Patent Description:
A gate valve is a valve that opens by lifting a round or rectangular gate out of the path of the fluid. The gate valve has sealing surfaces between the gate and seats that are planar, leading to gate valves being used when a straight-line flow of fluid and minimum restriction is desired. Generally, gate valves are used to permit or prevent the flow of liquids, for example in a pipe line system.

Liquid is able to flow when the gate of the gate valve is linearly retracted to open the flow path, whereas the liquid is prevented from flowing when the gate is linearly extended to a closed position. In the closed position liquid impinges a front side face of the gate and is prevented from passing between the gate and a body of the gate valve by rubber valve liners that surround the gate. Typically, the rubber valve liners are fixed in the body of the gate valve and rub against the gate as the gate opens and closes causing the rubber valve liners to wear away and lose their sealing ability. Furthermore, increasing compression of the rubber valve liners against the gate increases the wear rate of the rubber valve liners. Some gate valves employ spring components to maintain compression of the rubber valve liners, but compression force decreases as the rubber valve liners wear.

<CIT>, <CIT>, <CIT>, and <CIT> disclose prior art gate valve and seal configurations.

<CIT> discloses a gate valve assembly according to the preamble of claim <NUM>.

According to a first aspect of the present invention there is provided a gate valve assembly according to claim <NUM>.

Optional features are recited in dependent claims.

The present invention provides a gate valve including a seal with a wedging element for adjustably compressing the seal. The seal abuts a surface, such as a gate of the gate valve, to seal against the surface with a sealing force that prevents fluid flow therebetween. The compression sealing force of the seal may be increased or decreased by adjusting the wedging mechanism. For example, as the seal wears away due to friction between the seal and a sliding gate the compression sealing force diminishes and may diminish below a desired low threshold. The compression sealing force may be increased by movement of the wedging mechanism to increase the sealing force to at least the low threshold.

Also, the sealing force may be decreased below a high threshold to avoid wear on the seal. Adjusting the sealing force allows the seal to seal more effectively and allows increasing the usable lifespan of the seal. In particular, gate valves open and close using a gate that slides against a seal, which causes wearing of the seal. The wedge mechanism allows easily increasing the sealing force of the seal against the gate to counteract the loss of sealing force due to wear.

According to the invention, is a gate valve assembly comprising a valve body having an inlet and an outlet, a gate disposed within the valve body and slidably connected to the valve body such that the gate slides along a normal axis between an open position to a closed position, wherein in the closed position the inlet is fluidly disconnected from the outlet, a seal having a longitudinal axis perpendicular to the normal axis and extending along the gate such that the gate slides against a first seal surface of the seal when the gate slides between the open position and the closed position, and a wedging element abutting a second seal surface of the seal opposite the first seal surface, wherein the wedging element comprises a front side for engaging the second seal surface and a backside for engaging an opposite wedge surface such that movement of the wedging element along the longitudinal axis causes the wedging element to exert a force against the seal along a lateral axis perpendicular to the longitudinal axis.

The foregoing and other features of the invention are hereinafter described in greater detail with reference to the accompanying drawings.

The principles of this present application have particular application to gate valves for restricting, preventing, and allowing fluid flow in a fluid passage, such as oil flow in an oil pipeline, and thus will be described below chiefly in this context. It will be appreciated that principles of this invention may be applicable to other valves where it is desirable to restrict, prevent, or allow fluid flow using a seal.

Referring initially to <FIG>, a gate valve assembly <NUM> is illustrated. The gate valve assembly <NUM> includes a valve body <NUM> having an inlet <NUM> an outlet <NUM> (shown in <FIG>), a gate <NUM>, and a seal assembly <NUM>. The gate <NUM> is disposed within and slidable within the valve body <NUM> to open or close the gate valve assembly <NUM>. The gate <NUM> is shown in the closed position. When the gate <NUM> is in the closed position, fluid flows to the inlet <NUM> and impinges an inlet facing surface <NUM> of the gate <NUM>. The gate <NUM> prevents the fluid from flowing to the outlet <NUM>.

The gate <NUM> is slidable along a normal axis N into an open position. When the gate <NUM> is in the open position, fluid is able to pass by an outlet facing surface <NUM> of the gate <NUM> and flow through the inlet <NUM> to the outlet <NUM> along a direction perpendicular to the normal axis N.

Referring to <FIG> and <FIG>, the valve body <NUM> includes an inlet channel <NUM> extending along a longitudinal axis L<NUM> that is perpendicular to the normal axis N and parallel with the inlet facing surface <NUM>. The inlet channel <NUM> has an open end facing the inlet facing surface <NUM> of the gate <NUM> for allowing the seal assembly <NUM> to seal against the inlet facing surface <NUM>. The inlet channel <NUM> may include a cam channel (similar to a cam channel <NUM> referred to below) centrally disposed and extending longitudinally along the extent of the inlet channel <NUM> opposite the gate <NUM>.

