Patent Description:
The present invention provides for ameliorating at least some of the disadvantages of the prior art. These and other advantages of the present invention will be apparent from the description as set forth below.

The present invention relates to an end cap assembly as defined in claim <NUM> as well as a filter as set out in claim <NUM> and a method for attaching an end cap assembly to a hollow cylindrical filter element as set out in claim <NUM>.

An embodiment of the invention as defined in claim <NUM> provides an end cap assembly comprising (a) a first connector element comprising at least two first connector snap arches, each of the at least two first connector snap arches including a snap tooth lock; and at least two first connector snap arms, each of the at least two first connector snap arms including a snap tooth; the first connector element having a central cavity closed off with a wall; (b) a second connector element comprising at least two second connector snap arches, each of the at least two second connector snap arches including a snap tooth lock; and at least two second connector snap arms, each of the at least two second connector snap arms including a snap tooth; the second connector element having a central opening, and an annular channel for receiving an end of a hollow cylindrical filter element; and, (c) a gasket arranged between the first connector element and the second connector element, the gasket having a central opening; wherein the first connector element and the second connector element are lockably engageable with each other when placed in contact with each other and axial force is applied such that each first connector snap tooth is retained in each respective second connector snap tooth lock, and each second connector snap tooth is retained in each respective first connector snap tooth lock. The first and the second connector element each include two walls, each wall having a hyperbolic paraboloid shape.

An end cap assembly according to another embodiment of the invention as defined in claim <NUM> comprises (a) a first connector element comprising at least two first connector snap arches, each of the at least two first connector snap arches including a snap tooth lock; and at least two first connector snap arms, each of the at least two first connector snap arms including a snap tooth; the first connector element having a central opening with a side wall having an internal thread; (b) a second connector element comprising at least two second connector snap arches, each of the at least two second connector snap arches including a snap tooth lock; and at least two second connector snap arms, each of the at least two second connector snap arms including a snap tooth; the second connector element having a central opening, and an annular channel for receiving an end of a hollow cylindrical filter element; and, (c) a gasket arranged between the first connector element and the second connector element, the gasket having a central opening; wherein the first connector element and the second connector element are lockably engageable with each other when placed in contact with each other and axial force is applied such that each first connector snap tooth is retained in each respective second connector snap tooth lock, and each second connector snap tooth is retained in each respective first connector snap tooth lock. The first and the second connector element each include two walls, each wall having a hyperbolic paraboloid shape.

The present invention provides a filter as defined in claim <NUM>, said filter comprises (a) a first connector element comprising at least two first connector snap arches, each of the at least two first connector snap arches including a snap tooth lock; and at least two first connector snap arms, each of the at least two first connector snap arms including a snap tooth; the first connector element having a central cavity closed off with a wall; (b) a second connector element comprising at least two second connector snap arches, each of the at least two second connector snap arches including a snap tooth lock; and at least two second connector snap arms, each of the at least two second connector snap arms including a snap tooth; the second connector element having a central opening, and an annular channel receiving an end of a hollow cylindrical filter element; (c) the hollow cylindrical filter element, having a first end and a second end; and, (d) a gasket arranged between the first connector element and the second connector element, the gasket having a central opening; wherein the first connector element and the second connector element are lockably engageable with each other when placed in contact with each other and axial force is applied such that each first connector snap tooth is retained in each respective second connector snap tooth lock, and each second connector snap tooth is retained in each respective first connector snap tooth lock. The first and the second connector element each include two walls, each wall having a hyperbolic paraboloid shape.

In another embodiment, a filter as defined in claim <NUM> comprises (a) a first connector element comprising at least two first connector snap arches, each of the at least two first connector snap arches including a snap tooth lock; and at least two first connector snap arms, each of the at least two first connector snap arms including a snap tooth; the first connector element having a central opening with a side wall having an internal thread; (b) a second connector element comprising at least two second connector snap arches, each of the at least two second connector snap arches including a snap tooth lock; and at least two second connector snap arms, each of the at least two second connector snap arms including a snap tooth; the second connector element having a central opening, and an annular channel receiving an end of a hollow cylindrical filter element; (c) the hollow cylindrical filter element, having a first end and a second end; and, (d) a gasket arranged between the first connector element and the second connector element, the gasket having a central opening; wherein the first connector element and the second connector element are lockably engageable with each other when placed in contact with each other and axial force is applied such that each first connector snap tooth is retained in each respective second connector snap tooth lock, and each second connector snap tooth is retained in each respective first connector snap tooth lock. The first and the second connector element each include two walls, each wall having a hyperbolic paraboloid shape.

