the internal bore113of the hub112is shown with the head114removed therefrom. Also shown in the figure is the cover plate130mounted on the post120, as well as a locking ring assembly140positioned adjacent to cover plate130and on the head114. Within the wall defining the bore113is the circumferential groove121. The groove121receives elements of a locking ring assembly140. The cover plate130engages a portion of the locking ring assembly140and sandwiches the assembly between a surface of the head114and a rear surface of a cover plate130. As the cover plate rotates or pivots, the locking ring assembly140is actuated to extend or retract, locking or unlocking the assembly.

Also shown inFIG. 3, with the closure110open, the components of the head114may be discussed. The head114includes a generally circular peripheral edge150. The peripheral edge150extends between an outward facing side151(FIG. 4) of the head, upon which the locking segment assembly140is disposed in the exemplary embodiment, and an inwardly facing surface152. The inwardly facing surface152functions as an engagement surface which engages a corresponding surface154of the hub112.

Referring now toFIG. 4, a section view of the closure110is depicted. In this view the engagement between the hub112and the head114may be seen along interior surfaces of the hub112. The hub112is shown having a central bore113wherein the head114is positioned. Within the hub112, the head114includes a flat front surface151and a tapered surface153extending outwardly from the flat surface151to the radial edge of the hub150. Moving axially inward relative to the hub112, the hub engagement surface154extends radially inward and tapered surface157extends to an innermost surface of the head114.

The hub112has at least one head engagement surface154which varies the interior diameter of the hub112. At the opening of the hub112where the head114is inserted, the hub is of at least a first diameter. Moving inwardly through the hub112, upwardly in the figure, the surface154inwardly in a radial direction at the head engagement surface154. The surface154is at an angle of about 90 degrees to the peripheral edge150of the head114and the adjacent surface of the hub112. Although this angle is depicted as 90 degrees, this is not a limiting characteristic as various angles may be utilized depending on the angle of surface154to adjacent surfaces within the hub and also depending on the angle of the engagement surface152or alternatively the angle of the peripheral edge150. In summary, the surface154need not be perpendicular to the axis A of the hub112.

The head engagement surface154extends radially inwardly and engages the corresponding hub engagement surface154. Along the axially inward facing152is a sealing groove156. The sealing groove retains a seal160(FIGS. 5,6) which inhibits leakage of pressurized fluid between the hub112and the head114. The seal160and sealing groove156extend circumferentially about the head114. The seal160is recessed in the groove156but engages surface154of the hub when the system is pressurized. In alternative embodiments, the groove156may be located in the hub and the seal160disposed therein.

Referring now toFIG. 5, a detail section view of a first embodiment of a lip seal relief is depicted. In the detail section view, the head engagement surface154is depicted adjacent to the hub engagement surface152of the head114. The seal groove156is also shown within the head114near a peripheral edge150thereof.

Located along the engagement surface154is a step170which extends in an axial direction closer to the head152than the remaining portion of the hub154. As a result, the step170creates a clearance172between surface152and surface154. In the instant embodiment, the step170is located radially inwardly of the seal groove156. However, it is within the scope of the present embodiments that the step be located radially outward of the seal groove156.

This step170, according to the instant embodiment, has a surface which is perpendicular to the axis A-A (FIG. 4) of the hub. However, the step may alternatively include an engagement surface which is angled at an angle other than 90 degrees to the hub axis A-A. The step170is defined by a first leg174which extends from the head engagement surface154and an opposite leg176which defines a radially inner edge176of the hub112. Additionally, it should be noted that the leg174is parallel to the axis A-A of the hub but may alternatively be disposed at an angle to the hub axis A-A (FIG. 4). The step170is shown with a flat surface engaging surface152, however the step surface may be rounded or curved if desirable.

Referring now toFIG. 6, an alternate embodiment is shown wherein the hub step270is located radially outward of the seal groove156. The step270is positioned radially outward so that the clearance272between the hub112and the head114is radially inward of the seal160. The clearance in either of these embodiments allows the seal160to expand into the hub surface154so that the seal160is not crushed by the weight of the head114against the hub112. In alternate embodiments, the seal160may expand from the hub to the head. Additionally, one skilled in the art will note the different cross sectional shape of the head114and the hub112from the previous embodiments. The closure lip seal structures depicted in the disclosure may be utilized in various embodiments of hubs and heads shown inFIGS. 1,2,3,4and9and therefore the specific shapes of heads and hubs shown in the exemplary embodiments should not be considered limiting.

Referring now toFIG. 7, a third embodiment of a closure lip seal relief is depicted. In this embodiment, the step370is shown extending from the head114toward the hub112. The step370is radially outward of the seal groove156and the seal may be seated within the groove156. The step370is tapered along on side176toward said hub surface but may be tapered along both sides or may be non-tapered. In the depicted embodiment, the step370is shown radially outward of the seal groove156. Accordingly, the clearance372is located radially inward of the seal groove156.

Referring now toFIG. 8, a further embodiment is of the closure lip seal relief is shown. In the instant embodiment, the step470is again disposed extending from the head114toward the hub112. Additionally, the step470may extend on the radially inward side of the seal groove156. According to this embodiment, the clearance472is radially outward of the seal groove156.

According to any of the embodiments, the step may take various shapes and may be flat at the engagement surface with the opposite head or hub. The step may be continuous about the head or hub or alternatively may be formed of multiple circumferential segments.