The valve body <NUM> also includes an outlet channel <NUM> extending along a longitudinal axis L<NUM> that is perpendicular to the normal axis N and parallel with the outlet facing surface <NUM>. The outlet channel <NUM> has an open end facing the outlet facing surface <NUM> of the gate <NUM> for allowing the seal assembly <NUM> to seal against the inlet facing surface <NUM>. The outlet channel <NUM> may include a cam channel <NUM> centrally disposed and extending longitudinally along the extent of the inlet channel <NUM> opposite the gate <NUM>.

The gate <NUM> is disposed within the valve body <NUM> and slidably connected to the valve body <NUM> such that the gate <NUM> slides along the normal axis N between an open position to a closed position. In the closed position the inlet <NUM> is fluidly disconnected from the outlet <NUM>. Fluidly disconnecting the inlet <NUM> from the outlet <NUM> prevents fluid from passing through the gate valve assembly <NUM>.

The seal assembly <NUM> may include a seal <NUM> that extends along one or both longitudinal axes L<NUM>, L<NUM>. The longitudinal axes L<NUM>, L<NUM> are perpendicular to the normal axis N and extend along the gate <NUM> such that the gate <NUM> slides against the seal <NUM> when the gate slides between the open position and the closed position.

Cam assemblies <NUM>, <NUM>, also referred to as wedging elements, may abut the seal <NUM> opposite the gate <NUM>. The cam assemblies <NUM>, <NUM> are able to exert a compressive force on the seal <NUM> to increase sealing force of the seal <NUM> against the gate <NUM>. The cam assemblies <NUM>, <NUM> may also decrease the sealing force of the seal <NUM> against the gate <NUM>.

Each cam assembly <NUM>, <NUM> may include a first cam <NUM>, <NUM> and/or a second cam <NUM>, <NUM>, also referred to as wedging elements. Each first cam <NUM>, <NUM> is engageable with the seal <NUM> and the second cam <NUM>, <NUM> such that movement of the first cam <NUM>, <NUM> along the corresponding longitudinal axis L<NUM>, L<NUM> causes the first cam <NUM>, <NUM> to exert a force against the seal <NUM> along a lateral axis Z perpendicular to the longitudinal axes L<NUM>, L<NUM>.

The seal assembly <NUM> may include the first cam <NUM>, <NUM> and/or the second cam <NUM>, <NUM>, as well as the seal <NUM>, which extends along the longitudinal axis L<NUM> and/or longitudinal axis L<NUM>. The seal assembly <NUM> may be placed into the valve body <NUM> prior to assembly of the gate valve <NUM>.

Referring now to <FIG>, the seal assembly <NUM> may include the seal <NUM> for abutting the gate <NUM>, the first cam assembly <NUM> for wedging the seal <NUM> against inlet facing surface <NUM> of the gate <NUM>, the second cam assembly <NUM> for wedging the seal <NUM> against the outlet facing surface <NUM> of the gate <NUM>, and a U-shaped o-ring <NUM> for sealing the sides of the gate <NUM>.

The seal <NUM> is illustrated as one-piece and having an inlet seal portion <NUM>, an outlet seal portion <NUM>, two side seal portions <NUM>, <NUM>, and a o-ring channels <NUM>, <NUM>. Alternatively, the inlet seal portion, outlet seal portion, and two side portions may be separate components.

The inlet seal portion <NUM> has a gate facing surface <NUM> and a cam facing surface <NUM> opposite the gate facing surface <NUM>. The gate facing surface <NUM> extends along the longitudinal axis L<NUM> and abuts the inlet facing surface <NUM> of the gate <NUM>. The cam facing surface <NUM> extends along the longitudinal axis L<NUM> and abuts the cam assembly <NUM>.

When the gate <NUM> opens, the inlet facing surface <NUM> exerts a friction force upon the gate facing surface <NUM> such that the gate facing surface <NUM> may wear away during use.

Referring to <FIG> and <FIG>, the inlet seal portion <NUM> may include a cam facing surface <NUM> extending longitudinally across and opposite a protruding portion <NUM> of the gate facing surface <NUM> that faces the inlet facing surface <NUM>. The cam facing surface <NUM> may be disposed between leg portions <NUM>, <NUM> that extend longitudinally and away from the cam facing surface <NUM> along a lateral axis Z that is perpendicular to the normal axis N and at least one of the lateral axes L<NUM>, L<NUM>. The leg portions <NUM>, <NUM> engage a surface of the channel <NUM> of the valve body <NUM> to seal against fluid passing between the seal <NUM> and the valve body <NUM>.

The leg portions <NUM>, <NUM> may have a concave portion <NUM>, <NUM> at an end opposite the protruding portion <NUM>. The concave portions <NUM>, <NUM> extend longitudinally along the leg portions <NUM>, <NUM> and allow the seal <NUM> to seal against the surface of the channel <NUM> with less compressive force along the lateral axis Z. Also, the concave portions <NUM>, <NUM> allow a reduction of drag caused by the gate <NUM> sliding against the seal <NUM>. Thus, the seal <NUM> may be a low drag seal.

