Patent Description:
Pipes or conduits have traditionally been connected by welding and/or soldering them together using a torch. Soldering pipe fittings can be time-consuming and labor intensive. In recent years, push-fit technology has been employed with piping systems to reduce the time involved in soldering joints. Push-fit methods require minimal knowledge of pipe fittings and involve far fewer materials than soldering. An example of a push-fit pipe fitting is disclosed in <CIT>.

According to a first aspect of the present disclosure, in accordance with the invention, there is provided a fitting that includes a housing defining a bore having a first open end configured for receipt of a pipe or conduit. The bore of the housing at the first open end includes a first threaded section, a first annular shoulder located inboard from the first threaded section that extends radially inward, and a second annular shoulder located inboard from the first annular shoulder that extends radially inward. A grip ring having a plurality of flexible teeth is positioned within the housing and is configured to be seated against the second annular shoulder, wherein the flexible teeth are configured to grip an exterior surface of the pipe or conduit. A bonnet is seated against the first annular shoulder that has an exterior threaded surface that is configured to mate with the first threaded section of the bore. A bonnet washer is positioned between the grip ring and the bonnet, and a pair of seal members are positioned between the bonnet washer and the bonnet that are configured to sealingly engage with the exterior surface of the pipe or conduit.

The first annular shoulder includes an annular nub that extends axially outward therefrom, wherein the annular nub is configured to deform when bonnet is seated against the first annular shoulder.

According to the first aspect, the bonnet may include an interior surface having a first cylindrical section that defines a first diameter, a second cylindrical section located inboard from the first cylindrical section that defines a second diameter that is greater than the first diameter, and an annular surface that connects the first cylindrical section and the second cylindrical section, and the pair of seal members may be positioned in the second cylindrical section and seated between the bonnet washer and the annular surface.

According to the first aspect, the bonnet may include a third cylindrical section that is connected to the second cylindrical section by another annular surface that is configured as a seat for the bonnet washer.

According to the first aspect, the grip ring may include an annular lip that includes a plurality of spaced-apart circumferential sections, wherein each circumferential section includes a first end and a second end.

According to the first aspect, each tooth of the grip ring may include a first leg that extends outward from the first end and a second leg that extends outward from the second end, wherein a distal end of each of the first and second legs defines a biting surface that is configured to bite the exterior surface of the pipe or conduit.

According to the first aspect, a connection leg may connect the first and second legs, wherein the connection leg includes a radiused surface that connects each of the biting surfaces.

According to the first aspect, the pair of sealing members may be positioned upstream from the grip ring.

According to the first aspect, the bonnet washer may include an axially inwardly extending wedge that extends toward the grip ring.

According to the first aspect, the bore may include a second open end opposite to the first open end that is configured for receipt of another pipe or conduit that includes a nipple, wherein the second open end has a second threaded section and an angled surface located inboard from the second threaded section, and a conically-shaped seal may be seated against the angled surface.

According to a second aspect of the present disclosure, which is not in accordance with the invention, there is provided a fitting that includes a housing defining a bore having a first open end configured for receipt of a pipe or conduit. The bore of the housing at the first open end includes a first threaded section, a first annular shoulder located inboard from the first threaded section that extends radially inward, a first axially extending surface that extends inboard from the first annular shoulder, a second annular shoulder located inboard from the first axially extending surface that extends radially inward, a second axially extending surface that extend inboard from the second annular shoulder, and a radially inwardly extending tapered surface located inboard from the second axially extending surface. A grip ring having a plurality of teeth is positioned within the housing and seated against the second annular shoulder, wherein the teeth are configured to grip an exterior surface of the pipe or conduit and are flexible in a direction toward the radially inwardly extending tapered surface. A bonnet is seated against the first annular shoulder and has an exterior threaded surface that is configured to mate with the first threaded section of the bore. A bonnet washer is seated against the bonnet, and positioned between the grip ring and the bonnet. At least one seal member is positioned between the bonnet washer and the bonnet that is configured to sealingly engage with the exterior surface of the pipe or conduit. The first annular shoulder includes an annular nub that extends axially outward therefrom in a direction back toward the first threaded section. The annular nub is configured to deform when the bonnet is seated against the first annular shoulder and form a crush seal between the first annular shoulder and the bonnet.