A method of attaching an end cap to a filter element according to another embodiment of the invention comprises axially aligning (a) a first connector element comprising at least two first connector snap arches, each of the at least two first connector snap arches including a snap tooth lock; and at least two first connector snap arms, each of the at least two first connector snap arms including a snap tooth; the first connector element having a central cavity closed off with a wall; with (b) a second connector element comprising at least two second connector snap arches, each of the at least two second connector snap arches including a snap tooth lock; and at least two second connector snap arms, each of the at least two second connector snap arms including a snap tooth; the second connector element having a central opening, and an annular channel receiving an end of a hollow cylindrical filter element having a first end and a second end; wherein (c) a gasket is arranged between the first connector element and the second connector element, the gasket having a central opening; and, applying an axial force to the first connector element or the filter element such that each first connector snap tooth is retained in each respective second connector snap tooth lock, and each second connector snap tooth is retained in each respective first connector snap lock. The first and the second connector element each include two walls, each wall having a hyperbolic paraboloid shape.

A method of attaching an end cap to a filter element according to another embodiment of the invention comprises axially aligning (a) a first connector element comprising at least two first connector snap arches, each of the at least two first connector snap arches including a snap tooth lock; and at least two first connector snap arms, each of the at least two first connector snap arms including a snap tooth; the first connector element having a central opening with a side wall having an internal thread; with (b) a second connector element comprising at least two second connector snap arches, each of the at least two second connector snap arches including a snap tooth lock; and at least two second connector snap arms, each of the at least two second connector snap arms including a snap tooth; the second connector element having a central opening, and an annular channel receiving an end of a hollow cylindrical filter element having a first end and a second end; wherein (c) a gasket is arranged between the first connector element and the second connector element, the gasket having a central opening; and, applying an axial force to the first connector element or the filter element such that each first connector snap tooth is retained in each respective second connector snap tooth lock, and each second connector snap tooth is retained in each respective first connector snap lock. The first and the second connector element each include two walls, each wall having a hyperbolic paraboloid shape.

An embodiment of the invention provides an end cap assembly comprising (a) a first connector element comprising at least two first connector element snap arches, each of the at least two first connector element snap arches including a snap tooth lock; and at least two first connector element snap arms, each of the at least two first connector element snap arms including a snap tooth; the first connector element having a central cavity closed off with a wall; (b) a second connector element comprising at least two second connector element snap arches, each of the at least two second connector element snap arches including a snap tooth lock; and at least two second connector element snap arms, each of the at least two second connector element snap arms including a snap tooth; the second connector element having a central opening, and an annular channel for receiving an end of a hollow cylindrical filter element; and, (c) a gasket arranged between the first connector element and the second connector element, the gasket having a central opening; wherein the first connector element and the second connector element are lockably engageable with each other when placed in contact with each other and axial force is applied such that each first connector element snap tooth is retained in each respective second connector element snap tooth lock, and each second connector element snap tooth is retained in each respective first connector element snap tooth lock. The first and the second connector element each include two walls, each wall having a hyperbolic paraboloid shape.

An end cap assembly according to another embodiment of the invention comprises (a) a first connector element comprising at least two first connector element snap arches, each of the at least two first connector element snap arches including a snap tooth lock; and at least two first connector element snap arms, each of the at least two first connector element snap arms including a snap tooth; the first connector element having a central opening with a side wall having an internal thread; (b) a second connector element comprising at least two second connector element snap arches, each of the at least two second connector element snap arches including a snap tooth lock; and at least two second connector element snap arms, each of the at least two second connector element snap arms including a snap tooth; the second connector element having a central opening, and an annular channel for receiving an end of a hollow cylindrical filter element; and, (c) a gasket arranged between the first connector element and the second connector element, the gasket having a central opening; wherein the first connector element and the second connector element are lockably engageable with each other when placed in contact with each other and axial force is applied such that each first connector element snap tooth is retained in each respective second connector element snap tooth lock, and each second connector element snap tooth is retained in each respective first connector element snap tooth lock. The first and the second connector element each include two walls, each wall having a hyperbolic paraboloid shape.

In a typical embodiment, each connector element snap tooth includes a snap ramp.