The protruding portion <NUM> may have a convex shape extending longitudinally for sealing against the inlet facing surface <NUM>. The convex shape may be centrally disposed along the normal axis N for spreading force equally to the leg portions <NUM>, <NUM>.

Similarly to the inlet seal portion <NUM>, when the gate <NUM> opens the outlet facing surface <NUM> exerts a friction force upon a gate facing surface <NUM> such that the gate facing surface <NUM> may wear away during use.

The outlet seal portion <NUM> may include a cam facing surface <NUM> extending longitudinally across and opposite a protruding portion <NUM> of the gate facing surface <NUM> that faces the outlet facing surface <NUM>. The cam facing surface <NUM> may be disposed between leg portions <NUM>, <NUM> that extend longitudinally and away from the cam facing surface <NUM> along the lateral axis Z. The leg portions <NUM>, <NUM> engage a surface of the channel <NUM> of the valve body <NUM> to seal against fluid passing between the seal <NUM> and the valve body <NUM>.

The protruding portion <NUM> may have a convex shape extending longitudinally for sealing against the outlet facing surface <NUM>. The convex shape may be centrally disposed along the normal axis N for spreading force equally to the leg portions <NUM>, <NUM>.

When the seal <NUM> is assembled with the gate <NUM> and valve body <NUM>, the protruding portion may compress against the inlet facing surface <NUM> to increase a sealing force against the gate <NUM> and to transfer a compressive force to the leg portions <NUM>, <NUM>. The compressive force may cause the leg portions <NUM>, <NUM> to compress against the surface of the channel <NUM>, thereby increasing a sealing force against the channel <NUM>.

The seal assembly <NUM> may further include wipers <NUM>, <NUM> on opposite sides of the protruding portion <NUM>. The wipers <NUM>, <NUM> provide a rigid surface to protect the protruding portion <NUM> from damage due to particulate that may accumulate on the inlet facing surface <NUM>. When the gate <NUM> opens or closes, the wipers <NUM>, <NUM> slide against the inlet facing surface <NUM> to wipe away particulate or debris before it can reach the protruding portion <NUM>. In an embodiment, only a single wiper may be provided. For example, only wiper <NUM> may be provided. In another embodiment no wiper is provided.

Referring specifically to <FIG>, a wedging element <NUM> is provided between the inlet seal portion <NUM> and the valve body <NUM> for providing force along the lateral axis Z in response to longitudinal force exerted against the cam assembly <NUM>. Because the wedging element operates via the interaction of cam surfaces, the wedging element alternatively is referred to as a cam assembly <NUM>. The cam assembly <NUM> may include a plurality of first cam components <NUM> and second cam components <NUM> that are longitudinally aligned. For example, four first cam components <NUM> and four second cam components <NUM> may be longitudinally aligned side by side, respectively. Multiple longitudinally aligned first and second cam components <NUM>, <NUM> allows each cam component <NUM>, <NUM> to have a thicker lateral length compared to one longitudinally extending cam component extending the entire longitudinal length of the aligned cam components <NUM>, <NUM>. In an embodiment, only a single cam component <NUM> and a single second cam component <NUM> are provided.

Each second cam component <NUM> may be fixed relative to the valve body <NUM>. A longitudinal end of each second cam component <NUM> may abut either the valve body <NUM> or another second cam component <NUM> to prevent longitudinal movement. In an embodiment, the second cam components and the valve body are one-piece. In another embodiment, each second cam component is longitudinally slidable relative to the valve body.

Each second cam component <NUM> may have a valve body surface <NUM> and a second surface <NUM>, opposite the valve body surface <NUM>. The valve body surface <NUM> may engage the valve body <NUM>, and the second surface <NUM> may engage the cam surface <NUM> of the first cam component <NUM>.

The valve body surface <NUM> may be generally planar and generally parallel with the normal axis and the longitudinal axis L<NUM>. In an embodiment, the valve body surface is oriented in any other suitable manner. For example, the valve body surface may be inclined relative to the inlet facing surface to allow each second cam component to be fixed relative to the valve body.

The second surface <NUM> may be generally planar and inclined relative to the valve body surface <NUM>. For example, the second surface <NUM> may be inclined longitudinally to allow the first cam component <NUM> to slide laterally as the first cam component <NUM> moves longitudinally along the second cam component <NUM>.

A longitudinal end of each second cam component <NUM> adjacent a fastener passage <NUM> in the valve body <NUM> may abut a ledge in the valve body <NUM>. The longitudinal end adjacent the fastener passage <NUM> may have a lateral thickness less than the corresponding ledge and an opposite end of the second cam component <NUM>. As illustrated, the end of the second cam component <NUM> adjacent the fastener passage <NUM> is offset from the fastener passage <NUM>. Offsetting the fastener passage <NUM> allows the fastener to extend toward the first cam component <NUM> without abutting the second cam component <NUM>.