According to the second aspect, the bonnet may include an interior surface having a first cylindrical section that defines a first diameter, a second cylindrical section located inboard from the first cylindrical section that defines a second diameter that is greater than the first diameter, and an annular surface that connects the first cylindrical section and the second cylindrical section, and the at least one seal member is positioned in the second cylindrical section and seated between the bonnet washer and the annular surface.

According to the second aspect, the bonnet may include a third cylindrical section that is connected to the second cylindrical section by another annular surface that is configured as a seat for the bonnet washer.

According to the second aspect, the grip ring may include an annular lip that includes a plurality of spaced-apart circumferential sections, wherein each circumferential section includes a first end and a second end.

According to the second aspect, each tooth of the grip ring may include a first leg that extends outward from the first end and a second leg that extends outward from the second end, and a distal end of each of the first and second legs may define a biting surface that is configured to bite the exterior surface of the pipe or conduit.

According to the second aspect, a connection leg may connect the first and second legs, wherein the connection leg may include a radiused surface that connects each of the biting surfaces.

According to the second aspect, the at least one sealing member may be positioned upstream from the grip ring.

According to the second aspect, the bonnet washer may include an axially inwardly extending wedge that extends toward the grip ring.

According to the second aspect, a pair of seal members may be positioned between the bonnet washer and the bonnet that are configured to sealingly engage with the exterior surface of the pipe or conduit.

According to the second aspect, the bore may include a second open end opposite to the first open end that is configured for receipt of another pipe or conduit that includes a nipple. The second open end may have a second threaded section and an angled surface located inboard from the second threaded section, and a conically-shaped seal may be seated against the angled surface.

The description and specific examples in this summary are intended for purposes of illustration only.

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations.

It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the invention, which is defined by the appended claims.

<FIG>, <FIG>, and <FIG> illustrate a fitting <NUM> configured to connect a first pipe or conduit <NUM> to a second pipe or conduit <NUM> (<FIG>). In the illustrated embodiment, fitting <NUM> includes a body or housing <NUM>, a pair of grip rings <NUM>, a pair of bonnet washers <NUM>, two pairs of sealing members <NUM>, and a pair of bonnets <NUM>.

Housing <NUM> includes a first end <NUM> configured for receipt of first pipe <NUM> and a second end <NUM> configured for receipt of second pipe <NUM>. In the illustrated embodiment, first end <NUM> and second end <NUM> are flared. A connection section <NUM> extends between first end <NUM> and second end <NUM>. Inasmuch as first end <NUM> and second <NUM> are flared, a diameter D1 of first and second ends <NUM>, <NUM> is greater than a diameter D2 of connection section <NUM>. While the diameter D1 of first and second ends <NUM> and <NUM> is the same in <FIG>, it should be understood that the first and second ends <NUM> and <NUM> can have different diameters so that pipes <NUM> and <NUM> that are coupled to the first and second ends <NUM> and <NUM>, respective, may have different diameters. Regardless whether first and second pipes <NUM> and <NUM> have the same or different diameters, when first and second pipes <NUM> and <NUM> are coupled to fitting <NUM>, fluid communication between first and second pipes <NUM> and <NUM> is enabled.

Housing <NUM> may be formed of a rigid material such as a metal material. Example metal materials that may be used to form housing <NUM> include brass, copper, and other metal materials known to those skilled in the art. Housing <NUM> includes an exterior surface <NUM> and an interior surface <NUM>, with interior surface <NUM> defining a bore <NUM> that extends between first end <NUM> and second end <NUM> along axis X. At first and second ends <NUM> and <NUM>, bore <NUM> includes a threaded surface <NUM> that is configured to mate with a threaded end <NUM> of bonnet <NUM>. A first annular shoulder <NUM> that extends radially inward toward axis X is located inboard (i.e., in a direction toward connection surface <NUM>) from threaded section <NUM>. An annular nub <NUM> is formed on first annular shoulder <NUM> that extends axially outward from shoulder <NUM> in a direction back toward the threaded surface <NUM>. Nub <NUM>, which is shown in greater detail in <FIG>, is a sealing feature that is configured to deform when bonnet <NUM> is mated with bore <NUM>. In other words, nub <NUM> is a crush seal that assists in ensuring a leak-proof seal when pipe <NUM> or <NUM> is mated with fitting <NUM> and secured by bonnet <NUM>.