In another embodiment, a filter comprises (a) a first connector element comprising at least two first connector element snap arches, each of the at least two first connector element snap arches including a snap tooth lock; and at least two first connector element snap arms, each of the at least two first connector element snap arms including a snap tooth; the first connector element having a central cavity closed off with a wall; (b) a second connector element comprising at least two second connector element snap arches, each of the at least two second connector element snap arches including a snap tooth lock; and at least two second connector element snap arms, each of the at least two second connector element snap arms including a snap tooth; the second connector element having a central opening, and an annular channel receiving an end of a hollow cylindrical filter element; (c) the hollow cylindrical filter element, having a first end and a second end; and, (d) a gasket arranged between the first connector element and the second connector element, the gasket having a central opening; wherein the first connector element and the second connector element are lockably engageable with each other when placed in contact with each other and axial force is applied such that each first connector element snap tooth is retained in each respective second connector element snap tooth lock, and each second connector element snap tooth is retained in each respective first connector element snap tooth lock. The first and the second connector element each include two walls, each wall having a hyperbolic paraboloid shape.

In another embodiment, a filter comprises (a) a first connector element comprising at least two first connector element snap arches, each of the at least two first connector element snap arches including a snap tooth lock; and at least two first connector element snap arms, each of the at least two first connector element snap arms including a snap tooth; the first connector element having a central opening with a side wall having an internal thread; (b) a second connector element comprising at least two second connector element snap arches, each of the at least two second connector element snap arches including a snap tooth lock; and at least two second connector element snap arms, each of the at least two second connector element snap arms including a snap tooth; the second connector element having a central opening, and an annular channel receiving an end of a hollow cylindrical filter element; (c) the hollow cylindrical filter element, having a first end and a second end; and, (d) a gasket arranged between the first connector element and the second connector element, the gasket having a central opening; wherein the first connector element and the second connector element are lockably engageable with each other when placed in contact with each other and axial force is applied such that each first connector element snap tooth is retained in each respective second connector element snap tooth lock, and each second connector element snap tooth is retained in each respective first connector element snap tooth lock. The first and the second connector element each include two walls, each wall having a hyperbolic paraboloid shape.

In some embodiments of the filter, one of the first or second ends of the hollow cylindrical filter element is received in the annular channel of the second connector element, and the other of the first or second ends of the hollow cylindrical filter element is received in an annular channel of an additional second connector element which is lockably engageable with an additional first connector element, or, one of the first or second ends of the hollow cylindrical filter element is received in the annular channel of the second connector element, and the other of the first or second ends of the hollow cylindrical filter element is connected to a conventional end cap.

A method of attaching an end cap to a filter element according to another embodiment of the invention comprises axially aligning (a) a first connector element comprising at least two first connector element snap arches, each of the at least two first connector element snap arches including a snap tooth lock; and at least two first connector element snap arms, each of the at least two first connector element snap arms including a snap tooth; the first connector element having a central cavity closed off with a wall; with (b) a second connector element comprising at least two second connector element snap arches, each of the at least two second connector element snap arches including a snap tooth lock; and at least two second connector element snap arms, each of the at least two second connector element snap arms including a snap tooth; the second connector element having a central opening, and an annular channel receiving an end of a hollow cylindrical filter element having a first end and a second end; wherein (c) a gasket is arranged between the first connector element and the second connector element, the gasket having a central opening; and, applying an axial force to the first connector element or the filter element such that each first connector element snap tooth is retained in each respective second connector element snap tooth lock, and each second connector element snap tooth is retained in each respective first connector element snap lock. The first and the second connector element each include two walls, each wall having a hyperbolic paraboloid shape.

A method of attaching an end cap to a filter element according to another embodiment of the invention comprises axially aligning (a) a first connector element comprising at least two first connector element snap arches, each of the at least two first connector element snap arches including a snap tooth lock; and at least two first connector s element nap arms, each of the at least two first connector element snap arms including a snap tooth; the first connector element having a central opening with a side wall having an internal thread; with (b) a second connector element comprising at least two second connector element snap arches, each of the at least two second connector element snap arches including a snap tooth lock; and at least two second connector element snap arms, each of the at least two second connector element snap arms including a snap tooth; the second connector element having a central opening, and an annular channel receiving an end of a hollow cylindrical filter element having a first end and a second end; wherein (c) a gasket is arranged between the first connector element and the second connector element, the gasket having a central opening; and, applying an axial force to the first connector element or the filter element such that each first connector element snap tooth is retained in each respective second connector element snap tooth lock, and each second connector element snap tooth is retained in each respective first connector element snap lock. The first and the second connector element each include two walls, each wall having a hyperbolic paraboloid shape.