The first cam components <NUM> are slidable relative to the second cam components <NUM> to perform a wedging action against the cam facing surface <NUM> of the inlet seal portion <NUM>. Each first cam component <NUM> may include a cam surface <NUM> for engaging the second cam component <NUM> and a seal surface <NUM> for engaging the inlet seal portion <NUM>.

The cam surface <NUM> may be parallel with the normal axis and inclined longitudinally to allow the first cam component <NUM> to move laterally as the first cam component <NUM> slides longitudinally along the second cam component <NUM>.

As the first cam component <NUM> slides longitudinally the wedge configuration of the seal surface <NUM> translates such movement into a lateral force against the cam facing surface <NUM>.

Specifically, the seal surface <NUM> moves laterally against the cam facing surface <NUM> to increase a sealing force of the gate facing surface <NUM> against the inlet facing surface <NUM> of the gate <NUM>.

The seal surface <NUM> may define a plane that does not rotate as the seal surface <NUM> moves. In other words, the orientation of the seal surface <NUM> may remain fixed as its position changes. As the seal surface <NUM> moves longitudinally, the seal surface <NUM> also moves in a direction that is non-parallel with the defined plane of the seal surface <NUM>. For example, the seal surface <NUM> may move laterally as it moves longitudinally. The non-parallel movement allows the seal surface <NUM> to exert a compressive force against the cam facing surface <NUM> to increase the sealing force of the gate facing surface <NUM> against the inlet facing surface <NUM> of gate <NUM>. Alternatively, the seal surface <NUM> may move longitudinally in an opposite direction to decrease the sealing force of the gate facing surface <NUM> against the inlet facing surface <NUM> of gate <NUM>.

The alignment and abutment of each first cam component <NUM> allows each first cam component <NUM> to move together. For example, a fastener may be inserted into the fastener passage <NUM> and adjusted to move the adjacent first cam component <NUM> into the next first cam component <NUM>, which translates the movement from the previous first cam component <NUM> until the furthest first cam component <NUM> slides toward and possibly into a fastener passage <NUM>.

In an embodiment, each first cam component is fixed relative to the valve body and each second cam component moves longitudinally such that the second surface of the second cam component exerts compressive force as a function of how far it moves longitudinally.

The side portions <NUM>, <NUM> of the seal <NUM> are disposed at either side of and abut the gate <NUM>. The side portions <NUM>, <NUM> include the o-ring channels <NUM>, <NUM> for housing the o-ring <NUM> at a side of the gate <NUM>.

Referring to <FIG>, the valve body <NUM> may include an o-ring channel <NUM> extending along a side of the gate <NUM> (not illustrated), as well as a corresponding o-ring channel <NUM> (<FIG>) extending along an opposite side of the gate <NUM>. The o-ring channel <NUM> and opposite o-ring channel <NUM> bound the o-ring <NUM> and extend along the normal axis N to align with the o-ring channels <NUM>, <NUM> of the seal <NUM>.

The side portions <NUM>, <NUM> include lateral recesses <NUM> to allow a fastener <NUM> (<FIG>) to translate the first cam component <NUM> or second cam component <NUM> without interfering with the side portions <NUM>, <NUM>. For example, the valve body <NUM> may include recesses <NUM> adjacent each fastener passage <NUM>, <NUM>, <NUM>, <NUM> in the valve body <NUM> to allow a corresponding fastener to reach the corresponding first or second cam component <NUM>, <NUM>.

The fastener passage <NUM> and the second fastener passage <NUM> (illustrated in <FIG> and <FIG>) to allow a fastener, such as fastener <NUM> (<FIG>) to longitudinally force the corresponding cam assembly <NUM>, <NUM> to exert more force against the seal <NUM>. As best shown in <FIG>, the valve body <NUM> may include fastener passages <NUM>, <NUM> opposite the first and second fastener passages <NUM>, <NUM> relative to the gate <NUM>. The fastener passage <NUM>, <NUM> allow fastener <NUM> (<FIG>) to provide a maximum threshold for movement of the corresponding cam assembly <NUM>, <NUM>. In an embodiment, the fastener is able to longitudinally force the corresponding cam assembly to exert less force against the inlet seal portion or the outlet seal portion of seal.

Referring to <FIG> and <FIG>, the outlet seal portion <NUM> has the gate facing surface <NUM> and a cam facing surface <NUM> opposite the gate facing surface <NUM>. The gate facing surface <NUM> extends along the longitudinal axis L<NUM> and abuts the outlet facing surface <NUM> of the gate <NUM>. The cam facing surface <NUM> extends along the longitudinal axis L<NUM> and abuts the cam assembly <NUM>.

When the seal <NUM> is assembled with the gate <NUM> and valve body <NUM>, the protruding portion may compress against the outlet facing surface <NUM> to increase a sealing force against the gate <NUM> and to transfer a compressive force to the leg portions <NUM>, <NUM>. The compressive force may cause the leg portions <NUM>, <NUM> to compress against the surface of the channel <NUM>, thereby increasing a sealing force against the channel <NUM>.