Inboard from first annular shoulder <NUM> is a second annular shoulder <NUM>. A first axially extending surface <NUM> connects first annular shoulder <NUM> to second annular shoulder <NUM>. Second annular shoulder <NUM> is configured to act as a seat <NUM> for an annular lip <NUM> of grip ring <NUM>.

Inboard from second annular shoulder <NUM> is a radially inwardly extending tapered surface <NUM>. A second axially extending surface <NUM> extends between second annular shoulder <NUM> and tapered surface <NUM>. Tapered surface <NUM> is angled to account for the angled teeth <NUM> that extend radially inwardly from the annular lip <NUM> of grip ring <NUM>. That is, as will be described in more detail later, when a pipe <NUM> or <NUM> is inserted into fitting <NUM>, an exterior surface <NUM> of the pipe <NUM> or <NUM> will contact the teeth <NUM> and bend the teeth <NUM> in the inboard direction. Tapered surface <NUM> permits the teeth <NUM> to bend without damage thereto. That is, as teeth <NUM> bend in the inboard direction when pipe <NUM> or <NUM> is inserted into fitting <NUM>, there is the potential for teeth <NUM> to contact tapered surface <NUM>. Because surface <NUM> is tapered, however, any contact between the tapered surface <NUM> and the teeth <NUM> will not damage the teeth <NUM> such that a reliable grip between the teeth <NUM> and the exterior surface <NUM> of the pipe <NUM> or <NUM> will be maintained. A cylindrical surface <NUM> is located inboard from tapered surface <NUM>, which is located at connection section <NUM>. Cylindrical surface <NUM> may include an annular radially inwardly extending protrusion <NUM> that acts as a stop <NUM> that may be abutted with a terminal end <NUM> of the pipe <NUM> or <NUM> when pipe <NUM> or <NUM> is inserted into fitting <NUM>.

Now referring to <FIG>, grip ring <NUM> will be described in more detail. As noted above, grip ring <NUM> includes an annular lip <NUM> and a plurality of teeth <NUM>. In the illustrated embodiment, annular lip <NUM> includes a plurality of spaced-apart circumferential sections <NUM> rather than being formed as a continuous annular ring. Circumferential sections <NUM> are separated by spaces <NUM>. While grip ring <NUM> preferably includes circumferential sections <NUM> separated by spaces <NUM>, it should be understood that annular lip <NUM> may be continuously formed without departing from the scope of the present disclosure.

Circumferential sections <NUM> include a first end <NUM> and a second end <NUM>. Each tooth <NUM> includes a first leg <NUM> that extends outward from first end <NUM> and a second leg <NUM> that extend outward from second end <NUM>. First and second legs <NUM>, <NUM> each include a proximal end <NUM> connected to circumferential section <NUM> and a distal end <NUM> that defines a biting surface <NUM> that is configured to "bite" the exterior surface <NUM> of pipe <NUM> or <NUM>. A connection leg <NUM> connects first leg <NUM> and second leg <NUM>. Connection leg <NUM> includes a linear surface <NUM> that faces annular lip <NUM> and a radiused surface <NUM> that faces away from annular lip <NUM>. Radiused surface <NUM> connects the biting surfaces <NUM> that are formed at the distal end <NUM> of each of the first leg <NUM> and the second leg <NUM>. Because each tooth <NUM> includes a pair of biting surfaces <NUM>, additional touch points between the grip ring <NUM> and the exterior surface <NUM> of pipe <NUM> or <NUM> are created that improves the retention strength of the grip ring <NUM>.

It should be understood that in smaller-diameter fittings <NUM> that are configured for use with smaller-diameter pipes <NUM> or <NUM>, each component of the fitting <NUM> is smaller in size, including grip ring <NUM>. In these instances, grip ring <NUM> may not necessarily include a radiused surface <NUM> that connects a pair of biting surfaces <NUM>. In contrast, first and second legs <NUM>, <NUM> may be angled toward each other to form a substantially triangular-formed tooth (not shown) and an apex of the tooth defines the biting surface <NUM>. Notwithstanding the lack of a radiused surface <NUM>, the linear surface <NUM> may remain between the legs <NUM> and <NUM> if desired.