A filter device according to an embodiment of the invention comprises an embodiment of at least one filter arranged in a housing having an inlet and an outlet and defining a fluid flow path between the inlet and the outlet with the filter arranged across the fluid flow path.

A method of filtration according to an embodiment of the invention comprises passing a fluid along the fluid flow path through embodiment of the filter device.

A variety of fluids can be processed using embodiment of the filter. In one embodiment, the filter device comprises a coalescer, coalescing water and/or oil (and in some embodiments, removing particulate matter) from the stream of fluid being processed.

Advantageously, separate filters having various filter element lengths can be produced in advance and shipped, providing a cost-effective option for obtaining different filters for different applications. Alternatively, or additionally, different filter element end caps can be bound to filter elements to provide more options for the resultant final filter and filter device.

Each of the components of the invention will now be described in more detail below, wherein like components have like reference numbers. In accordance with the illustrated embodiments the first and second connector elements have some of the same corresponding elements, and thus, those components have the same names.

As will be discussed in more detail below, the illustrated embodiments of the first connector elements 50A and 50A1, and the second connector elements 50B each have the following like components (reference numbers will be provided with the figure descriptions below):.

Two cylindrical walls projecting upwardly from the base, each wall having a hyperbolic paraboloid shape with an uppermost part, wherein the cylindrical walls have uniform acclivity. Each connector element includes, projecting upwardly from the base, a concentrically arranged crown including a snap tooth lock, extending in a circumferential direction forming a snap arch wherein the connector elements each also include a snap arm including a snap tooth preferably having a snap ramp, and a centering rib and a snap root. The presence of centering ribs, that are present between the outside of a snap arm and the inside of a crown, can be desirable in reducing or preventing radial sliding, e.g., coaxial dislocation of the two connector elements once connected or assembled. Preferably, each first connector element and each second connector element has at least two crowns each including a snap arches, and at least two snap arms.

After the first and second elements are brought together, positioned coaxially with the respect snap teeth aligned with the snap teeth locks, and with a gasket placed coaxially between the elements, axial force is applied and the respective snap arches are engaged and the snap arms are slightly flexed inwardly and the snap arches are slightly deflected outwardly, and the snap teeth pass over the snap arches into the snap teeth locks. The snap ramps pass over the snap arches and secure the snap teeth into the snap teeth locks, and spring back to their original configuration such that the snap arches retain the trailing edges of the snap teeth and prevent reverse axial action out of the snap teeth locks.

<FIG> show, respectively, top and bottom perspective views of a first connector element 50A of an open end cap assembly according to an embodiment of the invention, the first connector element having a central opening 51A with a side wall having an internal thread <NUM>. The presence of the central opening with an internal thread allows the connection to a threaded adapter and/or threaded filter housing. <FIG> also shows an optional collar <NUM> and optional collar support ribs <NUM>.

<FIG> shows, respectively, top and bottom perspective views of a first connector element 50A1 of a closed end cap assembly according to another embodiment of the invention, the first connector element having a central cavity <NUM> closed off with a wall <NUM> having an inner surface <NUM>' and an outer surface <NUM>". While the outer surface <NUM>" can have a variety of configuration, e.g., planar or substantially planar, <FIG> shows an optional raised portion <NUM>.

<FIG> and <FIG> show perspective views of filters <NUM> comprising the first connector elements 50A (<FIG>) and 50A1 (<FIG>) connected to the second connector element 50B, forming an assembled embodiment of a connector assembly <NUM>, wherein a filter element <NUM> having a first and a second end has one filter end bonded to an embodiment of the second connector element 50B, and the other filter end bonded to an end cap <NUM>. While <FIG> and <FIG> show an end cap <NUM> illustrated as a conventional end cap (that can be open or closed; typically, if connector element 50A1 is at one end of the filter, the conventional end cap <NUM> at the other end of the filter element is open) bonded to the other filter end, in other embodiments, embodiments of the connector assemblies are provided at both ends of the filter element. For example, an embodiment of connector assembly <NUM> as shown in <FIG> can be at both ends of the filter element, or an embodiment of connector assembly <NUM> as shown in <FIG> can be at one end of the filter element, and an embodiment of connector assembly <NUM> as shown in <FIG> can be at the other end of the filter element.