The seal assembly <NUM> may further include wipers <NUM>, <NUM> (<FIG>) on opposite sides of the protruding portion <NUM>. The wipers <NUM>, <NUM> provide a rigid surface to protect the protruding portion <NUM> from damage due to particulate that may accumulate on the outlet facing surface <NUM>. When the gate <NUM> opens or closes the wipers <NUM>, <NUM> slide against the oulet facing surface <NUM> to wipe away particulate or debris before it can reach the protruding portion <NUM>. In an embodiment, only a single wiper may be provided. For example, only wiper <NUM> may be provided. In another embodiment no wiper is provided.

A wedging element <NUM> is provided opposite the cam assembly <NUM> (shown in <FIG>), between the outlet seal portion <NUM> and the valve body <NUM> for providing force along the lateral axis Z in response to longitudinal force exerted against the wedging element <NUM>. Because the wedging element <NUM> operates via the interaction of cam surfaces, the wedging element alternatively is referred to as a cam assembly <NUM>. The cam assembly <NUM> may include a plurality of first cam components <NUM> and second cam components <NUM> that are longitudinally aligned. For example, four first cam components <NUM> and four second cam components <NUM> may be longitudinally aligned side by side, respectively. Multiple longitudinally aligned first and second cam components <NUM>, <NUM> allows each cam component <NUM>, <NUM> to have a thicker lateral length compared to one longitudinally extending cam component extending the entire longitudinal length of the aligned cam components <NUM>, <NUM>. In an embodiment, only a single cam component <NUM> and a single second cam component <NUM> are provided.

Each second cam component <NUM> may have a valve body surface <NUM> and a second surface <NUM>, opposite the valve body surface <NUM>. The valve body surface <NUM> may engage the valve body <NUM> and the second surface <NUM> may engage the cam surface <NUM> of the first cam component <NUM>.

The valve body surface <NUM> may be generally planar and generally parallel with the normal axis and the longitudinal axis L<NUM>. In an embodiment, the valve body surface is oriented in any other suitable manner. For example, the valve body surface may be inclined relative to the outlet facing surface <NUM> to allow each second cam component to be fixed relative to the valve body.

A longitudinal end of each second cam component <NUM> adjacent the fastener passage <NUM> in the valve body <NUM> may abut a ledge in the valve body <NUM>. The longitudinal end adjacent the fastener passage <NUM> may have a lateral thickness less than the corresponding ledge and an opposite end of the second cam component <NUM>. As illustrated, the end of the second cam component <NUM> adjacent the fastener passage <NUM> is offset from the fastener passage <NUM>. Offsetting the fastener passage <NUM> allows the fastener to extend toward the first cam component <NUM> without abutting the second cam component <NUM>.

The first cam components <NUM> are slidable relative to the second cam components <NUM> to perform a wedging action against the cam facing surface <NUM> of the outlet seal portion <NUM>. Each first cam component <NUM> may include a cam surface <NUM> for engaging the second cam component <NUM> and a seal surface <NUM> for engaging the outlet seal portion <NUM>.

Specifically, the seal surface <NUM> moves laterally against the cam facing surface <NUM> to increase a sealing force of the gate facing surface <NUM> against the outlet facing surface <NUM> of the gate <NUM>.

The seal surface <NUM> may define a plane that does not rotate as the seal surface <NUM> moves. In other words, the orientation of the seal surface <NUM> may remain fixed as its position changes. As the seal surface <NUM> moves longitudinally, the seal surface <NUM> also moves in a direction that is non-parallel with the defined plane of the seal surface <NUM>. For example, the seal surface <NUM> may move laterally as it moves longitudinally. The non-parallel movement allows the seal surface <NUM> to exert a compressive force against the cam facing surface <NUM> to increase the sealing force of the gate facing surface <NUM> against the outlet facing surface <NUM> of gate <NUM>. Alternatively, the seal surface <NUM> may move longitudinally in an opposite direction to decrease the sealing force of the gate facing surface <NUM> against the outlet facing surface <NUM> of gate <NUM>.

In an embodiment, each second cam is fixed relative to the valve body and the first cam moves longitudinally such that the second surface of the first cam exerts compressive force as a function of how far it moves longitudinally.

The second cam assembly <NUM> may engage with the cam facing surface <NUM> of the seal <NUM> in a comparable manner to the first cam assembly <NUM> engaging the cam facing surface <NUM> of the seal <NUM>. Thus, the cam assembly <NUM> can adjustably engage and seal <NUM> and compressing the cam facing surface <NUM> increases the sealing force of the gate facing surface <NUM> against the inlet facing surface <NUM> of the gate <NUM>.