Again referring to <FIG>, <FIG>, and <FIG>, bonnet washer <NUM> is positioned between grip ring <NUM> and bonnet <NUM>. Bonnet washer <NUM> includes a ring-shaped body <NUM> having a first annular surface <NUM> that faces bonnet <NUM> and is configured be engaged with bonnet <NUM>, a second annular surface <NUM> that faces grip ring <NUM> and is configured to engage with annular lip <NUM> of grip ring <NUM>, and a cylindrical surface <NUM> that is configured to act as a bearing surface for exterior surface <NUM> of pipe <NUM> or <NUM> when pipe <NUM> or <NUM> is mated with fitting <NUM>. An axially inwardly extending wedge <NUM> extends outward from second annular surface <NUM>. Wedge <NUM> is defined by a portion of cylindrical surface <NUM> and an angled surface <NUM> that is configured to contact teeth <NUM> of grip ring <NUM>.

Still referring to <FIG>, <FIG>, and <FIG> bonnet <NUM> is generally a cylindrical member having an outer surface <NUM> that is threaded at threaded end <NUM> such it may threadingly engage with threaded surface <NUM> of housing <NUM>. Extending outward from threaded end <NUM> is an annular protrusion <NUM> having a plurality of gripping surfaces <NUM> that are configured to be engaged with a wrench or some other type of tool to rotate bonnet <NUM> relative to housing <NUM> to ensure a tight threaded connection between bonnet <NUM> and housing <NUM>.

Bonnet <NUM> includes an interior surface <NUM>. Interior surface <NUM> includes a first cylindrical section <NUM> as it extends from annular protrusion <NUM> in a direction toward sealing members <NUM> having a diameter D3. Interior surface <NUM> also includes a second cylindrical section <NUM> having a diameter D4 that is greater than the diameter D3. An annular surface <NUM> connects first cylindrical section <NUM> and second cylindrical section <NUM> that serves as a seat or abutment surface for sealing members <NUM>.

Interior surface <NUM> includes a third cylindrical section <NUM> that is connected to second cylindrical surface <NUM> by another annular surface <NUM>, which serves as a seat or abutment surface for bonnet washer <NUM>. When bonnet washer <NUM> is seated against annular surface <NUM>, seal members <NUM> are located between first annular surface <NUM> of bonnet washer <NUM> and annular surface <NUM> of bonnet <NUM>, which prevents or at least substantially minimizes sealing members <NUM> from being displaced during engagement of pipe <NUM> or <NUM> with fitting <NUM>. Although not necessarily required, bonnet <NUM> may also include a fourth cylindrical section <NUM> that is connected to third cylindrical section <NUM> by an annular sealing surface <NUM>.

Annular sealing surface <NUM> is configured to engage with nub <NUM> and deform nub <NUM> when bonnet <NUM> is fully engaged with housing <NUM>. As noted above, when nub <NUM> is deformed, a seal is developed between bonnet <NUM> and housing <NUM>. The seal developed between bonnet <NUM> and housing <NUM> is a beneficial aspect of the present disclosure because a separate sealing member or gasket is not required, which reduces the number of parts and costs associated with manufacturing fitting <NUM>. In addition, the seal that is developed through deformation of nub <NUM> assists with increasing the sealing ability of the fitting <NUM> when fitting <NUM> is used in, for example, a heating or cooling application where the fluid that passes through the fitting <NUM> is a refrigerant. In this regard, various refrigerants may include molecules that are smaller in comparison to other fluids such as, for example, water. The use of the seal developed by crushing nub <NUM> in combination with sealing members <NUM> prevents or at least substantially minimizes the small molecules of the refrigerant from escaping the fitting <NUM> during use thereof.