Each first connector element 50A (<FIG>), and 50A1 (<FIG>) includes, projecting upwardly from the base 30A, a concentrically arranged crown 90A, including a snap tooth lock 26A, extending in a circumferential direction forming a snap arch 25A wherein the connector elements each also include a snap arm 20A, including a snap tooth 22A, illustrated as having a snap ramp 21A. In these illustrated embodiments (see also, <FIG> showing like components in the second connector element 50B) first connector element 50A, 50A1 includes a centering rib 23A and a snap root 24A. The presence of centering ribs, that are present between the outside of a snap arm and the inside of a crown, can be desirable in reducing or preventing radial sliding. Preferably, each first connector element and each second connector element has at least two crowns each including a snap arches, and at least two snap arms as described with respect to <FIG> (see, for example, <FIG>). In the embodiment illustrated in <FIG>, each first and second connector element has crowns and snap teeth locks; snap arms and snap teeth/snap ramps; centering ribs and snap roots, equally spaced from one another in a circumferential direction.

The first connector elements 50A and 50A1 each include, projecting upwardly from the base 30A, two cylindrical walls 80A, 80A', each having a hyperbolic paraboloid shape with an uppermost part 81A, 81A,' wherein the cylindrical walls have uniform acclivity.

<FIG> shows an unassembled end cap assembly <NUM> according to an embodiment of the invention, comprising first connector element 50A, 50A1, and second connector element 50B, also showing an annular gasket <NUM> having a central opening <NUM>, arranged between the first and second connector elements, wherein one end of a hollow cylindrical filter element <NUM> is bound to the second connector element. The second connector element 50B includes a central opening S 1B for fluid flow.

<FIG> also shows that the second connector element 50B has, projecting upwardly from the base 30B, two cylindrical walls 80B, 80B,' each having a hyperbolic paraboloid shape, with uniform acclivity, and as shown in <FIG>, the uppermost parts 81A, 81A', 81B, 81B'of the walls of one connector element align with the lowermost parts of the walls of the other connector (see, for example, lowermost parts 82B and 82B' of the second connector 50B as shown in <FIG>) when the connector elements are joined.

<FIG> also shows, for second connector element 50B (similar to elements shown for first connector elements 50A and 50A1 described in <FIG>, <FIG>), second connector element 50B including, projecting upwardly from the base 30B, a respective concentrically arranged crown 90B, including a snap tooth lock 26B, extending in a circumferential direction forming a snap arch 25B, wherein the connector element also includes a snap arm 20B, including a snap tooth 22B, having a snap ramp 21B. In this illustrated embodiment (also shown in <FIG>), second connector element 50B includes a centering rib 23B and a snap root 24B. Preferably, each first and second connector element has at least two crowns each including a snap arches, and at least two snap arms as described with respect to <FIG> (see, for example, <FIG>). In the embodiment illustrated in <FIG>, each connector element has crowns and snap teeth locks; snap arms and snap teeth/snap ramps; centering ribs and snap roots, equally spaced from one another in a circumferential direction.

As discussed above, when the first and second elements are brought together, positioned coaxially with the respect snap teeth aligned with the snap teeth locks, and with the gasket placed coaxially between the elements, axial force is applied and the respective snap arches are engaged and the snap arms are slightly flexed inwardly and the snap arches are slightly deflected outwardly, and the snap teeth pass over the snap arches into the snap teeth locks. This action occurs simultaneously circumferentially with all of the snap arches and snap arms. The outermost diameter of all of the snap teeth should be congruent with the outermost surface of the snap teeth locks to maintain a fluid-tight seal.

The snap ramps pass over the snap arches and secure the snap teeth into the snap teeth locks, and spring back to their original configuration such that the snap arches retain the trailing edges of the snap teeth and prevent reverse axial action out of the snap teeth locks. As a result, the snap connector elements cannot be disengaged without damaging the elements, unless a special tool is used.

<FIG> and <FIG> show, projecting upwardly from the base 30A, concentrically arranged circular inner sealing wall 10A and outer sealing wall 11A of first connector elements 50A and 50A1, and <FIG>, and <FIG> show, projecting upwardly from the base 30B, concentrically arranged circular inner sealing wall 10B and outer sealing wall 11B of second connector element 50B. As shown in more detail in, for example, <FIG>, the angular peaks or tips of the sealing walls 10A, 10B, 11A, 11B compress the upper and lower planar surfaces of the gasket <NUM> when the connector elements are joined, providing a seal.