During use a fastener <NUM>, such as a set screw, is inserted into the fastener passage <NUM> (<FIG>) and/or the fastener passage <NUM> (and engaged with the first cam component <NUM>, <NUM> to slide the first cam component <NUM>, <NUM> longitudinally. Sliding the first cam component <NUM> longitudinally allows the sealing force of the seal <NUM> to be adjusted. For example, sliding the first cam component <NUM>, <NUM> longitudinally in a direction toward the fastener passage <NUM>, <NUM> may increase the sealing force exerted on the seal <NUM>. Thus, sliding the first cam component <NUM>, <NUM> longitudinally in a toward the fastener passage <NUM>, <NUM> may decrease the sealing force exerted on the seal <NUM>.

Turning now to <FIG> and <FIG>, an exemplary embodiment of the gate valve assembly is shown at <NUM>. The gate valve assembly <NUM> is substantially the same as the above-referenced gate valve assembly <NUM>, and consequently the same reference numerals but indexed by <NUM> are used to denote structures corresponding to similar structures in the gate valve assemblies. In addition, the foregoing description of the gate valve assembly <NUM> is equally applicable to the gate valve assembly <NUM> except as noted below. Moreover, it will be appreciated upon reading and understanding the specification that aspects of the gate valve assemblies <NUM>, <NUM> may be substituted for one another or used in conjunction with one another where applicable.

The gate valve assembly <NUM> includes a valve body <NUM> having an inlet (not shown) an outlet (not shown), a gate <NUM>, and a seal assembly <NUM>. The gate <NUM> is disposed within and slidable within the valve body <NUM> to open or close the gate valve assembly <NUM>.

The seal assembly <NUM> may include a seal <NUM> that extends along one or both longitudinal axes L<NUM>, L<NUM>. The longitudinal axes L<NUM>, L<NUM> are perpendicular to the normal axis (not shown) and extend along the gate <NUM> such that the gate <NUM> slides against the seal <NUM> when the gate slides between the open position and the closed position.

The seal assembly <NUM> may include the first cam <NUM>, <NUM> and/or the second cam <NUM>, <NUM>, as well as the seal <NUM>, which extends along the longitudinal axis L<NUM> and/or longitudinal axis L<NUM>. The seal assembly <NUM> may be placed into the valve body <NUM> prior to assembly of the gate valve assembly <NUM>.

The wedging elements <NUM>, <NUM> operates similarly to the wedging elements <NUM>, <NUM> for providing force along the lateral axis Z in response to longitudinal force exerted against the cam assemblies <NUM>, <NUM>. Because the wedging element operates via the interaction of cam surfaces, the wedging elements alternatively is referred to as a cam assembly <NUM>, <NUM>.

The cam assembly <NUM>, similar to the cam assembly <NUM>, may include a first cam component <NUM> and a second cam component <NUM>. The first cam component <NUM> may include a plurality of cam surfaces <NUM> that are longitudinally aligned. Thus, the first cam component <NUM> may be one-piece in contrast to the plurality of first cam components <NUM> of the cam assembly <NUM> of <FIG>. The first cam component <NUM> being one-piece reduces assembly components and allows for easier assembly of the cam assembly <NUM>.

The second cam component <NUM>, similarly, may include a plurality of second surfaces <NUM> that are longitudinally aligned. Thus, the second cam component <NUM> may be one-piece in contrast to the plurality of second cam components <NUM> of the cam assembly <NUM> of <FIG>. The cam component <NUM> being one-piece allows for easier assembly of the cam assembly <NUM>.

For example, four first second surfaces <NUM> and four cam surfaces <NUM> may be longitudinally aligned side by side, respectively. Multiple longitudinally aligned second surfaces <NUM> and cam surfaces <NUM> allows each cam component <NUM>, <NUM> to have a thicker lateral length compared to one longitudinally extending second surface or cam surface cam extending the entire longitudinal length of the aligned cam components <NUM>, <NUM>. In an embodiment, only a single second surface and a single cam surface are provided.

The second cam component <NUM> may be fixed relative to the valve body <NUM>. A longitudinal end of the second cam component <NUM> may abut either the valve body <NUM> or another second cam component <NUM> to prevent longitudinal movement. In an embodiment, the second cam component and the valve body are one-piece. In another embodiment, the second cam component is longitudinally slidable relative to the valve body.

The second cam component <NUM> may have a valve body surface <NUM> and a plurality of second surfaces <NUM>, opposite the valve body surface <NUM>. The valve body surface <NUM> may engage the valve body <NUM>, and each second surface <NUM> may engage the corresponding cam surface <NUM> of the first cam component <NUM>.

The valve body surface <NUM> extends longitudinally along the cam surfaces <NUM> and may be generally planar and generally parallel with the normal axis and the longitudinal axis L<NUM>. In an embodiment, the valve body surface is oriented in any other suitable manner. For example, the valve body surface may be inclined relative to the inlet facing surface to allow the second cam component to be fixed relative to the valve body.