In addition, with respect to the sealing ability provided by fitting <NUM>, it should be noted that sealing members <NUM> are located upstream from grip ring <NUM>. This is a beneficial configuration in comparison to a configuration where the sealing member(s) are located downstream from the grip ring <NUM> from the standpoint that when pipe <NUM> or <NUM> is inserted into fitting <NUM>, the exterior surface <NUM> of pipe <NUM> or <NUM> will not be scratched or damaged by the grip ring <NUM> before coming into sealing contact with the sealing member(s). When the exterior surface <NUM> of pipe <NUM> or <NUM> is scratched or damaged by the teeth of grip ring <NUM>, a fluid-tight seal between the sealing member(s) and the exterior surface <NUM> of pipe <NUM> or <NUM> cannot necessarily be ensured. Thus, because sealing members <NUM> are placed in sealing engagement with exterior surface <NUM> of pipe <NUM> or <NUM> before the exterior surface <NUM> is gripped by grip ring <NUM>, a fluid-tight seal between exterior surface <NUM> and sealing members <NUM> can be formed more reliably.

To assemble fitting <NUM>, grip ring <NUM> is first inserted into housing <NUM> and annular lip <NUM> is seated against second annular shoulder <NUM>. Bonnet washer <NUM> may then be inserted into housing <NUM> and seated against grip ring <NUM>. Sealing members <NUM> may then be seated against annular surface <NUM> of bonnet <NUM>, and bonnet <NUM> threadingly engaged with housing <NUM>. During engagement between bonnet <NUM> and housing <NUM>, bonnet washer <NUM> will seat against annular surface <NUM> and sealing members <NUM> will be properly located between bonnet washer <NUM> and bonnet <NUM>. As bonnet <NUM> is tightly engaged with housing <NUM>, nub <NUM> will deform and create a seal between housing <NUM> and bonnet <NUM> and complete formation of fitting <NUM> will be achieved. Pipe <NUM> or <NUM> may then be inserted into housing <NUM>.

As pipe <NUM> or <NUM> is inserted into housing <NUM>, pipe <NUM> or <NUM> will slide past sealing members <NUM> and reach bonnet washer <NUM>. While cylindrical surface of bonnet washer <NUM> acts as a bearing surface for pipe <NUM> or <NUM>, bonnet washer <NUM> may be slightly advanced forward toward grip ring 18As pipe <NUM> or <NUM> reaches teeth <NUM>, biting surfaces <NUM> of teeth <NUM> will engage the exterior surface <NUM> of pipe <NUM> or <NUM>, but permit pipe <NUM> or <NUM> to advance until reaching protrusion <NUM> where pipe <NUM> or <NUM> can no longer advance into housing <NUM>. Due to contact between sealing members <NUM> and exterior surface <NUM> of pipe <NUM> or <NUM>, and the seal created due to deformation of nub <NUM>, a leak-proof seal is achieved between pipe <NUM> or <NUM> and fitting <NUM>.

As noted above, when biting surfaces <NUM> of teeth <NUM> engage exterior surface <NUM> of pipe <NUM> or <NUM>, pipe <NUM> or <NUM> is permitted to advance until reaching protrusion <NUM>. This is because teeth <NUM> are angled in a direction toward protrusion <NUM> (<FIG>). Teeth <NUM> being angled toward protrusion <NUM> also assists in preventing pipe <NUM> or <NUM> from being removed from fitting <NUM> because if a force is exerted on pipe <NUM> or <NUM> to pull pipe <NUM> or <NUM> rearwardly or if a pressure within fitting <NUM> reaches an extent that attempts to push pipe <NUM> or <NUM> rearwardly, the teeth <NUM> will further bite into exterior surface <NUM> of pipe <NUM> or <NUM>. It should be understood, however, that when pipe <NUM> or <NUM> is formed of a relatively soft material such as copper or a polymeric material, the exterior surface <NUM> of pipe <NUM> or <NUM> can deform more easily. If a sufficient force is exerted on pipe <NUM> or <NUM> that is able to push or pull pipe <NUM> or <NUM> rearwardly, the teeth <NUM> may begin to deform by flattening out, which can cause teeth <NUM> to deform exterior surface <NUM> of pipe <NUM> or <NUM> radially inwardly.