As shown in <FIG>, each second connector element includes an annular channel (typically, generally U-shaped channel) 120B formed by concentrically arranged circular inner walls 110B and outer walls 111B, defining a space for receiving an end of the filter elements. While the filter elements are illustrated with an outer cage <NUM> contacting the outer wall 111B, the cages are optional. The ends of the filter elements in the channels are preferably bound therein, e.g., by adhesive or other bonding reagents and/or techniques known in the art.

In some embodiments of the filter, one of the first or second ends of the hollow cylindrical filter element is received in the annular channel 120B of the second connector element, and the other of the first or second ends of the hollow cylindrical filter element is received in an annular channel of an additional second connector element which is lockably engageable with an additional first connector element, or, one of the first or second ends of the hollow cylindrical filter element is received in the annular channel 120B of the second connector element, and the other of the first or second ends of the hollow cylindrical filter element is connected to a conventional end cap.

A variety of filter elements can be used in accordance with the invention, and are known in the art. In accordance with embodiments of the invention, the filter elements can have a hollow cylindrical configuration, in some embodiments, a pleated hollow cylindrical configuration. <FIG> and <FIG> show a pleated hollow cylindrical filter element <NUM> including pleats <NUM>.

A filter can include additional elements, layers, or components, that can have different structures and/or functions, e.g., at least one of any one or more of the following: prefiltration, support, drainage, spacing and cushioning. Illustratively, the filter can also include at least one additional element such as a mesh and/or a screen. <FIG>, <FIG>, and <FIG> show filter elements with an outer screen <NUM>.

At least one filter is typically disposed in a filter housing comprising at least one inlet and at least one outlet and defining at least one fluid flow path between the inlet and the outlet, wherein the filter assembly is across the fluid flow path, to provide a filter device. Preferably, the filter device is sterilizable. Any housing of suitable shape and providing at least one inlet and at least one outlet may be employed.

The connector elements can be fabricated from any suitable impervious material, e.g., a resilient plastic material that can temporarily deform and spring back to their original configuration, which is compatible with the fluid being processed.

The gasket is typically a pliant elastomeric material.

The filter device housing can be fabricated from any suitable rigid impervious material, including any impervious thermoplastic material, which is compatible with the fluid being processed. For example, the housing can be fabricated from a metal, such as stainless steel, or from a polymer.

Claim 1:
An end cap assembly (<NUM>) comprising:
(a) a first connector element (50A, 50A1) comprising at least two first connector element snap arches (25A), each of the at least two first connector element snap arches including a snap tooth lock (26A); and at least two first connector element snap arms (20A), each of the at least two first connector element snap arms including a snap tooth (22A); the first connector element having a central cavity (<NUM>) closed off with a wall (<NUM>) or having a central opening (<NUM>1A) with a side wall having an internal thread (<NUM>); wherein the first connector element includes two cylindrical walls (80A, 80A') projecting upwardly from a base (30A), each wall (80A, 80A') having a hyperbolic paraboloid shape with an uppermost part (81A, 81A'), wherein the cylindrical walls (80A, 80A') have uniform acclivity;
(b) a second connector element (50B) comprising at least two second connector element snap arches (25B), each of the at least two second connector element snap arches including a snap tooth lock (26B); and at least two second connector element snap arms (20B), each of the at least two second connector element snap arms including a snap tooth (22B); the second connector element having a central opening (51B), and an annular channel (120B) for receiving an end of a hollow cylindrical filter element (<NUM>); wherein the second connector element includes two cylindrical walls (80B, 80B') projecting upwardly from a base (30B), each wall (80B, 80B') having a hyperbolic paraboloid shape with an uppermost part (81B, 81B'), wherein the cylindrical walls (80B, 80B') have uniform acclivity; and,
(c) a gasket (<NUM>) arranged between the first connector element and the second connector element, the gasket having a central opening (<NUM>));
wherein the first connector element and the second connector element are lockably engageable with each other when placed in contact with each other and axial force is applied such that each first connector element snap tooth is retained in each respective second connector element snap tooth lock, and each second connector element snap tooth is retained in each respective first connector element snap tooth lock.