A longitudinal end of the second cam component <NUM> adjacent a fastener passage <NUM> in the valve body <NUM> may abut a ledge in the valve body <NUM>. The longitudinal end adjacent the fastener passage <NUM> may have a lateral thickness less than the corresponding ledge and an opposite end of the second cam component <NUM>. As illustrated, the end of the second cam component <NUM> adjacent the fastener passage <NUM> is offset from the fastener passage <NUM>. Offsetting the fastener passage <NUM> allows the fastener to extend toward the first cam component <NUM> without abutting the second cam component <NUM>.

The first cam component <NUM> is slidable relative to the second cam component <NUM> to perform a wedging action against the cam facing surface <NUM> of the inlet seal portion <NUM>. Each first cam component <NUM> may include the cam surface <NUM> for engaging the second cam component <NUM> and a seal surface <NUM> for engaging the inlet seal portion <NUM> laterally opposite the cam surface <NUM>.

The single-piece nature of first cam component <NUM> allows each each cam surface <NUM> to move together. For example, a fastener may be inserted into the fastener passage <NUM> and adjusted to move the adjacent first cam component <NUM> and corresponding cam surface <NUM>, which translates each cam surface <NUM> at the same time toward and possibly into a fastener passage <NUM>.

In an embodiment, the first cam component is fixed relative to the valve body and the second cam component moves longitudinally such that the second surface of the second cam component exerts compressive force as a function of how far it moves longitudinally.

The cam assembly <NUM>, similar to the cam assembly <NUM>, may include a first cam component <NUM> and a second cam component <NUM>. The cam component <NUM> may include a plurality of cam surfaces <NUM> that are longitudinally aligned. Thus, the cam component <NUM> may be one-piece in contrast to the plurality of cam components <NUM> of the cam assembly <NUM> of <FIG>. The cam component <NUM> being one-piece reduces assembly components and allows for easier assembly of the cam assembly <NUM>.

The first cam component <NUM> is slidable relative to the second cam component <NUM> to perform a wedging action against the cam facing surface <NUM> of the outlet seal portion <NUM>. Each first cam component <NUM> may include the cam surface <NUM> for engaging the second cam component <NUM> and a seal surface <NUM> for engaging the outlet seal portion <NUM> laterally opposite the cam surface <NUM>.

The single-piece nature of first cam component <NUM> allows each cam surface <NUM> to move together. For example, a fastener may be inserted into the fastener passage <NUM> and adjusted to move the adjacent first cam component <NUM> and corresponding cam surface <NUM>, which translates each cam surface <NUM> at the same time toward and possibly into a fastener passage <NUM>.

Turning now to <FIG>, an exemplary embodiment of the gate valve assembly is shown at <NUM>. The gate valve assembly <NUM> is substantially the same as the above-referenced gate valve assembly <NUM>. In addition, the foregoing description of the gate valve assembly <NUM> is equally applicable to the gate valve assembly <NUM> except as noted below. Moreover, it will be appreciated that aspects of the gate valve assemblies may be substituted for one another or used in conjunction with one another where applicable.

Referring initially to <FIG>, the gate valve assembly <NUM> is illustrated. The gate valve assembly <NUM> includes a valve body <NUM>, a gate <NUM>, and a seal assembly <NUM>. The gate <NUM> is disposed within and slidable within the valve body <NUM> to open or close the gate valve assembly <NUM>.

The seal assembly <NUM> may include a seal <NUM> with side seal portions <NUM>, <NUM>, which include lateral recesses <NUM>. The lateral recesses <NUM> allow a fastener <NUM> or a fastener <NUM> to translate the first cam component <NUM> or second cam component <NUM> without interfering with side seal portions <NUM>, <NUM> of the seal <NUM>.

Each fastener <NUM>, <NUM> may engage a fastener passage <NUM>, <NUM>, <NUM>, <NUM> to longitudinally force a corresponding cam assembly <NUM>, <NUM> to exert more or less force against the seal <NUM>. The fastener passages <NUM>, <NUM>, <NUM>, <NUM> may be inwardly threaded for engaging the fasteners <NUM>, <NUM>.

As shown in <FIG>, the fastener <NUM> may be self-adjusting. For example, the fastener <NUM> may be a spring pin assembly. The fastener <NUM> may include a body <NUM> that forms threading <NUM> and the fastener may include a piston <NUM> that is longitudinally extendable away from the body <NUM>.

For example, while in the extended state shown in <FIG>, the piston <NUM> may resiliently resist retraction longitudinally into the body <NUM>. From a retracted position, the piston <NUM> may be extended away from the body <NUM>. As the piston <NUM> extends longitudinally from the body <NUM>, the piston <NUM> may exert a longitudinal force against the cam assembly <NUM>, as shown in <FIG>.

Turning to <FIG>, the fastener <NUM> is illustrated in an unsecured position where the fastener <NUM> is not exerting any longitudinal biasing force against the first cam component <NUM>.

The valve body <NUM> may include fastener passage <NUM> for engaging radially outward threading <NUM> of the fastener <NUM>. The body <NUM> may define a central passage <NUM>, which may be cylindrical and may extend from a longitudinal end of the body <NUM> to allow extension and retraction of the piston <NUM>.