If the force exerted on pipe <NUM> or <NUM> that pushes or pulls pipe <NUM> or <NUM> rearwardly continues to increase, there is the risk that teeth <NUM> may completely flatten out and deflect rearwardly to an extent that pipe <NUM> or <NUM> can be released from fitting <NUM>. Wedge <NUM> of bonnet washer <NUM> is designed to interfere with the ability of teeth <NUM> to flatten out and/or deflect rearwardly. As best shown in <FIG>, there is some space between wedge <NUM> and teeth <NUM> of grip ring <NUM> that enables teeth <NUM> to deform and bite deeper into exterior surface <NUM> of pipe <NUM> or <NUM>. Due to wedge <NUM> of bonnet washer <NUM>, however, the teeth <NUM> are prevented from fully flattening out or deflecting to prevent pipe <NUM> or <NUM> from being removed from fitting <NUM>. Wedge <NUM>, therefore, is configured to act as a support feature for teeth <NUM> during use of fitting <NUM>.

<FIG>, <FIG>, and <FIG> illustrate a fitting <NUM> having a linear axis X. The present disclosure should not be limited thereto. In this regard, as shown in <FIG>, it should be understood that the teachings of the present disclosure are equally applicable to, for example, an elbow fitting <NUM>. Elbow fitting <NUM> is substantially similar to fitting <NUM> described above, but housing <NUM> is L-shaped rather than having an entirely linear axis X like fitting <NUM>. Specifically, connection section <NUM> of elbow fitting <NUM> is shaped to account for the L shape. Inasmuch as the remaining features of elbow fitting <NUM> are the same as those described above relative to fitting <NUM>, further description thereof will be omitted.

Now referring to <FIG> and <FIG>, yet another fitting <NUM> according to the present disclosure is illustrated. Fitting <NUM> is similar to fittings <NUM> and <NUM> described above, but second end <NUM> is not designed for receipt of a pipe <NUM> or <NUM>. Rather, second end <NUM> is configured for receipt of a pipe having a nipple (not shown) that can provide a fluid to fitting <NUM>. Inasmuch as the first end <NUM> of the fitting <NUM> is the same as shown at, for example, <FIG> and described above, description thereof will be omitted.

Second end <NUM> of fitting <NUM> includes an interior threaded surface <NUM> that is configured to mate with a threaded surface (not shown) formed on a pipe including a nipple (not shown). Inboard from threaded surface <NUM> is a cylindrical section <NUM> that transitions to an angled surface <NUM>. Angled surface <NUM> serves as a seat <NUM> for a conically-shaped seal <NUM> that is designed to provide a fluid-tight seal when the conically-shaped nipple (not shown) is engaged therewith. Seal <NUM> may be formed of a metal material such as copper, or a polymeric material if desired. Although not required, fitting <NUM> may be provided with a protective cap <NUM> that must be removed from fitting <NUM> prior to the pipe including the nipple (not shown) being coupled to fitting <NUM>. Cap <NUM> may be formed of, for example, a polymeric material.

Claim 1:
A fitting (<NUM>), comprising:
a housing (<NUM>) defining a bore (<NUM>) having a first open end (<NUM>) configured for receipt of a pipe or conduit (<NUM>), the bore (<NUM>) of the housing (<NUM>) at the first open end (<NUM>) including a first threaded section (<NUM>), a first annular shoulder (<NUM>) located inboard from the first threaded section (<NUM>) that extends radially inward, and a second annular shoulder (<NUM>) located inboard from the first annular shoulder (<NUM>) that extends radially inward;
a grip ring (<NUM>) having a plurality of flexible teeth (<NUM>) positioned within the housing (<NUM>) and configured to be seated against the second annular shoulder (<NUM>), the flexible teeth (<NUM>)
being configured to grip an exterior surface (<NUM>) of the pipe or conduit (<NUM>);
a bonnet (<NUM>) configured to be seated against the first annular shoulder (<NUM>) and having an exterior threaded surface (<NUM>) that is configured to mate with the first threaded section (<NUM>) of the bore (<NUM>);
a bonnet washer (<NUM>) configured to be positioned between the grip ring (<NUM>) and the bonnet (<NUM>); and
a pair of seal members (<NUM>) positioned between the bonnet washer (<NUM>) and the bonnet (<NUM>) that are configured to sealingly engage with the exterior surface (<NUM>) of the pipe or conduit (<NUM>);
characterized in that the first annular shoulder (<NUM>) includes an annular nub (<NUM>) that extends axially outward therefrom, the annular nub (<NUM>) being configured to deform when the bonnet (<NUM>) is seated against the first annular shoulder (<NUM>).