The fastener <NUM> may also include a resilient member <NUM> disposed within the central passage <NUM> of the body <NUM>. The resilient member <NUM> may abut an internal longitudinally facing surface of the body <NUM> and an opposite facing surface of the piston <NUM> to resist longitudinal movement of the piston <NUM> into the body <NUM>. <FIG> illustrates the resilient member <NUM> in a neutral state, and thus not providing any longitudinal biasing force against the body <NUM> or the piston <NUM>.

The central passage <NUM> allows the resilient member <NUM> to longitudinally compress and de-compress as the piston <NUM> engages the first cam component <NUM> of the cam assembly <NUM> while the body <NUM> moves longitudinally relative to the piston <NUM>.

Any of the fasteners <NUM>, <NUM> may be self-adjusting. When the fastener <NUM> is self-adjusting the fastener <NUM> may exert a longitudinal force against the first cam component <NUM> to exert a compressive lateral force against the seal <NUM> if the seal reduces in thickness. As the lateral thickness of an inlet seal portion <NUM> of the seal <NUM> reduces, the lateral compressive force exerted on the inlet seal portion <NUM> may reduce. As the first cam component <NUM> moves longitudinally relative to the body <NUM>, the lateral compressive force from the first cam component <NUM> against the seal <NUM> may increase, as discussed above. The increase of compressive force from the first cam component <NUM> may at least partially counteract the reduction of compressive force due to the reduced lateral thickness of the inlet seal portion <NUM>.

For example, the piston <NUM> may initially abut the first cam component <NUM> after initial assembly, as shown in <FIG>. As the seal <NUM> reduces in thickness, the resilient member <NUM> may urge the piston <NUM> longitudinally to continue to engage the first cam component <NUM> to exert a lateral force against the seal <NUM> as the first cam component <NUM> moves longitudinally relative to the body <NUM>.

<FIG> illustrates the fastener <NUM> in a secured position where the piston <NUM> is engaged with the first cam component <NUM> and receded into the central passage <NUM> to compress the resilient member <NUM>. The piston <NUM> is moveable relative to the body <NUM> to self-adjust the first cam component <NUM> when the seal <NUM> reduces in lateral thickness.

If desired, the fastener <NUM> may be in an extended secured position, as illustrated in <FIG>, where the piston <NUM> is fully recessed into the central passage <NUM> and the body <NUM> is longitudinally displacing the first cam component <NUM> to exert an additional lateral compressive force upon the seal <NUM>. The longitudinally opposite fastener <NUM> in the fastener passage <NUM> (shown in <FIG>) may be longitudinally recessed to accommodate the longitudinal displacement of the first cam component <NUM>, or to accommodate future potential longitudinal displacement of the first cam component <NUM> away from the fastener <NUM>.

Claim 1:
A gate valve assembly (<NUM>/<NUM>/<NUM>) comprising:
a valve body (<NUM>/<NUM>) having an inlet (<NUM>) and an outlet (<NUM>);
a gate (<NUM>/<NUM>) disposed within the valve body (<NUM>/<NUM>) and slidably connected to the valve body (<NUM>/<NUM>) such that the gate (<NUM>/<NUM>) slides along a normal axis (N) between an open position to a closed position, wherein in the closed position the inlet (<NUM>) is fluidly disconnected from the outlet (<NUM>);
a seal (<NUM>/<NUM>) having a longitudinal axis (L<NUM>/L<NUM>) perpendicular to the normal axis (N) and extending along the gate (<NUM>/<NUM>) such that the gate (<NUM>/<NUM>) slides against a first seal surface (<NUM>/<NUM>) of the seal (<NUM>/<NUM>) when the gate (<NUM>/<NUM>) slides between the open position and the closed position; and
a wedging element (<NUM>, <NUM>/<NUM>, <NUM>) abutting a second seal surface (<NUM>/<NUM>) of the seal (<NUM>/<NUM>) opposite the first seal surface (<NUM>/<NUM>);
wherein the wedging element (<NUM>, <NUM>/<NUM>, <NUM>) comprises a front side for engaging the second seal surface (<NUM>/<NUM>) and a backside for engaging an opposite wedge surface such that movement of the wedging element (<NUM>, <NUM>/<NUM>, <NUM>) along the longitudinal axis (L<NUM>/L<NUM>) causes the wedging element (<NUM>, <NUM>/<NUM>, <NUM>) to exert a force against the seal along a lateral axis (Z) perpendicular to the longitudinal axis (L<NUM>/L<NUM>); and
characterized in that the seal (<NUM>/<NUM>) is a low drag seal comprising a main body portion defining the second seal surface (<NUM>/<NUM>) and a first leg (<NUM>) extends from the main body portion away from the second seal surface (<NUM>/<NUM>), wherein the first leg (<NUM>) has a concave portion (<NUM>) at an end of the first leg (<NUM>) and opposite the second seal surface (<NUM>/<NUM>).